bits
at

i

 

OD
€

f
y
"

it
eit
iret

Le tN
eae
detail

2

eee
Sees

es
re)

 

 

 

 

ee
ee
ee

2

 

 
Qe.
282
RSF
JS2
ie 1S

 

Cornell Aniversity Library

BOUGHT WITH THE INCOME
FROM THE

SAGE ENDOWMENT FUND

THE GIFT OF

Henry W. Saqe

1891

 

 

 

 

 

DUBE ID cl ff GFOG
Cornell University Library
QE 262.R97J92 1875

The il of Rutland and the parts of

Nn

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

engr l
To face Title Page.

 

SEL

 

To ILLUSTRATE THE VARIATION:

_ we

“STROUD. ___ /2Atleg_ ~~ _ CHELTENHAM

Pye

Bradford

- yiles

‘al Ooll

Uppe

 

Clay

,

. Xx
Aone)

(U ‘pper

Aone |

BROADWAY

Fullers - Earth —

ae

1
Mi

= br Worest Marble

Great — Oolite

OE

Upper Freestones

lupeer kana

  

0
M

hower

YSOE HILL TO BANBURY

Freestones

Pt MAS

Creat

TOWCESTER.~

Freestones

             
 

ra

Xone)

 

UU ALI ANN, i

Stile Infervor —

Oolte ” Freestones /

  

 

 

\(Lower Xone )

~ Oolite

  

Inferior Oolite Midtord

- Sand

 

 

 
 

GEOLOGICAL SURVEY OF ENGLAND AND WALES.

SERIES OF COMPARATIVE VERTICAL SECTIONS

-E THE VARIATIONS IN THICKNESS, AND MINERAL CHARACTERS OF THE SEVERAL MEMBERS OF TE

IN THE MIDLAND DISTRICTS OF ENGLAND.

By John W. Judd F.G.S.

 

 

Scale — 30 Feet to 1 Inch.

_ MID LIT

=

ao Mules”

  
   

_UCRANTHAM- -~

   
  
 

_- STAMFORD -~
tyes ~~
gM

ROCKINGHAM --~ 5
a S
at
5 5
g eA [
Z od SR
NORTHAMPTON ’ : J F >
z S. “ = OF pe =
of ie Sp
x ae &
f 2
i |
af =|
3 3
ee :

  
  

(4o1safuy )

(torsazuz )

972190

amN°0 (401. ) aurysujonury
ENO

z|
&
&
|
3 |
&
aS

mE
“72.

CO

 

puvg uojdumypso4y

 

 
Plate. I.

 

 

y AND WALES.

.RTICAL SECTIONS

TERS OF THE SEVERAL MEMBERS OF THE Lower OoLitEs

OF ENGLAND.

G.S.

Inch .

_ MID LINCOLNSHIRE
\

 
    
   
 

   

X \ NORTH LINCOLNSHIRE.
:

auapsouUyvyp — dfdysuporuL'y

anysuposun)

  

(lolgyuT )

oe $e \
E - = ~
F 3 = 3
S 3 > > =
Be xX 3 > -:
Z 3 5 <i
> F S) \
>. 3} = \ F
~| © ry \
Se > \ \
2B \ \
z \
NE
=

    

ams

|
|
|
|
|
|
I

|

a) Bhs UOTE]

 

 

 

 

Vineet Erovks Day & Son Lith.
“MEMOIRS OF THE GEOLOGICAL SURVEY.

ENGLAND AND WALES.

Typ
aT hi

» THE GEOLOGY OF RUTLAND

=". AND

=

THE PARTS OF LINCOLN, LEICESTER, NORTHAMPTON,
HUNTINGDON, AND CAMBRIDGE,

INCLUDED IN

\
SHEET 64 OF THE ONE-INCH MAP OF THE GEOLOGICAL SURVEY;

WITH AN

INTRODUCTORY ESSAY ON THE CLASSIFICATION AND
CORRELATION OF THE JURASSIC ROCKS OF
THE MIDLAND DISTRICT OF ENGLAND.

a on BY
JOHN W. JUDD, F.GS.

APPENDIX, WITH TABLES OF FOSSILS, BY R. ETHERIDGE, F.R.S. ay’

‘
4

BARR AAR ARRAADARAARAARAR ERR Rn

PUBLISHED BY ORDER OF THE LORDS COMMISSIONERS OF HER MAJESTY’S TREASURY.

FRR R ARR ARRARARADARADIADADRAADAAAAAS BOA

; fh
7

LONDON:
PRINTED FOR HER MAJESTY’S STATIONERY OFFICE.
: PUBLISHED BY .
LONGMANS & Co., Paternoster Row;

AND BY

EDWARD STANFORD, Cudnine Cross, 8.W.

—

. 1875.
[Price 12s. 6d.]
\
NOTICE.

WHILE the mapping of the district was in progress,
the geology of which forms the subject of this Memoir,
I had several opportunities of verifying the accuracy
and skill with which Mr. Judd traced the geological.
boundary, lines, and the truly scientific manner in which
he formed those deductions, the result of which has been
expressed in a new classification of some of the forma-
tions comprised in the area. I may add that the
circumstances which led to the resignation by Mr. Judd
of his post on the Geological Survey have always been
matter of deep regret to me, for it is not often that
men are to be found who possess that rare combination
of knowledge on so many special branches of geological
inquiry which characterises the author of this memoir.
I also feel that we are deeply indebted to Mr. Judd for
- having so frankly consented, after he had left the Survey,
to make his work complete. by the a atuitous prepara-
tion of a memoir which he was in nowise bound to
write. That this important work has been thoroughly
well done all geologists will allow. No one but the
man who mapped the ground, who examined the fossils

in situ, and determined so many of the species, could

32108. : a2
iv
have done anything like equal justice to the subject,
and the generous devotion which Mr. Judd has shown
in giving so much valuable time to our work, after he

ceased to be a member of the Survey, deserves the most

grateful acknowledgment.

ANDREW C. RAMSAY,

Director-General.
18th March 1875.
To THE DIRECTOR GENERAL OF THE GEOLOGICAL
SURVEY oF THE UNITED KineDom.

Geological Survey Office,
28, Jermyn Street, London, S.W.,
20th: February 1875.
Sir,
THE country comprised in Sheet 64, which fakes
- in the whole of the county of Rutland, was surveyed
by Mr. J. W. Judd, between the years 1867 and 1871.

This Map is of special interest as being the first
published by the Survey upon which the limestone, that
was formerly considered to be a part of the Great Oolite,
has been referred to its true position in the geological
scale as a member of the Inferior Oolite, to which the
distinctive name of Lincolnshire Oolite was assigned by
Mr. Judd, from its great development in that county.

When Mr. Judd left the Survey, on the completion of
his fieldwork connected with the above area, he disin-
terestedly consented to write the Memoir in explanation
of the Map; and the present important work is the
result of his labours. :

In it, besides giving a. detailed description of the
geological structure of the district, Mr. Judd has dis-
cusséd at length the more general and purely scientific
questions connected with the subject, and has explained
the grounds upon which the conclusions were founded
that led him to propose an entirely new and altogether
original nomenclature and classification for the Oolitic
rocks of the midland district of England, which have
been since accepted. i the Geologists of this and other
~ countries.
vi

Mr. Judd has been aided by Mr. Etheridge in the
preparations of the tables shewing the geographical
and stratigraphical distribution of the fossils and in
the palzeontological portion generally. Several views of
oolitic scenery have been contributed by Mr. Rutley
from sketches made on the ground.

Mr. Whitaker has also assisted in the bibliographical
portion ; and Mr. Holloway has rendered valuable help
in constructing and drawing illustrative geological
sections, as well as generally in passing the work through
the press.

I have the honour to be,
Sir,
Your obedient servant,
Henry W. Bristow,
Director for England and Wales.

To Andrew C. Ramsay, Esq., LL.D., F.B.S.,
&e.. &e. ~ &e.
PREFACE.

In obedience to a very general demand for the more rapid
completion of the maps illustrating the coal-producing districts
of the country, the officers of the Geological Survey of Great
Britain, who were employed in tracing northwards the boundaries
of the Jurassic Strata, were nearly twenty years ago transferred
to the northern counties.

Thus the mapping of the Lias and Oolites remained during a
considerable interval in abeyance. This period was, however,
marked by many important advances made by geologists in their
knowledge of the rocks in question, and by the introduction of
new principles and methods of classification. The views gradually
elaborated by Quenstedt, Fraas, Marcou, Oppel, and others on
the continent, were applied by Dr. Wright and other geologists
to the rocks of this country, and the necessity for modifications
of the classification, adopted in some of the former publications
of the Survey, were thereby rendered manifest. In particular, we
may mention the conviction arrived at by many geologists, that
certain rocks supposed to be of Great Oolite age, ought in fact to
be classed with the Inferior Oolite.

Having been engaged during six or seven years in preparing
a geological map and description of that interesting county— so little
known to, geologists — Lincolnshire, 1 had been gradually led -
to the adoption of the, views referred to above; and in 1867,
when it was determined to resume the mapping of the Jurassic
rocks, I was requested to join for atime the staff of the Geological
Survey, and to devote my attention to the country intermediate
between Lincolnshire and the districts already mapped. It soon
became clear to me that not only would the doubtful beds have
to be classed with the Inferior Oolite, but, that, in consequence of
the very local character of many of the formations in the district,
a new classification and nomenclature was rendered absolutely
necessary in order to adequately represent them.
vill

During several years I was employed in working out the details

_ of this question and in mapping the most critical portion of the
district; and in 1870, after the results which I had arrived at had

‘been examined and approved by the responsible officers of the
Survey, the new classification was published in the Index, and
a little later, in sheet 64 of the Survey map. I then examined
the country to the southwards, revising the maps already published
and preparing new editions of them.

This task completed, my connexion with the Survey ceased,
and my attention was directed to entirely new fields of geolo-
gical inquiry. On its being pointed out to me, however, that
the want of a memoir, explaining the grounds of the classification
which I had originated, would be productive of inconvenience,
I undertook to write the present work; the form assumed by
which has been, to some extent, determined by the peculiar circum-
stances under which it has been prepared.

Questions of an exclusively scientific nature, such as those
involved in the methods of classification adopted, are discussed in
the Introductory Essay; while subjects of general and local
interest, in connexion with the district more especially. described,
are treated of, in large and small type respectively, in the second
part of the volume. The circumstance that the work has been
written in the intervals snatched from many other occupations
and studies, may not perhaps be accepted as any apology for
imperfections and inequalities in its mode of execution, but it must
be pleaded as an excuse for the delay in its completion.

_ Fortunately, however, geologists have not been compelled to
await the appearance of this volume for an illustration and defence
of the classification and nomenclature of the Jurassic rocks in the
Midland district, now employed by the Survey; for, not only
has my friend Mr. Samuzn Suarp of Dallington entirely adopted.
these views himself, but he has chivalrously maintained and ably
exemplified them in two memoirs read before the Geological
Society, a task for which his extensive knowledge of: the rocks
and fossils of the district eminently fitted him.

During my execution of the survey of the area, I received
much valuable assistance, not only from Mr. Saarp, but from
many other local geologists, among whom I may especially mention
Mr. BrrsLry of Banbury, the Rev. Mixes J. Brxx Ley, for-
merly of King’s Cliffe, Mr. Biaex of Islip, Mr. Benrixy of
Stamford, and the late Dr. Porrer of Peterborough. While
ix,

writing the memoir, too, I have had recourse to the kind aid of

several paleontologists including Dr. Lycerrt, the late PRoFEssoR
_ Paiuiips, Mr. Davipson, Proressor Morris, and PROFESSOR

Hux.ey, and especially to my former colleagues on the survey

Messrs. ETHERipGe and SHarman. Mr. EruHeriper has,
moreover, written an appendix to the work.

My labours in preparing the work and carrying it through the
press have been lightened in every possible manner by the kind
and able assistance of my friend Mr. W. H. Honioway, who is
now .engaged in carrying on the survey of the country to the
northwards. For the beautiful drawings of scenery which have
been copied in the lithographic plates, I am indebted to the skilful
pencil of Mr. Frank Rututxy. Mr. Warraxer has contributed -
very largely to the Appendix of Bibliography, and Mr. Bristow: |
the Director of the Survey, has afforded me the benefit of his
advice and general supervision.

JOHN W. JUDD.

Brixton,

30th January 1875.
TABLE OF CONTENTS.

 

Inrropuctory Essay oN THE CLASSIFICATION oF THE JuRASSIC Rocks OF THE
Mrptayp Disrxict or ENGLAND AND THEIR CORRELATION WITH THOSE OF
tHE CoTTeswoLp Hits ann THE Norru-East oF YORKSHIRE RESPECTIVELY.
Differences between the sections of the south-west of .England and those of York-
shire, p. 1, Key to their correlation found in the Midland district, p. 2. History of
previous opinion upon the subject, p. 2. Confusion produced by the identification
with one another of the fissile beds (“slates”) at different horizons in the Lower
Oolites, p. 5. Table illustrating the changes of the several formations as we pass
northwards from the Cotteswolds to the south of Yorkshire, pp. 7, 8. Variations
in the subdivisions of the Oxford clay, p. 7. Variations in the subdivisions of the
Great Oolite, p. 7. Variations in the subdivisions of the Inferior Qolite, p. 1]. _
Thinning out of Lower Qolite beds northwards and eastwards, accompanied by
changes in petrological character, p. 13. Northampton Sand, the attenuated and
littoral representatives of the Inferior Oolite and the Lower Zone of the Great
Qolite, p. 18. . Descriptign and comparison of the principal sections of the Lower
Oolite strata on either side of the vale of Moreton, pp. 14,17. Northampton
Sand, of South Midland district, p: 30. Upper and Lower Estuarine Series, p. 31.
Appearance of a new formation (the Lincolnshire Oolite Limestone) between them,
.p. 38. Great thickness and importance of-this formation. Extent and peculiar
characters. Physical and paleontological evidences of its age, p. 36. Unconformity

* between the Great and Inferiur Oolite beds of the Midland district, p.'36. Lincoln-
shire Oolite represents the Zone of Ammonites Sowerbyi, p. 38. Formations absent,
p. 40. lLias,. Changes as we pass northwards. Penarth or Rhetic, p. 40.
Persistence of two series of “fish and insect beds,” p. 41. Appearance of new
series of beds in the Lower Lias. Characters of the zone of Ammonites semicostatus,
p. 42. Limits of the Middle Lias, p. 45. The Upper Lias, p. 47. Value of
Paleontological Zones, p. 48. Local character of many of the Jurassic deposits.
Importance of the study of the conditions under which beds were deposited.
Facies, p. 49. Accumulation of beds dependent on amount of subsidence in the’
area, p. 50. Zones absent or rudimentary at some points, very finely developed at
others, p. 50 Remarkable examples in the Zones of Ammonites Sowerby and
A, semicostatus, p. 51.. General conclusions, p. 52.

Description oF SHEET 64.

Cuapter J.
‘ ? : Page
Physical Features, §c. Extent. Configuration “of the surface. Rainfall.
Drainage. Relation of Physical features to Geological structure. Soils.
Minerals. Two groups of beds in the area. Jurassic and Post-Tertiary.
Difference of age. Unconformity of two series. Table of strata - 53

Cuarrer II.
Tue Lias. Extent. Subdivisions. .
The Lower Lias. Classification of its beds: Extent - - ~ 57
Caarter III.
The Middle Lias, Subdivisions. Great variation in thickness. The great

escarpments. Inliers. Outliers - - - - 64
* ; Cuapter IV.
The Upper Lias. Subdivisions. Area covered by it. Main line of outcrop.
Tuliers. Outliers - - - - - - - 79
Cuarter V.
Tam Lowsr Ooxites. Two'great divisions. Great Oolite and Inferior Oolite.
Distinct separation in this district. Unceonformity - - 90

Northampton Sand, with the Lower Estuarine Series. General characters.
Outer escarpment. Valleys of the Nene and its tributaries. Inliers.
Outliers. Iron-ore of the Northampton Sand - - - 90

‘
xi CONTENTS.

Cuarrer VI.

Oniein or tar Nortnampron Sanp. General. features of the Northampton
Sand. Lithological characters of the Northampton Sand. Microscopical
characters of the Northampton sand. Chemical characters of the North-
ampton sand. Mode of formation of the Northamptonshire iron-ore.
Causes of the redistribution of the iron in the Northamptonshire ore. Con-

clusions - Bs
Cuceinii VIL

Lincolnshire Oolite Limestone, with the Collyweston Slate, General characters.
‘Two facies. Distribution. Main line of outcrop. Inliers, &c. Outliers.
Building-stones. “Slate” beds. Origin of the Oolitic structure of the
rocks - - - -

‘Cuarrer VIII.

The Great Oolite Series. Its subdivisions. Correlation < -

The Upper Estuarine Series, Extent. Line of outcrop. Inliers. Outliers -
The Great Oolite Limestone. (Upper Zone.) Outcrop. Outliers

The Great Oolite Clays. Characters. Extent. Outliers

The Cornbrash.‘ Characters. Extent. Outliers. Inliers -

Cua¥Ter IX. . \

Tue Mippre Ootites. Subdivisions. Representative of Kellaways Rock.
Oxford Clay. Extent, Outliers - - = <

,

CuarTer X.

Tue Post-Tertiary Deposits. Classification. Characters -

The Pre-Glacial Deposits. Lacustrine beds. River eranese Brick-earths.
Pebbly gravels and sands -

The Glacial Deposits. Boulder Clay. Great boulders. Glacial gravels.
Glacial sands _- -

The Post-Glacial Deposits. Cave deposits. High-level valley gravels.
Low-level valley gravels. Estuarine gravels. Marine gravels of the
Fenland. Peat interstratified with Marine Silt. Alluvium of Fen
lakes. Alluvium of present rivers. Marine Alluvium or Warp of
the Fenland -

Cuaprer XI.

Position snD DisTURBANCES OF THE Strata, Faurts, &c. General dip.
, Coincidence of faults with changes of the general dip and strike. Synclinal
and Anticlinal folds of the strata. Great lines of Fault. Billesdon and
Loddington Fault. Tinwell and Walton Fault. Smaller faults. Trans-
sais oa Probable. presence of other lines of disturbance. Age of
the ts . - - - -

Cuaprer XII.

Miscentanzous. Denudation. Scenery and the Causes of its peculiarities,
Springs. Swallow-holes. Subterranean streams. Mineral springs. Mineral
resources of the district. Soils: Conclusion - -

Aprunprx I,
Tasies of Fossins from the various Jurassic formations of the Midland
district - - “ . « é
APPENDIX II,

List. of Works containing notices ot the Geology of the district Chrono-
logically arranged - - - 7 -

Page

113

139

186
188
201
214
218

232

240
240

245

249

254

260

273

293
xiii

TLLUSTRATIONS. |

PLATES. .

Puate I. (facing title page). Srries or Comparative VERTICAL SECTIONS TO
ILLUSTRATE THE VARIATIONS IN THICKNESS AND MINERAL CHARACTERS OF THE
SeveraL Mempers or THE Lower Oo.ites In Tue Mipianp Districts or
Enoianp.—In these vertical sections the maximum thickness of each formation
in the particular area is represented. For the Bath district I have followed to a
great extent the original memoirs of Lonsdale, while in the three sections in the
Cotteswold Hills, namely, those of Stroud, Cheltenham, and Broadway, I have been,
guided by the descriptive writings of Drs. Lycett, Wright, and other geologists, but
have also incorporated results previously published by the Geological Survey.
In the remaining ten sections I have been obliged to depend mainly on my own
observations made either during my connexion with the survey or before that
period, with such aid as could be obtained from wells, borings, &c. The main
object of this series of sections has been to show how rapidly the various members of
the Lower Oolites thin out or vary in character as they are traced over even limited
areas ; the constancy of character in them being actually not greater than those of
banks of mud, sand, or shells, at comparatively moderate depths upon the existing
sea bottom. The lines drawn between the several sections indicate the approximate
equivalences’ of the different formations in each, as derived from paleontological
evidence. Inthe upper dotted line the distances in miles between the points at
which the several sections are obtained is given. The shading in these sections
illustrates the nature of the rock, the conventional indications for clay, limestone,
sandstone, &c., being employed. The colours indicate the geological positions of the
various beds, and correspond with those employed upon the Index Sheet and the

- maps and sections of the Geological Survey of the United Kingdom.

 

Puare Il. (facing page 52.) Diagrammatic Sxcrions InbustRatine THE
THINNING-OUT OF THE LINCOLNSHIRE (INFERIOR) OOLITE.—These sections are
not drawn upon a true vertical and horizontal scale, as this would not be prac-
ticable in the case of an illustration in a book. _ Such will, however, be published in
forthcoming sheets of horizontal sections of the Geological Survey. The object of
the two sections on this plate is to show the manner in which the great masses of
limestone of Inferior Oolite age (the Lincolnshire Oolite) in the North Midland
district, thins out rapidly southward and eastward, thus giving rise to very different
successions of beds according to its presence or absence. A similar section showing
the same easterly attenuation of this great calcareous formation has been given by
Mr. Sharp in his paper on the district. See Quart, Journ. Geol. Soc., vol. xxix.
(1878), Plate X. ~ : ‘

In the upper section the attenuation, towards the south, of the Lincolnshire Oolite,
asseen near Sutton Basset, Leicestershire, when it is traced to the point where it
finally disappears near Warkton in Northamptonshire, is illustrated.

In the lower section a similar dying out of the calcareous strata of the Inferior
Oolite as they were traced from near Stamford, south-eastward into the Nene

Valley is made apparent.

Prats Ill. (at end of volume). Diacrammatic Sections IttustraTing THE
PositIoNn AND RELATIONS OF THE STRATA IN SHEET 64.—The insertion of a
small index map in this volume having been found impracticable owing to the rather
complicated structure of the district, two horizontal sections have been drawn
through the northern and southern portions of the area respectively, which will
serve to illustrate the position of the several escarpments, lines of valley, and outliers
of the district specially described in the memoir. The manner in which the whole
structure of the district is dependent on the general dip of the rocks to the south-
eastward, combined with the occurrence of hard beds of limestone, sandstone, or
ironstone rock in the midst of thick masses of clays, will be made clearly apparent
by an inspection of these sections. ~Like those of Plate II., and for similar reasons, .
these sections are purely diagrammatic, and no attempt has been made to conform
the vertical to the horizontal scale. 5 :

The upper section shows the two great escarpments formed by the Marlstone
Rock-bed and the Inferior Oolite respectively, and the general decline of the
whole plateau eastward towards the Fenland. 5 : ‘

The lower section illustrates the great drift covered area of Lower Oolite rocksin the
centre of the area, outliers of which also, having escaped denudation, are seen to
xiv ILLUSTRATIONS.

the westward, while beds higher in the series are exposed to the eastward along
the sides of the river valleys which intersect the district. :
In these sections, and also in those on Plate II., the faults and curvatures of the
strata have been omitted in order to avoid complicating the appearance of the
‘sections, and thereby, defeating the object in view, that of making clearer the
general relations of the several formations as described in the text of this volume.

Puare'lV. (facing page 53). Castip Hirt, Wesr or Ureincuam, ILvstRAaTING
some or THE Botper Fratures TO WHICH THE Tass AND OOLITES GIVE
RISE IN THIS Disrrict.—In this and the seven succeeding plates, which are
lithographed after sketches from the able pencil of my former colleague, Mr.

- Franx Rutiexy, F.G.S., some of the most characteristic features of the scenery
of the district depending ’on its geological structure are represented. Plate IV...
shows, in the steep’ escarpment on the left capped by Northampton Sand (and
crowned by an old Roman? camp), and in the undulating and well-wooded
country in the distance, how much the scenery of the district has gained in
boldness and character over that to the southward,in consequence of the greater
thickness of the masses of clays between the hard beds which give rise to the for-
mation of theescarpments. The plateau on the left of the landscape is consti-
tuted by the Inferior Oolite, that on the right by the Marlstone rock-bed and the
overlying beds of the Upper Lias covered with Boulder Clay, and clothed, as is
so frequently the case, with ample woods. The view is taken from the north-
east.

. Puare V. (facing page 77). Siawston Hi, Leicesterssine. OUTLIER OF
MarisTone AND Uppzr Lias carpep By Nortuampton Sanp. — This is one
of the best illustrations to be seen within the district of an outlying mass of strata
isolated by denudation. _The hill crowned by the windmill is composed of a
vestige of the Northampton Sand with the underlying Upper Lias Clay, as will
be seen by a reference to the lower section on Plate III. which passes through
this hill. The whole rises from a plateau formed by the rock-bed of the Marl-
stone. The view is taken from the southwards.

Pratu VI. (facing page 93). View or THE GREAT EscaRPMENT OF THE LOWER
Oourtzs Near Gretron, NortHampronsuine.—This view illustrates the great
line of the escarpment northward from Rockingham, the bold spurs, one of which

_is crowned by the village and church of Gretton, and the deep receding bay-like
hollows being alike conspicuous. In the foreground is shown the comparatively
steep slopes of the Upper Lias Clay, with the broken ground resulting from the
slipping of the overlying strata as a consequence of the outburst of springs. The
view is taken from the south-west.

Puate VII. (facing page 106). Roxiy-a-tirTors, Leicestersuire. AN Out-
LIER OF THE NORTHAMPTON Sanv.—No hill.in the district could be chosen as
showing better the characteristic tabular forms assumed by the outliers of harder
strata in the district. The view is taken from the southwards, and the gentle dip
of the hard beds of Northampton Sand capping the hill, which exhibits traces
of old entrenchments at its summit, is well illustrated by.it. The steep slopes of
the hill are of course constituted by the Upper Lias Clay, the flat ground around
it by the Marlstone rock-bed, a quarry in which is shown on the left of the pic-
ture, near the farm-house. A deep ravine cut by a small stream, the sides of
a are densely wooded, cuts down into and exposes the clays of the Middle

jas. : :

Prats VIL. (facing page 200). Suction or tm Urrer Estuarine SEeRies
Avp LIncOLNsHIRE OOLITE AT THE RAILWAY-cUTTING AND BRICKWORKS AT
litte Byruam.—Travellers to or from the North by the main line of the
Great Northern Railway can hardly fail to notice this interesting exposure of the
rocks, which for the district is an unusually extensive one. The sectiqn is
crowned by traces. of the beds of Great Oolite Limestone ; the strikingly hori-
zontal banded strata are the clays,of the Upper Estuarine Series, here extensively
dug for brick-making. The rocks exposed in the sides of the railway-cutting
belong to the Lincolnshire Limestone, the false-bedding of the highest course of -
rock here at once arresting the attention of the geologist.

‘

‘Puate IX. (facing page 211). Section or tHe Grear Ooure Limesronxs
with THE Unprrtyinc Urrex Esruarinn Ciays srrn In Tun EsseNpINy
Curtine or tie Great Norrurrn Kamway.—In this section the Great
Oolite Limestones resting on the variegated clays are seen in a deep railway-
cutting. At this place some of the best specimens of the freshwater shells in the :
Estuarine Clays were collected during the formation of the railway; in the lime-
stones were obtained the bones of the gigantic Cetiosaurus.

ILLUSTRATIONS.

XV

The contrast pre-

sented between the jointed limestones above and the laminated clays below is well
seen in this drawing. This section, like the last, may be noticed by passengers on
the main line of the Great Northern Railway.

Prats X. (facing page 231). View or run Low TasuLar HILLs FORMED BY
tHE Great Oorits Beps art GrimstHorre Park, LincoLNsHIRE.—This view
taken from the north-west well illustrates the general characters presented in the
numerous small valleys cut through the alternating limestone and clay heds of the
Great Oolite Series. The broad flat hills are capped by Cornbrash, while the
Great Oolite Limestone and the Upper Estuarine Series crop out in the lower

parts of the valleys.

The flat bed of the valley is formed by the limestones of

the Lincolnshire Oolite, and hence the stream is subterranean during the greater
part of the year. :

‘

Piare XI. (facing page 264). Ituustratine THe TaBULAR OUTLINES OF THE
Hitts West or Urrineuam.—This view, taken from Wardley Hill and looking
over Bushy Dales and the neighbouring ravines, illustrates very clearly the flat-
topped hills with steep slopes below and the general tabular outlines characterising

this district.

The hills are capped by the Marlstone rock-bed, and the deep

- valleys between are cut into the beds of the Lower Lias Clays, the whole being

masked and their outlines. somewhat s
Boulder Clay in the area.

2

 

WOODCUTS.

1.—Section exhibited in a pit at the Race-course near Northampton -
2.—Section in sandpit west of Weekley, Northamptonshire - -
3.—Section at Old Head Wood, Northamptonshire - es
4,—Diagrammatic Section illustrating the relations of the beds of the
s _ zone of Ammonites semicostatus of the Lower Lias, in North

Leicestershire and South Lincolnshire - = =

5.—Village of Somerby, Rutland, situated in one of the deep sinuous
valleys of the great escarpment formed by the Marlstone Rock-

bed - - - ‘. - -
6.—Section exhibited in a pit between Keythorpe and Hallaton (Leices-
tershire) 3 - = a
‘7,—Section exposed in a railway-cutting at the Stamford Station of the
Midland and London and North-western Railways - -

8.--Section of the Northampton Sand seen in a pit east of Ufford,

Northamptonshire - - - - - ee
9.—Pit in the “Northampton Sand between Ufford and Marholm,
Northamptonshire. - - = ss

10.—Sketch of ‘section in pit above Hallaton Ferns, showing a small
outlying patch of the Northampton Sand capped by Boulder
Clay ~ - -~ te 0 - - - -

11.—Stone-pit near Uppingham, on the road to Stockerston - .

‘12,—-Stone-pit in shelly beds of the Lincolnshire Qolite Limestone, near _

Pipwell Abbey - - - - - a
13.—Section in Lincolnshire Oolite Limestone, east of Market Overton
14.—Clay-pit at Lime-kiln, corner of Collyweston and Wornstocls

Woods - = - : = s = a
15.—-Section exposed in the Danes’ Hill Cutting, Lincolnshire, on the
Main Line of the Great Northern Railway - : a
16,--Section in gravel-pit, near Upper Benefield - e
17.-Gravel-pit on south side of Newell Wood - 2 = <
18.—Section of Gravel, Freshwater bed, and the Oolites of the Casewick
cutting - : - - a

19.—Pit in Glacial Gravels between Whadborough and Ouston -

ae

oftened by the extensive development of the

Page

34
37
38

43

58

738
108
104
105
107
108

148.
168
192

196
241
242

244
248
INTRODUCTORY ESSAY.

On THE CLASSITICATION OF THE JURASSIC STRATA OF THE
Mrptanp District AND THEIR CORRELATION WITH
THOSE OF THE CoTTESWOLpD Hints anpD THE NorrTH-
EAST OF YORKSHIRE RESPECTIVELY.

e

The present memoir is the first issued by the Geological
Survey, in which some important modifications of the Classifica-
tion and additions to the Nomenclature of the Lower Oolites are
employed ; these it has been found necessary to adopt in order
to explain the relations of the beds of this age as they are
traced northwards into the Midland district. It has, therefore,
been thought advisable to preface the description of the area, to
which the memoir more especially refers, with some account of
the grouping of the strata employed for the purposes of the
survey, of the terms used to indicate them, and of the reasons
which have led to the adoption of that classification and ter-
minology. In doing this it has necessarily been found impos-
sible to avoid a more technical mode of treating the subject than
is employed i in the later and purely descriptive portions of the
memoir.

No-fact in connexion with the English Jurassic strata is of Difference be-
more striking character and significance than the wonderful oSWof
differences between the sections displayed in the typical localities England and
of the -south-west. of England, and those of the north-east of Y°"**re
Yorkshire. The more thoroughly and minutely the recks in
.these two districts are studied, the more striking do the dis-
crepancies between the several members of the two series appear ;
these differences being equally marked alike in regard to their
thickness, their petrological character, and the distribution of their.
organic remains.

It was by the careful study of the Oolites in the south-west
of England that the accepted classification of the Jurassic
system was first arrived at; but it was in Yorkshire that this
classification, and the principle on which it was founded, (that
of the identification of strata by their organic remains) were
submitted to a crucial test. Never had a new tHeory to pass
through a severer ordeal than when the conclusions, arrived
at. from the study of the alternations of the limestones, sands,

82108. A

.
nn GEOLOGY OF RUTLAND, &C.

/

and clays, of the Bath district, were first applied to the eluci-
dation of the massive coal-bearing sandstones and shales of the
Moorlands of the north-east of Yorkshire; and never, certainly,
did a theory come out of such trial more triumphantly, or with
stronger- proofs of its general soundness and great capabilities,
than did this.

Since the period of the pioneer labours of Smith and his coad-
jutors Richardson and Townsend, the Oolites of the south-west
of England have been made the object of indefatigable: study
by many observers, such as Conybeare, Murchison, Buckland,
De la Beche, Lonsdale, Buckman, Strickland, Lycett, Wright,
Etheridge, Moore, Brodie, Day, Hull, and others; while the
whole district has been mapped and described by the officers of
the Geological Survey. The magnificent sections of the York-

shire coast; which were first brought into general’ correlation

Key found in
Midland dis- °
trict.

H istory of pre-
vious opinion.

with those of the south by the skill of Smith and Phillips, have
also attracted the attention of many stbsequent writers, includ-
ing Williamson, Louis Hunton, Wright, Leckenby, and Oppel,
who have succeeded in explaining some, at least, of the anomalies
which remained after the labours of the two former geologists.
But the intermediate Midland district, where we might
reasonably hope to find a key to many of the unsolved problems,
which still confronted the geologist who should attempt an
exact correlation of the strata of the northern and southern areas,
has unfortunately received far less attention. Smith’s county
maps of Northamptonshire and Lincolnshire were, at the time
of his death, left incomplete and unpublished, and comparatively
little has been done by subsequent explor ers to supply the great
gap thus left in our knowledge concerning the Jurassic rocks of

‘England.

The general maps of . England, by Smith and Guuieae repre-
sented the thick limestone series, which constitutes so conspicuous —
a feature in Lincolnshire, as being of Great Oolite age, while the j
underlying ferruginous sands, which have since proved to be of
such great commercial value, are placed.in the Inferior Oolite ;
and in this view most succeeding writers have.concurred. It
must be remembered, however; that at the early date of Professor
Phillips’ work on the Geology. of Yorkshire—in which beds, in
that county, now regarded as Inferior Oolite, were called Bath or
Great Oolite-—but little had been done in working out the faunas
and showing the essential points of distinction between the two
series which together make up the Lower Oolite. A striking
illustration of this may be found in the description of the Oolites
on the north of the Humber by the Rev. W.- Vernon Harcourt and
Professor Phillips, published in 1826.(Thompson’s Ann. of -Phil.,
INTRODUCTORY ESSAY. 3

new series, vol. xi., pp. 435-439). In this paper the strata
forming the most northern development of the Lincolnshire
Oolite limestone are shown to be of Inferior Oolite age, and the
identification is supported by a number of fossils which are cited.
It is true that this correlation—undoubtedly the correct one—which
was then maintained both by Smith and Phillips, was to some extent
abandoned, and in subsequent works the identity of the Lincoln-
shire with the Great Oolite indicated; but as Professor Phillips
~ pointed out in 1854, this correlation was, in the first instance,
put forward rather as a useful suggestion than as an established
‘fact.* It must be borne in mind too that there is an unfortunate
confusion, not even yet removed from works on Systematic Geology,
as to the sense in which the term “ Bath Oolite” should be
used. The majority of authors employ it as synonymous with
“Great Oolite,” but several geologists, including Professor Phillips
and the late Professor Jukes, have constantly used it as alternative
with “ Lower Oolite.”

The identification of the Lincolnshire Oolite with that of Bath,
which was for a long period so generally accepted among geolo-
gists, appeared to receive the strongest support from the fact of
the existence, at the base of either of the great calcareous series,
of the fissile sandy rocks known as the Stonesfield and Colly-
weston Slates respectively. This striking circumstance appears
to have had great weight with Lonsdale in preparing his manu-
script_maps of the Oolites of the Midland districts, which were
constructed for the Geological Society+; and equally does it
appear to have influenced Professor Morris in drawing up that
description of the country about Peterborough and Stamford, the
result of repeated studies, which in conjunction with Captain
Ibbetson, he laid before the British Association in 1847.}

It is true that the Rev. P. B. Brodie, on submitting a series

of fossils collected by him in the Lincolnshire Oolite near
Grantham, to Dr. Lycett, was confirmed by that paleontologist
‘in the view which he had been led to adopt, namely, that the
beds which contained them were of Inferior rather than of Great
- Oolite age, but as he proposed to place the beds in question below
the Collyweston Slate, Mr. Brodie’s views, which were published
in 1850,§ did not attract much attention from those acquainted
_ with the general succession of beds in the area.

- 3
* Quarterly Journal, Geol. Soc., vol. xiv. 4857) p- 85.
+ These maps are still preserved in the Library of the Geological Society.
{ Notice of the Geology of the Neighbourhood of Stamford and Peterborough,
Rep. Brit. Assoc. for 1847, Trans. of Sections, p. 127. ; : ;
§ Sketch of the Geology of the Neighbourliood of Grantham, Lincolnshire, and
a comparison of the Stonesfield Slate at Collyweston, in Northamptonshire, with

s
4 GEOLOGY OF RUTLAND, &c. '

Fhe publication in 1858 of Professor Minnis most valuable paper

“ On some Sections in the Odlite District of Lincolnshire” marks
an important era in the history of the geology of the Midland

districts.* ' The general succession of beds as seen in the cuttings —
of the Great Northern Railway was very clearly described, and the”
great differences between the fauna of the Lincolnshire Ooliteand
that of the Great Qolite distinctly recognised. In spite of this, how-
ever, the resemblance of the beds above the limestone in question to -
the Forest Marble, and of the beds below it to the Stonesfield Slate,
were considered to be: so great, that this supposed stratigraphical - nt
evidence was allowed to outweigh the palzontological, and the great-
limestone series was referred, though with much-doubt and: hesita-
tion, to the Great Oolite. Professor Morris has, however, more
recently (in 1869) taken the opportunity of correcting this point
and of expressing his adhesion to the view that the Lincolnshire
Oolite, as well as the “ slate beds” below it, belongs: to the Inferior
Oolite.t

The conviction that the Lincolnshire Oolite and the N orthamp-
ton Sand are really of Inferior and not of Great Oolite age has
gfadually gained ground among geologists. It has been main-
tained by Dr. ‘Lycett ever since the year 1850 on purely palzeon-
tological grounds; and in 1858 the Rev. T. W. Norwood, in a
paper read before the British Association, and subsequently at
Professor - Phillipe’ request published in the first volume of the
“ Geologist,” showed that the fauna of the northern prolongation of .
the Lineainahive Oolite about Hotham and Cave, especially the
Echinodermata, agreed very closely with that of the pea-grit which
forms the base of the ‘Inferior Oolite of Cheltenham, but that it
had but few, if any, resemblances to that of the Great Oolite.
Mr. Sharp of Northampton, and Mr, Beesley of Banbury, were,
by the study of the fossils in their respective areas, independently
led to similar ‘conclusions, While studying the ‘general relations
of the Lincolnshire strata and the characters of their faunas in
the year 1866, the author of the present memoir was induced,
both on stratigraphical and palaontological grounds, to regard ©
both the great calcareous series in that county, so frequently

referred to, and also the ferruginous beds below it, as undoubted
Inferior Oolite. -
that in the Cotteswold Hills. Ann. Mag. Nat. Hist., Ser. 2, vol. vi, p. 256, and
' Proc. Cotteswold Nat. Club, vol. i., p. 52.
Remarks on the Stonesfleld Slate at Collyweston, near Stamford, and the Great

Oolite, Inferior Oolite, and Lias in' thé neighbourhood of Grantham. Rep. Brit.
Assoc. for 1850, Trans. of Sections, p. 74.

* Quart. Journ., Geol, Soc., vol. ix., p. 317,

t Geological Notes on Bate of Northampton andl incotnshite Geol. Mag.
vol. Mt, p. 446.

5
INTRODUCTORY ESSAY. ; 5
K

When the officers of the Geological Survey found that the

Lower Zone of the Great Oolite (which included the well known
Stonesfield Slate) passes in its northern extension into a sandy
and ferruginous rock, they were led to regard the whole of that
‘formation—to which they gave the appropriate name of the
“ Northampton Sand’—~as representing the base of the Great.
“Oolite. The subsequent progress of the Survey, however, fur-
nished the strongest grounds, both paleontological and strati-
graphical,.for the 1 modification of this view, and in the year 1870
the changes found to be necessary were introduced into the maps
and index of the Survey.

It is an interesting circumstance, and one by.no means devoid Confusion
of suggestiveness, that a similar confusion to that we have noticed ee
in the case of the Midland district, long prevailed with regard to “slate beds.”
the correlation of the beds of the. Great Qolite series in the
south-western area. The difficulty arose in this case in con-
sequence of the: erroneous identification of the Stonesfield
Slate with the fissile beds of the Forest Marble, which is worked
for roofing materials at Fairford, Chavenage, &e. on the skirts
of the Cotteswold plateau. In 1832 Lonsdale—by demonstrating
that these two sets of beds were, in spite of their resemblances in
mineral character, of very different age*—at once made clear the
true order of sequence of the Great Oolite strata of the Southern
Cotteswolds, concerning which such conflicting opinions had been
before maintained. The separation of the Collyweston. from the
Stonesfield Slate has produced a similar revolution in our views
concerning the correlation of the Oolites of the Midland district ;
it has also been attended with a great simplification of our classifi-
cation and the removal of many apparent anomalies.

_ It may be interesting to notice that the occurrence of these so

called “slate beds” of the Oolites, which have been the source of
such great confusion in the classification of the Jurassic Rocks
of England, is in almost every instance a phenomenon of very
local character. The presence of such beds depends on the
existence, in a rock mass of a finely laminated structure, of a
due admixture of calcareous and arenaceous materials; and as the
. hecessary conditions for their formation can scarcely be expected to
prevail over any extended district, we are not surprised to find that
the peculiar features ‘of such rocks are only found over compara-
livelysmall areas ; the “slate ” passing within very short distances
either into loose sand on tha one hand, or into solid-limestone
. rock on the other. This is the case alike with the Stonesfield,
the Collyweston, and other similar “slates,”

 

‘ * Proc. Geol. Soc., vol. i., p. 415.
6 GEOLOGY OF RUTLAND, &C.

It will be.instructive to exhibit’ in a tabular form the various
horizons of these several ‘slate beds” at present known in the
Lower Oolites of this country.

aes ‘Slates. of Fairford, Sheerness
Great : - Forest Marble.
~ Oolite. | st of Stonesfield, Byeford,
Sevenhampton Common, &c. - Base of Great Oolite.
(Slate of Brandsby (Yorkshire) - Middle part of Inferior Oolite
7 i (Zone of Ammonites Hum-
phresianus ?)..

Slates of Collyweston, Kirby,
Dene Park, &c.- - - Lindolnshire Oolite (Zone of
Ammonites Sowerbyi)..
Northampton Sand (Zone of
Ammonites Murchisone).

Inferior ‘|
Oolite.

| Slate of Duston - -

 

The progress of exact observations among the Jurassic Rocks
has shown how much more local in character are many of the
subdivisions of that system than was formerly supposed. At one
‘time names like Kellaways Rock, Cornbrash, Forest Marble,
and Bradford Clay were applied to many deposits upon the
continent, which were of about the same age and at the same
time happened to resemble in mineral character the English
beds to which the names were originally applied. The
fallacy of such nomenclature and its mischievous results have
been pointed out by many authors, and by none with more
force of argument and justice of illustration than by Jules
Marcou, in his “ Lettres sur les Roches du Jura.” The prac-
tice of identifying distant strata on the ground of petrological .
resemblance, which has been almost wholly, abandoned in
France and Germany, lingers to a somewhat greater extent
_ perhaps in this country; but as the accurate mapping of the
several formations proceeds, the unsoundness of the method
_becomes every day more ‘and more obvious. To be convinced
of this it is only necessary to compare the successive editions of
the Index Sheet of the Geological Survey. In the earlier ones
each formation is represented by a single column, one series of
subdivisions answering for all the courtry then mapped; but as -
the survey proceeded it was found ‘necessary to adopt distinct
systems of classifications for different areas, these being represented
_in parallel columns. The portions of the Geological , series in-
which we find this change most marked, or in other words the
‘systems which exhibit beds of the most local character, are the
Jurassic and Carboniferous. The very slight persistence of many
_of the well marked Oolite beds, and the manner in which they
thin out or entirely change their characters, often within distances

of a few miles only, has been admirably illustrated in-the descrip."
INTRODUCTORY ESSAY. va

tions of the strata of the Cotteswold Hills by Drs. Wright, Lycett,
and Holl, and Mr. Hull.

In the introductory essay to this memoir we propose to notice
the changes which take place in each of the subdivisions of the
Jurassic strata of the Cotteswold Hills (where their characters
and faunas have been so well illustrated by the labours of many
abservers) as we follow them northwards through the Midland
Counties into Yorkshire. The following table (see next page)
illustrates the succession of Lower Oolite strata in the Northern
Cotteswolds as illustrated by Mr. Hull, Dr. Wright, and other
observers, with their equivalents in the Midland district and
South Yorkshire respectively.

The highest of the Jurassic formations which it is necessary
to notice in the present essay is the Oxford Clay. The several
horizons (each marked by the successive appearance of certain
species of Ammonites and other fossils, and the simultaneous dis-
appearance of others) which have been distinguished alike in
Germany, Switzerland, France, and England, are clearly traceable,
as will be shown in the present memoir, in our Midland district.
The well known Kellaways Rock of Wiltshire has been found in
a more or less rudimentary condition as far north as Tetbury ; in
Oxfordshire, according to Professor Phillips, it is entirely wanting,
but in Bedfordshire, Northamptonshire, and Lincolnshire irregular
sandy beds, often crowded with the characteristic fossils of the zone,
make their appearance at the base of the Oxford Clay. In South
Yorkshire the whole of the Middle Oolite is greatly reduced in
thickness, and is represented by more or less ferfuginous sandy
beds, evidently deposited in shallow water near land. These beds
have been called the Kellaways Rock ; but an examination of their
fauna appears to indicate that they represent a littoral condition
of the whole of the Middle Oolite series. It is not necessary, for
the purpose of this memoir, to describe the remarkably inter-
esting manner in which the various zones of the Middle
Oolite series are represented in the North Yorkshire area,
the strata in question being entirely cut off from those of the
district under consideration by the overlap of the upper Cretaceous
series.

Table illus-
trating changes
in Oolites.

Variations in

Oxford Clay.

The Cornbrash is one of the most strikingly persistent beds of Variations in

the Jurassic series. Although of such insignificant thickness, it can
be traced through the whole of the Southern and Midland districts
of England, everywhere maintaining its well marked mineral and
palzontological characteristics. But in North Lincolnshire even
this most constant bed begins to undergo a change; its thickness
is greatly reduced, it exhibits evidence of more littoral conditions,

Great Oolite
strata.
s

GEOLOGY OF RUTLAND, &o.

 

¥

“sTunUt

 

 

 

 

, *kelO serry taddp | - ej sery teddy | - - epg sevy teddy) | - - £elQ sery soddy | - - &vIQ sey seddg | -ux0osoytuouury jo euoz | - - - ery
4 “4 4 ir 4 é Spues pure Spoq wpodorsydep| - -  pUBy PLOJPL]L | - SeLOG UONIsUBIT,
( “ “puvg uoydusyg10 N *puvg uo,dureqyIoN’ , | -° “LI, woq eT} jo . ‘emostyd =f)
‘op ‘aang jo souoys \| pueg uoydmenqson on; | oy} Jo SuoIed AeMOory | oY Jo SUOHAOd AeMOT] | SOUOJSeaAIY AOMOT OY], | “IN SozTMOMUTY JoouUog | |
OUT «pus spurg " ~  “Hquaaog
OPLOO SATYSUTOOULT OU | - = - guasqy | - - -  guesqy | - * BVH SP100 OWL | SeyuOMUTy =— JO UOT | |
~~ a , . oe : '
“quesqy | - -) = guasory | - : = quesqy | - . - quesqy | - souojsoarg reddy ony, see ae iL Q41[00 JOLoyUT
: f ‘ I i :
aa FILO BlzyruMTey
¢ May snedsiO Urq? [ “ot ony ap ay ie) | |
y We T 5 “qt T “TMOSULYIE,
quesqy | - : o AUReCLY | = - FOSAV 2 | oyy “KG poquasecderz | ou} ‘STI pe cin oan soyTuomMy Jo a oe |
. SULPNOUL, “4T[OQ 10110} i J
\ “Ul OY} JO SoUO{Ssuy OL,
-. = yoo Uyzeg :
“quesqy |,- * a fuesdy | - . Ss i > qUOSQY 4} SATIN O49 TILA ee . ° FET SANT | - SoMeg uolpisuedy,
ae | 8 ‘(| Stojg domoy pur aoddy
: “pug uojdme’ | ‘aferg preysoulgg yyLA “O78TS PISYSou0}S YITA
_ quasqy |;, selteg oujrenysyy todd ,,| MONT OY Jo xed teddy | ouoysoUNTTT 71]00 FwoAH | SOMOISOMMPT F100 4¥EIH | eUOZ 1oMOT ‘aqT[0Q yVOAYD,
SOUOISOML'T OF[OO FVOLH | SOMOFSOTNI'T OFTOO IBoAH) | SOTOISOTUIT OFTTOY YBaIH | - SOMOJSOUIVT OF[OO FRITH
“FUOSOY 4 | ~< SABIO OOO 4BALD,, es st - quesqe ‘Ae[O ploypes ey - A£8TD po: ‘ ig - 9u0Z - OTITOO 7BO1)
{ ‘Spoq Snogseyteate UT, suasary { jnodurounperueysoiee] (pue “orate Mpsarog |S744N OHIO ywaIH | -
“quosqy | - - _ YSBIQusoy | - - Yserquiog | - - YsBiqutog | - . + Yseaqusoy | - - yseiquiog ‘s
“aseq Sqt 42 SABAVT
“*BUNG] UBIP.0y “PY Suyussorder speq ag OS8Q SII 48 YOoy shea
“XO UA vyerjs Apusg THES Y}LM ‘LET PAOFXO | - * ABIQ PAOFEQ | - - KD PAOFTO | VTA BLA ‘AvlQ pxogxO | - - UBIPLOFXO | - 99190 eIPPTAL
‘ouTsujooury WNog “adTqsu0} Cd uey4I0 NE -antys : a
“OITYSHAOX YO @ OTIS nog pue sits - : “STE O.MS99 40} *SUOZLIO E30]O9: “SUE
- -uoxdreng20N mon | -pIOFEO swe DT ON, | “PMOFFO 389.44 Pu HIMOS a ili po ae i

 

 

 

 

“LOIMLSIG] GNVWIGIPL OY} Ut OB19pUN ALTIIOG ALAMO OY} Jo Saag OY} POI SNOILVINVA Oy) SuNWaysnyT xtavy,

 
INTRODUCTORY ESSAY, 9

and it is in places almost wholly made up of beds of small oysters,
a feature never presented by it in its normal aspect. Before we
reach the Humber, the Cornbrash is found to have altogether
thinned out and disappeared. The so-called Cornbrash of the
North of Yorkshire is not only not continuous with that of the
South and Midland districts of England, but, as shown by Dr.
Lycett,* presents essential points of difference from that forma-
tion in its mineral character and still more striking ones in its
fauna. It would be well if a local and distinctive name were
applied to the Yorkshire rock, which is perhaps the only repre-
sentative of the Great Oolite series in the northern area.

The Forest Marble, which was evidently a shallow-water deposit,
and as Professor Phillips has shown, sometimes even exhibits
estuarine characters, everywhere presents great variability in the
succession and thickness of its various beds of clay, sand, and
shelly limestone. In Oxfordshire the limestones thin out and dis-
appear altogether, and the clays with occasional shelly bands,
become so thin and insignificant in North Oxfordshire, South
Northamptonshire, and the adjoining counties, that it was found
impracticable by the Geological Survey to map them separately,
and hence they are in those districts grouped with the Great
Oolite. As we go northwards into North Northamptonshire and
Lincolnshire these beds of clay again thicken, and become of greater
importance, but they do not include the characteristic shelly
limestones of the Forest Marble of the south of England. They
are mapped in sheet 64, and that to the north of it, under the
name of “ Great Oolite Clays.” It is true that the strata of the
Upper Zone of the Great Oolite in the Midland district occasionally
contain fissile limestones identical in character with those of the
Forest Marble, but this is evidently the result of a local similarity
of conditions, and neither paleontological nor stratigraphical evi-
dence can be adduced in favour of considering them as part of
that formation. The Bradford Clayis a more local and incon-
stant stratum even than the Forest Marble; important and
interesting as are its characters in the Bath district, it loses almost
all its importance in the Cotteswolds. The identity of the stratum
at Tetbury with that at Bradford has even been doubted by some
geologists, and it has been found quite impracticable by the
Geological surveyors to map it as a separate formation.

The Upper Zone of the Great Oolite is, in its persistency
and uniformity of character, only second to the Cornbrash itself.

 

* Supplementary Monograph on the Mollusca from the Stonesfield Slate, Great
Oolite, Forest Marble, and Cornbrash, by John Lycett, M.D. Published by
Palzontographical Society, 1863, p. 117.
10 GEOLOGY OF RUTLAND, &c.

- Everywhere exhibiting alternations of white marly limestones and
_ Clays, crowded with a highly distinctive fauna, in which the
Myade, Ostreide, and Echinodermata are especially noticeable by
their abundance both of species and individuals, these strata (which
are constantly burnt for lime in the districts where they are
developed) are well known to all who have studied the geology
of the Northern Cotteswolds, Oxfordshire, Northamptonshire, and
Lincolnshire. At times, it is true, they exhibit local variations ;
passing in some places into shelly and occasionally oolitic fen
stones which afford good, building stones, and in others into fissile
beds which present appearances similar to those of the Forest
Marble. When the formation is traced through the country, how-
ever, the observer cannot doubt.of the continuity of the series of
beds. In Mid-Lincolnshire the Upper Zone of. the Great Oolite is
very greatly reduced in thickness, and its lower calcareous portion
finally thins out and disappears altogether, at a point considerably
to the south of that at which the Cornbrash is Jost.

The Lower Zone of the Great Oolite, which, in its frequent
oblique lamination,:its numerous remains of terrestrial organisms,
and the often prevailing arenaceous elements of its composition,
suggests, like the Forest Marble above, with which indeed its beds
were at one time confounded,-the littoral conditions under which.
it was deposited. The thick shelly freestones of Minchinhampton
Common pass northwards into fissile shelly and often sandy lime-
stones, which in the Northern Cotteswolds and South Oxfordshire
present at their base, in local patches, fissile beds ; these at Eyeford,
Sevenhampton Common, and Stonesfield are capable of being
split, by the aid of frost, into “slates” used for roofing purposes.
It was found by the Geological surveyors that these “slate”
yielding beds, as they are traced northwards, lose their.calcareous
characters and are represented by sands, which occasionally become
ferruginous. As we shall hereafter show, certain beds of the
Inferior Oolite undergo a precisely similar change of character in
the same area; and the two series of sandy beds repr ‘esenting the
attenuated and more littoral conditions of two important limestone
formations of the Cotteswolds (namely the Leckhampton and
Minchinhampton freestones) ‘thus brought together, being
frequently altogether destitute of fossils, the line of demarcation
between them can no longer be traced. These sandy | strata,
which in places are reduced to only a few inches in thickness,
have been mapped together under the name of the “ Northampton
Sand.” As we go vonthuterdes however, the sandy representative
of the Lower, Zone of the Great Oolite is found gradually to
change i in character and to become mainly argillaceous i in its com-
position. These beds of clay are evidently of estuarine character
INTRODUCTORY ESSAY. 11

presenting alternations of bands with freshwater and marine
fossils, and mineral characters identical with those of the Purbeck
and the beds which form the top of the Wealden. These strata,
which in North Northamptonshire and Lincolnshire present very
marked characters, have been mapped by the Survey under the
name of the “ Upper Estuarine Series ;” they form the base of
the Great Oolite. The strata in question were first described by
Professor Morris in 1853, from their exposures in the cuttings of

the Great Northern Railway, then in course of construction; °

the beds were at that time however regarded as the equiva-
lents of the Forest Marble. As we pass northwards in the
county of Lincoln the Upper Estuarine Series, like the other
members of the Great Oolite, becomes gradually reduced in thick-
ness, and by the thinning out of the Upper Zone of the Great
Oolite, the two argillaceous series, representing the Forest Marble
and the Stonesfield Slate respectively, are brought together ;
thus the only vestige of the Great Oolite formation below the
Cornbrash in North Lincolnshire is a thin series of clays of more
or less estuarine character. It is doubtful whether any represen-
tative of these argillaceous beds extends to the north of the
Humber.

The Fuller’s Earth, which appears by its fauna to form a
transition series between the Great Oolite and Inferior Oolite
of the Cotteswolds, is a very variable member of the Jurassic
series. Near Bath it is 150 feet thick, at Sapperton Tunnel only
70, and in the northern part of the Cotteswolds it thins out
and disappears altogether.

The Ragstones of the Inferior Oolite, as shown by Dr. Lycett in
his valuable “* Handbook to the Cotteswold Hills,” undergo many
variations in character within that area. -As we pass northward
and westward into Oxfordshire, however, this portion of the Inferior
Oolite no longer presents its well-marked subdivisions, but, as
was shown by Mr. Hull, is represented only by the “Clypeus
Grit,” which, becoming gradually more and more reduced in
thickness, finally disappears near Chipping Norton, and to the
north of Witney. The Ragstones of the Inferior Oolite are
shown by Dr. Wright to represent the Zone of Ammonites
Parkinsoni.

The Upper Freestones, which in places are almost destitute of
fossils, have been shown by Dr. Wright to be represented at
Cleeve Hill by a series of strata, yielding the characteristic
fossils of the Zone of Ammonites Humphresianus. This division
is “perhaps the least constant of all the beds of the Inferior
Oolite of the Cotteswolds ; besides undergoing numerous and rapid

Variation in
the Inferior
Oolite strata.
12 | GEOLOGY OF RUTLAND, “&C. »

-

changes in mineral character, it thins out and disappears north-
wards and eastwards before even the Oolite Marl.

The Oolite Marl is a thin, but an interesting and well marked, _
stratum, which has been regarded by Dr. Wright as representing
the upper part of the Zone of Ammonites Murchisonez, but by
Dr. ‘Waagen has been referred to. the Zone of Ammonites Sower-
byi: It can only be traced over the middle and northern parts
of the Cotteswolds, and even within those areas undergoes very
considerable changes in mineral character and thickness.

The Lower Freestones, which form so large a portion of the
mass of the Inferior Oolites of the Cotteswolds, partake of the
general attenuation of the beds of that series towards the north
and east. , Near their base the Lower Freestones become sandy
and sometimes ferruginous, and thus graduate into the Pea Grit
below. In their northern extension thege sandy and ferrugi-
nous characters become still more marked, as may be well seen
in the Great Outliers of Ebrington and Bredon Hills.

‘The Pea Grit, with the “roe-stone” in its upper part, and the
sandy ferruginous beds at its base, has but a very limited range
in the Northern Cotteswolds. North. of Stanley Hill it can. no
longer be recognised asa distinct bed; but it may possibly be
represented, together with the freestones above, in the sandy and
ferruginous beds which constitute the base of the Inferior Oolite
in those northern spurs and outliers of the Cotteswolds, known as
Broadway, Campden, Ebrington, and Bredon Hills.

The Midford Sand appears to form a transition series between
the Upper Lias Clays and the Inferior Oolite. At this horizon in
Swabia there is developed a series of most richly fossiliferous beds
distributed by the.German geologists into two Zones—the Zone of
Ammonites Jurensis and the Zone of-Ammonites torulosus; and
between these is the line which is generally accepted upon the con-
tinent as separating the Upper Lias from the Inferior Oolite. In
this country, however, the strata at this horizon, though attaining a
great thickness in some places, are almost wholly unfossiliferous, ex-
cept in one ortwo thin bands; hence a division similar to that adopted
by foreign geologists does not appear to be practicable in England.
From a thickness of 150 ft. in the Southern Cotteswolds they thin
out rapidly in going northward, and cannot be mapped asa separate
bed farther in that direction than Chipping Campden; as pointed
out however by Dr. Holl, there are some grounds for believing that, -
in the sandy and ferruginous beds of the extreme northern spurs of
‘the Cotteswold range, the Midford Sand as well as the Pea Grit’
and the Lower Freestones are represented: The paleontological
INTRODUCTORY ESSAY. 13

evidence in favour of this view is not, however, altogether con-
clusive. See the Series of Vertical Sections in Plate I.

It has usually been thought that the sandy and ferruginous
beds of the northern spurs and outliers of the Cotteswolds, which
represent the Zone of Ammonites Murchisone, are entirely lost
“as we pass northwards and eastwards. Such however is not the
case. Crossing the broad Vale of Moreton we pass from the
northern promontories of the Great Cotteswold plateau to the hills
of North Oxfordshire: in the nearest of these, Brailes Hill, we
find the same rocks as in Ebrington Hill, namely oolitic limestone
alternating with sandy ferruginous beds, the only difference being
the preponderance of the latter at the more easternly locality.
The position of these beds in the series is put altogether out of
question by the fauna which they yield; and this unmistakeably
indicates that they are the representative of the Zone of Ammo-
nites Murchisone.

We have already noticed how the beds of limestone, constituting
the base of the Great and Inferior Oolite series respectively, pass
into strata of an arenaceous character to the northwards and
eastwards, while they are at the same time greatly reduced in
thickness. We have also seen how the intermediate subdivisions
of the Lower Oolite thin out and disappear as we trace them to
the northwards. Consequently we have in North Oxfordshire
and South Northamptonshire that series of sandy and sometimes
ferruginous strata, known as the “ Northampton Sand,” lying
between the Upper Lias Clay and the Upper Zone of the Great
Oolite.

As the facts which have been ascertained with regard to the
relations of the beds representing the Lower Oolites in ‘the
northern part of Oxfordshire, taken in connexion with the
changes which the several members of the series undergo as they
are traced northwards and eastwards, form the grounds on which
the classification of these beds in the Midland district, that has
been adopted by the Geological Survey, is based, it will be necessary
to explain them in this introductory essay in some detail.

We have described the manner in which the strata representing
the Zone of Ammonites Murchison in the Cotteswolds, namely the
Pea Grit and Lower Freestones, as we trace them to the northwards,
undergo considerable changes in mineral character, becoming
sandy and ferruginous, while the highest bed of the Zone, the Oolite
Marl, thins out altogether. This change of mineral character of

32108, B

Changes of
Inferior Oolite
Strata to north
and eastward,

The “* North-
ampton Sand.”
Rocks on west
side of the Vale
of Moreton,
vide Sheet 44
of the Geo-
logical Survey.

14 GEOLOGY OF RUTLAND, &.

the Inferior Oolite is well displayed at Broadway Hill, and in the
great outliers of Bredon Hill and Ebrington Hill, which lie to
the north of the Cotteswolds.

In the former of these outliers the Inferior Oolite strata which
cap it have been preserved from denudation by the great fault,
that has let them down far below their original level. Above
the village of Kemerton there are extensive pits in the ferruginous,
sandy, oolitic rock, which here forms the base of the Lower Free-
stone series. This rock is occasionally banded with iron, and
precisely agrees in character with the beds included in the North-
ampton Sand at many localities, both in Oxfordshire and North-
amptonshire. In places certain of the beds are almost wholly
made up of fragments of Pentacrinus. Above the sandy and
ferruginous beds the white freestones, presenting their usual
characters, are quarried.

In an old pit opposite to “ Kemerton Castle House” we find
the upper beds composed of white freestone, and passing down
into a ferruginous rock of the most variable character; some-
times consisting of loose brown sand, at others of brown sand
indurated by carbonate of lime into a hard rack, and at others again
becoming oolitic and shelly, as in the last pit. Certain beds consist
of brown sandstone, including hard calcareous ramifying masses,
which cause the whole to weather into blocks with very rough
surfaces. Some of the stone has a curious vesicular structure, being
made up of rounded fragments of white or pink oolitic limestone
cemented together hy crystallized carbonate of lime, the interstices
being filled with brown sand. Occasionally the rock is traversed
by bands of hydrated peroxide of iron, and in places these
assume that cellular and concentric arrangement, due to weather-
ing from the joint planes, which is so commonly presented by
both the calcareous and arenaceous varieties of the Northampton
Sand.

In the same great outlier of Bredon Hill, we find, above the
villages of Conderton and Overbury, a similar series of sections.
The higher beds consist of the ordinary white freestones, and pass
down gradually into a rock of more or less ferruginous character.
In some places the rock is a fine oolite limestone often with large
oolitic grains; in others it is very sandy; and it is occasionally
seen to be almost wholly made up of fragments and joints of
Pentacrinus, with plates and spines of other Echinoderms, a few
fragments of shells, and waterworn corals and Polyzoa. In this
latter variety of the rock, all the constituents exhibit evidence
of having been drifted. The ferruginous rock forming the
base of the Inferior Oolite in this outlier is often intensely hard
INTRODUCTORY ESSAY. 15

and compact, and fossils can only be obtained from the surfaces
which have been weathered. The most abundant shell in the
sandy and ferruginous rock at the base of the Inferior Oolite at
Bredon Hill is Pecten personatus, Miinst.; Brachiopoda, including
Terebratula perovalis, Sow.; T. submaxillata, Mor.; Rhynchonella
Gingensis ? Waagen, and Rhynchonella cynocephala, Rich., are
not rare, but almost always occur with their valves separated and
much waterworn. With these are found, but in lesser abundance,
Belemnites ellipticus, Mill.; Ostrea Sowerbyi, Mor. and Lye;
Hinnites abjectus Phil. sp., and drifted, waterworn corals,

Crossing the Vale of Evesham, we find in the northern spur of
the Cotteswolds which forms Campden and Broadway Hills, and in
the outlier of Ebrington Hill, the same alterations in the characters
of the strata belonging to the Zone of Ammonites Murchisonz,
well exemplified. At Campden Hill is seen the Oolite Marl,
which is here about 6 feet thick, presenting its usual characters of a
soft white chalky-looking rock, sometimes highly indurated and
crowded with fossils, among which are Natica Lechhamptonensis,
Lyc.; Ostrea flabelloides, Lam.; Modiola imbricata, Sow.; Lima
pectiniformis, Schloth; Perna quadrata, Sow.; Trigonia costata,
Sow.; Terebratula fimbria, Sow.; T. plicata, Buckm., Rhynchonella
concinna, Sow., and R. Lycetti, Dav.; and beneath this occur
representatives of the Lower Freestones and Pea Grit. These are
about 45 feet thick, and consist of oolitic limestones of a yellowish
colour, which, as we trace them downwards, are seen to become more
and more sandy and ferruginous in character; they rest on the
representative of the Midford Sand (here reduced to a rudi-
mentary condition). Towards the base of the series occurs
a very sandy oolitic rock with ferruginous banding, like that
so common in the Northampton Sand. ‘The attenuated beds
of the Lower Freestones are also séen at many points on Broad-
way Hill; and here we find the upper parts everywhere con-
sisting of yellow or brown oolitic limestone, and the base of
very variable beds, but usually of a more or less sandy and
ferruginous character, passing locally into tolerably pure oolitic
or shelly limestone.

In Ebrington Hill the beds of the Inferior Oolite, which con-
stitute an outlying mass, consist mainly of yellow and brown,
somewhat silicious and coarsely oolitic limestone rock, and exhibit
in places ferruginous banding like that of the Northampton Sand.
Some of the beds are composed of a ferruginous shelly rock, in
places almost wholly made up of plates of Pentacrinus, with abun-
dant specimens of Pecten personatus, Goldf.; Trigonia signata,
Ag.; Terebratula perovalis, Sow., &c. In one of the pits we have

B 2
16 GEOLOGY OF RUTLAND, &c.

a very instructive section. At its southern end are yellow and
ferruginous sands, a little to the northward irregular hard beds
occur in these sands, and still farther north the whole passes into
a calciferous sandstone rock with ironstone banding ; in fact there
is presented to us in one section examples of the different aspects
which the Northampton Sand assumes at various’ points. Still
further north, however, the rock becomes more and more oolitic in
structure, and thus passes into the ordinary yellow oolitic limestone
which caps the hill. All these changes take place within a distance
of about 40 yards. Everywhere on this outlier of Ebrington Hill,
the limestones of the Lower Freestones may be seen to assume
arenaceous characters, thus graduating in piaces into calcareous
sand-rock, or into sandy calcareous stone with some imperfect
cellular ironstone. Above Ilmington Downs, on the north side of
the Hill, we find the ordinary yellow freestones passing down
into beds of sand, sometimes containing “ pot-lids,” and graduat-
ing into a mass of fissile calecareo-siliceous rock with ferruginous
banding. Similar beds to these are found above Stoke Wood. In
the extensive pits above Little Hilcote occur courses of the fine
oolitic rock with ferruginous banding, sometimes interstratified
with beds of sand. At the rabbit-warren above Great Hilcote,
though no good faces of rock are exposed, the strata which
constitute the lower part of the Inferior Oolite are seen to
consist of yellowish-red, calcareo-ferruginous sand, with layers
of fissile, iron-banded, calcareo-siliceous stone. These beds are
undistinguishable in character from many portions of the North-
ampton Sand, as seen in Oxfordshire and Northamptonshire,

The whole of the strata hitherto described are admitted on all
hands to be the northerly prolongation of the Pea Grit and
Lower Freestones of the Inferior Oolite and to represent the
Zone of Ammonites Murchisonee. That this is the case is proved,
not only by the fact that their beds can be followed continuously
from the typical section of Leckhampton Hill to their develop-
ment in the Northern Cotteswolds, but also by the interesting
series of fossils characteristic of the horizon which they yield. Dr.
Holl has suggested that these limestones may also include a
representative of the Midford Sand, which as a distinct series of
beds can only be obscurely and doubtfully recognised in the
Northern Cotteswolds. It is certain that the great mass of ferru-
ginous and often sandy limestones, forming the lower part of
the Inferior Oolite in this district, contains Rhynchonella cyno-
cephala, Rich, in its lower beds, as does also the Northampton
Sand. It may, however, be doubted whether the presence of
this single species, which is occasionally found above the Midford
INTRODUCTORY ESSAY. 17

Sand in the Cheltenham area, can be considered as sufficient to
establish the correlation in question.

Crossing another area occupied by the Lias, that of the Vale Rocks on east
of Moreton, we arrive at other outliers of the Oolites capping a oh, i
number of more or less isolated hills in the north of Oxfordshire, vide Sheet 45
such as Brailes Hill, Mine Hill, Tysoe Hill, Shenlow Hill, Epwell 7104, S"" 0,
Hill, Long Hill, and the high grounds above Epwell, Sibford,
and Whichford. ‘The variable beds of limestones, sands, iron-
stones, &c., which form these outliers have been classed with the
Northampton Sand, and indeed they can be traced from this point
northward and eastward almost continuously with that series of
more or less ferruginous beds, which in the counties of Oxford
Northampton, Rutland, and Lincoln are designated by that term
and immediately overlie the Upper Lias Clay.

Whether we study the mineral characters presented by these
beds, or the series of fossils which they yield, we shall be con-
vinced that the strata capping the hills on the western side of the
Vale of Moreton are identical with those which form the outliers
on the eastern side of that valley. No one who examines the
sections presented in the two areas and compares the series of
fossils obtained from them, can doubt that the beds called Inferior
Oolite Freestone in North Gloucestershire once extended con-
tinuously over what is now the Vale of Moreton into North
Oxfordshire, where the portions of the same series now preserved
‘are known as part of the Northampton Sand. Thus we are led
to the conclusion that a part, at least, of the beds known as “ North-
ampton Sand” represents the Zone of Ammonites Murchisona,
that is the lowest portion of the Inferior Oolite, and possibly also
the Midford Sand, or the strata which constitute a transition series
between the Inferior Oolite and Upper Lias.

On the opposite side of the Vale of Moreton to the Ebrington
Outliers, at a distance of only six miles, is situated Brailes Hill.
Here we find, in the pits opened at the summit of the hill, a series
of beds identical with those in Gloucestershire. In the upper
part of the principal pit now open (1869) are seen beds of white
oolitic freestone, but slightly siliceous, which by weathering
assume a somewhat fissile character. Among these upper beds
is a white, coarsely oolitic rock, graduating into a regular freestone
undistinguishable from that of the Lower Freestones of Glouces-
tershire ; in its upper part this bed becomes shelly and contains
numerous Corals and fragments of Echinoderms, Below is an
irregular bed of brown sand and good ironstone, presenting the
usual features of the Northampton Sand. Beneath the sand and
ironstone, a thickness of about 8 feet of calcareo-siliceous rock is
18 -GEOLOGY OF RUTLAND, &c.

exposed, one bed near the bottom being crowded with shells,
among which I recognised the following :—

CEPHALOPODA.
Belemnites giganteus, Schloth.
or ellipticus, Mill, (Abundant.
a Aalensis, Ziet.
Ammonites Murchisone, Sow. (Very large.)
» 99 var. corrugatus, Sow.

GaASTEROPODA.
Nerinza sp.

LAMELLIBRANCHIATA DIMYARIA.
Pholadomya spec. nov. (Very large.)
Ceromya Bajociana, d’Orb. (Very fine.)
Gresslya peregrina, Phil., sp.

Myacites sp.
Cucullea oblonga, Sow.
Trigonia costata, Sow.
Astarte elegans, Sow.

» Minima, Sow.

LAMELLIBRANCHIATA MONOMYARIA.
Hinnites abjectus, Phil., sp.
Pecten demissus, Phil.

»  personatus, Méunst.

»  articulatus, Schiloth.

EcHINODERMATA.
Pentacrinus Milleri, Aust,

ZOANTHARIA.

Montlivaltia trochoides, Edw. & Haime.
Latomeandra Davidsoni, Edw. § Haime.
Thamnastreea Defranciana, Mich.

PLANT.
Wood.

Less than two miles to the south-east of Brailes Hill, we find
anothor outlier of the Oolite strata, capping the Upper Lias Clay
at Mine Hill. In the several old pits on this hill, calcareo-
arenaceous beds are seen, passing in places into ferruginous
INTRODUOTORY ESSAY, 19

sandstone and ironstone rock. In these pits the following fossils
were collected :— 5

CEPHALOPODA,

Belemnites giganteus, Schioth.
4 ellipticus, Mili. (Abundant.)

LAMELLIBRANCHIATA DIMYARIA,

Pholadomya fidicula, Sow.

” spec. nov. (Very fine.)
Ceromya Bajociana, @ Orb. (Very large.)
Gresslya peregrina, Phil. sp. ,
Trigonia signata, Ag.

x»  costata, Sow.
Cucullea cucullata, Goldf.

a4 oblonga, Sow.
Astarte minima, Sow.
Macrodon Hirsonensis, d’ Arch.
Modiola imbricata, Sow.

LAMELLIBRANCHIATA MONOMYARIA.

Pecten articulatus, Schloth.
»  personatus, Minst.
»  demissus, Phil.

BRaCHIOPODA.
Terebratula submaxillata, Mor.

ANNULOSA.
Serpula socialis, Goldf.
3) sp. a
ECHINODERMATA,

Pentacrinus sp.

ZOANTHARIA.
Montilivaltia sp.

PLaNntz,
Wood.

The most northernly of the outliers of “ Northampton Sand”
on the east side of the Vale of Moreton are those of Shenlow
20 GEOLOGY OF RUTLAND, &c.

Hill and Tysoe Mill Hill. At the former no section can be seen,
but it is evidently capped by ferruginous sand, which in places
passes into more or less calcareous flaggy beds. The hill on
which Tysoe Mill stands, however, yields an interesting section in
a pit about 20 feet deep; this exhibits the silicious limestones with
ironstone bandings, in some places passing into loose calcareous
sands, in others into the ordinary iron-ore of the Northampton
Sand. At this place marine fossils appear to be rare in the
beds, but fragments of wood and plant-remains are very abundant.
The following species were obtained from the pit near Tysoe
Mill:—

CEPHALOPODA.

Belemnites giganteus, Schloth.

LAMELLIBRANCHIATA DIMYARIA.

Macrodon Hirsonensis, d’ Arch.
Astarte elegans, Sow.

Trigonia compta? Lyc.
Lucina Wrightii, Opp.

LAMELLIBRANCHIATA Monomyaria.

Lima pectiniformis, Schloth.
Pecten demissus, Phil.

BracHiopopa.

Terebratula submaxillata, Mor.

In the long spur capped by Northampton Sand, which stretches
northwards as faras Compton Winyate, we find many illustrations
of the variable character of the beds which lie upon the Upper
Lias Clay. Sometimes, as near White House Warren, white
sands with numerous bands of carbonaceous matter occur; in
some places these white sands are found passing into hard sand-
rock, at others into ferruginous sand, and at others again, as near
Broom Hill Farm, into cellular ironstone rock.

At not a few points the sands graduate, within very short
distances, into a more or less fissile calcareo-siliceous rock traversed
by hard ferruginous bands. The same rapid variations—so charac-
teristic of the Northampton Sand throughout its whole range—
from arenaceous to more or less ferruginous and calcareous
rocks, is seen in the numerous outliers to the east of this spur,
INTRODUCTORY ESSAY. 2)

one of which, Epwell Hill, rises to an elevation of 836 feet, and
constitutes the highest point in the county of Oxford. °

Tracing the same beds to the southwards, we find in the outlier
above Whichford and Long Compton, thick beds of white free-
stone underlaid by sands; beneath these occur beds of the
calcareo-siliceous stone with but few well preserved fossils. The
succession of beds here is evidently the same as at the other
points we have noticed, both on the east and west side of the Vale
of Moreton. Near Long Compton a specimen of Ammonites
Garantianus, @Orb., was obtained from the Northampton
Sand.

Near Hotley Hill Farm, a mile and a half north-west of the
village of Hook-Norton (or Hogs-Norton) there are several very
interesting sections in the Northampton Sand. In the higher of
these is seen a whitish, oolitic, siliceo-calcareous rock (like that
which forms so large a part of the formation to the north of
Northampton) with bands of brown hematite in many of the
beds. In this upper part of the series, which is well exposed in a
pit above the farm-house, we find scarcely any marine fossils, but
fragments of wood are especially abundant. Lower down the
hill, however, and just above the junction of the Northampton
Sand with the Upper Lias Clay, we find in another pit the base
of the series; this is seen to consist of beds precisely similar in
mineral character to those of the upper pit, but which yield large
numbers of marine fossils, including many corals. In this section
there are bands almost wholly made up of oyster-shells and a
bed of stone exhibiting borings of Lithodomus.

The following fossils have been collected from this pit by
Mr. Richard Gibbs, the former fossil-collector of the Survey, and
myself; they clearly show that this part of the Northampton
Sand is referable to the Inferior Oolite, and to its lower part, the
zone of Ammonites Murchisonz :—

CEPHALOPODA.
Ammonites Murchisone, Sow.

‘“ 53 var. corrugatus, Sow.
Belemnites Aalensis, Ziet.
a ellipticus, Mzii.
Nautilus, spec. nov. (Very large.)

G-ASTEROPODA,

Pleurotomaria ornata, Zéet.
Natica sp.
Nerinza sp.
GEOLOGY OF RUTLAND, &c.

LAMELLIBRANCHIATA DIMYARIA,

Pholadomya fidicula, Sow.

5 ovulum, 4g.

5 Zieteni, -Ag.

5 Heraulti, Ag.

% spec. nov. (Very large.)
Gresslya latirostris, Ag.

» peregrina, Phil., sp.
Ceromya Bajociana, d’ Orb.
Cypricardia sp.

Isocardia cordata, Buckm.
Trigonia costata, Sow.
a signata, Ag.
+ pullus, Sow.
»  producta, Lyc.
os Spec.
Cucullea oblonga, Sow.
Lucina Wrightii, Oppel.
Modiola Lonsdalei, Lyc. § Mor.
»  Leckenbyi, Lyc. & Mor.

LAMELLIBRANCHIATA MONOMYARIA.

Pinna cuneata, Phil.

9 Sp.
Lima pectiniformis, Schoth.

» punctata, Sow.

»  cardiiformis, Lyc. & Mar.
Gervillia Hartmanni, Goldf.

9 lata, Phil.

Hinnites abjectus, Phil, sp.
Pecten articulatus, Schoth.

>»  demissus, Phil.

x» _ lens, Sow.
Ostrea flabelloides, Lam. (O. Marshii, Sow.)

»  Sowerbyi, Lye. & Mor,

BRACHIOPODA.

Rhynchonella sp.
Terebratula globata, Sow.
33 submaxillata, Mor.

» sp.
INTRODUCTORY ESSAY. 23

POLYZOA.
Berenicea (sp.) on Terebratula,

ZOANTHARIA,

Isastrea Richardsoni, Edw. & Haime,
Montlivaltia trochoides, Edw. § Haime.
Thamnastrea Terquemi, Edw, & Haime.
Thecosmilia gregaria, M’ Coy.

PLANT.
Wood (abundant).

As we pass eastward from the localities particularly described
above, we find many opportunities for studying the very variable
strata of the Northampton Sand ; these consist in some places of
white unfossiliferous sands, in others, of red sandstone graduating
into ironstone, and, in not a few localities, pass into beds of
generally fissile, calcareo-siliceous rock; in this latter condition
they are seen at many points about Sibford-Ferris and Sibford-
“ Gower, Great Tew, and Milcomb Hill, and also in the neigh-
bourhood of Hook-Norton and Great Rollwright (or Rollreich).
The fossiliferous beds appear to occur towards the base of the
Northampton Sand series, but are by no means constantly present ;
the fossils which they yield are always those of the Zone of
Ammonites Murchison of the Inferior Oolite.

At several pits in the vicinity of Sibford and Hook-Norton the
following fossils have been collected in. the impure siliceous lime-
stones of the Northampton Sand :—

CEPHALOPODA.
Ammonites Murchisonz, Sow,
corrugatus, Sow,
Belemnites Aalensis, Ziet.
% ellipticus, Mzll.
Nautilus, spec. nov. (Very large.)

GASTEROPODA.

Cerithium limeforme, Rom.

Natica sp.
Patella cingulata, Goldf.

LAMELLIBRANCHIATA DIMYARIA.

Pholadomya fidicula, Sow.
Ceromya Bajociana, @’ Orb.
24

GEOLOGY OF RUTLAND, &C.

Gresslya peregrina, Phil., sp.

»  abducta, Phil. sp.

»  latirostris, Ag.
Myacites sequatus, Phil., sp.

9 dilatatus, Phil., sp.

35 compressiusculus, Lye.
Arcomya sp.
Goniomya angulifera, Sow.
Isocardia cordata, Buckm.
Unicardium gibbosum, Lye.
Tancredia axiniformis, Phil, sp.
Cyprina dolabra, Phil.
Trigonia signata, Ag.

o v-costata, Lye.
35 costata, Park.
<5 pullus, Sow.

Lucina Wrightii, Opp.

Astarte elegans, Sow.
Macrodon Hirsonensis, D’ Arch.
Cucullea oblonga, Sow.
Modiola Sowerbyana, D’ Orb.

LAMELLIBRANCHIATA MONOMYARIA.

Lima pectiniformis, Schloth.
Pinna cuneata, Phil, sp.
Gervillia prelonga, Lye.
Hinnites abjectus, Phil.
Pecten personatus, Minst.
x»  demissus, Phil.
»  articulatus, Schloth.
o> ~=s Sp.
Grypheea sp.
Ostrea acuminata, Sow.
»  Marshii, Sow. var.

BRACHIOPODA.
Rhynchonella sp.
Terebratula submaxillata, Mor. ‘
i globata, Sow.
39 perovalis, Sow.
ZOANTHARIA.

Montlivaltia trochoides, Edw. & Haime.
Isastreea Richardsoni, Edw. & Haime.
INTRODUCTORY ESSAY. 25

As we pass eastwards, the Northampton Sand is found to con-
tain fewer beds of a calcareous character and to be more usually
made up of loose white sand and sandrock, graduating in many
places into ironstone ; these strata yield numerous plant remains,
but contain scarcely a trace of marine fossils. Occasionally,
however, as near Milcomb, they are seen passing into a shelly
calcareous rock which yields similar series of fossils to those
already quoted. About a mile north-west of Deddington, in the
parishes of Barford St. John and Barford St. Michael, there are
two small outliers which have been preserved, in consequence of the
Inferior Oolite having been let down by faults. In these the lower
beds of the Inferior Oolite exhibit evidence of a local, but remark-
able and highly interesting, recurrence of conditions, very similar
to those which must have prevailed during the deposition of the
beds of this age in their typical development in the Cotteswold
area.

In the small outlier north of the River Swere (Combe Hill) we
find about 15 feet of white oolitic limestone, some of the beds being
very shelly. The rock, which here shows considerable signs
of disturbance, consists of a number of courses, each from
18 inches to 2 feet in thickness, separated by marly partings.
Fossils are extremely abundant in these beds, but are generally
very difficult of extraction. The following species have been
found at this place by Mr. Beesley of Banbury, Mr. Richard
Gibbs, and myself :—

Fossils from Combe Hill, near Deddington, Oxfordshire.

CEPHALOPODA.

Ammonites Murchisonze, Sow.
Belemnites ellipticus, Mill.
Nautilus spec. nov. (Very large.)

GASTEROPODA.

Natica Leckhamptonensis, Lyc.
Patella rugosa, Sow.
Pleurotomaria ornata, Defr.

|
Trochus sp.
Cerithium limeforme, Rém.
Nerinza Jonesii, Lyc.
Phasianella striata, Sow.
26

GEOLOGY OF RUTLAND, &c.

LAMELLIBRANCHIATA DIMYARIA.

Arca Pratti, Lyc. & Mor.
a

Myoconcha crassa, Sow.

Mytilus lunularis, Lye.

»  imbricatus, Sow.
Modiola aspera, Sow.
Macrodon Hirsonensis, d’ Arch.
Astarte elegans, Sow.
Trigonia pullus, Sow.

a Beesleyana, Lyc.
Lucina Wrightii, Opp.

LAMELLIBRANCHIATA MONOMYARIA.

Lima cardiiformis, Lyc. & Mor.
» pectiniformis, Schloth.
» Rodburgensis, Zyc. MS.
» Spec. nov. (Very large.)
» Sp.
Pecten demissus, Phil.
x» lens, Sow.
>»  Vimineus, Sow.
»  articulatus, Schloth.
»  annulatus, Sow.
personatus, Miinst.
Hinnites abjectus, Phil, sp.
Perna rugosa var. quadrata, Mor. & Lye.
Gervillia pernoides; Desi.

Harpax sp.
Ostrea flabelloides, Lam. (O. Marshii, Sow.)
9 ” var,
BRACHIOPODA.
Terebratula globata, Sow. _
93 perovalis, Sow.
»  Phillipsii, Mor,
5 submaxillata, Mor.
Pr fimbria, Sow.

plicata, Buckm.
Rhynchonells sp.
INTRODUCTORY ESSAY. 27

ANNULOSA.

Serpula socialis, Goldf.
»  convoluta, Goldf.

” sp.

ECHINODERMATA.
Pentacrinus Milleri, Ausé.

POLYzOa.
Spiropora (Cricopora) straminea, Phil. sp.

ZOANTHARIA.

Thamnastrea Defranciana, Mich.
” sp.
Montlivaltia trochoides, Edw. & Haime.
” Delabechii, Edw. & Haime.
Cladophyllia sp.

On the south side of the River Swere, at a place known as
Blackingrove, we find a pit opened in beds of stone similar to that
on the other side of the river at Combe Hill; as we go lower in
the series, however, the oolitic limestones are seen passing down
into beds of a more siliceous and shelly character, and finally into
the hard siliceo-calcareous rock, which occurs so commonly in the
Northampton Sand. The whole of these beds are crowded with
shells which ‘have been collected both by the late Mr. Faulkner,
of Deddington, and the officers of the Geological Survey; thus
we have been made acquainted with a very large and interesting
fauna from this locality, which enables us to refer the beds with-
out doubt to the base of the Inferior Oolite. The strata repre-
senting the Northampton Sand here, as at many other places,
contain numerous rounded pebbles of argillaceous limestone; it
is in places banded with brown oxide of iron in its lower part,
and rests directly upon the Upper Lias Clay.

The fossils which have been collected at Blackingrove in the
sandy limestone of the Northampton Sand are as follows :—

Fossils from Blackingrove, near Deddington, Oxfordshire.
Pisces.
Strophodus magnus, Ag.
CEPHALOPODA.

Ammonites Murchison, Sow.
” ” var, corrugatus, Sow.
28

GEOLOGY OF RUTLAND, &c.

Ammonites Murchisonze var. sublaevis, Sow.
29 Sp.

Belemnites giganteus, Schioth.
‘5 ellipticus, Mill.

Nautilus spec. nov. (Very large.)

GASTEROPODA.

Patella rugosa, Sow.
Pleurotomaria sp.
Natica Leckhamptonensis, Lyc:

x»  cincta, Phil.
Turbo sp.
Trochotoma calix, Pazi.
Chemnitzia sp.
Cerithium sp.
Nerinza sp.

LAMELLIBRANCHIATA DIMYARIA.

Pholadomya fidicula, Sow.
x5 spec. nov. (Very large.)
Gresslya peregrina, Phil,, sp.
Cardium Buckmani, Lyc. & Mor.
” sp.
Cucullea cucullata, Minst.
Astarte elegans, Sow.
Trigonia costata, Sow. “
» . Beesleyana, Lyc.
Mytilus lunularis, Lye.
Modiola imbricata, Sow.

LAMELLIBRANCHIATA MONOMYARIA.

Lima pectiniformis, Schloth.
»  cardiiformis, Lyc. & Mor.
» rvigida, Sow.
» Spec. nov. (Very large.)
» spec. nov.
Avicula sp.
Pteroperna plana, Lyc. §& Mor.
Perna rugosa, var. quadrata, Lyc. & Mor.
Pinna cuneata, Phil.
Gervillia sp.
Placunopsis ‘sp.
Hinnites abjectus, Phil., sp.
Pecten. lens, Sow.
INTRODUCTORY ESSAY. 29

Pecten personatus, Munst.
Ostrea flabelloides, Zam. (O. Marshii, Sow.)

» Sp.

BRACHIOPODA.

‘Terebratula perovalis, Sow.
ss submaxillata, Mor.
Rhynchonella sp.

ANNULOSA.

Serpula socialis, Goldf.
» «8p.

EcHINODERMATA. x

Clypeus Plotii, A7ein.

_ » var. altus, M‘Coy,
Pygaster semisulcatus, Phil., sp.
Hyboclypus agariciformis, Forbes.
Stomechinus germinans, Phil. sp.
Pseudodiadema depressa, Ay. sp.
Acrosalenia (spines).

Pentacrinus Milleri; Ausé.

ZOANTHARIA.

Montlivaltia trochoides, Edw. & Haime.

Over a considerable area in the neighbourhood of Banbury
the Lower Oolites have been almost wholly removed by denuda-
tion; but we nevertheless get evidence at a few points, of the
occurrence of calcareous and shelly beds in the Northampton

Sand series.

The fossils which these yield agree for.the most

part with those of the preceding ‘lists, and prove that the lower
portion of the Northampton Sand in this area also belongs to
the Zone of Ammonites Murchisonez or the base of the Inferior

Oolite.

32108.

7
Northampion
Sand in the,
South Midland
district,

30 : GEOLOGY OF RUTLAND, &0.

We have seen how the shelly limestones of the Inferior Oolite, as

they are traced northwards and eastwards, assume sandy characters
and. exhibit evidence of having been deposited under more littoral |
conditions, but that, nevertheless, the series of fossils collected at _

a number of different points place the age of the beds beyond’
question. It has been shown by the Geological Survey that the
Lower Zone of the Great Oolite, which ingludes the Stonesfield
Slate, is found to undergo precisely similar changes when it is
followed in the same direction. Thus the two series of sandy beds,

’ _ yepresenting the attenuated, littoral, and sometimes estuarine ‘con-

ditions of the lower parts of the Great and Inferior Oolite respec-
tively, are brought together. The. higher parts of this mass of are-.
naceous strata are unfortunately almost: always unfossiliferous, and
it is found impracticable i in the Oxfordshire area, except at a few
widely-distant points, to separate that portion of them which

‘belongs to the Great Oolite, from that which is included in the

Inferior.- Indeed, although the sandy beds at the top of the Lias
never disappear altogether, they are at some points, as near
Towcester, reduced to. only a few inches in thickness. It" has
consequently been found impracticable in this district to draw

-a line of boundary between the representatives of. the Great’ and

Inferior Oolite. Thus it has arisen that under the term
“ Northampton Sand” are included, in North Oxfordshire and’

(passing at some points into imperfect ironstones, and at others
into impure limestones,) which intervene between the Upper
Lias Clay and the marly, limestones of the Upper Zone of the
Great Oolite. At a few points in the south of Northamptonshire

~ we find the Northampton Sand passing locally. into a calcareous

rock, as at Thorpe Mandeville, Stowe, &c., but in the northern
part of the county, especially in the neighbourhood of Northamp-
ton, Pitsford, Moulton, Sywell, Brixworth, Lamport, Wold,

Draughton, &c., it is frequently represented by thick masses of —

more or less shelly, oolitic, siliceo-calcareous rock, of ‘the kind so
frequently alluded to in the description of the country to the south.
At Duston a thin bed of this siliceo-calcaréous rock, in the midst
of the Northampton Sand series, exhibits such a fissile character,
that it.was formerly largely dug and used for roofing purposés
under the name of “the Duston Slate.” At a spot one mile and
a half north-east of Draughton, calcareous beds occur in
the Northampton Sand of sufficient purity to be. burned for
lime. To the northwards, although the beds of this forma-

tion .often become very shelly and highly calearéous, they —

do not, except at a few points, pass into the remarkable fissile
oolitic rock so frequently alluded to. The -places at which

South Northamptonshire, the whole mass of variable sandy strata, _

s
INTRODUCTORY ESSAY. 31

calcareous beds are developed to a considerable extent in the
Northampton Sand series are indicated by the sign CALC. upon
the maps of the Geological Survey.

We have further seen how remarkably the beds of the Inferior
Oolite and the Lower Zone of the Great Oolite become rapidly
attenuated as we pass northwards and eastwards, so that the strata
representing these formations which, in the Cotteswold Hills,
attain a thickness of about 300 feet, are reduced ina distance of
30 to 40 miles to the few inches of irregularly ferruginous sandy
rock ; these, in some parts of South Northamptonshire, alone
separate the Upper Lias Clay from the white, marly limestones,
forming the Upper Zone of the Great Oolite. It is probable that at
some points the extremely variable beds, constituting the Northamp-
ton Sand, thin out altogether, and that the higher beds of the Great
Oolite series lie directly upon the Lias. Over considerable tracts
it has been found impracticable by the Geological Surveyors to
represent the Northampton Sand at all on the maps, so thin and
inconstant are its representatives. The diminution in thickness
of the lower beds of the Oolite series is attended with changes
not less striking and remarkable in their mineral characters; the
massive marine limestones of the south-western area being replaced
‘by the variable sandy, usually littoral, and sometimes estuarine
deposits of the South Midland districts.

While the changes above described fake? sews in the Inferior fi

Ipper and
ower Estua-

Oolite and the lower part of the Great Oolite, it is interesting inn rine Series.

notice the relative constancy of the characters “presented by-the
formations, ° ‘which respectively underlie and succeed this variable
series of beds, in the district in question. The Upper Zone of the
Great Oolite and.the Cornbrash are remarkably persistent in
character over the whole of the district, and apparently do not
undergo any very marked variations in thickness. The Forest
Marble, on the other hand, which lies between these two divisions,
; presents us with a series of changes on a small scale, parallel with
those of the oldest beds of the Lower Oolite. The very variable
shelly limestones, sands, and clays of the Forest Marble become
rapidly reduced in thickness as we pass northwards and eastwards.
In North Oxfordshire, as shown by Professor Phillips, they some-
times assume estuarine’ characters, while still further northwards this
formation is of such. insignificant thickness and inconstant characters
that its outcrop could no longer be represented on the Survey maps.
In the North Midland district beds of clay, which, lying as they

€ 2
382 GEOLOGY OF RUTLAND, &C.

do, between the limestone series of the Cornbrash and the Upper
Zone of the Great Oolite, may be fairly assumed to be the
approximate equivalent of the Forest Marble, assume sufficient
thickness and importance to be represented on the maps ; to
these beds the name of ‘ Great Oolite Clays” has been given.

The Midford Sand, which underlies the Inferior Oolite series,
either thins out altogether in the northern spurs and outliers of
the Cotteswolds, or its attenuated representative is lost in the
Northampton Sand. The thickness of the Upper Lias Clay is
at places in North Oxfordshire reduced to about 30 feet, and
the Middle and Lower Lias are also probably of considerably
less thickness in the South Midland area than in the country to
the north and south of it respectively. :

Professor Hull has shown in how remarkable a manner the beds
of the Jurassic series are reduced in thickness as we pass to the
south and east, so that the Inferior Oolite, Upper Lias, and
Middle Lias, which at Leckhampton Hill measure severally
about 300, 200, and 115 feet, are near Burford reduced to 20, 20,

and to 24 feet, and near Ascott to 10, 6, and 10 feet respectively.

‘In North Northamptonshire the variable beds of the North-
ampton Sand rapidly increase in thickness, so that in the neigh-
bourhood of Northampton, where their palzontological and general
characters have been perseveringly and successfully studied by
Mr. Sharp, they exhibit their maximum development, and attain a
thickness of more than 70 feet. Here it is possible to draw a
line of demarcation between the beds of the formation which
represent the Great and the Inferior Oolite respectively. The
upper strata consist of clays of a more or less sandy character,
‘which occasionally exhibit such alternations of beds containing
fresh water and marine species of fossils, with old terrestrial
surfaces, &c, as to prove them to be of estuarine origin. These
beds have been separately mapped by the Geological Surveyors
since the year 1867 under the name of the “ Upper Estuarine.
Series ;” and, as will be shown in a later chapter of this memoir,
they acquire a considerable development and present very interest-
ing features and relations in the country to the northwards. The
lower part of the Northampton Sand (to which the name is here
more strictly confined) in the Northampton district, consists in-
its upper part of sands with inconstant beds of clay; these beds
are usually unfossiliferous, but occasionally exhibit the same
evidence of the alternation of marine, freshwater, and terrestrial
conditions as the beds above, and they have been accordingly

called the “ Lower Estuarine. Series?’ The base of the North-. -

ampton Sand is composed of marine beds yielding at a few
points a most interesting fauna, which is unmistakeably that
INTRODUCTORY ESSAY. 33

of the Zone of Ammonites Murchisone ; unfortunately the great
majority of the fossils of these beds are preserved only in
the condition of surface casts and internal moulds. ‘Sometimes
the whole thickness of the Northampton Sand is made up of
white sands with occasional beds of clay ; ‘at many points it passes
into an oolitic, siliceo-calcareous rock; but in the majority of
instances a greater or less portion of its mass, usually towards its
lower part, is converted into a solid bluish -or greenish ironstone
rock of oolitic structure, exactly resembling many parts of the
Dogger and Middle Lias ironstones of Yorkshire; this rock, by
weathering action set up from its joint planes, assumes a brown
colour and a banded or cellular structure of a very peculiar and
striking character.

«

Wherever the junction of the Upper and Lower Estuarine
Series can be examined there are seen to be proofs of an uncon-
formity between them. The bottom bed of the Upper Estuarine
Series, whenever this formation is distinctly developed, is found to
be a band of ironstone nodules, and these always rest on an eroded
surface of the Northampton Sand beds beneath. As an example,
among many which might be cited, of the appearance presented by
the junction of these two series of beds, the sketch on page 34,
of a pit near the Race-course at Northampton is given. Here we
have, in the lower part of the pit, beds of well stratified white
sand with vertical plant markings and sandrock (the latter
quarried as a building stone), passing downwards into a dark
brown sandstone with a very thin representative of the North-
amptonshire ironstone at its base. On the eroded surface of
these beds lies the light-blue, and often highly carbonaceous, clays

Appearance of
@ new forma-
tion, the Lin-
colnshire
Oolite,

of the Upper Estuarine Series, with the very constant layer of °

nodules (“ ironstone junction-band ”) at its base. (Fig. 1, p. 34.)

Bearing in mind the existence of an uncomformity between
these two series of estuarine. beds, we are not surprised to find
that, in the country to the north, a thick series of beds (the Lincoln-
shire Oolite) comes in like a great wedge between them. ~ Thus
in the northern part of the county of Northampton, along the
valley of the Nene, the succession of beds is the same as that
which we have already pointed out as presented in the neigh-
bourhood of Northampton, while along the valley of the Welland
and in the country to the westward and northward we have
the same series of beds, with the addition of a new forma-
GHOLOGY OF RUTLAND, &c.

34

> ‘(pueg woydurey310 7) sowag' omen 3 go “9 * “ie
ua ¢ Weg sulenisy] 1aAO0'T oy} JO ‘a “qoor pus oyuT Surgsed pues ay AA “p .
puvq-uorjoun euoanory a ‘soliog emumenysg sodd py 04} JO -osg ‘shuyo Apueg +g we mae ca My

ee ee
ran \ “¥ “ nr a) y oe Yh oe :
pnt __ ee : AN ees - os G AR J Lee .
7 . y 2 GO, a

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 
35

INTRODUCTORY ESSAY.

!

 

all sco

 

wT

o)

“heIQ sory weddg *¢
“saL1Ig sulLrenysy ToMOT ou}. Sarpnyout pueg a0;dureT3.10 NT °F
‘ASV 7
SLI LV ELVIG NOLSTMATION) AHL HLM HLIIOQ IAIHSN'IOONIT

‘solag euLrenjsyy Jedd) ‘g

“souojsouurry pue sfe[Q 211100 qwory B
’

“qgetquiog “1

‘JOLISIC, PUPTPIL
91 JO spIeg UIO}S9\\ PUY UIEY}ION 94} Ul spag] JO UoIsseooNg

*

 

- ‘keg sery reddg ‘¢

“SOTIOG SULIUNIST IOMO'T O73 Surpnyout pueg woydureqs0 NF

“song eunenisy teddq -¢
‘gaTOJSoUATT] pus sherg a}OO ywaay) % |

“YSBIqUION “T

‘OLS. PUBLPIPL
ay} JO syeT UleqNog pus UIE\sey ay} Ur spog Jo WOTssa00ng

¥

 

#

_INOLSUMIT HULHSN'TIOONI'T

ayy JO yno Suruuryy og} Aq posneo. ‘vary aNvIGI oy} VIGIL sdag Jo NOIssdooNg oy}. ur SO NMAATIC. oY} SUNVISNEL LIAV,T,

 
Paleontolo-
gical and
Physical evi-
dences. of age.

r

Onconformnity
between Great
and Inferior
Oolite.

36 GEOLOGY OF RUTLAND, &C.

tion, to which the Geological Sufvey has given the name of “ the.

‘Lincolnshire Oolite Limestone.” See Table on page 35.

These facts with regard to the relations of the great series of
limestones of Lincolnshire and the adjoining counties were first
made out during the survey of the. area in 1867, and a nomen-
clature and grouping of the beds adopted in accordance with
them. They‘have since been illustrated in great detail in a paper
on the Lincolnshire Oolite by my friend Mr. Sharp,* who on
these questions has been led by his own studies to adopt in their
entirety, the views put forward in the maps and other publications
of the Geological Survey. a

The two horizontal diagram sections (Plate II.) ‘will serve to
illustrate clearly, the manner in which the beds of the Lincoln-.
shire Limestone make their appearance in the midst of the Lower
Oolite series and rapidly acquire preponderating thickness and
importance in it.

That the Lincolnshire Limestone was of Inferior wahee. than
Great Oolite age has been suspected, as we ‘have already seen, by
many authors, and may now-be considered as generally adopted by
geologists. If any doubts were still alter tained on the subject it
would only be necessary to point to the overwhelming paleon-
tological evidence on the subject, which has. been published by-
Mr. Sharp in his valuable paper, together with’ the tables,drawn
up by Mr. Etheridge from Mr. Sharp’ s and the Survey collections,:
and appended to the present memoir. The not less conclusive
physical evidences afforded by the unconformable relation of the
beds representing the Lower Zone of the Great Oolite with the
limestones below, which-were first made manifest during: the ©
mapping of the area, are now illustrated and explained in this-
essay.

We have seen how the Upper Estuarine Clays, forming ‘the
base of the Great Oolite series, usually rest on an eroded surface
of the Northampton Sand. The same phenomenon is presented.
by the junction of the former beds with the Lincolnshire Lime-
stone. Further—at some points, as for example the Ketton
Quarries, the upper surface of the Lincolnshire Oolite is seen to
be not only waterworn and denuded, but to have been bored by

_ Lithodomi before the deposition of the beds-of the Great Oolite series.

But there exist sections which show in a much more marked -
and striking manner the interval that must have elapsed between -
the deposition of the Lincolnshire Limestone and the commence-

ment of the Great Oolite period. In openings near the north
end of the village of Weekley (Fig. 2), and at Old Head Wood

* Quart. Journ. Geol. Soe. vol. xxix. (1878), p. 225,

 
37.

INTRODUCTORY ESSAY.

qd stq3 Jo qsea o[I91] B y[ULJ B[qusopisuod dzour B Ayareyz00 SI o10Y IT, “SCA OY) 0} MOAITAOP v YA yey [ems v sopry Ayqrssod snyv} oy,

“gid Jo w10}}0q- 09 ‘sIa}oVIEY. Y ‘@uT09 “ur g 07  *(,, pueq-uorjounf snouisnasay ,,) SeyNpou oucys ‘(e100
Teusn WY e10-uom safysuojdureyjION oy, .,yoor-pey,, *6| sowwayuy) — -uo4r Surureynoo soovd Ul ‘spuvq snouLsniley sseq 10 o10py ‘p | yeerx)
ee ° ‘yg 07 & ‘survas U1 { satiag “YP ‘SsuLyIeU snosdeUOgres YILA Avpo Apues oy AA ‘9 4 So11Eeg
ur Aypereuds ‘seyy"UE snosseMOgreo Yon yA spuvs oy M off ouENST ‘Ul 9 “YJ [ ‘9 OUI SuIssed pue spreao} | oulrenysiy
a ‘H 8 03.9 ‘Gyorgy soqout g 03 dn) Avjpo ontq-31q37] Jo IdMOT pemoyoo 1034.81] Surmt00aq SAvjo ‘snosoeNogieo ‘peynerys ‘on[g “9 | reddg
surves SuuTEyuOD ‘spus paytfers ‘ay pue “pamojoo-ysy ‘2 : cn ‘IS OT Tog ‘vy i

me tin pr” Ny
a AY

~

  

i *advysuop dun y}.L0 NT “hepyaayy fo san pdpuns ur wouseg *% aunbyy

 
.

Age of Lin-
colnshire
Oolite,

x

38 GEOLOGY OF RUTLAND, &c. '

(Fig. 3), both localities a few miles north-east of Kettering,
we have the most complete evidence that the Inferior Oolite beds

Figure 3. Section-at Old Head Wood, Northamptonshire.

 

 

 

a. Soil, &e.

b Gravelly drift.

.¢, Light-blue, estuarine clays. te

d. White, marly. clays. Upper Estuarine Series,

e. Ironstone junction-band. / ° .

ze ave ier ole Tock olite rock, } Lincolnshire Limestone?
of the area were disturbed, upheaved, and denuded, and that on
their truncated edges. the ‘strata of the Great Oolite were laid
down, with consequently unconformable relations to them. Indeed,
there is every reason to believe that at Weekley a small fault -
traverses the Inferior. Oolite strata, but does not affect the Great
Oolite beds ‘above ; so that this fracture must have been produced
in the interval between the deposition of these two series of beds.
In mapping the small inliers of Inferior Oolite at Brigstock Parks
and between Little-Oakley and Stanion, I met with numerous
evidences of the fact, that the lower series of beds underwent
considerable disturbance and denudation before the deposition
upon it of the younger series of strata.

’

We are now met by the problem of the exact age ‘of the,
several beds representing the Inferior Oolite in the Midland
district. The fauna of the Northampton Sand, as already pointed
INTRODUCTORY ESSAY. 39

out, is that of the Zone of Ammonites. Murchison. Possibly
its lowest beds may in some lovalities-repredent the Midford Sand,
but the existence of Rhynchonella cynocephala, Rich., and some
other Brachiopods cannot, as we have seen, be regarded as con-
elusive upon the subject. It is true that specimens of Ammonites
‘bifrons, Brug., have been collected in the lowest stratum of the
‘Northampton Sand near Northampton ; but the bed which yielded
these specimens contains’ numerous pebbles of at'gillaceous lime-
stone, and I have found that the chambers of the Ammonites in
question are filled with a similar material, and not with the sandy
ferruginous rock of the matrix; moreover, there is still con-
siderdble doubt among paleontologists whether the species in
question has ever been obtained above the Upper Lias Clay. I
cannot, therefore, help regarding these specimens of Ammonites
bifrons, Brug., as having been derived, with the associated pebbles,
from the septaria of the latter formation, which, in rhany districts,
shows signs of having undergone denudation prior to the deposi-
tion of the Inferior Oolite upon it. This is especially the case,
as might be anticipated, when no representative of the Midford
Sand is present ; and we must, therefore, regard it as still very

doubtful whether any equivalent of the last-mentioned beds

‘exists in the Midland district.
_ The researches of several German geologists, especially those
of Dr. Waagen,* have shown that the higher beds of the Zone of
Ammonites Murchisonz, which Dr. Oppel regarded as constituting

a district sub-zone, and to which he applied the name of the Zone

of Ammonites Sowerbyi, in some districts acquires a great’ develop-
ment and very distinct characters.. If this zone be ‘represented
at all in the Cotteswold area, it is probably the insignificant and
inconstant Oolite Marl or Fimbria Bed -which, as ‘suggested by
Dr. Waagen himself, must be regarded as its equivalent. But
in the Lincolnshire Limestone we appear to have a magnificent
local development of the beds of this horizon in the Midland
district. ‘That this is really the case is proved, not‘only by the
marked absence of numerous forms which are, as shown by Dr.
(Oppel and Dr. ‘Wright, highly characteristic of the upper portions
of the Inferior Oolite (namely, the zones of Ammonites Parkinsoni

and Ammonites Humphresianus), but by the presence of a number
’ of very interesting species which have been shown by the German
' * ‘paleontologists to be especially characteristic of this horizon, such
' as the Ammonites Sowerbyi, Mill, Ammonites polyacanthus, Wasgen,

_. * Der Jura in- -Frahken, Schwaben und der Schweitz vergleichen nach seinen
" paleontologischen Horizonten, von W. Waagen (Munich, 1864). Ueber die Zone des
- Ammonites Sowerbyi, von Dr. W. Waagen (Benecke, Geognostische-paleontologische
Beitriige, Erster Band, p. aos Munich, 1867).

: , :
Zone of Am-
monites
Sowerbyi.
‘Formations
absent.

». Changes in the

Lias strata.

Rhetic beds,

40 GEOLOGY OF RUTLAND, &c.

,

several peculiar varieties of Ammonites. Murchisone, Sow. (to
which distinct names have been applied in Germany), Belemnites,
brevispinatus, Waagen, Pecten aratus, Waagen, and some other —
forms, which may be regarded either as new species or as distinct
varieties, characteristic of this horizon. -

We are thus led to see the sjgnificance of the unconformity
which has been shown to exist in the Midland district between the
Great Oolite series and the beds of the Lincolnshire Limestone ;
for in this area, strata representing the Fuller’s Earth and the
Ragstones and Upper Freestones of the Inferior Oolite (Zones of
Ammonites Parkinsoni and Ammonites Humphresianus) appear
to be wholly wanting.

It is true that a considerable number of species pass from the
Lincolnshire Oolite to the Great Oolite, but the differences between
the faunas of these two series are at least as great as- exist
between those of the Coralline Crag and of the deposits now taking
place in the adjacent sea. The signs of unconformity between
the two series of Jurassic deposits, which we have pointed out in
this memoir, need not awaken greater surprise among geologists
than the proofs of considerable disturbance and denudation
which are so frequently found in deposits of Pliocene age, ani.
the unconformity which must necessarily exist between these
rocks and such as are now in course of formation.

-

When we trace the beds of the Lias northwards, we find them .

to undergo changes in mineralogical composition and thickness,

not less considerable in degree nor less striking in character than
those which we have described as occurring in the case of the
Lower Oolites. Unfortunately, however, owing to- the paucity of
sections in the argillaceous strata of ‘the former series. and the
extent to which they are covered with drift, it is found to be
much more difficult, than in the case of the latter, to trace the
variations which take place in the beds representing its several
zones. - :

The junction of the Lias and Keuper is almost everywhere
concealed by drift; but, wherever an opportunity of observing it
occurs, the Rhetic beds are seen. They appear to -exhibit,
almost everywhere, very similar mineral characters, but to vary
very greatly in thickness; and although there are such consider-
able areas in the Midland district, within the limits of which they
have not yet been detected, yet, as no section has been observed -
in which they are undoubtedly absent, we may for the present.
conclude. that their outcrop is continuous across England. I am
familiar with a number of exposures of the Rhetic beds in North,
2 . INTRODUCTORY ESSAY. 41

Mid-, and South Lincoloshire and also in Nottinghamshire ; ; but
to the southwards they have only been detected in outliers until
we come to Warwickshire.

The two series of “ Fish and Insect Beds,” at the base of the
Lower and Upper Lias respectively, first detected, and since so

© Fish and
Insect Beds.”

admirably illustrated, by the Rev. P. B. Brodie, appear to stretch -

continuously from the south-east of England quite into Yorkshire ;
and everywhere these strata yield, in greater or less abundance,
their characteristic and remarkably interesting fossils.

The fine-grained argillaceous limestones, constituting the Zone
of: Ammanites planorbis, with the accompanying Oyster-beds, also
appear to be continuous throughout the Midland district, and are
present_in South Yorkshire. They are worked at many points
for hurnitig into hydraulic lime ; and, in the sections exposed, the
beds, while preserving great: constancy in mineralogical character,
are seen to present considerable variation in their order of suc-
cession and ‘thickness. 4

The interesting strata of the Zone of Ammonites angulatus are
still more variable in character. At Barrow-on-Soar this division
of the Lias-is represented by only 12 feet of blue clays, with
Ammonites and other fossils preserved in pyrites. Northwards
it increases. greatly in thickness,-and beds of stone containing
numerous fossils are found alternating with the clays. In Mid-
Lincolnshire the beds representing this zone are of great thick-
ness, and at one point have yielded Mr. R. Tate * a very interesting

series of characteristic fossils. In North Lincolnshire I have.

traced the beds, gradually diminishing in thickness, and in South
Yorkshire they are, like all the divisions of the Jurassic series,

. reduced to comparatively insignificant proportions. Their cha-

racters and fossils in this district have been described by the
Rev. J. Blake.t

As noticed by Professor Phillips, the great series of alternating

limestones and clays constituting the “ Lima-” or “ Bucklandi-beds”
of palzontologists are generally very feebly representéd in the Mid-
land districts ; beds of clay, often of insignificant thickness, with

scattered shells of Gryphea arcuata, Tarn: (G. incurva, Sow.),

in this district take the place of the great oyster-banks made up of
shells of that species which occur in the South of -England.

Passing northwards into Lincolnshire we find the normal condition

of these beds reappearing and the series gradually i increasing in
thickness, till in the northern part of the county ‘we observe in the
Froddingham Cutting of the Manchester, Sheffield, and Lincoln-

 

* Quart. Journ, Geol. Soc., Vol. xxiii. (1867), p. 305.
ft Quart. Journ. Geol. Soc., Vol. xxviii, (1872), p. 183.
Zone of Am-
monites semi-
costatus.

42 GEOLOGY OF RUTLAND, &C.

shire Railway one of the finest illustrations of the typical characters
presented by the beds on this horizon. Here we see a thickness
of probably not less than 600 feet of alternating limestones and
shales, yielding in the greatest abundance the characteristic fossils
of the Zone of Ammonites Bucklandi. Still farther northwards,
in South Yorkshire, these beds thin away, and within a remarkably
short distance are reduced to the most insignificant proportions.

x

The upper part of the great series just noticed was separated
by Dr. Oppel as a sub-zone, under the name of the Zone of
Ammonites geometricus, and the study of the Lias of the Midland
district demonstrates what good grounds exist for this distinction.
The Ammonites geometricus of Dr. Oppel is quite distinct from
Phillips’ species of: that name, which is the Ammonites spinatus
of Bruguiére ; Oppel’s species on the other hand appears to be
identical with that known in this country as the Ammonites semi-
costatus of Young and Bird, and is so accepted by Dumortier and
other paleontologists. In the South of England and at certain
points in the South Midland district there are to be found sections
in which a rudiment of this zone may be traced ; but it is not until
we reach the neighbourhood of Grantham that it acquires any im-
portant development. In the country about Redmile, Barkston,
and Plungar beds of slightly ferruginous stone, which make a
distinctly marked escarpment rising above the Lias plains, and have

-been very constantly mistaken for the Marlstone Rock-bed, clearly

belong to the Zone of Ammonites semicostatus, and have yielded
a very interesting fauna. The succession of beds here is illustrated
in the accompanying diagrammatic section (Fig. 4). The fossils
collected from the beds of f the Zone of Ammonites semicostatus are
recorded in the following list :—

Fossils from the hard ferruginous beds in dix Lower Lias (Zone
“of Ammonites semicostatus) Redmile, §c., Vale of Belvoir, Lincoln-

shire.
CEPHALOPODA.
Belemnites acutus, Mill.
Ammonites semicostatus, Y. & B,
Ammonites, sp.

GASTEROPODA.
_Pleurotomaria precatoria, Desi.
princeps, K. & D.
Terebra sp.
Chemnitzia sp.
¢
€

43

INTRODUCTORY ESSAY.

has \ *
es oe *(zadnoyy) umsdé3 yyt_syreur used? pue poy «7 i ve ‘sheIQ pue spueg sBrry OTPPI °a
ee ‘spoq yyreueg 10 neq *y (2 spaqappoy uoysyseyy -p

ame ‘ong ‘shulQ serETeMoy yo ; “fog wer] deddy) *9 ;
“SnYVISOOTUIAS SazTMOUIULY Jo aUOT oN} jo oor snomfnar9 5 3 ee : . ‘pueg uoydureyyz0 N 9
ssherg sary pAoT “ff @ weed “OUOPSOWIT] OITYSUTOOULT ‘Dp

     

; i
1 i ' 1 ‘
( ie 1 Ve ‘ '
i | tt, ' ! : '
i i ' ' 1 Mh '
1 ! 1 2 1 ‘ . t
: 4 a) : bie ,
“poo my : aia “w0Ae _ ‘osu: edgy. ‘opTOIpayy “NOIR
. SUreyey. >» TOART, TLOATOS moapg =~ : * = ie
os e > 5 1 +
* i *auLYSUJODUYT YINOY puDn aLiyssajsaoIarT
YHON uw eae Janory ay, fo snqnjsoorwas Sajruowump fo auoz ayj fo spag ayy fo suorzn7as ayy burgosjongye uotzoag suumiworlong, 'P aunbuy

 
.

44 : GEOLOGY OF RUTLAND, &c.

7? Cerithium ligaturalis, Tate.
3 subfistulosa, Yate.
Trochus imbricatus, Sow.

sy) SP.
x» Sp.
Turbo sp.

Rotella expansa, Sow., sp.

a

LAMELLIBRANCHIATA DIMYARIA.

Modiola scalprum, Sow. (var. Morrisi, Oppe/).
»  Hillana, Sow.
Cardinia gigantea, Quenst., sp.

»» copides,de Ryck.

»  Listeri, Sow., sp.

»  hybrida, Sow., sp.

3»  ovalis, Stutch.
Pleuromya unioides, Rém., sp.
Unicardium cardioides, Phil,
Cardium sp.

Astarte sp.

LAaMELLIBRANCHIATA MONOMYARIA.

Gryphza arcuata, Lam.
Pecten textorius, Schloth.
zquivalvis, Sow. (disparilis, ? Quenst.),_
» liasianus, JVysé.
Lima gigantea, Sow. -
pectinoides, Sow.
punctata, Sow.

33

Lb)

3

ANNULOSA.

Serpula capitata, Phil.

BRACHIOPODA.

Terebratula punctata, ? Sow.
Rhynchonella variabilis, Schloth.

ZOANTHARIA.
Lepidophyllia Hebridensis, Dune.

I have traced these beds through the county of Lincoln, and
found that they acquire great thickness and importance as we follow,
them northwards, till in the country about Scunthorpe and

,
INTRODUCTORY ESSAY. 45

Froddingham they attain their fullest development and include
beds of ironstone with a maximum thickness of 27 feet. These
are of the highest commercia] value and bid fair to lead to the
transformation of the district of North Lincolnshire into a second
Cleveland. The fauna of the Zone of Ammonites semicostatus,
as developed in North Lincolnshire, is a remarkably beautiful one,
being exceedingly rich in new and interesting forms, as I have
seen by the inspection of the splendid collection made from these
beds by the Rev. John Edward Cross, F.G.S., of Appleby. It is to
be hoped that a description of this very important fauna may at no
distant date be given to science.* Tracing them still farther north-
wards, we find the representatives of the Zone of Ammonites
semicostatus thinning away as rapidly as those of the Zone of
Ammonites Bucklandi on which they rest ; and in South Yorkshire,
though still recognisable, they are perfectly rudimentary.

The different horizons of the Lower and Middle Lias, which are
so well characterised, as shown by Quenstedt, Oppel, Wright, and
other paleontologists, by particular assemblages of fossils, can be
proved to exist in the Midland district of England; but the
limits and the extent of the development of these zones can only
be very imperfectly made out in an area, which is so greatly obscured
by drift as is that referred to, and in which, therefore, the strata
are only exposed in widely scattered artificial openings. Thin lime-
stone bands, like the so-called Banbury Marble, which occur in the
midst of the thick series of clay, prove on examination to be of
a merely local character, and afford us but little help in tracing
the outcrops of the different zones over an extended area.

On one point, however, there exists much difference of opinion
among geologists, and concerning which the course adopted by
the Geological Survey may require some explanation. I allude
to the question of the line of division between the Lower and
Middle Lias. Of the six stages into which Quenstedt as early as
1843 divided the Lias, the members « and 8 have been usually
grouped by German geologists as Lower Lias, y and as Middle
Lias, and « and ¢ as Upper Lias. On the other hand French
‘geologists have usually. carried the base of the Middle Lias much
lower down, and made it to include the divisions 8 and y and a
great part of g. In England, however, our Marlstone or Middle
‘Lias series has usually been restricted to the Lias } of Quenstedt.
If the question be made one of priority, there can be little doubt
that this last would be the method that ought to be adopted. If on
the contrary it be made to depend on the existence ot breaks in

 

* See Note on page 52.
32108.

Limits of
Middle Lias.
46 GEOLOGY OF RUTLAND, &c.

the Liassic series, different answers to the question would pro-
bably be returned by geologists working in different districts,
accerding to the more or less complete development of the series
at their respective localities. Mr. R. Tate has shown that in
the Cheltenham area, as in Swabia, a tabulation of the species
occurring in the several divisions of the Lias points to the existence
of a break between the Liasy and @ of that district. This would of
course incline us to adopt the classification of the German palzon-
tologists. But, on the other hand, when we turn to the North-
Midland district, we there find largely developed beds, apparently
intermediate between these two series, and representing probably
the Zone of Ammonites armatus, which is only reckoned as a
sub-Zone by Dr. Oppel. These beds appear to contain many
fossils both of the Lias @ and the Lias y, and thus to link these
two series together.

Ii is very possible that no sharp lines of division which might
be adopted for the grouping of the beds of the Liassic series
would be found to continue satisfactory over any very considerable
areas. This we may regard as a necessary consequence of the
fact that the breaks at any particular spot are in all probability
due to the non-development of certain zones, and that such zones
may in another locality be well represented, thus causing the break
to disappear. We find many illustrations of this conclusion in
tracing the Liassic beds over any large district. Even in the
case of the Upper Lias, the planulate Ammonites (A. communis, A.
annulatus, &c.), which appear usually to be so eminently charac-
teristic of that division, are found in the Midland counties passing
downwards and becoming associated with a well marked Marl-
stone fauna.

The restriction of the Middle Lias in England to the stage 8 of
Quenstedt has been to a great extent determined by the fact, that
between the periods y and? a more or less considerable change
evidently took place in the conditions of deposition of the beds ;
and consequently over large areas a marked change in mineral
character is found to occur at this horizon, while no such change
is found between the deposits of the stages @ and y.

The limits between the clays of the Lias ¢ and y and that of
the sands, sandy shales, and ferruginous limestone of 3 can usually
be conveniently represented ina map; while it is almost impossible
to draw a line of boundary in the midst of a series of clays of
almost uniform character like those composing the Lias and y.
On the other hand there are not wanting good paleontological
grounds for the division of the Jias adopted in this country as
was to some extent shown, even as early as 1836, in the pioneer
INTRODUCTORY ESSAY. 47

work of Louis Hunton. At the top of the stage y of Quenstedt
Ammonites of the group of the Capricorni disappear and are
replaced in the Lias } by the remarkable forms of the Amalthei
group; and this appearance of a considerable number of new forms,
with the disappearance of others. at the same horizon points to
the conclusion that, in some areas at least, the line of division is
a defensible one. On these grounds the lines of division of the
Lias adopted by the Geological Survey, before the results of
more accurate paleontological research were known, have been
continued. It has been thought advisable, hpwever, in continu-
ing the mapping of the country to the northwards to séparate
by a boundary line the distinctly marked, and often economically
valuable, “‘ rock-bed ” of the Marlstone, from the sands, clays, &.
below, a division not attempted in the eatlier maps.

It may here be necessary to point out that a little confusion in
terminology has arisen, from the name “ Marlstone” being often
used in two somewhat different senses in the south of England and
in Yorkshire respectively. William Smith applied the name to
the whole series of limestones, sands, and clays, between the thick
argillaceous formations of the Upper and Lower Lias respectively ;
but not a few authors by the term indicate only that hard,
ferruginous, and often highly fossiliferous, limestone which forms
its upper member, and to which the Survey applies the name of
the “ Marlstone Rock-bed.” On the other hand, Professor Phillips
has named the Middle Lias of Yorkshire, “the Ironstone and
Marlstone Series ;” the representative of the “‘ Rock-bed ” of the
south appearing to be his top ironstone bed, while the term
Marlstone is restricted to the sandy clays at the base of the
series. .

The Upper Lias Clay, like all the other members of the Jurassic
series, exhibits great differences in thickness as we trace it north-
wards through the Midland district. Attaining a thickness of
nearly 300 feet in parts of the Cotteswold Hills, it rapidly
diminishes as we pass northwards, till in parts of Oxfordshire it
is only about 30 feet thick at its outer escarpment, while it is
greatly attenuated and almost lost towards the south-east, as has
already been pointed out by Mr. Hull. Still going northwards,
we find it gradually i increasing again in thickness, till in South
Lincolnshire it is probably not ‘Tess than 200 feet; and from
this point it again gradually diminishes and seems to disappear
altogether in South Yorkshire. Whether this attenuation of the
whole formation is due to the disappearance of certain of its
members, or whether all of its subdivisions are simultaneously
reduced in thickness, it is not in most cases easy to determine ;

D2

The Upper
Lias.
Value of
Paleontolo-
gical “ Zones.”

48 GEOLOGY OF RUTLAND, &c.

but from the constant presence at least over very great areas, of
the Fish and Insect Limestones and the Serpentinus beds at its
base, and the clay, characterised by the abundance of Ammonites
belonging to the group of the Planulati in its upper part, perhaps
the latter view may be regarded. as the more probable.

The remarkable variations presented by the strata of the Lower
Oolite and Lias series are suggestive of a number of considerations
of great interest to the geologist, which have important bearings
alike on his theoretical researches and the practical applications
of his science. In no group of formations do the great principles
which must guide the geologist in his studies find more fitting
illustration than in that which constitutes the Jurassic System ;
for not only does it present us with a series of formations,
possessing many features of the highest intrinsic interest but it is
also that which was first systematically studied, and which has been
subsequently made the subject of the greatest amount of patient
and minute research over very considerable areas.

The importance and value of a careful study of the distinctive
faunas of the zones, into which paleontologists have shown the
Jurassic Series to be divisible, can scarcely be exaggerated ; but
there are some errors on the subject, which though neither partici-
pated in nor promulgated by those who have been the founders
of this method of classification, constitute a source of danger
in geological reasoning which it may be necessary to point out.
It has been found necessary to use the name of some prominent
species in each fauna (usually an Ammonite) as the index of the
zone. Unfortunately, some have taken it for granted that
wherever this particular species occurs, the zone which takes
its name from it may at once be assumed to be represented by the
beds containing it. Some, indeed, have raised objections to
the whole method of classification, on the ground that they have
not realized the expectations founded on this unwarranted defini-
tion of a paleontological zone. By the adoption of zones of life,
palzontologists simply endeavour to indicate the well ascertained
fact that in consequence of the mode of distribution of the forms of
life ina formation, certain horizons in it can be recognised—either
by the restriction‘ of the range of certain groups of species, or by the
peculiar assemblage of these, or by their greater or less relative
abundance between certain vertical limits. These species are not
uniformly the same over a great area ; many of the highly abundant
and most characteristic forms of one locality, indeed, becoming rare
or entirely disappearing, or being replaced by others at a different
INTRODUCTORY ESSAY. 49

point, while the general assemblage of forms, nevertheless,
remains the same. Though the zones have a real existence,
their limits are not usually sharply defined; and even when
such is the case the cause of the break may usually be traced
in the absence of beds representing the intermediate zones.
The tendency of continued study over large areas is, by the
detection of intermediate zones of life at particular points, to make
our knowledge of the whole series more complete, and thus to
render the gradation between its subdivisions more imperceptible.

It must be remembered too, that every zone may present several Facies depen-
facies; the petrological and paleontological features which em  s
characterize these being dependent onthe conditions under tion.
which the strata were deposited at different points. The faunas
of deposits belonging to two facies of the same zone may differ
from one another more widely than those of beds of corre-
sponding facies of different zones. Thus, the ragstones of the
Inferior and the Coralline Oolite, or the freestones of the
Great Oolite and Inferior Oolite respectively, are found to have
more species in common than the freestone and ragstone of
either series. Consequently, in comparing the faunas of two sets
of strata, the conditions of their deposition require to be in all
cases most carefully studied and taken into account.

As we trace a deposit over a considerable area, too, we must
be prepared to find gradual changes taking place in its fauna, from
the more or less limited distribution in space of each of the
species which constitute it.*

Every fauna therefore is the resultant of three sets of causes,
namely geological age, condition of sea bottom (such as depth,
temperature, nature of sediment, &c.) and geographical position ;
and the changes which we find to take place in the grouping of
species must be resolved into its elements; those which are
attributable to each of these three sets of causes being carefully
ascertained. Thus the determination of the age of a series of beds
from the study of its fauna often becomes a most complicated
and difficult problem. The laws of the succession of life forms is as
much a fact for the Geologist as are the laws of planetary motion
to the Astronomer; both, however, have ever to bear in mind the
circumstance of the existence of perturbing causes ; and these require

 

* No paleontologist supposes that such zones of life can be traced beyond the limits
of the areas which formed the provinces of marine life of the period ; but these were
probably not less extensive than those of the present day. A careful study of faunas
by many workers, has shown conclusively that the Jurassic strata of England,
Northern France, and Western Germany were all deposited within the same life
province.
Effects of
subsidence on
nature of
deposits.

50 GEOLOGY OF RUTRAND, &c.

to be as carefully studied and allowed for in the determinations
of the one as in the calculations of the other.

In cases, like those which we have been considering, the Lower
Oolites, of which many of the deposits are of such a remark-
ably local and peculiar character, the careful study of the condi-
tions under which each of the beds was deposited becomes a point
of the first importance; in order that we may not refer to
difference of age, that which is due to a change of the nature of
the sea bottom, or vice versd.

The causes of the phenomena of the rapid qanenen in the thick-
ness and mineral characters of the sedimentary deposits on a sea-
bottom, which are made so strikingly apparent by a careful study
of the changes that take place in the several subdivisions, of the
Jurassic rocks, were long ago pointed out by Mr. Darwin, and
more fully illustrated in his recent works. Except.in the case of
beds formed under abysmal conditions, such as the chalk, the

deposition of a considerable thickness of strata must be dependent

on the continued subsidence of the sea-bed on which the accumu-
lations are taking place. As long as deposition and subsidence
keep even pace with one another, the formation of beds of uniform
character goes on continuously. If the subsidence either dimi-
nishes in its rate of progress or altogether ceases, while the
deposition of sediment continues as before, the depth. of water
will begin to decrease, and a change will take place both in the
mineral character of the deposits and in the facies of their fauna.
When, on the other hand, the deposition of sediment goes on more
slowly than the subsidence of sea-bottom, changes of an opposite
kind, both in mineral character and in the fauna of the beds, at
once manifest the nature of the movement. If, however, elevation
of the sea bottom take place, not only does deposition cease,
but the rocks last deposited run the greatest risk of being again
removed by denundation. ;
These considerations serve to explain the phenomena ‘so.
strikingly presented by the English Jurassic rocks, and to which
we have specially to allude in the present memoir—namely, the
repeated change in the character of the beds both vertically and
horizontally, the total absence of certain members of the series
at many localities, and the very unequal and capricious manner in
which that series is represented in all cases. Only where con-
tinued subsidence takes place, accompanied by a tolerably equal
deposition of sediment, can a thick mass of strata belonging to
any particular zone be found ; and during the prevalence of move-
ments which do not comply with these ‘conditions we shall have,
either a gap in the series, the formation of a rudimentary deposit,
INTRODUCTORY ESSAY. 51

or the production of a more or less complete unconformity ; the
latter phenomenon resulting from the disturbance and destruction
of the strata already formed, in the interval which elapses before
the laying down of the newer sediments.

Of formations belonging to the first of the categories indicated
above, we may perhaps point to the Oxford Clay .and parts of the
Lias Series. In these, very favourable conditions of subsidence
combined with an uniform supply of sediment, appear to have
given rise to a remarkably even deposition of beds. We therefore
find that, within a thickness of some hundreds of feet of evidently
very slowly deposited strata of fine clays, the several zones of
life are all represented, and the changes take place from one to
the other in the most imperceptible manner ; the several species in
each of the faunas becoming more and more rare and finally extinct
one by one, while new forms make their appearance in an equally
gradual manner. The extinction and appearance of species takes
place in these cases by individuals and not in groups. When
especially favourable conditions of subsidence coincide with the
existence of an abundant supply of sediment during the period
characterised by a particular assemblage of life-forms, the zone may
attain abnormally fine representation, both as regards thickness of
beds and abundance of fossils. When, by deposition going on
faster than subsidence, the sea bottom is raised, the fine sediment
of clays passes into sands, and then, as a shallowness of water is
attained favourable for the development of numerous shell bearing
mollusca, into shelly limestone. When a movement of an opposite
character occurs this series of changes takes place in reverse order.
The former case is illustrated in the Midland district by the
passage of the clays of the Lower Lias, through the sands, &c. of
the Middle Lias up to the Marlstone Rock-bed; the latter case,
by the passage of the shelly Cornbrash through the sand _ repre-
senting the Kellaways Rock into the Oxford Clay.

The absence of the representatives of a zone, from the cessation
at that particular period of the subsidence, which is necessary
to the deposition of beds containing its relics, is illustrated at
many points of the Midland district; as is also the reduction of
the representatives of a particular period toa rudimentary con-
dition; this will be seen by a glance at the series of vertical
sections in Plate I.

The abnormal development of beds representing particular Cases of the
horizons finds admirable exemplification in the cases of the Zone seine 3
of Ammonites Sowerbyi, and the Zone of Ammonites semicostatus, Zones.
which have been fully explained in the foregoing pages.
General con-
clusions,

52 : GEOLOGY OF RUTLAND, &C.

OF cases of the non-representation of certain periods, and the
production in the interval of changes giving rise to an uncon-
formable relation of the succeeding beds, we have a good illus-
tration in the case of the junction of the Inferior and Great
Oolites of the district. We find that in the Midland area the
upper part of the Inferior Oolite period is unrepresented by beds
of rock, for there are’no strata yielding the faunas of the Zones
of Ammonites Humphriesianus and Ammonites Parkinsoni. There
is, however, clear evidence that the period—of which these strata
are in other areas the relics and monnments—was, in the Midland
district, marked by considerable subterranean movements, of which
we see the effects in the peculiar relations of the overlying
estuarine beds to those which represent the lower part of the
Inferior Oolite series.

The phenomena explained in this Introductory Essay appear to
point to the fact that, during a considerable portion of the Jurassic
period, the area now forming the county of Oxford underwent a
far less amount of subsidence than that to the North-east and
South-west of it respectively. The consequences of this inequality
of movement are manifested in the disappearance of some members
of the series, the attenuation of many others, and the littoral
characters presented by nearly all of them.

 

Note to page 45. Since the writing of this Introductory Essay in 1871, the hope
expressed in the text has been realized through the publication by the Geological
Society of an interesting paper on the strata of North Lincolnshire of which the
Rev. J. E. Cross is the author.

The new edition of the late Professor Phillips’ Geology of Yorkshire, now being
completed by Mr. Etheridge, will also contain many details illustrative of the rapid
variations within short distances of some of the Jurassic formations and of the very
local characters of certain of the beds which compose them.
GEOLOGICAL SURVEY OF ENGLAND AND WALES. , pee sid <9
DIAGRAMMATIC SECTIONS ILLUSTRATING THE THINNING OUT OF THE LINCOLNSHIRE |

By J.W. Jupp F.G.S._

SECTION FROM ROAD NEAR SUTTON BASSET ( LEICESTERSHIRE)10HUTCHES LODGE NEAR WARKTON (.NORTHAI

Distance about 10 Miles g

e

Road , Stream’ Slream Stream Stream

 

 

 

 

 

 

 

SECTION FROM THE RiveR WELLAND, NEAR TINWELL, (RUTLANDSHIRE )TOBATESS LODGE NEAR HADDON

Distance about 11 Miles.

River Rwer
Welland Easton Easton Heath Farm Road Road Stream en

 

H Hi way delt.

a Marlstone Sands and Clays ce Upper Lias Clay e = Lincolnshire (Inferior) Oolite g Great Oolite Limestone
6 Marlstone Rock -bed ad = Northampton Sand Upper Estuarine Series h Great Oolite Clays
Plate Ito fsce Page 52

LUSTRATING THE THINNING OUT OF THE LINCOLNSHIRE (INFERIOR) OOLITE

By J.W. Jupp F.G.S._

IN BASSET ( LEICESTERSHIRE)10 HUTCHES LODGE NEAR WARKTON (NORTHAMPTONSHIRE )

Distance about 10 Miles.

e

Stream — Stream River

Ise Warkton Warkton Lodge Hutches Lodge

 

ELLAND, NEAR TINWELL, (RUTLANDSHIRE )TOBATESS LODGE NEAR Happon ([fUNTINGDONSHIRE/
Distance about 11 Miles.

Ruer

Road Stream en load Bates s Lodge

 

Lincolnshire (Inferior) Oolite g Great Oolite Limestone k  Cornbruh m Boulder Clay

Upper Estuarine Series h Great Oolite Clays lL Oxford Clay n Glacial Gravel
- TODELSIG SIAL MI YSTH TALEO SBLITOO ANY SYPI THL HOIHM OL

GNOS ONTIVEISOTIL WYHOMIddA JO LSEM THR a

 

 

 
53

THE GEOLOGY OF RUTLAND, WITH PARTS
OF LINCOLN, LEICESTER, NORTHAMPTON,
HUNTINGDON, AND CAMBRIDGE.

&

 

 

a ee
Mar wm

ae
et fat

 

. Figure 5. Village of Somerby, Rutland, situated in one of the deep sinuous
valleys of the great escarpment formed by the Marlstone Rock-bed.

CHAPTER I.
PHYSICAL FEATURES, &e.

Sheet 64 of the Ordnance map of England embraces an area
of rather more than 800 square miles. Its eastern portion
includes a part of the Fenland, while its western belongs to the
great table-land of the Midland counties ; the intermediate tract
forms a segment of the very undulating but, on the whole, gra-
dually rising land which lies between the former and the
latter. While parts of the Fen district in this map are only a few
feet above the sea level, the height of the general surface in the
western part is about 500 feet, and many of the hills attain to
more than 700 feet. The highest point included within the sheet
appears to be the Ordnance station at Tilton-on-the-Hill which
is 755 feet above the level of the sea, but a number of other
points as Burrow Hill Camp, Whadborough Hill, Colborough Hill,
Robin-a-Tiptoes,. Ram Head, Cold Overton, and Neville Holt,
attain to scarcely inferior elevations.

Owing to the greatly increased thickness of several members
of the Lias and Oolite, the escarpments in this area are consi-
,

54 GEOLOGY OF RUTLAND, &c.

derably higher than in the Oolitic districts immediately to the
south-west, namely central and south Northamptonshire and Ox-
fordshire ; indeed the country included in the western part of this
sheet and that immediately to the north presents features almost
comparable for boldness with those of the Cotteswold Hills. The
thickness of the Upper Lias Clay, which reaches 200 feet, the
important character locally assumed by the Marlstone Rock-bed,
and the appearance of a great mass of limestone of Inferior: Oolite
age, principally contribute to this result. See Plate IV. p. 53.

From Wilbarston northward the Inferior Oolite forms an
unbroken escarpment as far as Harringworth ; between this last
point and Burley-on-the-Hill the escarpment is cut through by
the river Welland with its tributaries the Chater and Gwash ;
from Burley northward to the limits of the sheet, the escarpment is
again continued and indeed runs through the whole of Lincolnshire,
where it is known as “the Cliff,” being intersected only at two
points, namely at Grantham and Lincoln, by the river Witham.
To the west of the line of the Inferior Oolite escarpment the
Upper and Middle Lias form a plateau gradually rising towards
the north-west, and terminating in a number of bold spurs and
outliers; capped by the Marlstone Rock-bed, which overlook the
plains of Lower Lias. Situated upon this plateau are a number of
outliers of Upper Lias, often surmounted by Inferior Oolite, some of
them being of great size. East of the Inferior Oolite escarpment
the country occupied by the Lower and Middle Oolites forms
another plateau gradually sinking towards the east until it
reaches the Fenland. This plateau, which is to a great extent
covered with Boulder Clay, is intersected by the sinuous valleys
of numerous streams, along the sides of which valleys the various
Oolitic rocks are admirably exposed. ‘The surface of the Fenland
itself is by no means an uniform one; tracts of clay land or
gravel, which were once islands, and still bear names pointing
to that fact,* rise above the level of the peat, silt and warp, and
constitute the sites of most of the towns and villages.

Owing to the position of this area in relation to the great moun-
tain and hill chains and to the sea, the amount of rainfall within
it is very small; mdeed it is not exceeded in dryness by any
other district in England. ;

The drainage of the district is effected by the Nene (with ita
tributaries the Barford Brook, Harper’s Brook, the Willow
Brook and Billing Brook), the Welland (with its tributaries the
Eye Brook, the Chater and the Gwash), the Glen and the Witham
(which last rises in the northern part of the sheet). All of these
flow into the Wash. A small tract in the north-west is drained
by the River Eye, which flows by the Wreak, the Soar, and the
Trent into the Humber.

An examination of the district by the aid of the geological map
will show how completely the contours and scenery have been

 

* Such as Eye, Whittlesey, Ramsey, Thorney, Ely, Estrea, Manea, &c.
PHYSICAL FEATURES, &c, 55

determined by the presence of beds of different degrees of hard-
ness, arid of varying susceptibility to denuding forces. It will also
illustrate in a striking manner how the sites of all the towns and
villages, and the general distribution of the population, have been
determined by the outcrops of water-bearing beds.

In ancient times the Fen district of this area consisted of
almost impassable marshes and meres, which yielded little besides
fish and wild fowl. The high table-lands of Boulder Clay also
were formerly vovered by extensive woods; Rockingham Forest
alone occupying the whole of the centre of this sheet. Now, how-
ever, the Fens are completely drained, their lakes have disappeared,
and a large part of the Fenland is now unrivalled for the wonderful
crops which it produces: on the other hand, the forests of the
high lands have been almost wholly cleared, and the heavy clay
soils on which they grew now constitute, when sufficiently drained,
very valuable corn land, continually increasing areas of which are
being brought under the plough. The western portion of this
sheet, which is occupied by Lias clays usually covered with drift,
still remains for thé most part as pasture land, and constitutes a
portion of the most celebrated hunting district in England.

Within the limits of this map heaths and waste lands have now
almost disappeared.

In former times the district was celebrated for the manufacture
of iron, and traces of the old workings in the form of slag heaps
abound; but, as the wood became less abundant and the method
of smelting iron with coal was introduced, this manufacture gra-

~ dually forsook the district. Of late years iron-ore has begun to
be dug rather extensively in the south-western part of the area,

- and the erection of iron-furnaces commenced. The district has
always been celebrated for the beautiful building-stones yielded
by its various limestone and the other strata, the several clay
beds have been used for brick-making, and occasionally for the
production of finer and more ornamental materials. The peat
of the Fenland is still extensively dug and used locally for fuel.
The occupations of the inhabitants of this district are, however,
still mainly agricultural.

The rocks which form the area included in Sheet 64 fall
naturally into two groups, which are of widely different age, the
Jurassic and the Post-Tertiary.

The Jurassic rocks form regular strata which have all a general,
though very slight, dip towards the south-east. In consequence
of this dip some of the oldest beds of the series, as the Marlstone

‘ Rock-bed, form the highest ground in the western part of the

area, while the younger beds of the series, as the Oxford Clay,
occupy the low ground of the Fens. But although the general
dip of these beds is thus seen to be towards the south-east, they
are nevertheless sometimes found to be locally inclined in various
directions, while occasionally they are even bent and contorted
and not unfrequently thrown far from their proper position by
great dislocations or “ faults.”
56 GEOLOGY OF RUTLAND, &c.

Between the periods of the deposition of the Jurassic and the
Post-Tertiary rocks there is evidence of the lapse of an enormous
interval of time, during which the older series of beds was
upheaved, bent, faulted and extensively denuded.

In this vast interval the whole of the Cretaceous and Tertiary
beds, which are not represented in this area, were deposited. The
Post-Tertiary deposits, which are usually of a much more local and
inconstant character than the Jurassic strata, lie indifferently on
the eroded surfaces of the latter, and are often to a great extent
made up of their detritus.

The following table exhibits the several formations which occur
within the area included in this sheet, arranged as far as possible
in chronological order.

POST-TERTIARY.

Marine Alluvium or warp of the Fenland.
Alluvium of present rivers.
Alluvium of old fen lakes.
_| Peat interstratified with marine silt.
Marine gravels of the Fenland.
Estuarine gravels. ‘
Low-level valley gravels.
High-level valley gravels.
Cave deposits.

Glacial or Boulder Clay.
GLACIAL. | Grels.
Sands.

a gravels and sands.

Post-
GLACIAL.

Brick-earths.
River gravels.
Lacustrine deposits.

PrE-
GLACIAL?

JURASSIC.

‘ MrippLe OoxitEs.— Oxford Clay with Kellaways sands and sandstone at its
ase.

LowErR Oolite. | Great Oolite Limestones (Upper Zone).
Oo.ITEs. Upper Estuarine Series.
Inferior cata Oolite Limestone with Collyweston Slate.
. Oolite. | Northampton Sand with Lower Estuarine Series.

'( Upper Lias Clay.
Marlstone Rock-bed.
Lias. = Clays, ironstones, sands, &c.
Lower Lias Clays. a
{ 3 »» Limestones and Shales.

Cornbrash.
Great {Se Oolite Clays.
CHAPTER II.
: THE LIAS.

In the district we are describing the Lias formation is very
fully developed, and attains a thickness of probably not less than
800 feet. Consisting, however, almost entirely of clays it has
been very extensively denuded, both before and since the deposi-
tion of the glacial series, and its beds are toa great extent con-
cealed by the masses of drift which lie upon them. , The Rock-bed
of the Marlstone has, however, owing to its superior hardness
resisted denudation to a greater extent than the rest of the forma-
tion, and everywhere forms a bold escarpment, constituting indeed
some of the highest points in the district ; other hard beds in the
Lias, even when only a few inches in thickness, frequently give
rise to perceptible features in the contour of the country.

The great mass of the Lias appears to have been deposited
under moderately deep-water conditions, but the two series of
finely laminated shales and limestones, which occur at the base
of the Upper and Lower Lias respectively, and are crowded with
the remains of plants, saurians, fish, crustaceans and insects,
exhibit evidence of the alternation of very shallow water, if not
of estuarine, conditions. That the deposition of the Lias occupied
a period of vast duration there can be no question; although a few
species might be cited which are found passing from the bottom to
the top of the Lias, and even recurring in the overlying Oolites,
yet the great majority of the forms have undergone very striking
changes within the period. During the Lias epoch certain genera
make their first appearance, and others die out, while the entire
range of a few (such as Cardinia and Hippopodium) is included
within its limits; in some groups too, as the Cephalopoda, the
species have been almost wholly replaced several times over during
the Lias period. Of great and sudden breaks in the succession
of life, the Lias exhibits but little evidence; the transition from
one fauna to another appears to have been in almost every
instance a gradual one, the several species disappearing indi-
vidually and not in groups.

Tue Lower Lrias,

Nearly the whole thickness of this division, including repre-
sentatives of most of the paleontological zones into which it has
been divided, occur within the limits of Sheet 64. We do not,
however, find any sections which exhibit the actual base of the
‘Lias, and its junction wtth the Rhetic or Penarth beds; as, how-
ever, these latter appear in the district immediately to the north,
it is possible that, if the necessary sections existed, they would be
found just beyond the area included within the north-western
corner of the Sheet; the beds directly above them in the series
being present there as will be shown in the sequel. The Rhetic
beds of the district consist of highly pyritous black shales crowded
58 GEOLOGY OF RUTLAND, &c.

with Avicula contorta, Portl. Cardium Rheticum, Mer., Axinus
cloacinus, Quenst., &c., alternating with fissile sandy beds. These
strata, good sections of which are rarely seen, rest directly upon
the red and green gypsiferous marls of the Keuper, so extensively
developed in the country to the westward.

Although occupying a considerable area the beds of the Lower
Lias rarely appear at the surface, for they are to a great extent
covered with drift, while the exposures of the several members
of the formation are few and insignificant, being restricted to
occasional brickyards, with some railway-cuttings, and temporary
field-drains. By far the best illustration of the succession of its
beds is afforded by the cuttings on the Syston and Peterboro’
Railway between Kirby and Whissendine; unfortunately, however,
these were not studied when first opened, and, as they are now
turfed up, we are dependent for information as to the beds and
fossils on the exposures caused by occasional slips, and the
opening of field-drains, holes for telegraph-posts, &c.

a. “ Fish and Insect Limestones.”*— Traces of these beds are
found in the railway-cutting at Kirby, which is just beyond the
limits of Sheet 64. They consist of a number of finely laminated
and much jointed beds of argillaceous limestone of a blue colour,
but weathering nearly white when near the surface, and alternating
with thicker beds of laminated shale. They abound with the
remains, often very beautifully preserved, of fish, crustaceans,
saurians, plants, and sometimes insects, and are very extensively
dug (as at Granby and Barrow-on-Soar, in adjoining sheets of the.
map), for the manufacture of hydraulic cement.

b. Above the last are coarser grained, sometimes shelly, lime-
stones, alternating with shale; the number and thickness of these
courses of limestone and shale being very variable. They are
very imperfectly seen in a railway-cutting at Sysonby. These
beds are characterised by the abundance of varieties of a species
of Ammonite known by the names of A. planorbis, Sow., and
A, Johnstoni, Sow. Some of these acquire a well marked keel
and an approach to lateral furrows, and thus approximate to Am.
Conybeari, Sow. This appears to be the Am. laqueus, Quenst. and
the Am. Kridion of some authors, but is not the form originally
described under the latter name by Zieten. With the Ammonites
there also occur Nautilus striatus, Sow., the dwarfed and il] defined
form of Gryphea arcuata, Lam., known as Ostrea irregularis,
Miinst., Lima gigantea, Sow. (which never, however, attains its
full dimensions in these beds), Lima Hermanni, Ziet., and Rhyn-
chonella variabilis, Schloth. These beds aré like the last, some-
times worked for lime-burning.

 

* These beds, which were first made known by the researches of the Rev. P. B.
Brodie, might be appropriately called, from the locality where a section of them
was first noticed, the ‘“ Strensham Series,” to distinguish them from the similar beds
at the base of the Upper Lias ; these latter might on similar grounds be distinguished
as the “Dumbleton Series.”
THE LOWER LIAS. 59

c. At Barrow-on-Soar the preceding beds are overlaid by a
thick mass of clay, containing several bands of pyrites, one of
which is crowded with many different varieties of Ammonites an-
gulatus, Schloth. I have not been able to find any exposures of
this part of the series within the limits of this map.

d. The beds of limestone and shale, the former almost made
up of Gryphea arcuata, Lam., Lima gigantea, Sow. (of great size),
and Ammonites which make so marked a feature in Dorsetshire,
North Lincolnshire, and elsewhere, appear in this district, as well
as in most of the Midland counties, to be represented only by blue
clays with numerous scattered specimens of Gryphea arcuata, Lam.
and Ammonites of the group of the Arietes. These beds appear to
have been reached by a deep well in Stapleford Park.

e. The bed of ferruginous limestone containing Ammonites semi-
costatus, Y. & B., Cardinia gigantea, Quenst., C. Listeri, Sow.,
Gryphea arcuata, Lam., and other fossils, which, in the sheet
immediately to the north of 64, is so well developed, making
a conspicuous feature in the Vale of Belvoir, and exhibiting
mineralogical characters, which have caused it to be generally
mistaken for the Rock-bed of the Marlstone, appears in this
district either to have wholly thinned out, or to have become much
diminished in importance. It has not as yet been recognised
within the limits of Sheet 64.

Jf. In Freeby cutting we find beds of the clay with much
pytites (producing selenite by its decomposition) and small light
brown septaria. Belemnites clavatus, Schloth., and Plicatula spinosa,
Sow., are abundant. s

g. About this horizon is found a series of beds which, although
nowhere well exposed in Sheet 64, can be well studied at many
points in Lincolnshire and Leicestershire. At Loseby brick-
yard, which is just beyond the western limits of Sheet 64, there
occurs one of the best sections of these beds with which I am
acquainted, and which will be hereafter described in detail. The
strata appear to consist everywhere of clays, usually very sandy,
which alternate with sands, sometimes indurated into an imperfect
sandstone or sandrock, like that which occurs at the base of the
Oxford Clay of the district, and to be hereafter described.

At some points the beds of indurated sandy stone acquire a much
greater thickness and importance than at this place. The fossils
of this horizon are numerous, and include abundant specimens
of the unsymmetrically developed Ammonites, which D’Orbigny
placed in the genus Turrilites, with some other Cephalopods,
Cardinia hybrida, Sow., and somewhat more rarely of specimens
of a variety of Hippopodium ponderosum, Sow. These beds appear
to represent the “ Zone of Ammonites armatus” of Dr, Oppel,
which in the Midland district of England attains to some im-
portance, and appears to constitute a link between the Lias ¢
and the Lias y of Quenstedt; that is between the Middle and
Lower Lias of most German authors. The considerations which
have induced English geologists to adopt the limit of the Lias y
60 GEOLOGY OF RUTLAND, &C.

and the Lias 5 for the boundary of the Middle and Lower Lias
have already been adverted to in the Introductory Essay.

h. In Saxby cutting there are exposed light-blue, laminated,
highly pyritous shales with some thin bands of limestone, almost
made up of Pentacrinites and small bivalve shells. They contain
also small septaria, concentric balls of ironstone and pieces of jet.
The same beds were exposed in a deep ditch to the south of
Thorpe Langton. The most abundant fossils were Ammonites
bipunctatus, Rom., Plicatula spinosa, Sow., Inoceramus substriatus,
Goldf., Lima acuticosta, Goldf., Spirifer Walcotti, Sow, Rhyn-
chonella variabilis, Schloth., and Pentacrinus punctiferus, Quenst.

k. At Dalby and near Staunton Wyville there are found beds
with thin bands of shelly limestone, containing Cardinia attenuata,
Stutch. sp. and Hippopodium ponderosum, Sow.

1. In the railway-cuttings by the side of Stapleford Park, as
well as in some openings in the Park itself, and about Little
Dalby, there occur clays with septaria and some thin bands of
indurated argillaceous sand. These beds abound with Ammonites
of the groups of the Armati and Capricorni, including Ammonites
latecosta, Sow., A. brevispina, Sow., A. Jamesoni, Sow., A. Nor-
manianus, D’Orb., A. armatus, Sow., &c; also Panopea elongats?
Rom., Pholadomya decurata, Hartm., Gryphea obliquata, Sow., and
Pentacrinus punctiferus, Quenst.

m. The highest beds of the Lower Lias consist of dark blue
clays with much pyrites and many septaria, the latter acquiring
ared colour and concentric structure by weathering, and fre-
quently containing thin amine of Specular Iron. These beds
abound with specimens of Ammonites capricornis, Schloth., and
also contain, but more rarely, Pentacrinus robustus, Wr., and some
other fossils. They are exposed in the railway-cutting at Galley
Hill, and also at Neville-Holt and Little Bowden brickyards.

The Lower Lias occupies a strip of country stretching along the west of the
district included in Sheet 64. This area is divided into two portions by the
elevated spur of ground, composed of Middle Lias and higher beds, which
form the steep escarpments about Billesdon and Tilton. The northern of
these two districts of Lower Lias forms portions of the valleys of the River Eye,
and its tributaries, and of the Twyford Brook; the southern constitutes parts

‘of the valleys of the Eye Brook (a tributary of the Welland) and of the
Welland itself.

Everywhere these tracts are covered by enormous masses of Boulder Clay
and gravels, which not only cap the hills but are of such thickness that the
existing valleys rarely cut through them so as to expose the Lias strata below.
The sections of the Lower Lias in this area are, therefore, as already intimated,
few in number and widely separated. ,

In the northern of the two areas indicated, the deep brickyards of Melton
Mowbray have been thought ‘to reach the Lower Lias clay, as many beautiful
specimens of Liassic fossils have at various times been procured from them. As
will, however, be shown in this Memoir the strata exposed here belong, without
exception, to the drift, and the fossils obtained from them are all derived.

The various sections exposed along the Syston and Peterborough branch of
the Midland Railway between Sysonby and Whissendine, namely, at Sysonby,
Freeby, Stapleford, and Galley Hill cuttings have already been sufficiently
noticed (pages 58, 59, and 60). Boe ss, be :

To the southward the Lower Lias clays with Gryphea arcuata, Lam.
(G. incurva, Sow.) have been reached in a well in Stapleford Park; and it is
THE LOWER LIAS. 61

probable that the mineral (chalybeate) springs of Burton Lazars and Little
Dalby rise from the same strata. At a part of the parish of Great Dalby a
series of field-drains exposed beds belonging to the higher part of the Lower
Lias. From this place I procured specimens of Ammonites Jamesoni, Sow., and
Hippopodium ponderosum, Sow., Gryphea obliqua, Sow., Avicula sp. Belemnites,
&c. ‘There was formerly a brickyard near this place which is to the south of
Garrety Hill.

Near Little Dalby I found in several ditches on the slopes of the hills to the
south-east and south-west of the Hall, evidence of the existence of the same set"
of beds as at Great Dalby. They consisted of somewhat sandy clays, with septaria
and ferruginous nodules, which yielded Ammonites Jamesoni, Sow., Gryphea
cymbium, Lam. (G. Maccullochi, Sow.) and joints of Pentacrinus. On the other
side of the village some ditches by the roadside exposed clays with thin bands
of impure limestone, which yielded Ammonites Maugenesti, D’Orb., Belemnites
sp., Gryphea obliqua, Sow., Plicatula spinosa, Sow., and Montlivaltia rugosa,
Wr. sp. Near the park were seen clays with fine specimens of Ammonites
armatus, Sow., and at the village an excavation for a cistern exhibited 12 feet
of dark blue clay belonging to the Lower Lias, but without septaria or fossils.

At the bottom of the new brickyard at the village of Whissendine blue clays
forming the upper beds of the Lower Lias appear to have been reached under
a considerable thickness of drift. From this locality I obtained good specimens
of Ammonites capricornus, Schloth.

Along the banks of the River Eye, where it passes through Stapleford Park,
there are a number of small exposures of the clays of the Jamesoni beds at the
top of the Lower Lias. These have yielded the following interesting series of
fossils.

Specimens from openings in the Lower Lias clays of Stapleford Park.
Ammonites latzcosta, Sow. abundant.

iy brevispina, Sow. rare.

5 capricornus, Schioth rare.

33 Jamesoni, Sow. var. confusus, Quenst. rare.
es Jamesoni, Sow. var. Bronni, Rom. rare.

3 Normanianus, D’Ord. rare.

‘ss Jamesoni, Sow.

2 polymorphus lineatus, Quenst.

Belemnites clavatus, Schloth.

35 elegans, Simps.

Trochus sp.

Lima Hermanni, Ziet.

Lima acuticosta, Schloth.

Plicatula spinosa, Sow.

ss levigata?, D’Orb.

Gryphza cymbium, Lam.

Unicardium cardioides, Phil. (U. Ianthe, D’ Orb. ?)

Cypricardia cucullata, Goldf. sp.

Serpula sp.

Pentacrinus punctiferus, Quenst.

‘The above, with some small openings along the sides of the Twyford and
Marefield brooks, exhibiting some of the harder calcareous bands with Pen-
tacrinites and fragmentary shells, are the only exposures of the Lower Lias
strata in the northern area, which I was able to find during my survey of it.

At Loseby brickyard, which is a little beyond the western limits of Sheet 64,
we have an interesting section of a series of strata, which, though present, are
nowhere so well exposed within the area. They consist of beds of blue clay
with soft septaria of a whitish colour, and some bands of ironstone balls. These
clays alternate with grey sandy beds, which are sometimes indurated into a sand-
rock or easily decomposing sandstone, like that of Kellaways age to be here-
after described. The section is as follows :—

(1.) Beds of clay, with a few septaria and ironstone balls- 6 feet.

(2.) Band of large septaria - - - 6 inches.

(3.) Clay - - - - - 3 feet. i
(4.) Sandy beds indurated into stone —- - - 6 inches to 1 ft.
(5.) Clay with septaria and ironstone balls - - dug to 12 feet.

32108. E
62 GEOLOGY OF RUTLAND, &c.

The fauna of these beds is a very interesting one, namely,—

Vertebre of Saurians, &c. .
Ammonites Loscombi, Sow., sometimes very large, the specimens covered
with attached oysters, serpule, &c.
» armatus, Sow., abundant.
5 (Turrilites) Coynarti, D’Orb.

These always exhibit, but in very various degrees, the
curious unsymmetrical character which led D’Orbigny
to place this and similar forms in the genus Turrilites.

Nautilus truncatus, Sow., very large.

Belemnites acutus, Mill.

Gryphza cymbium, Lam, (G. Maccullochi, Sow.)
33 obliqua, Sow.

Modiola scalprum, Sow.

Hippopodium ponderosum, Sow., large rugose variety.

Avicula sp.

Lima Hermanni, Ziet.

Panopea elongata, Rom.

Pholadomya ambigua, Sow., var. ?

Cardinia sp.

Pentacrinus sp.

Near Billesdon Coplow a boring for coal, which was made nearly 30 years
ago, is said to have been carried to the depth of more than 600 feet. It com-
menced at some distance below the bottom of the Marlstone Rock-bed, and it is
evident from the descriptions of those who watched the work that it did not
pass through the Lower Lias Clays and reach the Keuper.

The southern of the two districts occupied by the Lower Lias is almost
equally obscured by the thick overlying masses of drift. With the exception
of a few somewhat doubtful openings along the courses of the Eye Brook and
the Medbourn Brook, the only places at which the beds were seen during the
survey of the area, were the brickyards of Neville-Holt, Medbourn, Little
Bowden and Staunton-Wyvile (the last of these, however, being a little to the
west of the limits of Sheet 64), some deep ditches which were opened along
the side of the road running southwards from Thorpe-Langton, and in a road-
section and railway-cutting south of Market Harborough.

At Neville-Holt the brickyard at the foot of the hill is seen to be opened in
the beds immediately underlying the Middle Lias ferruginous rocks and clays,
which, as will be pointed out in the sequel, are here only developed to a very
limited extent. ‘The Clays seen in the brickyard are dark-blue and pyritous,
with a few septaria and concentric ferruginous nodules: they yield Ammonites,
capricornus, Schloth, Ammonites fimbriatus, Sow., and Nucula variabilis, Quenst.,
and evidently belong to the top of the Lower Lias.

The brickyard at Medbourn is probably opened in the same beds, but the
clays were very imperfectly exposed during the time of the survey of the dis-
trict, and I was unable to obtain any fossils from them.

At Little Bowden brickyard the same beds are beautifully exposed, being
dug under thick masses of drift; the fossils obtained here which are numerous
and well preserved are given below, The rock is a deep-blue, highly micaceous
and ferruginous clay.

Ammonites capricornus, Schloth.
Belemnites clavatus, Mill.
Crenatula ventricosa, Sow.
Modiola scalprum, Sow.

»  Hillana, Sow.
Trochus imbricatus, Sow.
Pentacrinus basaltiformis, Mill.

At Hallaton brickyard (to be noticed hereafter) it is possible that the same
beds are reached at the bottom of the clay-pit.

Staunton Wyvile pit (which is now in part filled up) exposes the hard shelly
limestone bands crowded with Cardinia attenuata, Stutch, sp., and C. hybrida,
Sow., sp.. and many other shells, including Hippopodum ponderosum, Sow.,
and the Ammonites of the Zone of Ammonites Jamesoni usually found associated
THE LOWER LIAS. 63

with these species ; also Belemnites clavatus, Schloth, Gryphca obliqua, Sow.,
Littorina imbricata, Sow., sp., Pentacrinus, &c.

These bands of limestone, although so insignificant in thickness, yet, occur-
ring as they do in the midst of a great mass of clays, are sufficient to produce
by their greater relative hardness and power of resisting denudation, a well
marked feature wherever the country is sufficiently free from drift. This may
be seen at several points in the southern area of the Lower Lias in this sheet ;
thus the ridge on which the village of Thorpe Langton is built owes its ex-
istence to the presence of these limestone bands of the Zone of Ammonites
Jamesoni. A deep ditch south of the village afforded me an admirable exposure
of these beds in the year 1867, and yielded Ammonites bipunctatus, Rom.,
Belemnites elongatus, Mill, Plicatuia spinosa, Sow., Pecten sublevis, Phil.
Modiola, sp., Ostrea, and Pentacrinites (very abundant). *

South of Market Harborough, and in the immediate vicinity of Little
Bowden’ brickyard, the same beds as are seen in the pit, are exposed in a road-
cutting, and also by the side of the Northampton and Leicester Branch of the
London and North-Western Railway.

The greater part of the valleys occupied by the drift covered Lower Lias of
this area remain in the condition of pasture lands, and form the eastern
extremity of the great hunting and stock-rearing district of Leicestershire.
64 GEOLOGY OF RUTLAND, &c.

CHAPTER III.
THE. MARLSTONE OR MIDDLE LIAS.

This division, which in the northern part of the area embraced.
in Sheet 64 is more than 150 feet thick, but is reduced to less than
half that amount in the southern -part, consists of two principal
members, The upper is a mass of ferruginous limestone known
as the “ Rock-bed,” the lower a series of sandy and micaceous
clays and ironstones with some beds of sand. ‘The latter strata
it is not always easy to separate from the Lower Lias Clays, and
we have represented their boundary on the map by a broken line.
The succession of beds in the Marlstone is as follows, beginning
at the base.

a. Soft, yellowish brown, sandy and micaceous ironstone, crowded
with casts of shells and alternating with light blue clays. These
ferruginous bands vary very greatly in number and thickness,
and are sometimes nodular. They are especially characterised by
the abundance of several small varieties of Ammonites margari-
tatus, De Montf.,and of Cardium truncatum, Sow. They are exposed
in the Melton and Oakham Canal between Edmondthorpe and
Whissendine station, in the hill east of Whissendine station, at
Blaston, Loddington, and Deepdale.

b. Beds of blue, highly micaceous, clay, with large septaria
crowded with fossils. ‘There are at present only two brickyards
in these beds within the area, namely, at Ouston, and between
Whissendine and Pickwell. The most abundant species in these
beds are Ammonites margaritatus, De Mont. (the large typical
form), Belemnites elongatus, Mill., Helicina expansa, Sow.,sp., Avicula
inequivalvis, Sow., Mytilus hippocampus, Y. & B., Modiola scalprum,
Sow., (very abundant), Cardium truncatum, Sow., Pleuromya
unioides, Rém., and Pentacrinus subangularis, Mill.

c. Beds of blue clay with septaria, the latter not unfrequently
containing Specular Iron, and weathering to a red colour. They
contain many of the fossils recorded from the preceding beds, but
less abundantly. They are exposed in Belton, Hallaton, and
Cranhoe brickyards.

d, Light blue clays, with bands of ironstone balls of con-
centric structure, and usually very unfossiliferous. These beds
are exposed in some brickyards about Oakham, at Langham, and
at Market-Harborough. At some places they contain beds of
green and brown sand, as near Horninghold.

e. The “ Rock-bed.” This is a mass of limestone, more or less
ferruginous, and occasionally passing into a good ironstone.
When unweathered it is a hard crystalline rock of a blue or green
colour, but as usually seen, it is brown and moderately soft. It
THE MARLSTONE OR MIDDLE LIAS, 65

is usually crowded with fossils, its mass being often made up of
fragments of crinoids, spines of echinoderms, serpule, and frag-
ments of shells, while certain beds in it (locally known to quarry-
men as “ jacks”) consist of an agglomeration of shells of Rhyncho-
nella tetrahedru, Sow., and Terebratula punctata, Sow., usually
filled with finely crystallized calespar. Belemnites (of the species
B. pazillosus, Schloth, and B. elongatus, Mill., are extremely abun-
dant in the Marlstone Rock-bed, and serve to distinguish it from
the Northampton Sand, which often resembles it in mineralogical
characters, but in which Belemnites are exceedingly rare. Ammo-
nites are not abundant in the Rock-bed in this district, but at
some points, as Edmondthorpe, Loddington and Horninghold,
Ammonites communis, Sow., and A. annulatus, Sow., occur in con-
siderable numbers; A. spinatus, Brug, and some varieties of A.
margaritatus, De Mont. are also found in it, but much more rarely,
in this district. Large specimens, of Pecten equivalvis, Sow., with
the highly-characteristic P. dentatus, Sow., also P. sublevis, Phil.,
Hinnites abjectus, Phil., sp. and -Avicula inequivalvis, Sow., are
among the most abundant forms inthe Rock-bed. Certain beds,
especially in its lower part, contain flattened nodules or concre-
tions of argillaceous limestone, similar to those which occur in the
bottom beds of the Northampton Sand.

The Marlstone Rock-bed is very variable both in thickness and
mineralogical character; it is finely developed in the neighbour-
hoods of Tilton-on-the- Hill and Somerby, near the former of which
places itis seen to measure 18 feet 6 inches in thickness; towards
the east and south, however, it attenuates very rapidly, being only
8 or 9 feet thick about Oakham, 2} feet at Allexton, 2 feet at
Godeby and at Horninghold, and less than 1 foot between Key-
thorpe and Hallaton. Besides being greatly diminished in thickness
the Rock-bed sometimes loses its calcareous character and be-
comes sandy, in these cases often resembling the other hard beds
which occur lower in the Marlstone series. When the junction
of the Upper Lias clay and the Marlstone Rock-bed is seen, the
latter often presents the appearance of having suffered erosion
before the deposition of the former. Insignificant, however, as
the Rock-bed often becomes, I have obtained no certain evidence
of its actual disappearance within the limits of this sheet, but in
places, its presence being doubtful, it is indicated by broken lines
only. ‘Taking into account all the characters presented by the
Marlstone Rock-bed, and remembering the evidence of shallow
water conditions which the beds immediately lying upon it
exhibit, it seems probable that an interval occurred between the
deposition of the Marlstone and the Upper Lias; but when we
remember the fact of the passage of certain species from one to
the other, especially of the Planulate Ammonites, it is clear that
this interval was not one of long duration.

The Rock-bed is nowhere in this area dug as an ironstone, as
it certainly was in former times, and as it still is at Adderbury,
King’s Sutton, and Fawler in Oxfordshire. Wherever it attains
a fair thickness, however, it is extensively quarried for building
66 GEOLOGY OF RUTLAND, &C.

purposes, for which it is well adapted; near Tilton-on-the-Hill it
is burnt into tolerably good lime.

Where the Rock-bed forms the substratum, as in the Vale of
Catmos, and on the spurs at Somerby and Tilton, the land which
is of a red colour* and highly productive, is almost everywhere
under the plough, forming a marked contrast with the districts
occupied by the clays above and below it, which almost always
remain as pasture.

In tracing the outcrop of the Middle Lias beds through the
area included in Sheet 64, no circumstance is more striking than
the remarkable variations of the beds which compose it both in
thickness and mineral character.

The line of outcrop of the Middle Lias formation is greatly
interfered with in this district by the great east and west fault,
which passes by Billesdon and Lodington and throws down the
strata on the north to the extent of several hundred feet. In
consequence of this fault the Marlstone strata appear far to the
west of their normal line, forming the great spur at Pickwell,
Somerby, and Burrow-on-the-Hill, and that of Tilton-on-the-Hill
and Billesdon. It is at this part of its course through the district
that the Marlstone Rock-bed attains its greatest thickness, and,
lying between two thick series of clays, it has formed a series of
magnificent escarpments overlooking the plains of Lower Lias.
These escarpments are diversified by deep ramifying valleys which,
surrounded by the cliff-like masses of the Rock-bed, give rise to
very picturesque scenery. See Woodcut, Fig. 5, page 53.

The great mass which, rising gradually from south-east to north-west,
culminates ‘in Burrow or Borough Hill (crowned by a fine Roman camp) is the
most northerly of the two great spurs referred to. The strata of the Rock-
bed are exposed in a number of pits about the villages of Somerby, Pick-
well, and Burrow-on-the-Hill, the stone being used for building and road-
metal.

At the west end of the village of Pickwell the Rock-bed is dug to the depth
of about 16 feet, and is seen resting on the clays below. The rock, as seen
here, is a fine, blue, crystalline limestone, and at about 6 feet from the top a bed
is seen almost wholly made up of specimens of Terebratula punctata, Sow., and
Rhynchonella tetrahedra, Sow. The other portions of the rock at this place
contain but few shells. Scattered through some of the beds of the rock are a
number of rounded and flattened nodules of light-coloured, compact, argillaceous
limestone, probably slightly phosphatic.

In the neighbourhood of Somerby there are some very extensive quarries
in the Rock-bed, from which fine building-stone is extracted. It is not
customary at this place to quarry the rock below the depth of about 10 or 12 feet,
only the upper weathered beds, which are of arich brown colour and ‘80 soft
as to be easily worked, being used for building. The hard, unweathered, blue
limestone beneath is seldom dug, except for road-mending.

Between Ouston and Somerby, but nearer the latter village, there are a
number of good exposures of the Rock-bed. Here, as at many similar points,
there is evidence, along the sides of valleys cut back into the escarpment, of a

 

* The county of Rutland (red land) probably acquires its name from the preva-
lent colour of its soil. The greater part of the county is occupied by the Lincoln-
shire Oolite Limestone, the Northampton Sand, and the Marlstone Rock-bed, with
the clay slopes below them, which are coloured by their down-wash.
THE MARLSTONE OR MIDDLE LIAS. 67

number of landslips having taken place, the thick, jointed strata of limestone
sliding easily over the blue clays below.

The sandy and micaceous clays, sometimes passing into ferruginous sands
and sandrock, which immediately underlie the Rock-bed, are seldom well
exposed on this spur, and have, at the few points where they are seen in the
deep roadside cuttings leading down the steep escarpments, yielded no fossils.
There is only one place at which the deeper-seated, blue, micaceous clays, which
yield such a beautiful fauna, are exposed, namely, the brickyard between
Somerby and Ouston.

At this place we have the following section :—

(1.) Soil.
(2.) Light-coloured clay only partially exposed.
(3.) Band of ironstone - - - - 6 inches.
(4.) Blue, highly-micaceous, and pyritous clay - 3 to4 feet.
(5.) Blue, sandy, calcareous and highly-micaceous rock

crowded, in places, with fossils - - 2 feet.

(6.) Clay similar to (4), but with bands of septaria - 21 feet to
bottom of the pit.
This pit has afforded a very interesting series of beautifully pteserved fossils,
which are enumerated in the following list :—

Fossils from the Middle Lias Clays of Ouston Brickyard.

Ammonites margaritatus, De Montf., typical form, very abundant ; many
of the specimens attaining a great size.

Ammonites Normanianus, D’ Ord.

Belemnites elongatus, Mill.

Belemnites sp.

Helicina expansa, Sow., sp.

Ostrea sp.

Pecten zquivalvis, Phil.

sublevis, Phil.

Avicula inzquivalvis, Sow.

Mytilus hippocampus, Y. & B.

scalprum, Sow. Very variable in form; very abundant.

Cardium truncatum, Sow.

Pleuromya unioides, Rém. sp.

Pholadomya decorata, Hartm.

ambigua, Sow., var. ?

 

 

 

Serpula sp.
Pentacrinus sp.

 

The southern of the two great spurs of the Marlstone rises into the high escarp-
ments of Halstead, Tilton-on-the-Hil), Billesdon Coplow, and Billesdon; and
at its western extremity stretches beyond the limits of Sheet 64. As in the
northern spur, the beds are well seen on the sides of the steep escarpments, and
in the numerous pits opened for economic purposes.

Between Ouston and Tilton-on-the-Hill the escarpment gradually rises, and
the base of the Rock-bed can be easily traced, the junction of the limestone
and clay being marked, as usual, by the outflow of numerous fine springs.
About Halstead and Tilton-on-the-Hill there are a number of exposures of the
Rock-bed in small pits and roadside cuttings; the beds, however, dip away
gradually to the south and west, and then become covered by glacial
clays and gravels. The Rock-bed is, however, well exposed in a small pit
about three-quarters of a mile south-west of the village of Tilton near the head
of a small stream. The steep escarpments and deep sinuous valleys of this
southern spur are an exact counterpart of those of the northern one, and give
rise to equally striking and pleasing scenery.

In the valley about half a mile west of Wildbore’s Lodge there are several
pits (situated in the lordship of Tilton-on-the Hill) at the foot of the bill
called Robin-a-Tiptoes, which together furnish one of the best sections of the
Rock-bed in the district. Some of the stone was here formerly dug for lime-
burning, and is said to have produced a fairly good material for dressing the
68 GEOLOGY OF RUTLAND, &C.

land ; its use for this purpose is now altogether abandoned throughout thi
nC § pu ea
district. The following is the section exposed at this place :—

(1.) Light blue clay of the Upper Lias, with frag-
ments of Ammonites communis, Sow., passing
2 down into - - - - 1 to 2 feet seen.
(2.) Laminated, ferru inous, sandy and marly clay,
forming a gradation from the Upper Lias
Clay to the Middle Lias Rock-bed - 2 feet.
(3.) Hard, blue or greenish, ferruginous limestone,
where weathered passing into a soft brown
rubbly stone, which owes its peculiar cha-
racters probably to the removal by solution

of the calcareous matter - z - 4 feet. |
(4.) Bed almost made up of fragments of crinoids,

serpule, and shells - - - 1 foot,
(5.) Beds similar to (3) - - 3 feet.

(6.) “Fist jack” almost wholly made up of
shells of Terebratula punctata, Sow., and
Rhynchonella tetrahedra, Sow., the interiors
of which are filled with beautifully crystal-
lized carbonate of lime + - “

(7.) “ Building-stone,” consisting of two beds of
“hards” and two of “softs” -

(8.) “Second jack,” similar to (6), but much
thicker. This bed contains some flattened
nodules or concretions, and has a parting
of clay in its midst - =

(9.) Two beds of “ building-stone,” one “soft”?
and one “hard.” These lower beds where
dug at some depth become very hard and
blue-hearted. They contain the flattened
nodules or concretions = - - - together 1 ft. 6 in.

Total thickness of the Marlstone Rock-bed, 18 ft. 6 in.

Probably this is nearly the maximum thickness attained by the Rock-bed in
ra district. The fossils which were found in the rock at this place were as
ollows :—

6 inches.

together 6 feet.

2 feet 6 inches.

Fossils from the Marlstone Rock-bed at Robin-a-Tiptoes.

Ammonites spinatus, Brug. Rare.

Belemnites paxillosus, Schloth.| Abundant and often of large size
elongatus, Mili. found scattered throughout the rock.

Cerithium sp.

Ostrea, small sp.

Placunopsis (attached to, and avsuming the markings of a Rhyn-
chonella). :
Pecten dentatus, Sow. Abundant; a species very characteristic of the

Marlstone Rock-bed in this district.

Pecten liasianus, Nyst.

zquivalvis, Sow. Very large.
Hinnites abjectus, Phil., sp. Not rare.
Lima pectinoides, Sow. a
Terebratula punctata, Sow. jh prodigious abundance, and exhibit-
Rhynchonella tetrahedra, Sow. ing great variation in form.
Rhynchonella acuta, var. bidens, Phil, Very rare.
Serpula quinque-sulcatus, Goldf.
Pentacrinus levis, Mill.
Other crinoids.
Wood. Rather abundant.

It is a remarkable fact that in this district Rhynchonella acuta, and all its
varieties are excessively rare, while Rhynchonella tetrahedra is so prodigiously
abundant. This is one of the numerous examples found in the Jurassic
rocks illustrating the remarkably local distribution of certain forms among the

Brachiopoda.

 
THE MARLSTONE OR MIDDLE LIAS. 69

The Marlstone beds are also seen again on the north side of the fault, in the
sides of the small valley to the south-east of Wildbore’s Lodge.

At the east end of the village of Billesdon two brickyards, one on either side
of the great coach-road from Uppingham to Leicester, furnish us with a
valuable section of the strata immediately below the Rock-bed, and although
the locality is just beyond the limits of Sheet 64 it will be advisable, on account
of the rarity of such sections, to notice it here.

The higher beds are shown in the pit on the north side of the road ; although
no section of the Rock-bed is seen at this point, there can be no doubt, from
the occurrence of springs, the form of the ground, etc. that this bed is in place
at less than 10 feet above the top of the following section.

(1.) Laminated, light-blue clay, banded and stained by peroxide

of iron ;—some scattered ironstone balls - - about 10 ft.
(2.) Band of brown, cellular ironstone - - - - 6 to 12 in.
(3.) Clay like (1) but darker in colour and containing scattered

ironstone balls - - - - - - 5 ft.
(4.) Band of ironstone similar to (2) - -. - - 6 to 12 in.
(5.) Beds of dark-blue clay to bottom of section - - 6 to 8 ft.

The upper part of the series appears to be very destitute of fossils, with the
exception of a few fragments of Belemnites. Towards its base, however, the
clay (5) yields, large flat septaria, some of which decompose by exposure to
the air, and assume a reddish brown colour, rapidly falling to pieces. These
septaria yield numerous organic remains. The blue clays at the base are
sometimes very micaceous, and the septaria contain in their fissures Specular
iron, Zinc-blende and Pyrites. The pit on the south side of the road exhibits
a section of about 15 feet of dark-blue clay with flat septaria containing fossils.
From these two pits we learn that the succession of the Middle Lias beds here
is as follows :—

(1.) Rock-bed.

(2.) Light-blue clays with bands of sandy ironstone (few

fossils - - - - - - about 30 feet.
(3.) Dark-blue clay with Septaria (numerous fossils) - 15 feet seen.

Fossils from the Billesdon brickyard. (Clays below the Marlstone Rock-bed.)

Belemnites paxillosus, Schloth.

Ammonites margaritatus, De Montf. Abundant; large, normal forms, and
numerous varieties.

Plicatula spinosa, Sow.

Lima pectinoides, Sow.

Pecten sublevis, Phil.

Modiola scalprum, Sow.

Goniomya sp.

As we proceed northwards, southwards and eastwards, from the two great
spurs just noticed, which exhibit the Middle Lias strata in their condition of
maximum development, the various members of the formation become greatly
diminished in thickness while they lose some of the well marked characters
which distinguish them in the district described.

Between Pickwell and Whissendine the Rock-bed, though it still forms a
well marked escarpment, is almost wholly concealed by the enormous masses
of drift which cover the country. At the foot of this escarpment, however,
and about midway between the two villages mentioned, at the place called
Rocart on the map, a brickyard gives us an interesting section of the blue
micaceous clays (Zone of Ammonites margaritatus) which occur at some
distance below the Rock-bed. This section is as follows :—

(a.) Boulder clay, of the usual character, crowded with fragments of chalk
and flint with a few boulders of Oolitic and other rocks. The boulders
often exhibiting fine glacial polishing and striation. The glacial
beds rest on an eroded surface of,—

(6.) Beds of dark-blue clay, with numerous layers of septaria, containing
many fossils. Cardium truncatum, Sow., is especially abundant here,

some of the septaria being almost wholly made up of specimens of
that shell. :
70 GEOLOGY OF RUTLAND, &¢.

The following fossils were collected at this place :—

Fossils from the Old Whissendine brickyard at Rocart.

Ammonites margaritatus, De Montf. Normal form; specimens very
numerous, often of large size and great beauty.

Belemnites paxillosus?, Schloth. Very large.

Pecten sublevis, Phil.

Cardium truncatum, Sow.

Lima pectinoides, Sow.

Modiola scalprum, Sow. Very abundant and large specimens.

Myacites (Pleuromya) unioides, Rém., sp.

Terebratula punctata, Sow. ‘

Rhynchonella tetrahedra, Sow.

Serpula sp.

In the valley south of Whissendine the Rock-bed is exposed in a number of
field-drains, &c. but there are no good sections. The same rock is seen in the
road-cutting at the west end of that village, and also in several small openings
between it and Ashwell.

Stretching from Ashwell southwards to Oakham and Egleton we have a
broad valley, the bottom of which is formed by the Marlstone Rock-bed and
the sides by hills of Upper Lias, capped on the eastern side by the Lower
Oolites. This is the celebrated and fertile vale of Catmos, which is traversed
by a branch of the Midland Railway running between Luffenham and Melton

owbray. Along the bottom of this valley we find many exposures of the
Middle Lias formation; stone-pits and railway-cuttings furnish many
opportunities for studying the Rock-bed, while the small brooks which traverse
the valley cut through the platform formed by that hard stratum into the
clays, &c. which lie below it. :

Near Ashwell station a railway-cutting affords an excellent section of the Rock-
bed. At Langham a pit which furnishes an excellent section occurs, exhibiting
a representative of the Upper Lias, beneath which the Rock-bed, 9 feet thick,
is seen to be underlaid by 14 feet of shaley clay without fossils, followed by a
thin ferruginous band of 18 inches, also in turn underlaid by clay.

About Oakham and Barleythorpe we find a number of pits in the Rock-bed,
which is dug for building-stone and also as road-metal. The calcareo-
ferruginous rock is here evidently greatly reduced in thickness and probably
never exceeds 6 or 8 feet. In several brickyards about the town we find
tolerably good sections of the beds of clay, &c. immediately underlying the
Rock-bed.

A brickyard a little north of Oakham on the road to Ashwell furnishes the
following section :—

(1.) Marlstone Rock-bed at top of the pit, full of the

usual fossils - - - - - thickness not seen.
(2.) Soft, brown, sandy bed - - - - I foot.
(3.) Hard, shaley,micaceous clay (without fossils?) a iayer
of ferruginous nodules near the top, and others
scattered through the mass; towards the base the
clay abounds in flat nodules of iron pyrites - about 10 feet.
(4.) Sandy, blue rock (worthless) - ; 1 ft. 6 in.
(5.) Light-blue clay, sometimes good enough for tile-
making, at others full of ferruginous nodules,
&c., and worthless - to bottom of pit.

South of Oakham, on the road to Uppingham, another brickyard exhibits the
Rock-bed and the clays lying below it, as follows :—

(1.) Marlstone Rock-bed at the top of the pit contain-

ing the usual fossils; it also exhibits numerous
very hard, round and flattened concretions of fer-
rugino-argillaceous limestone -

- thickness not seen.
(2.) Clay without fossils, containing large quantities

of iron pyrites = - - - - about 9 ft.
(3.) Two beds of thin and very variable, soft, sandy, fer-
ruginous rock - - - only a few inches

thick.
THE MARLSTONE OR MIDDLE LIAS, 71

The road from Oakham to Uppingham and the railway from the former
town to Manton cross several small valleys, cut through the Rock-bed into the
clays below, and there are several exposures of these beds, both there and in
the brook running through the village of Egleton; these however present no
features of special interest. :

Northward from Ashwell the Rock-bed of the Marlstone forms a fine
escarpment about the villages of Teigh, Edmondthorpe, and Wymondham.
The Northampton Sand and the Marlstone Rock-bed form successive plateaux
with very gradual inclinations to the south-east, while the steep slopes below
on the north-west are constituted by the clays of the Upper and Middle Lias
respectively.

Near Rdmouditiorpe the Marlstone Rock-bed is well exposed along the sides
of the Oakham and Melton Mowbray Canal, and a little to the north-west
of the village there is a stone-pit, which has yielded numerous fossils, in-
cluding :—

Ammonites communis, Sow.
s annulatus, Sow.
5s spinatus, Brug. Rare.

Belemnites paxillosus, Schloth.

5 clavatus?, Schloth.

Terebratula punctata, Sow.
ey numismalis? Lam.

Rhynchonella tetrahedra, Sow.

About Wymondham there are numerous openings in the Rock-bed, the
positions of which are indicated on the map. As, however, they offer no
characters of any novelty it is not necessary to do more in this place than to
notice their existence.

Along the banks of the old canal between Edmondthorpe and Whissendine
Station we find traces of the soft, brown, sandy strata, which form the real
base of the Marlstone or Middle Lias series; at this place, however, the beds are
not conveniently exposed for study. On the hill east of Whissendine Station
there are traces of some old stone-pits, which appear to have been opened in
these beds, and a ditch on the side of the hill still exposes them in situ. They
consist of soft, earthy, light-brown ironstone full of shells; Cardium truncatum,
Sow., being specially abundant. These strata appear to be in every respect similar
to those seen at Neville-Holt, Blaston, and other points; though composed of
such soft materials they yet make a recognizable escarpment, which can often
be traced for considerable distances.

North of Wymondham, though the Rock-bed escarpment still remains to
guide us, there are no exposures of the stratum, and in consequence the re-
mainder of its outcrop in Sheet 64 has been represented by broken lines.

South of the great Billesdon and Lodington fault, the Middle Lias beds
appear again about the village of Lodington, where however their outcrop is
much concealed by drift. At the north-western end of the village there were
formerly a number of pits in the Rock-bed, but these are now all closed;
within the park and on the north side of the village a pit exhibits a fair
section of the same stratum, and its junction with the Upper Lias Shales. At
this place the Marlstone Rock-bed yields the usual fossils, Ammonites communis,
Sow. being by no means rare.

Between Lodington and Belton the outcrop of the Rock-bed can generally
be traced by the form of the ground, though there is but one exposure of it on
the hill sides. At the latter village a brickyard, now abandoned, was opened.
in the beds below the Rock-bed, and on the same horizon as the brickyards
at Billesdon. Although the Belton brickyard is now closed, heaps of the
septaria obtained from the clay pit may still be seen; these are changed by
exposure, to a dark red colour, and are so decomposed that they fall to
pieces with a slight blow from the hammer. From these septaria I collected
the following fossils :

not rare.

Ammonites margaritatus, De Montf. Several varieties and of all si
Pleurotomaria Quenstedti, Goldf. e Rene eee
Myacites or Panopcea (fine specimen).

Leda complanata, Phil.
72 GEOLOGY OF RUTLAND, Sc.

Cardium truncatum, Sow. (in masees).
Pecten demissus, Phil.

»  equivalvis, Sow.
Lima pectinoides, Sow.

sp.

Plicatula spinosa, Sow.

Avicula inequivalvis, Sow.

Rhynchonella tetrahedra, Sow. (one specimen).

The deep, winding, branching, and picturesque little valleys which lie on
either side of the spur, capped by Inferior Oolite, overlooking Wardley, reveal
on either side, in their steep and scarped slopes, many indications of the
presence and some good sections of the Marlstone Rock-bed. The valley to
the north-west, known as Bushy Dales, exhibits the junction of the Marlstone
with the overlying Upper Lias; in the south-eastern or Deepdale we can trace
below the Rock-bed, in the sides of the stream, the blue clays, sandy beds, impure
ferruginous bands, and courses of argillaceous nodules of the lower part of the
Marlstone. ;

Along the south bank of the Eye Brook there are but few exposures of the
Middle Lias. At Allexton is a pit passing through the base of the Upper Lias
into the Rock-bed, the details of which section will be given hereafter. Near
the great coach road at the village of East Norton there are several small
and unimportant exposures of the Marlstone, but about the village of Tugby
it can generlly be traced only by the form of the ground.

At Godeby the Marlstone Rock-bed can be seen in- some ditches on the
spurs above the village. The remarkable manner in which the stratum is here
reduced to only a foot or two in thickness, while it has at the same time
almost wholly lost its calcareous character and its hardness, is very striking ;
especially when we remember that the locality is only about four miles distant
from that of Robin-a-Tiptoes, where, as we have seen, the rock attains its
maximum dimensions. But insignificant as the rock has become, it has still
been able to resist denuding forces to a much greater extent than the clays above
and below it, and consequently forms a well marked and very conspicuous
escarpment. At Cross Barrow Hill between Gloostone and Cranhoe, the Rock-
bed is still very thin but harder and more calcareous than at Godeby ; it is
here dug, under seven or eight feet of boulder clay, for road metal, the shallow
pits being filled up again as soon as the stone is taken out. At this place
a considerable number of fossils, of the usual species found in the rock, were
collected. Above the village of Cranhoe the Rock-bed is exposed at a few
points of the steep escarpment.

Along the whole of their outcrop from Deepdale to beyond Cranhoe the
lower beds of the Middle Lias series are almost wholly unknown, owing to the
prevalence of drift at the lower levels at which they are developed. But at
Cranhoe brickyard we have an interesting exposure of these beds, consist-
ing of light-blue, stratified clays, with layers of concentric balls of ironstone
which fall to pieces on exposure to the air. These nodules contain numerous
but imperfectly preserved fossils, and it is evident that the beds which contain
them are near the junction of the Middle and Lower Lias; the species collected
here were as follows :—

Fossils from Cranhoe brickyard (base of the Middle Lias series).

Belemnites sp.
Ammonites Henleyi, Sow.
3 sp. indet.
Pecten liasianus, Nyst., sp.
>» ‘equivalvis, Phil.

Avicula inequivalvis, Sow.
Lima pectinoides, Sow.
Cardium truncatum, Sow.
Leda complanata, Phil,
Cucullea sp.
Crenatula ventricosa (?), Sow.

: Pentacrinus sp.

Some of the nodules here contain Specular Iron.
THE MARLSTONE OR MIDDLE LIAS. 73

The same ‘beds are seen in the Cranhoe brickyard; they appear also in
the western slope of Cross Barrow Hill and on an adjoining eminence, where
they were exposed in field drains.

series of narrow and sinuous valleys cut by the Hallaton Brook and its
numerous tributaries exhibit the escarpment formed by the Rock-bed running
round the flanks of the hills which bound them; but there are few good ex-
posures of the Middle Lias beds.

Near the bridle-road leading from Keythorpe to Hallaton, and at the point
where it crosses the brook, some old pits exhibit the following section :—

Upper Lias.—(1.) Laminated shales with traces of the “ fish
: and insect beds” at the top _- ~ 5 to 6 feet.
Middle Lias.—(2.) Marlstone Rock-bed with usual characters
containing numerous Belemnites, Am-
monites annulatus, Terebratula punc-
tata, &c. Asis often the case with this
rock. it here contains numerous rounded
pebbles or concretions - - - 1 ft. seen.
(3.) Light-blue clays passing down into.
(4.) Clays with bands and layers of nodules of
ferruginous and micaceous rock.
The irregular mode of recurrence of the diminutive representative of the
Marlstone Rock-bed is illustrated in the following sketch of a section seen at
this point (Fig. 6).

Figure 6. Section exhibited in a pit between Keythorp and Hallaton (Leicester-
shire.)

 

 

 

 

 

 

 

 

 

 

 

a. Soil, &e.
J 5. Nodular limestones of the Fish and Insect limestones.
Le Clays.
5 : + Marlstone Rock-bed.
Middle Lias 4 Clays, &e. :

Upper Lias

_Along the sides of the valley near this spot there are numerous traces of old
pits which have been opened in the Rock-bed, and the same formation is again
seen near the entrance to the village of Hallaton.
74 GEOLOGY OF RUTLAND, &c.

At Hallaton brickyard we find nodular ferruginous beds alternating with
blue, micaceous, sandy clays, which yield the following fossils :—

Ammonites margaritatus, De Montf. varieties.
Avicula inequivalvis, Sow.

» SP
Pecten liasianus, Nyst.

52 ‘SP:
Cardium truncatum, Sow.

Below these beds dark-blue clays, with many fossils, were formerly dug.

Near Hallaton Ferns the Marlstone Rock-bed, with the overlying Upper Lias
shales, were exposed in a series of field drains along the side of the brook.
See page 83.

Just above Horninghold, on the road to Hallaton, the Rock-bed is seen as a
thin band of brown, micaceous, sandy stone, full of casts of fossils including —

Ammonites annulatus, Sow.
Rhynchonella tetrahedra, Sow.

Below are light-blue clays, in places full of thin ferruginous bands. Traces
of the same sandy and ferruginous beds are seen in the banks of several brooks
in ie neighbourhood, and were also exposed in some field-drains about the
village.

By the side of the brook at Blaston St. Michael’s, and near the road leading
to Stockerston, we find the beds representing the bottom of the Middle Lias
series. These consist of a soft, ferruginous and micaceous sandstone full of
casts of fossils, including—

Cardium truncatum, Sow.
Avicula novemcostx, Brown.
Nucula sp., &c.

Near to the same village we find traces of sandy, ferruginous beds similar to
those representing the Marlstone Rock-bed at Neville-Holt, and underlaid as
at that place by light-blue clays containing ironstone balls.

Near Medbourn the lowest calcareous and nodular beds of the Upper Lias
(the “ Serpentinus Beds,” &c.) are of a ferruginous character, and, but for the
highly characteristic fossils which they yield, might be mistaken for the Marl-
stone Rock-bed. The latter is represented in a very attenuated form by a
bed of ferruginous sandy rock with few fossils; itis underlaid by clays more
or less sandy, with bands of concentric, ferruginous nodules.

At the foot of the Hill on which the Neville-Holt ironworks were opened we
find, ina cutting made for the railway incline, the “ Serpentinus-Beds ” and the
“ Fish and Insect Beds” of the Upper Lias underlaid by the Middle Lias
series, which is here constituted as follows :—

(1.) Irregular beds of micaceous and ferruginous, sandy rock full of casts of
shells. These form two or three beds of stone, which are in places
more or less calcareous. They do not, however, present the character-
istic features of the Rock-bed, but are always of a more or less
nodular character. They contain Belemnites, usually grouped together
in considerable numbers in certain parts of the rock, and also a few
rounded pebbles or concretions like those of the Rock-bed. ‘The species
of fossils found in these bands were as follows :—

Pecten liasianus, Nyst. (large, 5 inches in diameter).
Avicula novemcoste, Brown (A. zquivalvis, Sow. var.).
Cardium truncatum, Sow.

Leda complanata, Phil. . ;

(2.) Light-coloured clays containing bands of ironstone nodules. These are
of considerable thickness. . : :

(3.) The lowest beds seen at this point are exposed in the brickyard below,
and consist of blue, micaceous clay, containing flattened nodules of
clay-ironstone with a few fossils :—

Belemnites (fragments).
Ammonites capricornus, Schloth.
Leda complanata, Phil.
Cardium truncatum, Sow.
Ostrea sp.

Wood.
THE MARLSTONE OR MIDDLE LIAS. 73

It may be considered by some as open to question whether, at this and some
other points, the Marlstone Rock-bed has not been wholly removed by denuda-
tion before the deposition of the Upper Lias Clay. The more probable opinion,
and that which has been adopted by the Survey, is that the Marlstone Rock-
bed is represented in a greatly attenuated and rudimentary condition by the
nodular bands which occur at the top of the Middle Lias Series. Indeed, at
some points there occurs a transition from the irregular and inconstant nodular
bands to a well defined rock-bed presenting the characteristic features, both
lithological and paleontological, of the highest member of the Middle Lias.

Near Ashley, on the road to Wilbarston, the Rock-bed of the Marlstone is
clearly exposed, and is seen to consist of several beds of stone, sometimes of
a decidedly calcareous character, and containing the peculiar flattened nodules.
‘These beds are interstratified with clays; they are underlaid by a thick series
of shales and covered by the beds containing the “Fish and Insect Lime-
stones ” of the Upper Lias. At several other points near the same village the
beds at the junction of the Middle and Upper Lias are more or less distinctly
seen, and the Rock-bed is of sufficient importance to give rise to a very distinct
feature in the contour of the country. The same rock, with precisely similar
characters, is seen about the village of Ashley, especially in a cutting beside
the road leading to Stoke Albany. Between East Carlton and Ashley beds
of sandy, brown clay were exposed in field drains; these yielded a specimen of
Ammonites margaritatus, De Montf.

About the village of Sutton Basset beds of light brown, sandy stone occur,
which must probably be regarded as the representative of the Marlstone Rock-
bed, though they have yielded but few of its characteristic fossils.

The lower beds of the above section were seen in a well, the higher beds in
the pits of the brickyard.

In another brickyard, lying to the north of the last, we find the following
section :—

(1.) Soil and Boulder Clay - - - - - 38 feet.
(2.) Upper Lias Clay = - - - - - 2 feet.
(3.) Rock-bed of the Marlstone (as in last pit) - - 4 feet.
(4.) Brown Clay, containing nodules of ironstone - - 3 feet.
(5.) “ Skerry,” a thin band of ferruginous, micaceous rock,
crowded with fossils - - - Ginches.

(6.) Laminated, light-blue clay containing much mica, weathering

brown near the joint planes - - - - 8 feet.

(7.) A thin band similar to (5).

In another pit to the north of this the bed (7) is found to be underlaid by
about 7 or 8 feet of clay, and this in turn by a continuous bed of stone.

At Little Bowden brickyard, which is probably not much below the level of
these pits, we find the micaceous clays of the Capricornus-beds forming the
top of the Lower Lias series. These have been already noticed. It is clear
from the sections about Market Harborough that the whole Middle Lias is
there very thin and its several beds of a somewhat inconstant character.

Southwards from Harborough, the outcrop of the Middle Lias bedsis almost
wholly obscured by drift, until we come to the Oxendon Magna tunnel on the
Northampton. and Market Harborough Branch of the London and North-
Western Railway. In this tunnel and the cuttings near it the Marlstone
Rock-bed, with its characteristic fossils, was exposed. It is remarkable, con-
sidering the insignificant character of its beds, how bold an escarpment is formed
by the Middle Lias in the country immediately to the west, namely, the ridge
on which stands the villages of East Farndon, Clipston, Sibbertoft, &c.

Behind Dingley Lodge is a pit showing the “ Serpentinus-beds,” and a trace
of the “ Fish and Insect Limestones ”’ of the Upper Lias, lying upon the Rock-
bed of the Marlstone, which is here distinctly calcareous and contains the
usual fossils.

About Market Harborough and Great and Little Bowden the Middle Lias is
seen in a very attenuated condition, as already noticed, and is exposed to obser-
vation in some very interesting sections. In the brickyard opposite to the
railway station, under the lower beds of the Upper Liss (which are here,
as at many points in the Midland district, sandy and ferruginous, and might
76 GEOLOGY OF RUTLAND, &C.

easily, if regard were not paid to the fossils, be mistaken for the Middle
List we find the following beds, underlying those noticed on page 87.
(10.) Rock-bed (?) consisting of a laminated, ferruginous sandstone, con-
taining much mica; with
Ammonites margaritatus, De Monéf, (several varieties).
Belemnites paxillosus, Schloth.
Cardium truncatum, Sow.
Lima sp.
Avicula novemcostz, Brown.
(11.) Brown clay - - - - - 2 to 3 feet.
(12.) “Skerry” or “ Kale,” with nodules, containing—
Cardium truncatum, Sow.
Lima sp.
Avicula cygnipes, Phil.

(13.) Brown Clay - - - - - 2 ft. 6in.
(14.) Blue Clay - - - - - - 709 ft.
(15.) “ Skerry ” (brown sandy stone) - - - - 1 ft. 6in.
(16.) Brown Clay - - - - - 2to3 feet.
(17.) Rock in which an abundance of water was obtained, and

which prevented further sinking - - dug to the depth of 2 feet.

Inliers—South of the Vale of Catmos, two long narrow inliers
of the Middle Lias strata are exposed, in consequence of the rivers
Chater and Gwash having cut their valleys down through the
Boulder Clay and Upper Lias, which form the high plateau in
that part of the district. In these inliers the Marlstone Rock-
bed is found cropping out, like a ledge near the sides of the
valleys, or sometimes forming tolerably level floors at their
bottoms. Where the Rock-bed is cut through, the underlying
clays, sands, &. of the Middle Lias are occasionally exposed in the
river banks.

Along the valley of the Gwash at the village of Braunston, and from that
village eastwards towards Brook and westwards towards Knossington, as also
along the valley of the small tributary which the stream receives from the
north, the Middle Lias beds are exposed at a number of points. The Rock-
bed has been dug south of Flitteris Park, and a large pit opposite to Brook
Hall shows the formation with its usual characters and fossils. The outcrop
of the hard calcareous rock makes a very distinct feature in this valley, and
below it, in artificial openings at the village of Braunston and in the river
banks at some other points, I saw traces of the underlying beds of the Middle
Lias series presenting their usual characters. ;

The River Chater, at Laund Abbey and in the valley westward and eastward
for a total length of about four miles, has similarly denuded away the Boulder-
Clay and Upper Lias covering, and exposed the beds of the Middle Lias below.
On both sides of the stream below Laund Abbey we have a tolerably good
section exposed of the calcareous and somewhat shelly Rock-bed, which is here
of moderate thickness, and of the light-coloured clays with ironstone balls and
the ferruginous, sandy beds which underlie it. Near Coles’ Lodge there is a
pit in the Marlstone Rock-bed ; the stone is here full of the usual fossils, and
contains bands (“jacks ”) almost wholly made up of specimens of Rhynchonella
tetrahedra, Sow., and Terebratuta punctata, Sow., all filled with calcspar. In
the deep lateral valleys west of Withcote Lodge, and between Coles’ Lodge and
Swinthley Lodge, other pits in the same bed have been opened; also to the east-
ward, on the opposite side of the valley to Leighfield Lodge, where a tolerably
good section of the Rock-bed was at one time exposed. Near the sources of
the River Chater and at the foot of Whadborough Hill and Robin-a-Tiptoes,
temporary openings yielded other good sections of the Rockbed which is found
to thicken rapidly towards the west.

Outliers.—The outliers of the Middle Lias in the district are
small and of comparatively little importance. They constitute two
 

NOLENVHIMON 2G GHdd¥O SVT Wedd INV SNOLSTAVN 40 SETILNo Ny

: ;  PMINSULISHOET ‘TWH NOLS

“ng -eT Spogarnyy|

 

 

ae]
THE MARLSTONE OR MIDDLE LIAS. 77

hills in the south-west corner of Sheet 64, one of which is crowned
by Slawston Windmill, while the other was formerly the site
of the Staunton Wyvile Mill. In both cases the upper portions
of the hill are formed of beds higher in the geological series
than the Middle Lias ; in the former case of the Upper Lias Clay
with a very thin capping of the Northampton Sand, in the latter
of the lower beds only of the Upper Lias. In each case the hard
beds at the top of the Middle Lias Series give rise to a very
marked feature in the contours of these hills, namely a flat
ledge and steep declivity intervening between the gradual slopes
formed by the Upper and Lower Lias Clays respectively. (Plate V.)

The Hallaton Brook separates the outlier of Slawston Hill from the main
mass of the Middle Lias. Near Medbourne Mill the thin beds of Marlstone
Rock-bed were exposed in some road-cuttings; above them were well seen
the “ Serpentinus-beds ” and the “ Fish and Insect beds”? of the Upper Lias;
below them, ferruginous, sandy, micaceous shales with layers of concentric
nodules of ironstone. The Marlstone Rock-bed is here constituted by several
layers of soft, brown, sandy, micaceous, and ferruginous rock, each layer being
about one foot thick, interstratified with light-blue, micaceous clays; the stone
bands contain Avicula novemcoste, Brown, and Leda complanata, Phil. sp.
Owing to the small quantity of calcareous material in it, the Rock-bed here does
not present its usual characters, but more nearly resembles some of the bands
usually found lower down in the Middle Lias Series. In the road east of
Slawston Mill a number of ditch-cuttings show the succession of beds to
be as follows :—

(1.) Clays.
(2.) Ferruginous beds with Ammonites serpentinus, Rein.
(3.) Clays with nodules of the Fish and Insect limestone.
(4.) Brown, sandy, ferruginous beds with but very little calcareous
matter. - Casts of shells. :
Cardium truncatum, Sow.
Leda complanata, Phil., sp. :
(This is here a very inconspicuous bed and does not at all
resemble the Rock-bed in its normal aspect.)

(5.) Whitish clays with nodules of ironstone.

On the south side of the same hill we have a good exposure of the beds
forming the Middle Lias and the base of the Upper Lias. The surface of some
of the fields here is literally strewn with fragments of Ammonites serpentinus,
Rein., Ammonites falcifer, Sow., Ammonites bifrons, Brug., and Belemnites.

We have at this place the following succession of beds :—

(1.) Ferruginous, sandy beds with Ammonites serpentinus, Rein., &c.
(2.) Paper-shales with limestone nodules.
(“ Fish and Insect beds ”’)
(3.) Marlstone Rock-bed, here very inconspicuous and scarcely trace-

able.

(4.) Clays with bands of soft, yellow and brown, sandy ironstone full of
small shells, Cardium truncatum, Sow., Pecten equivalvis, Phil.,
&ce. ;

(e) Clays with ironstone balls.

6.) Clays (imperfectly seen). :

(7.) Hard, ferruginous and somewhat calcareous bed, perhaps the
lowest of the Middle Lias series.

The Middle Lias at this spot may be from 60 to 70 feet in thickness.

At the north-west end of Slawston Mill outlier the Rock-bed of the Marl-
stone presents its usual characters, and consists of a hard calcareous rock con-
taining Avicula novemcoste, Brown, Rhynchonella tetrahedra, Sow., and Tere-
bratula punctata, Sow. Large masses of carbonate of lime, crystallized in the
forms known as “ Dog-tooth Spar” and “Nail-head Spar,” are seen in the
rock at cot ae A series of road-cuttings also: exhibited the beds at the
base of the Upper Lias, which are here ferruginous, together with the series of

32108. F
78 GEOLOGY OF RUTLAND, &c.

light coloured, very ferruginous, sandy shales, containing ironstone nodules of
concentric structure and some sandy bands, which here underlie the Rock-bed of
the Marlstone. These beds are similar to those exposed in the Cranhoe brick-
yard on the opposite side of the valley.

In the hill on which Staunton Mill formerly stood, thin beds of brown,
sandy ironstone cap the long ridge and are at the northern and highest part of
the hill covered by a small patch of the Upper Lias Clay. The brown, sandy rock
is shown by its fossils to be an attenuated form of the upper rock of the
Middle Lias; it is underlaid by a series of ferruginous, sandy shales, now very
imperfectly exposed, but which were formerly dug for brickmaking in a pit on
the eastern side of the hill.
79

CHAPTER IV.
THE UPPER LIAS.

This division occupies a large area in Sheet 64; it is usually,
however, concealed by Drift, except on the steep slopes of the
escarpments formed by the Inferior Oolite. Throughout the
district its thickness is about 200 feet, and it consists almost
entirely of clays. Its principal members are as follows :—

a, “ Paper-Shales with Fish and Insect Limestones.”*—These
consist of finely laminated, blue shales, with bands of flat nodules
composed of argillaceous limestone of a blue colour, but weathering
white ; these beds under the influence of frost become extremely
fissile. The surfaces exposed by the bedding planes, both in the
shales and limestones, are often completely covered with scales
and other portions of fish with fragments of crustaceans and
insects. Complete specimens appear to be very rare, but a very
fine example of a fish is said to have been found at Edmondthorpe
in making the Oakham and Melton Canal. Besides the fossils
we have already mentioned there occur in these beds plant
remains and wood converted into jet, a few Ammonites of the
same species as in the “ Serpentinus-beds” above, but always ol
small size, numerous minute univalyes and some small bivalves
as Inoceramus dubius, Sow., Pecten sp. Ostrea sp., &e. Slight
exposures of these beds have been found at many points and they
appear to be everywhere present in the area, though varying greatly
in thickness, and in the number of bands of limestone which they
contain ; they may be best studied in pits at Allexton, Barley-
thorpe, between Keythorpe and Hallaton, and beside the canal
at Edmonthorpe. As is well known, these beds extend southwards
into Gloucestershire and Somersetshire, where they have been
described by the Rev. P. B. Brodie and Mr. C. Moore. At
Allexton these limestones are dug and sent to Tugby, where
they are burnt and make a hydraulic lime said to be equal to
that of Barrow-on-Soar.

b. “ Serpentinus-Beds.” These beds are always found lying
immediately above the former; they consist of clays with layers
of nodules of limestone of much coarser texture than those of
the “ Fish and Insect Beds.” These beds are crowded with
Ammonites, mostly belonging to the group of the Falciferi, and
often of large size, such as A. serpentinus, Rein.; A. falcifer, Sow. ;
A. Lythensis, Y. & B.; A. elegans, Sow. ; A. concavus, Sow.; and
A, radians, Rein., with some Belemnites and other shells. So abun-
dant are these Ammonites that when the Jand has been recently
drained it is strewn with their fragments, and it is almost always

 

* These beds, as I have before suggested, might conveniently be named the
“ Dumbleton Series” from the locality at which they were first studied by the
Rey. P. B. Brodie.

F2
80 GEOLOGY OF RUTLAND, &c.

possible by their means to detect the outcrop of the beds containing
them, even in ordinary ploughed fields. Occasionally, as at Market
Harborough and near Hallaton Ferns, the Serpentinus limestones
become ferruginous, when they are liable to be mistaken for
part of the Marlstone Rock-bed, from which, however, they are
readily distinguished by their fossils.

c. © Communis-Beds.” Ata little distance above the “ Serpen-
tinus-beds” there are found beds crowded with small specimens
of Ammonites usually of the group of the Planulati (4. communis,
Sow., A. annulatus, Sow., &c.), Belemnites irregularis, Schloth. ;
Astarte sp. and other shells also occur. These beds were well
seen in the foundations of the blast furnaces at Neville-Holt, in
a railway-cutting between Oakham and Ashwell, in that near
Manton station, in a pond in Tugby Park, and in the Tugby
brickyard, as well as in numerous field-drains, &c.

d, The middle portion of the Upper Lias Clay, to the thickness
probably of about 100 feet, consists of dark-blue clays charged
with large quantities of pyrites and jet, often in Jarge masses;
when exposed to the atmosphere these clays become light-coloured
and exhibit much selenite with numerous bands and concentric
balls of hydrated peroxide of iron formed by the decomposition of
nodules of iron pyrites. Fossils are usually very rare in these
beds which are exposed in the brickyards at Moor Hill Lodge,
Great Easton, and that at Oakham on the road to Knossington,
also in the railway tunnels at Manton and Morcott.

e. “ Leda ovum Beds.”—The highest beds of the Upper Lias
consist of clays with numerous layers of septaria, everywhere dis-
tinguished by the abundance of specimens of Leda ovum, Sow., sp.
The prevailing Ammonite is A. bifrons, Brug., which occurs in
great numbers; the Planulate Ammonites are also numerous, and
attain to a much larger size than in the “ Communis-beds ” below ;
they are represented by A. communis, Sow., 4. annulatus, Sow.,
A. crassus, Phil., A. fibulatus, Sow., A. Holandrei, D’Orb. &e.;
species of the group of the Falciferi are comparatively rare,
but Am. heterophyllus, Sow, is tolerably abundant. Belemnites,
Myacites donaciforme, Phil., Arca truncata, Sow., Discina reflexa,
Sow., also abound in these beds. I have seen them well exposed
at Thornhaugh, Manton, Stamford, and Stanion Mill; they are
dug for brick-making at Rockingham, Gretton, Helpstone, Pilton,
and Seaton Station. ; ;

The clays of the Upper Lias occupy the wide undulating plains,
which lie between the two escarpments formed by the Inferior
Oolite and the Marlstone Rock-bed respectively. Composed of
beds which are easily denuded and are almost always covered with
drift, the exposures of this formation are few in number, and not
often of such a character as to enable us to study its relations to
other strata or the succession of its own beds; in these respects
it resembles the Lower Lias Clays.

The great mass of the Upper Lias in this area, which stretches
from the north of Wymondham to south of Braybrook, and attains
its greatest breadth between Tilton-on-the-Hill and Barrowden,
THE UPPER LIAS, 81

is intersected by many winding valleys, which cut down deeply
enough to expose the Middle Lias strata, sometimes forming
inliers in the midst of the Upper Lias. On the other hand, the
higher portions of the Upper Lias are capped by the beds of the
Inferior Oolite, which form outliers, often of great size, scattered
over the district of the Upper Lias. The valleys which breach
the great escarpment of the Inferior Oolite, namely those of the
rivers Gwash, Chater, and Welland, and their numerous tribu-
taries, are cut down to the level of the Upper Lias, but the bottoms
of these valleys being masked by superficial detritus, its beds are
seldom exposed in them.

A few small outliers of Upper Lias rising above the plateaux
of the Marlstone Rock-bed also exist, as those of Great Bowden,
Slawston, Staunton Mill, and Barleythorpe, and some of these are
capped by beds of Inferior Oolite.

The Upper Lias also forms a series of inliers in the midst of
the Lower Oolite plateaux. Some of these form the bottoms of
the valleys of the rivers which cut through these strata, which, as
we shall show, thin out rapidly to the eastward, so that the Upper
Lias is reached at comparatively small depths. This is the case
in the parts of the valleys of the Glen, the Wansford Brook, and
the Welland. In other cases, as at Stanion, Corby, and Help-
stone brickyard, the Upper Lias is brought up by faults and
exposed as inliers along the lines of certain small valleys.

Along the line of the Barford Brook, by Desborough, Rushton, Newton and
Geddington, the Upper Lias Clays can be easily traced at the base of the
escarpments of Northampton Sand, which form the sides of the valley. But
along this line there are no valuable and instructive sections.

Near Braybrook there are some small exposures of the Upper Lias,
principally in ditch-cuttings.

The Oxenden Magna tunnel, on the London and North-Western Railway,
leading from Market’ Harborough to Blisworth, and situated on the edge of
Sheet 64, passed through the Upper Lias Clay, which is here thickly covered
with Boulder Clay and other drift. In the heaps of clay brought out from this
cutting numerous Upper Lias fossils may be collected, including,—

Ammonites serpentinus, Rein.

as falcifer, Sow.

a communis, Sow.

99 Holandrei, D’Orb.
&e. &e.

Behind Dingley Lodge a pit shows the Serpentinus beds with traces of the
fish and insect limestones which lie at the base of the Upper Lias series. These
are seen to repose on the thin representative of the Marlstone Rock-bed, which
contains the usual fossils. .

From Stoke Albany northwards, the Upper Lias forms the slope of the
steep escarpment of the Inferior Oolite and also the plains which stretch along
its foot; sections are however very scarce. ;

At Sutton Basset Mill the Upper Lias Clay was reached in sinking a well. Just
above Ashley, on the road to Stoke Albany, the lowest beds of the Upper Lias,
containing Ammonites serpentinus, Rein., are seen. Between East Carlton
and Ashley a number of field-drains exposed some of the middle beds of the
Upper Lias, consisting of stiff, blue clays which yielded,—

Ammonites communis, Sow. Very abundant.
5 bifrons, Brug.

Belemnites, sp.

Fossil wood.
82 GEOLOGY OF RUTLAND, &¢.

At Rockingham brickyard (half way between Rockingham and Cottingham)
the highest beds of the Upper Lias are exposed. The blue clays, which are
dug for brick-making, contain much pyrites and the fossils are badly preserved.
They include the following :—

Ammonites bifrons, Brug.

” Sp.
Belemnites compressus, Voléz.
Ostrea sp.
Pecten sp.
Inoceramus dubius, Sow.
Leda ovum, Sow., sp.
Astarte sp.
Rhynchonella sp.

Between Rockingham and Harringworth the straight and steep slope, forned
by the Upper Lias lying under the great plateau of Inferior Oolite, is very
striking. In the sides of the numerous roads leading up this slope the Upper
Lias Clay can be frequently examined, but there are few deep sections. It is
also sometimes exposed along this escarpment in ditches and field-drains.

At Great Easton there is a brickyard in the Upper Lias Clay. In one part
of the pit a layer of ironstone nodules is seen in the midst of the clays.
Ammonites, Bélemnites, and wood in the form of jet are found in this pit.

At the iron-works at Neville-Holt we have a number of interesting sections
illustrating the Upper Lias Series. The upper portions, consisting at the top
of dark-blue, pyritous clays, and lower down of lighter-coloured clays with
ferruginous banding, are imperfectly seen. Towards the lower part, the
excavations for the foundations of the blast-furnaces showed clays crowded
with small specimens of Ammonites communis, Sow., and its varieties. The
fossils obtained here were :—

Ammonites annulatus, Sow.
e communis, Sow.
ss Holandrei, D’Orb.
i crassus, Phil.
35 bifrons, Brug.
Belemnites compressus, Voléz.

Nucula sp.

Astarte sp.

Posidonomya Bronnii, Voltz.
&e. &e.

Below these, in a cutting for the railway incline, we find the Serpentinus beds
consisting of clays with argillaceous limestone nodules, containing Ammonites
serpentinus, Rein., Am. elegans, Sow., &c. &c. Under these again occur the
finely laminated clays (paper-shales) containing the flattened nodules of light
coloured argillaceous limestone, with remains of fish, insects, and crustaceans.
The “fish and insect beds”? rest directly upon the thin representatives of the
Middle Lias. (See page 74.)

At the bottom of the valley, on the road from Neville-Holt to Blaston, a
number of field drains exhibited, at the time ‘the district was being surveyed,
admirable sections of the paper-shales and fish and insect limestones of the
base of the Upper Lias, with their usual characters and fossils. Above them
the Serpentinus beds were well seen, crowded, as usual, with specimens of
Cephalopods, including—

Belemnites compressus, Voltz.
Ammonites serpentinus, Rein.

5 falcifer, Sow.

53 bifrons, Brug.

8 radians, Rein.

a heterophyllus, Sow.
a communis, Sow.

98 crassus, Phil,

Just above the village of Blaston St. Giles, on the road to Medbourn, a pit
opened for obtaining clay to puddle a pond, exposed the Serpentinus beds, the
paper-shales and the fish and insect beds at the base of the Upper Lias Series.
A little above this was another pit in the ordinary Upper Lias Clays.
THE UPPER LIAS. 83

On the left bank of the stream at Hallaton Ferns the junction of the Upper
and Middle Lias was well seen in a number of field-drains. The succession of
beds here is as follows :—

1. Dark-blue clays.

2. Ferruginous beds with Ammonites serpentinus, Rein.
Upper Lias. (abundant), and Am. bifrons, Brug.

3. Paper-shales, with fish and insect limestones (usual

fossils).

4, Sandy, ferruginous band with casts of shells. (Marl-
Middle Liss] stone Rock-bed ?)

5. Light-coloured clays with ironstone balls.

Near the bridle road from Keythorpe to Hallaton, at the point where it
crosses the brook, some old pits show the base of the Upper Lias, consisting
of 5 or 6 feet of laminated shales, with traces of the nodular limestones, with
fish and insect remains; these rest upon the Middle Lias beds which have
been already described at this place. (See page 73.)

Opposite to Moor Hill Lodge there is an extensive brickyard in the Upper
Lias Clays. In this and a pond above we have a section of at least 50 or 60
feet of the series. The highest beds seen consist of laminated, light-coloured
clays, with irregular, brown, ferruginous bands in the lines of stratification.
The lower part consists of blue clays with few septaria, but with much pyrites,
both in nodules and disseminated through the mass, and, in consequence, the
weathered beds exhibit much Selenite, often in very large and beautiful
crystals. Fragments of Belemnites occur in this pit, and Ammonites are also
found, but I saw none sufficiently well preserved for identification. The clays
exposed in this pit probably belong to the middle portion of the Upper Lias,
which is generally very unfossiliferous.

In Keythorpe Park a pond, dug in the lower part of the Lias Clays, exhibited
the richly fossiliferous bands crowded with small Ammonites, &c., which
characterise that part of the series. I collected here—

Ammonites communis, Sow. (Very abundant.)
55 annulatus, Sow. (Very abundant.)
35 Holandrei, D’Orb.
35 radians, Rein. (Abundant.)
5 bifrons, Brug.

Belemnites compressus, Voltz.

Leda ovum, Sow., sp.

Inoceramus dubius, Sow.
&e. &e.

The brickyard opened on the opposite side of the road to Tugby Hall
exhibits the same beds, consisting of finely laminated, blue clays with a few
septaria. These clays when dug show a few small crystals of Selenite. The
beds are crowded with small fossils of the same species with those found at the
last noticed locality. : ;

At several points about the village of East Norton, and also at Finchley
Bridge, roadside cuttings and field-drains have exposed the fish and insect
beds with the usual fossils. Small bivalves, such as Inoceramus dubius, Sow.;
and Pectens with dwarfed Ammonites occur in some of the bands of flattened.
limestone nodules. ‘

An interesting pit at Aliexton exhibits the following sectiori of the lower

beds of the Upper Lias.
1. Soil - - - - - - - 1 ft.
2. Blue, laminated clay = - - - - 6 ft.
3. Irregular, stony band (“kale”) full of Ammonites serpen-
tinus, Rein., Belemnites, and other fossils - - lto2 ft,
4, Laminated clay = - - - - = - 6in.
5. First, irregular bed of hard, argillaceous limestone - - 6in.
6. Laminated clay - - - - - - 1 ft.
7. Second, irregular bed of hard, argillaceous limestone - Gin.
8. Laminated clay 3 s = - - 1 ft.
9. Third, or Best bed of limestone - - 3to 6 in.
10. Laminated clay = - - - - - 43 in.
1l. “Kale” - < < = e s - 6in,
12. Marlstone Rock-bed full of the usual fossils; 4 courses of

stone - - - - - together 2 ft.
84 GEOLOGY OF RUTLAND, &c.

In the cava large masses of wood, converted into jet, are found. These, after
being soaked in oil to prevent cracking, are used by the workmen and others
for whetting razors.
The three layers of limestone contain the usual fragments of fish, insects, and
crustaceans with the following shells :
Belemnites sp,
Ammonites serpentinus, Rein,

55 elegans, Sow.
35 annulatus, Sow.
i sp.

Small univalves.

Astrea, (small species),
Tnoceramus dubius, Sow.
Astarte sp.

Lima sp.

Pteroperna sp.

Other small bivalves.
Fragments of wood.

_ The limestone, which is hard and fissile, and of a blue colour weathering white,
occurring sometimes in continuous bands and at other times in nodules, is carried
to Tugby where it is burnt for lime. It is said to produce a hydraulic lime
fully equal in quality to the celebrated “ Barrow lime,’ which is made from the
fish and insect limestones of the Lower Lias series.

It is worthy of notice that the Serpentinus bed, which in many places is
ferruginous and has often, when attention has not been given to the fossils,
been mistaken for the Marlstone Rock-bed, is at Allexton, either not-at all, or
only very slightly coloured with oxide of iron.

+ Deepdale traces of the fish and insect limestones of the Upper Lias are
seen lying on the Marlstone. At several points about Lodington there are
small exposures in the road-cuttings of the same beds. On the road between
Tilton-on-the-Hill and Burrow-on-the-Hill, but near the former place, there
is good evidence of the existence of the fish and insect limestones immediately
above the Rock-bed of the Marlstone. The same beds are seen at the top of a
pit in the Marlstone at Pickwell. ;

At Uppingham there is a brickyard opened in the highest beds of the
Upper Lias clays, and here their junction with the Northampton Sand is well
seen. The same portion of the Upper Lias series is again exposed at the brick-
yard and in some roadside cuttings at Seaton. Here I collected—

Ammonites communis, Sow.

8 Holandrei, D’ Orb.

a bifrons, Brug.

39 serpentinus, Rein.
Belemnites compressus, Voliz.
Leda ovum, Sow, sp.,

&c. &e.

The tunnel at Morcott, on the Rugby and Stamford Branch of the London
and North-Western Railway, passed through the Upper Lias clays, and from
the spoil heaps about the air-shafts many of the characteristic Ammonites and
other shells may be collected. ‘ ote

In the railway-cuttings about Luffenham the Upper Lias clays are exhibited
at several points, and between that village and Pilton a brickyard has recently
been opened in the beds of the same formation.

At Manton, on the Leicester and Stamford branch of the Midland Railway,
the Upper Lias Clays were dug in the shafts, cuttings, and tunnel, and the
clays are now used for brickmaking. The tunnel passed through the clays at
about 100 feet below their junction with the Northampton Sand. The clays
here abound with masses of iron-pyrites. Ammonites bifrons, Brug, is abundant
here, and Am. elegans, Sow., rare.

At Manton Station a ditch-cutting exposes the “ Communis-beds,” lying
towards the lower part of the Upper Lias. They consist of blue clays with
small white septaria, the whole crowded with fossils, among which are the
following species,—

Ammonites communis, Sow. Very abundant.
a annulatus, Sow. y
» Holandrei, D’Ord.

Pey
THE UPPER LIAS. 85

Ammonites serpentinus, Rein. Rare.
Belemnites compressus, Voltz.

» SP.
Leda ovum, Sow., sp.
&e. &e.

South of Oakham on the road to Brook a small roadside cutting exposes
the Fish and Insect limestones and clays, lying on the Marlstone Rock-bed
end. covered by the Serpentinus beds, here consisting of a single layer of
nodules.

At Langham brickyard (see description, page 70), the Serpentinus beds are
present, and some bands of septaria below them seem to represent the Fish
and Insect beds, but the characteristic fossil remains of the latter were not
found at this place.

The railway-cuttings between Oakham and Ashwell pass through the Upper
Lias clays, and a slip in one of these exhibited, at the time. the district was
being surveyed, the beds crowded with small specimens of Ammonites com-
munis, Sow., &c.

The long valleys which run up into the great plateau formed by the Lower
Oolites, are often cut down to the Upper Lias, which is, however, seldom ex-
hibited in sections. Along the valley of the Gwash near Empingham, at
Wild’s Ford, where the Lias is thrown up by a fault, near Tickencote Lodge
and at Ingthorpe the clays of the Upper Lias are seen. In the tributary of
the Gwash which runs through Exton Park, the Upper Lias clays were well
exposed in making the reservoirs and ornamental water near the new Hall.

From Burley-on-the-Hill northwards the Upper Lias clays form the slopes of
a steep escarpment. They are exhibited at a number of points about Burley,
below Cottesmore and around Barrow and Market Overton, but do not in this
neighbourhood exhibit any features of special interest, nor are they exposed in
any deep sections.

Che banks of the Oakham and Melton Canal, between Teigh and Edmond-
thorpe, exhibit a number of good exposures of the bottom beds of the Upper
Lias resting on the Marlstone Rock-bed.

A little south of Edmonthorpe there is a very fine section in the Fish and
Insect beds. Here the limestones are very poorly developed, but the paper-
shales themselves, which are of considerable thickness, are crowded with
fragments of fish, insects, and crustaceans. At this place a very perfect
specimen of a fish is said to have been found during the cutting of the
Canal.

North of Wymondham and in the neighbourhood of the village, the Upper
Lias is completely covered and concealed by drift.

Inliers.—In the valleys of the Welland and Chater, the Upper
Lias clays, which, through the easterly dip, were lost at Barrowden
and Luffenham, reappear in consequence of the great faults which
run near Duddington and Ketton. The Upper Lias clays
here form the steep slopes below the Lower Oolites, but seldom
afford good sections. Their junction with the beds above is,
however, almost always marked by the outburst of numerous
springs.

At Collyweston Parks there are the remains of a number of reservoirs or fish-
ponds which have been dug in the clays and filled by such springs. At the
Collyweston Quarries some of the deeper wells have been sunk into the Upper
Lias clay to a considerable depth. At Stamford the Lias clay forms the bed of
the river; in a deep excavation made at the gus-works I found Ammonites bi-
frons, Brug., Belemnites compressus, Voltz., Leda ovum, Sow., &c. &c.

The same beds are met with in many wells in the southern part of the town of
Stamford, where the great Stamford and Helpstone fault has thrown the Upper
Lias clay to a much higher level. The Upper Lias clay’is dug at Lumby’s Terra
Cotta Works. A boring here is said to have passed through 140 feet of Upper
Lias, and to have been carried to a depth of 500 feet. Unfortunately, however,
I was unable to obtain any reliable information as to the nature and thicknesses
of the several beds passed through. This boring was undertaken in an attempt
86 GEOLOGY OF RUTLAND, &c.

to find coal. The ornamental water of Burleigh Park rests on the Upper Lias
clay, some small exposures of which may be seen in the neighbourhood. Its
junction with the overlying Inferior Oolite beds can be traced by means of
numerous springs in the Park.

The great Stamford and Helpstone Fault also brings up the Lias clay so that
it is exposed along the valley of the Wansford Brook. The best exposure
within the inlier thus formed, is at Thornhaugh, where a deep drain and well
showed thick beds of blue clay, the highest beds of the Upper Lias, containing
much selenite and many fossils. Among the latter were :—

Ammonites bifrons, Brug. Very abundant.
Belemnites compressus, Voltz.
Leda ovum, Sow., sp.

Arca, sp.
Myacites donaciformis, Phil.
5 &e. &e.

Near this place a well was sunk for upwards of 70 feet in the blue clay
without reaching the bottom.

Along the valley of the Nene the Upper Lias clay forms the bed of the river,
but it is very seldom that it is exposed, owing to the thick strata of gravel
and alluvium by which it is covered. Deep wells, however, reach it, and I
was able to detect it at a number of small openings between Wansford and
Fotheringhay, at Cotterstock, Oundle (where it was reached in a deep excava-
tion by the side of the railway), and at Wadenhoe near the Mill.

At Helpstone brickyard we have a very interesting exposure of the Upper
Lias Clay in a small inlier, which has been produced in consequence of the
removal by denudation of the upper part of a small anticlinal, into which the
beds are here bent. The beds consist of blue, pyritous clays with much
selenite, and are the highest of the series; they yield,—

Ammonites bifrons, Brug. Abundant.
55 serpentinus, Rein. Rare.

Belemnites compressus, Voltz.

Nucula ovum, Sow., sp.

Along the line of Harper’s Brook faults bring in the Upper Lias clays as
small inliers at Pipwell Abbey, Little Oakley, and Stanion. Although the
position and relations of the Upper Lias clays can be readily traced in these
inliers, there are no good sections in any of them, except the last mentioned.
At Stanion Mill some excavations gave a good exposure of thedark-blue,
pytitous clays of the Upper Lias, yielding abundantly Ammonites bifrons,
Brug., and Leda ovum, Sow., sp. *

The two small branches of the Willow Brook also expose, through the action,
of a fault, two inliers of Upper Lias, and in roadside cuttings, field-drains,
and wells, tolerably good sections of these have been obtained.

Lastly, in a small brook at Brigstock Parks where the beds are much
faulted, an inlier of Upper Lias clay of very small size is exposed.

Outliers. — At the hill south-west of Cranhoe, which was
formerly the site of the Staunton-Wyvill Windmill, we find the thin
and imperfect representative of the Marlstone Rock-bed, capped
by a mass of Upper Lias Clays. These are seen near the foun-
dations of the old mill, and in the ploughed fields numerous
fragments of the small specimens of Ammonites communis, Sow.,
may be picked up. oe

In the outlier which forms Slawston Hill, and which is just
capped by a vestige of the Northampton Sand, the highest beds
of the Upper Lias are seen on the slopes of the hill.

On the south side of the hill, where field-draining had lately been going on,
T found the surface of the ground literally covered with fragments of Am-
monites serpentinus, Rein., Ammonites bifrons, Brug., Am. falcifer, Sow., and
Belemnites compressus, Voltz., also occur. Below, fragments of “the fish and
insect limestone’ abound. For the sucoession of beds here see the section given:
THE UPPER LIAS. 87

on page 77. Near the same place I found some beautiful exposures of the
“Fish and Insect Limestones,” with the usual lithological characters and
organic remains. ‘They are interstratified with the ordinary paper-shales, and,
as usual, are immediately covered by beds crowded with Ammonites serpentinus,
Rein. In the neighbourhood the “Serpentinus-Beds”’ are markedly ferru-
ginous, and, unless due attention is paid to the fossils, they may be easily
confounded with the Marlstone Rock-bed. On the east of Slawston Hill by
the road leading to Medbourn we have the following section :—

(1.) Clay.

(2.) Ferruginous bands. Serpentinus beds with usual characters, but

no fossils were found here.
(3.) Fish and Insect Limestones and Shales.
(4.) Marlstone Rock-bed (imperfectly seen).

At the north-west of Slawston Hill on the road to Cranhoe the ferru-
ginous, rocky bands occur crowded with Ammonites serpentinus, Rein, and its
allies, and resting on the shales containing the “ fish and insect limestonenodules.”
Field-drains in the neighbourhood afforded some beautiful exposures of the
same beds, and a considerable number of fossils.

At Great Bowden and Market Harborough there are two small outliers of
Upper Lias. The only important sections here are in the Market Harborough
brickyard, opposite to the railway station, and in the adjoining railway-cutting.
Here we have the following section,—

1. Soil - - - - - - 1 ft.
2. Boulder Clay - - - - - - 2to3 ft.
3. Upper Lias Clay with Ammonites communis, Sow., and
Belemnites compressus, Voltz. It consists of laminated,
blue clay weathering to a yellow colour - 1 to 4 ft. seen in the pit.
(" 4. Hard, brown, ferruginous band of impure ironstone - 9 in.

z 5. Softer and more sandy bed completely full of,—

A. Ammonites serpentinus, Rein.

B's $5 bifrons, Brug.

aS _ communis, Sow.

a 2 33 Holandrei, D’Orb.

: Belemnites compressus, Voltz.; and other shells - 9 in.

(6. Hard, very ferruginous bed - ” - - 38to6 in.

7. Light-blue, laminated clays = - - - - 3to4 ft.
8. A thin vein of sandstone (very inconstant) - - about 1 ft.
9, Light-blue, laminated clays - - ~ - 6 ft.

10. Marlstone Rock-bed.
For remainder of this section, see p. 76.

At the Market Harborough brickyard, the “Fish and Insect Limestones ”’
were not detected. In the cutting just north of Market Harborough station
the Serpentinus beds are again well exposed, and are seen to be crowded with
the usual fossils.

At Barleythorpe, near Oakham, there is a vestige of the Upper Lias Clay
which has escaped denudation, and is seen lying on the top of the Marlstone
Rock-bed. The section at a stone-pit here is as follows :—

(1.) Soil. /
(2.) Blue clay - - - - - - 3 feet.
(3.) Bed of white, very fissile, limestone with many com-

pressed shells, and some obscure markings, which

may be the remains of fish (and insects P) - 9 inches.
(4.) Very finely laminated, whitish, shaley beds, with

masses of jet and many hard, flattened septaria,

which give forth a fetid odour under the

hammer - - - - - - 38 feet.
(5.) Dark-blue, laminated, ochraceous shales with jet - 2 feet.
(6.) Marlstone Rock-bed, with the usual rounded con-

cretions and fossils,

The limits of this small outlier are somewhat uncertain, and it may be stated
generally that the boundary between the Upper and Middle Lias is a very
difficult one to trace, and over a large part of the area it has in consequence
been represented on the map by a broken line.
88 GEOLOGY OF RUTLAND, &c.

In concluding the description of the Lias strata in this area,
it may be convenient to exhibit its subdivisions in a tabular form,
and to show their correlation, as nearly as this can be made out,
with the several paleontological zones, as defined by geologists in
England, France, and Germany respectively. These latter are
based on the study of more complete sections, yielding finer
series of fossils, than can be obtained in the drift-covered areas
of the English Midland counties. It must be remembered, how-
ever, that the correlation suggested is approximative only; that
in every fresh district examined, new groups of beds appear, more
or less completely filling up the gaps, which their absence had
caused in earlier studied series; and that, as these breaks con-
stitute the limits of divisions necessarily adopted by geologists,
in their classification of the strata of a district, the boundaries
between the several groups of strata become continually less
sharply defined, us the formations are traced over more extended
areas.

The following table exhibits the several series of Liassic beds
described in this Memoir; their position in the paleontological
scale being shown by reference both to the divisions first sug-
gested by Quenstedt in his “ Flotzgebirge Wiirtemburgs ” in 1843,
and also to the more modern classification by Ammonite Zones,
adopted by Jater authors, such as Oppel, Hébert, and Wright.
89

 

THE UPPER LIAS.

 

 

*(spissoy Auwut) spureq otog TFTA ‘gopeqs snoyakd ATSIY “HORT = = B410JUOO BMITAY jo ou0Z, *(qaed 7
“spoq, aTIssy FByAoUos ‘snoswoyeo “ApuBy “selT OWTLAA OTL} JO oalyequesaider UrGL > 5 = do “(oreeyY) UpTened ur) gSeleguy | - grade yy
*(s[Issoy snoremmu) : >
SO[VYS PoPVULUAB] YYLA Fayer109[e §. 82188 ULBYSUIG,,) — «« SIUOPSOUWYT JOOSUT PUD UST », "B . - SIqaourld ‘ury JO oll0Z ,
*(S[ISSOJ SNOLOMINT) SOTBYS ULM SuIyeUI;[S ‘quoysomny ‘Ay[OUS SOTATJOMIOS “POUTVId OSTBOD “A
“goquicd Sq pazipedourur sayyuoULULY Sururezu00 ‘supa snoqlidd ‘onig-yrep Jospeg "9 |- = - snyepnsue “ury Jo ou07, D seryT
“STLOYS 10440 TILs Woy} YSNoIYy Po1o44Bos aaydhtpy snoreumnu yy ‘Kepo onyq Jospeg “P|- ~ baile ay “Try jo ou0Z |
*(jeddO Jo snoLyout
*(spissog Aeon) £BTO YALA ZUyeUE}[e OMOYSaTAL] SHOMLANIIeJ JO spog “9 -003 “Y) snyeysoormes ‘UTY JO OU, J = SBI JOAO'T |
(‘posodxe
Tes exoyaon ore Loyy ystxo Loy Ft “JOLUSTP OU} UT amosqo s10A OLB UOZILOT SI} 48 Speq ou,L) - = = (snsnqqo ‘ary Jo eu0Z) } g sery | b= sery 1eM0'T
“etreydes UMOIG F4ST [[euIs pue soqaid youu y4tM Avy onyq Jo sped 3 -  - = snjoufxo ‘uly Jo eu07, |
*(spissoy AueUt) et1048 OFA! poywINpUy ATYBUOTSBIIO SPUBS YALA § ve a 3i]- + = snjzeunte ‘uy jo on07
jo dn opem ysomye omoyseuny Jo spadq DIg UqLA ‘apeqs snoyiisd ‘poyeutmeyl ‘on[q-FqsrT “W }. = TOSOMIBP ‘IY JO 9u0Z, A sevy
“STISSOJ UILA PEPAO.1O SOUIIZOUIOS “OUOISOTATT ATIOUS JO Spueq YILA SABI “YL as
*(sTIssoy) pues SNOSdE|[IZ1e PoyeINpul JO spULq UIT} ULOS pur ‘eteydas qt shBIN “T]- 7 (a) Xoqt‘ury jo ou0Z
*(qyUwpange s]Issoj) eiteydos Anew pus sopiddd TORU YpTAA ‘sXepo oniq-yaeq "wk |} -” SNULOOLIdeo ‘AY JO ou0Z, ee "
LE TAL
*(STISSOJ JO S]sBO oun 9eu0}SuOsT Jee pue Se dein eee = | 1
*(quepunge £104 S[Isso}) BLreydos oSrey HAL ‘sAepoO snosdworal AT ary “ony ‘ 9 3 .
a ciyeunes aneep) ai ‘pal @ 04 SULIoTywom wiIeydes Yq ‘Aupo our °O SNyEIVaTEUT “UY JO AtoZ, gswr J: is [ SBrT OIPPIAL
“pues Jo spoq [euoIseos0 pur ‘s[reg euoysuOI Jo spued WIA ‘sep onjq-yqSvT “Pp ; * y
“STISSOS Krew UTA ouoysouny Apuss SNOUL QTc PUOPSIMOA 42 fO P2Q-YOON ML », “® | ~ . snyeulds ‘Uy JO eu07, J
: (,cBeLlos WOJeTAUINE,,) .SauopsaulyT FOISUT pup yser yn git ene » B i
TWOTAUTY) MOUIFnA19} SeUMIZEUOS ‘oNOySaATT JO seTMpOU YA ShelQ SPIT snunguadsag ,, "A |v. - stam . > sur 7 :
we Te80y sth fegeaair gatureyuco spueq WIL SABO ont “‘poyeulaey SPIT svunméMo, e 0 r pr eae : M sery saddg
, *(spissop 0g) SooeTd Ur gol Youu yA ‘sMelo snoyad ATG STH “PD | -suvgaeddg |J
*(spissoy Aueut) eLreydes Jo spueq snoremMu YyLs Shel. Speg wnno-ppeT ,, “2 . .
*(44aed JaMOT)) PURg TO,duTGy 1.10 NT - - sisuain{ ‘ury go ouog | 3 ser 8
. [9RESTOND | a7 ‘
. 9 BYE *sauog, aytuoun IYBOHISSBI) | “UOLYVOTTSSBID
TOMO PL OY} Ul PoqtLosep JOLA4sIC, OY} Ut POPS BPRS Z a4 wy eee a ace [einaurjW0D asnsugy

 

 

 

 

 

“LOLULSIC, oY} Ul SVI'T 94} JO SAG SNOLeA oy} JO N

OLLVITUAOD Uf} FVTYSNITI 0} TIAV,],

t
é

 
90 GEOLOGY OF RUTLAND, &c.

CHAPTER V.

THE LOWER OOLITES.

Tue strata of this age present, in the district under consi-
deration, a somewhat novel and peculiar type. The relation of
the several groups into which they are classified, with the for-
mations of the same age either of the Yorkshire series or that
of the Cotteswold Hills, are by no means obvious. As great
diversity of opinion has existed on these questions of classification
and correlation, and as it is necessary to go into some details
concerning districts outside the limits of this sheet, in order to
explain the grounds on which the grouping of strata, adopted in
the maps of the Geological Survey, has been arrived at, it has
been considered advisable to devote to the discussion of these
more purely theoretical questions the introductory essay which
is prefixed to this memoir.

The strata of the Lower Oolites in the area embraced within
Sheet 64 fall naturally into two very distinct groups, the lower of
which is equivalent to the older part of the Inferior Oolite, while
the upper appears to represent the whole of the Great Oolite.
The lower of these series appears to have been to a certain extent
disturbed and denuded, before the deposition of the latter which
lies unconformably upon it. The evidence on this subject has
been fully considered in the introductory portion of this memoir.

The Inferior Oolite formation consists of two members, the
lower of which is mainly arenaceous and is known as the “ North-
ampton Sand,” while the upper is almost purely calcareous and
is distinguished by the name of the “ Lincolnshire Oolite Lime-
stone.” These two divisions, however, frequently pass into one
another by insensible gradations ; and occasionally, at their junc-
tion, beds of fissile sandy limestone occur, which constitute the
* Collyweston Slate.” Like other similar ‘‘slates ” these are very
local in their mode of occurrence. The Great Oolite strata are
divisible into four groups (the highest of which is the well
characterised Cornbrash), which have been separately mapped in
Sheet 64. A series of clays apparently representing the Forest
Marble of the south of England underlies the Cornbrash and
reposes on the white, shelly, argillaceous limestones of the Great
Oolite, which are scarcely ever oolitic in structure. The last-
mentioned strata in turn rest on a variable set of beds, some of
which contain shells of marine, others of freshwater species, while
thin bands of lignite and vertical plant remains indicate the former
presence of old land surfaces. ‘These beds, which we have called
the “ Upper Estuarine Series,” appear to represent the “ Stonesfield
Slate” or Lower Zone of the Great Oolite of the South of England.

TuE NorgtHAMPTON SAND WITH THE LowER ESTUARINE
; ~ SERIEs.

These beds constitute the base of the Inferior Oolite in this dis-
trict, and are often seen lying upon an eroded surface of the Upper
Lias Clay. In their mineralogical composition they are extremely
variable, but almost everywhere arenaceous characters prevail in
THE LOWER OOLITES. 91

them. Sometimes they are almost wholly made up of beds of white,
or but slightly ferruginous, sands, with occasional thin seams of clay;
but usually more or less of their lower portion is converted into
arich ironstone rock. This ironstone, when not altered by the
percolation of atmospheric water, is a hard, compact rock of a
blue or green colour, composed of carbonate and silicate of iron,
and usually made up, as is shown when sections of it are examined
under the microscope, of rounded grains with an oolitic structure.
In this form, however, the ironstone is seen only when it is dug
in deep wells, under a considerable thickness of clays. As it more
commonly occurs near the surface, it presents very different
characters, consisting of a brown, by no means compact, rock usually
with a very remarkable “cellular” structure. This structure is
due to the chemical action set up in the mass by the atmospheric
waters, which, penetrating from the joint and bedding planes, have
caused the concentration of hydrated peroxide of iron along surfaces
having a general parallelism with those planes. The hard bands are
often concentrically arranged. Frequently the change by weather-
ing from blue and green carbonate and silicate to brown hematite
has only partially taken place, and the centres of the blocks
consist of the former while their outer portions are constituted by
the latter, displaying the usual hard bands. The brown ore, when
examined microscopically, is often seen to retain the same oolitic
structure which is found in the unweathered rock.

In places, the rock of the Northampton Sand contains a con-
siderable proportion of calcareous matter, and it is then extensively
used as a building material and even for lime-burning ; beds of
this character, however, are not so frequently seen in this district
as in that to the south-west. Examples occur at Desbro’ and
near Uppingham.

The thickness of the Northampton Sand is very variable; in
the area to which this memoir specially refers, it probably never
exceeds 40 feet, while it is frequently reduced to very insigni-
ficant proportions, and sometimes, as about Luffenham, almost
entirely disappears.

The Northampton Sand is usually very barren of fossils; at
certain points, however, very fossiliferous bands have been found
which have yielded a very rich fauna. In the lower ironstone
beds the fossils are all marine. Cephalopods are far less rare
than in the overlying limestone, the various varieties of Ammonites
Murchisone, Sow., Belemnites giganteus, Schloth, and a gigantic
Nautilus being the prevailing forms. Among the other very
abundant fossils we may mention Astarte elegans, Sow., Lucina
Wrightii, Opp., Ceromya Bajociuna, D’Orb., Pholadomya fidicula,
Sow., Isocardia cordata, Buckm., and Pecten personatus, Goldf.,
with the Echinoderms Galeropygus agariciformis, Forbes sp., and
Pygaster semisulcatus, Phil. sp.* The study of this fauna enables
us to refer these marine beds at the base of the Northampton
Sand, without doubt, to the lower part of the Inferior Oolite. In

 

* Very beautiful series of the interesting fossils of the Northampton Sand have
been collected at Duston, near Northampton, and at other points by Mr. Samuel
Sharp, F.S.A., F.G.S., &e. Vide Quart. Journ. Geol. Soc., vol. XXVL, p. 382.
92 GEOLOGY OF RUTLAND, &C.

the lowest part of the Northampton Sand Rhychonella cynocephala,
Rich., and some closely allied forms .occur; and in a band full
of pebbles or concretions (like those of the Marlstone Rock-bed)
which is frequently seen quite at its base, specimens of Ammonites
bifrons, Brug., have been found at several localities; but a
number of circumstances seem to point to the conclusion that this
Ammonite was derived from the Upper Lias Clays below. As
yet we have no conclusive evidence that any part of the North-
ampton Sand represents the ‘‘ Midford Sand” of the south of
England and Yorkshire.

The upper part of the Northampton Sand contains beds of
white sand with plant remains, sometimes vertical, also thin seams
of lignite and miniature “ underclays”; very occasionally thin
seams containing Cyrena occur in this part of the series. These
highest beds of the Northampton Sand, which are well exposed
about Helpstone, Ufford, Edith Weston, &c., were, like those
above the Lincolnshire Oolite which we shall presently describe,
evidently deposited under Estuarine conditions; we have therefore
called them the “ Lower Estuarine Series.” :

When we study the equivalents of the Northampton Sand in
the eastern Moorlands of Yorkshire, we find the upper or estuarine
portion attaining to a great thickness and simulating in its general
characters the strata of the coal-measures. ‘These beds are known
as the ‘* Lower. Sandstone, Shale and Coal of Yorkshire.” The
lower or marine portion of thé series, however, retains in York-
shire its more moderate dimensions; the representative of the
“ Midford Sand” or “ Upper Lias” sands being more distinctly
developed. The marine beds at the base of the Inferior Oolite in
Yorkshire are called the “ Dogger,” and at Rosedale yield an
ironstone, almost identical in character with that of the Northamp-
ton Sand.

Southward and eastward, owing to the thinning out of the
Lincolnshire Oolite Limestone, the Upper and Lower Estuarine
series are brought into contact, the former graduating in Oxford-
shire into the Stonesfield Slate, and the latter into the Lower
Freestones of the Inferior Oolite. :

The ironstone rock of the Northampton Sand often yields from
30 to 50 per cent. of metallic iron ; but its highly siliceous charac-
ter causes it to be of more value when used in admixture with
other ores than when smelted alone. This ore is now (1869) very
extensively worked at many places in Northamptonshire ; the only
points within the limit of Sheet 64 are about Desborough and
Rushton; some years ago this ore was raised at Neville-Holt and

_ the erection of blast-furnaces commenced, but these works are now
abandoned.

The ferruginous or calcareous rock of the lower part of the
Northampton Sand is locally largely used for building purposes,
but it does not usually possess much durability. The white sands
in the upper part of the series are extensively dug at many points
for making mortar; certain of the beds of clay in the same part
of the series are used for brick-making, as at Cottingham and
Deene; while at Stamford-Baron one such bed is used for the

manufacture of terra-cotta.
“WYIHSNOLINVHIMON |i

aie

OQ

ILYHO VIN ‘SHLTIO

sea ea

 

JEMOT FHL JO INENGUVOSH DVO FHL JO META

 
THE LOWER OOLITES. 93

The beds of the Northampton Sand constitute a rather light
soil, and where, as is usually the case, they are ferruginous this is
ofa redcolour. This soil is a very rich one, especially adapted for
the growth of spring-crops.

Outer Escarpment of the Northampton Sand.

The ironstones and superimposed sands and clays of the Lower
Estuarine Series, capping the Upper Lias Clay, forms a bold
escarpment, which in the southern half of the area included within
Sheet 64, has a general direction from south-west to north-east,
namely, from Desborough to the valley of the Welland; but in
the northern half of the area the bearing of this escarpment
changes to due north, which direction it maintains through the
whole of Lincolnshire and South Yorkshire. Thus we have within
the area the commencement of the remarkable feature known as
“the Cliff” of Lincolnshire, a bold escarpment facing the west and
running in an almost straight line for about 90 miles. Along the
top of this escarpment for a great part of its length runs the
celebrated Roman road known as the “ Ermine Street.” The
escarpment of the ‘ Lincolnshire Cliff” is breached by valleys
at two points only, namely, those forming the site of the towns of
Grantham and Lincoln; the same river, the Witham, which rises
in the oolitic plateau first cutting its way westward through a
gap in the escarpment at Grantham into the Liassic Valley, and
then back again through the still more'striking gorge in which the
city of Lincoln is built, away to the Wash. The Upper Lias
continually diminishing in thickness as we go northwards, the
“Cliff” of Lincolnshire gradually decreases in height, until in
South Yorkshire, though still recognisable, it becomes quite in-
conspicuous. (Plate VI.)

As the Upper Lias Clay is, in the district under consideration,
about 200 feet thick, the escarpment of the Northampton Sand
makes a well marked feature, and in that portion of the area
where the River Welland runs at its foot, namely between
Rockingham and Harringworth, it presents very bold characters.

At the extreme southern part of the area a branch of the River Ise, a
tributary of the Nene, cuts out the long valley in which are situated the villages
of Desborough, Rushton, Newton, and Geddington.

At Geddington the ironstone forming the base of the Northampton Sand is
seen in some small openings, and was well exposed at the time of the survey in
the foundation of some houses. Copious springs arise at the line of its
junction with the Upper Lias, and over one of these the beautiful Eleanor
Cross, which forms such a striking ornament to this village, is erected. At
several other points in the neighbourhood of Geddington, the sands and clays
forming the Lower Estuarine series can be traced.

At Rushton Station on the Midland Railway, the light-coloured, carbonaceous
clays and sands of the Lower Estuarine series attain a considerable develop-

ment, and are seen covered by the Lincolnshire Oolite Limestone. . The section
at this place is as follows :—
1. Rubbly, slightly oolitic rock (Lincolnshire Oolite Limestone).
2. oe sandy limestone, 1 ft. (Representative of the Collyweston
Slate). ..
3. Brown sand, becoming nearly white below, 2 ft. 6 in. ae Estuarine
4. Brown, ferruginous sand, 1 ft. Series.

32108. G
94 GEOLOGY OF RUTLAND, &c.

5. Light-bluish, sandy clay, with carbonaceous markings
and ferruginous nodules, 9 in.

6. Similar clay of much darker colour, 2 ft. (Lower

7. Light-coloured, indurated, argillaceous sands, passing Pemioeine

into sandy clay, with carbonaceous markings, 4 to Series—cont.)

f 5 ft. seen.

The deep valley at Rushton cuts quite down into the Upper Lias, and many
good exposures of the ironstones of the Northampton Sand are seen along its
sides. To the south of Rushton the very deep Glendon cutting on the Midland
Railway exposes a fine section of the ironstone beds, covered by the Lower
Estuarine sands and clays. Here the ironstone is largely worked by the
Glendon Iron Company, but these sections are just beyond the limits of
Sheet 64, and have been described by Mr. Sharp.*

At Desborough the ironstoncs and overlying sands and clays are well
exposed in a deep railway-cutting near the station, where they are covered by
Boulder Cla , and also in the numerous large pits at which the iron-ore is very
extensively dug for the purpose of being sent away by rail into Staffordshire,
Derbyshire, and Yorkshire. Near this place we have an interesting example of
the development of calcareous beds in the midst of the Northampton Sand,
perhaps the best within the limits of the area now under description. These
calcareous beds form a band of hard, blue, ferruginous and very shelly limestone
in the midst of the ironstone beds; this ferrugino-calcareous rock is dug for
road-metal. In the country to the southwards, however, the Northampton Sand
often locally assumes calcareous characters, and passes, sometimes throughout
the greater part of its thickness, into an impure limestone of oolitic structure.
Such limestones in the Northampton Sand are very extensively developed to the
north of the town of Northampton, and as shown by Mr. Sharp, include at one
point a bed of fissile rock, once quarried for roofing purposes, and known as
the Duston Slate. These limestones of the Northampton Sand usually contain
much siliceous matter; they are quarried for building purposes, and in one
place, namely, near Draughton, were formerly even burnt for lime. At
several points within the limits of Sheet 64 calcareous bands occur, and their
position is indicated upon the map by the sign CALC. The development
of thick-bedded, oolitic limestones in the midst of the Northampton Sand
appears, however, to be confined to the area to the south, and we find such
beds both in the northern and the southern portions of the county of
Northampton.

The iron-ore which is dug about Desborough forms the upper 6 feet of the
ironstone beds of the Northampton Sand, the lower portions not being found
rich enough to pay for working. The upper 12 inches consist almost wholly
of the hard, dark-brown fragments of the septa, forming the characteristic
cellular structure, which by the removal through meteoric causes of their sandy
admixture are separated from impurities and constitute an ore of greater
richness than the rest of the deposit; this is known to the workmen as “ curley.”’

Between Desborough and Stoke Albany the Northampton Sand stretches
westwards in two spurs, which are, however, obscured by tliick masses of
Boulder Clay; hence we find along these spurs but few sections, and the
boundaries of the hard beds which cap them are very obscure. ;

The ironstones and overlying clays and sands of the Lower Estuarine Series
can be traced a& many points in the vicinity of Stoke Albany, Wilbarston, and
East Carlton, but they present no good sections or features of special interest.
Here, as at almost all points of their outcrop, we find evidence, in heaps of old
slags, of the extensive working of these beds in former times. At Cottingham
we have a series of interesting sections illustrating the junction of the Lincoln-
shire Oolite and the Northampton Sand. Ina great pit in the Inferior Oolite
we see a section of about 20 feet of that rock, which in its lower part contains
numerous plant remains (Polypodites Lindleyi, Gépp. sp.), Wood, &c., and in
other pits we find the series continued in descending order.

1. Calcareous sands.
2. White clay.
3. Ironstone rock (very thin).

* The Oolites of Northamptonshire, Part II.— Quart. Journ. Geol. Soc. vol. xxix.
pp. 231-282.
THE LOWER OOLITES. 95

Pit in the Lower Oolites, below Cottingham Church.

(1.) ee brown, sandy beds at the bottom of the
incolnshire Oolite (representative of the
Collyweston Slate) - - " s - 2to 3 feet,

(2.) Dark bluish-black marl full of plant remains - 4 inches.
(3.) Marl of lighter bluish-black colour with plant
remains running through it (“‘ plant-bed”’)- 3 feet.
(4.) Whitish and drab, laminated sands - - 2 feet 6 inches,
(5.) Dark-blue clay - - - - 3 feet.
(6.) White sand - - - - - 2 feet.
(7.) Ironstone - - - 6 feet to 8 feet.
(8.) Hard, red rock with greenish centres (rock used
for building)- - - - - 20 feet seen.
In a pit still lower down we find—
(1.) Whitish sands and clays - - - 6 to 8 feet.
(2.) Light-blue marl with plants - - 1 foot.
(3.) Light-coloured sands and clays, becoming
ferruginous at their base - - 8 feet.

Ironstone beds and red rock below.

At Cottingham brickyard the beds of the Lower Estuarine Series are dug for
brickmaking. The sections exposed show that at this place the Northampton
Sand, which is so variable a formation, both in thickness and mineral cha-
racters, has acquired considerable importance, both of its members being well
represented. ‘The Lower Estuarine sands and clays attain a thickness of at
least 20 feet, the beds exhibiting great variations within very short distances ;
the ferruginous rock is probably nearly 30 feet thick in places, its higher
portions, as is usual in this immediate neighbourhood, affording the richest
iron-ore.

The Northampton Sand is seen at a number of points along the small valleys
which traverse Rockingham Park, and also in the deep cuttings in the sides of
the great road passing through Kettering and Uppingham, above the village of
Rockingham. :

At a new farm beside Long Mantle Wood a deep well exhibited an interest-
ing section in 1867.

(1.) Boulder Clay - - .

(2.) Whitish and light-blue sands and sandy clays,
(Lower Estuarine series) - -

(3.) Hard, blue, green, or grey, ferruginous, sandy
and pseudo-oolitic rock. Not dug to bottom,
for at 10 feet down in it a powerful spring
was found.

It may be necessary here to call attention to the fact that whenever the iron-
stone of the Northampton Sand is dug under a considerable covering of
Boulder or other clays, which have prevented atmospheric action upon it, its
normal character of a dark brown cellular rock is never exhibited, but, on the
contrary, it is always compact or oolitic in structure, and blue, grey, or green
in colour. ;

Between Rockingham and Gretton numerous exposures of the ironstone
beds occur in the frequently slipped masses along the steep escarpment. Ata
few points the beds of white sand or of whitish, sandy clay, with numerous
plant remains, which overlie that rock, are also seen. At Gretton the Lower
Estuarine beds were well exposed in an artificial opening; and, between that
village and Harringworth, we have many exposures of the ironstone beds, while
we can everywhere trace their junction with the Upper Lias by means of the
numerous springs. . :

Following the Northampton Sand eastward into the valley of the Welland, it
is found to diminish rapidly in thickness. At the bridge between Barrowden
and Wakerley, it is seen lying upon the Upper Lias, and is apparently, at this
place, not more than two or three feet thick. In the same diminished form the
Northampton Sand was seen in the foundations of a house at the village of
Wakerley, but as we go eastwards all trace of it is lost, and the Lincolnshire
Oolite appears to rest directly upon the Upper Lias Clay.

a 2

12 feet.
96: GEOLOGY OF RUTLAND, &c.

Along the spur which runs out to Morcot, the ironstone beds can be traced,
but are of no great thickness; near this village they are overlaid by beds of
white sand, dug for building purposes. On the opposite side of the valley to
Morcot, we find the usual white and light-blue clays overlying the ferruginous
sands. As we pass into the valley of the Chater, the Northampton Sand is
again found to become rapidly attenuated, and its beds almost or quite
disappear to the eastward, in the same manner as they do in the valley of the
Welland.

At Luffenham Railway Station the Northampton Sand was found, in an
excavation, to be very thin ; within a space of ten feet we pass from the Lincoln-
shire Limestone into the Upper Lias Clay, the white sands, clays, and ironstone
rock being present, but reduced to insignificant proportions. In the South
Luffenham railway-cutting the ferruginous rock of the Northampton Sand is
seen, but is not more than three or four feet in thickness. The white sands
are seen underlying the representative of the Collyweston Slate in North
Luffenham churchyard when new graves are opened there.

At Edith Weston the white sands forming the higher part of the North-.
ampton Sand’are well seen, and have frequently been dug for mortar at several
different points within the lordship. Between the last named village and
Martinsthorpe, the Inferior Oolite beds stretch westward in a long spur, along
the sides of which the Northampton Sand can be seen at several points. The
exact boundaries of the strata on this spur are greatly obscured, however, by.
the thick masses of Boulder Clay and Gravel which cover it. The causes
which have*brought about the variation of the outcrop of the beds from their
normal direction in this place are easily discovered in the series of faults, which.
traverse the Martinsthorpe spur and the neighbouring outliers of Wing and
Pilton, Lyndon, Hambleton, Normanton, and Whitwell; these faults will be
further alluded to hereafter.

A great bréach is effected in the escarpment by the river Gwash. The fer-
ruginous beds of the Northampton Sand are exposed in the steep river-banks at
the village of Empingham, but the series does not appear to attain to any
great thickness at this place. The tributary brooks which flow by the villages
of Greetham and Exton have cut deep, gorge-like valleys quite through the
Inferior Oolite limestones and sands, down to the Upper Lias. Clay. At Horne
Mill the beds of light-blue clay of the Lower Estuarine Series are seen
lying upon the ironstone beds of the Northampton Sand. At Exton a
number of interesting sections in the Inferior Oolite were exposed during the
works about the New Hall; one of these behind the new memorial chapel was
as follows :—

ft. in.
(1.) Soil - - : SS - + 20
(2.) Light-blue, laminated, sandy clay, with ferruginous
stains in the bedding planes, and traces of plant .
. remains - - - : - - 14
(3.) Fawn-coloured and ferruginous sands, finely lami-
nated, with one or two argillaceous bands, each
overlaid by a lamina of hard brown hydrated
eroxide of iron - - - BO us
(4,) Light-coloured, finely stratified, sandy clay, occasion-
ally passing into sand and then becoming very
ferruginous - 7 7 = - 3 0
5.) Ordinary cellular ironstone-rock - - - 2 0 seen.

Farther back behind the Hall the beds are again dug, and this pit showed
that the highest stratum in the foregoing section is covered by 2 feet of light
brown sand, and this again by beds of hard sandy fissile stone, the base of the
Lincolnshire Oolite, and the representative of the Collyweston Slate. A well
in the kitchen of the Hall showed the thickness of the ferruginous rock a
to be 11 feet, the Upper Lias Clay being reached at its base. The generalise
gection at Exton is therefore as follows :— —

(1.) Representative of the Collyweston Slate -
(2.) Lower Estuarine sands and clays - - 9 0
(3.) Ironstone rock of the Northampton Sand - 110
(4.) Upper Lias Clay - - - - top only seen.
THE LOWER OOLITRHS. 97

As illustrating, however, the great variations in thickness and
mineral character to which the strata of the Northampton Sand
are liable, we may notice a section seen in the small lateral valley,
north of the boat-houses in Exton Park.

This section is described in detail, as it’ presents some features which have
a very important bearing with reference to the mode of formation of the
deposit. It is as follows :—

_ (1.) Oolitic limestone, with hard, flaggy, siliceous beds at the base; the
latter is the equivalent of the Collyweston Slate.

(2.) Bed of light-blue, tenaceous clay about 1 foot thick.

(3.) Beds of light-coloured sand, with ferruginous stains in the lines of
bedding and interstratified with thin seams of clay and lamine of hard, dark
brown ironstone, about 2 feet thick.

(4.) Beds of ironstone of the usual cellular structure, characteristic of the
Northamptonshire iron-ore. These attain a considerable thickness.

(5.) Upper Lias Clay.

The stratum (3.) presents some interesting characters. The interbedded
lamine of ironstone, which are dense and brittle, and in every respect similar
to the harder portion of the iron-ore below, vary in thickness from 34 to 3 of
aninch. On careful examination it is seen that each of these lamine rests on
a seam of clay, and is covered by a layer of sand of greater or less thickness.
Similar sections are seen in other pits in the immediate neighbourhood ; but
this, though a very curious and suggestive, is by no means a common _ aspect
of the Northampton Sand. It finds a curious parallel in parts of the Bagshot
Sand series of the Lower Tertiaries.

Between Oak Inn Farm and Greetham Mill, the junction of the North-
ampton Sand and the Upper Lias is well seen. There is here exposed a good
section. of the ferruginous sands, very copious springs flowing out at their base.
As a general rule, however, along these narrow valleys the sands and clays are
altogether concealed by the masses of the Lincolnshire limestone which have
almost everywhere slipped over them.

At Whitwell we find the flaggy beds at the base of the Lincolnshire lime-
stone underlaid by white sands. At this place a small east and west fault,
approximately parallel to that which traverses the Hambleton outlier, brings
down the beds of the Northampton Sand to the south, giving rise to a small
outlier. In a deep road-cutting near Whitwell we have an admirable exposure
of the succession of beds at this place, though their exact thicknesses cannot
be measured. The series is as follows :-—

(1.) Oolitic limestone (Lincolnshire Oolite).

(2.) White siliceous limestone with mammillated surfaces (equivalent of
Cont we Slate). ‘ 4

3.) White and fawn coloured sands . . .

(4.) Light blue clays. } Lower Estuarine Series.

(5.) Ironstone beds of the Northampton Sand.

(6.) Upper Lias Clay. ;

At Burley Park the Northampton Sand beds form a very steep escarpment
above the Upper Lias Clay, the numerous landslips having given rise to a very
sinuous boundary line between the two formations. This line can be easily
traced by the numerous springs, which flow out along the junctions of the
pervious with the impervious beds; several of these are utilized for the sup-
ply of the reservoirs in the park. There are many small openings in the
Northampton Sand, which present the usual characters; at one or two points
thin beds of whitish clay are seen intercalated in the ironstone series. From
Burley northwards, to the extreme limit in this direction of the area under de-
scription, the Lincolnshire Oolite does not reach the edge of the escarpment, the
sands forming a tract about a mile wide at the top of the ridge on which stand
the villages of Cottesmore and Market Overton. The junction of the limestone
and sands of the Inferior Oolite in this part of the district is often greatly
obscured by drift; the boundary between the latter and the subjacent Upper
Lias Clay is, however, very distinct and easily traceable until we get to Wymond-

ham, where the great Boulder Clay sheet overlaps the edge of the escarpment
on to the Lias plateau below. Below Cottesmore, at Barrow, and under Market
Overton, numerous small sections of the ironstone rock and of the overlying
Estuarine sands and clays can be seen, but they afford only a repetition of the
98 GEOLOGY OF RUTLAND, &C.

characters so fully described at Hany Bans to the south. The escarpment
along this line, from Burley-on-the-hill to Market Overton, is nearly as bold

and striking in appearance as that between Rockingham and Harringworth.

Valley of the Nene and its tributaries.—Along the Nene Valley
we find the Lower Oolites, which are here comparatively thin, cut
through completely, so that the beds of the streams are in the
Upper Lias Clay. In this part of the district the Northampton
Sand, which is itself often very thin, constitutes the only repre-
sentative of the Inferior Oolite ; the Lincolnshire Oolite, as already
explained having quite thinned out and disappeared, so that the
structure of this part of the country is precisely similar to that of
the district south of Kettering where the Lincolnshire Oolite has
disappeared in the same manner, and the estuarine beds at the base
of the Great Oolite, rest directly upon those of the Inferior. As
we go northward along the course of the Nene and its tributary
the Willow Brook, we find the Lincolnshire Oolite coming in as a
wedge between the two Estuarine series, the beds of which, west-
ward and northward, gradually assume great thickness and
importance.

Immediately to the south of the area included in the sheet under description
we have, in the Aldwinkle and Tichmarsh railway-cuttings, interesting ‘natee:
tions of the non-ferruginous characters presented locally by the N orthampton
Sand. Here we see the Great Oolite limestones resting on the clays of the Upper
Estuarine Series, these last reposing on an eroded surface of the Northampton
Sand, which is here constituted by beds of white sand and sandy clay yielding
in some bands freshwater fossils and plant remains, and in others marine
shells; the marine characters prevail altogether at the base of the series, where
there is a band of ironstone usually only about six inches thick. As showing
the extreme liability to variation in mineral characters in the beds of this series,
we may mention that in a road-drain, only a short distance from the railway-
cuttings, the Northampton Sand was seen with its normal characters and having
thick beds of ferruginous rock in its lower part.

The section of the Tichmarsh cutting presents some features of special interest.
The Northampton Sand is here composed principally of white sands which
abound in carbonaceous matter, occurring either in minute fragments between
the lamin, in larger masses scattered irregularly through the beds, or forming
thin seams of lignite. As at Ufford, and many other points, the lower beds of
sand become gradually more and more ferruginous, and thus pass almostinsen-
sibly into a bed of ironstone, which forms the base of the formation and presents
all the usual characters of the Northamptonshire iron-ore, but is never more
than one foot in thickness. The sudden variations in character of the North-
ampton Sand are strikingly exemplified in this case, for in several places in

the immediate neighbourhood of this section, as at'Thrapstone and Wadenhoe,
the beds of ironstone acquire a considerable development. ;

But the most noteworthy circumstance in connexion with the section at
Aldwinkle, is the presence of beds containing well-preserved organic remains.
In the lower part of the cutting is seen a bed of sand, cemented by calcareous
matter and about one foot thick, which is crowded with shells. These fossils
are tolerably well preserved, the substance of the shell usually remains, some-

times even, when first exposed, retaining the nacreous lustre. The Conchifera
and Brachiopoda have their valves united, and neither they nor the univalves
exhibit any trace of erosion; these circumstances of course negative the idea
that they might be drifted shells, and indicate that they lived at or near the
spot where they are now found. That the fanna of this bed is a truly marine
one, will be at once demonstrated by the following list of genera :—

Ostrea. Arca. Pholadomya.
Gervillia. Lucina. Trigonia.
Modiola. Astarte. Euspira.
Perna. Tancredia. Terebratula.

Cardium. Neera,
THE LOWER OOLITES. “99

Athin seam in the sand, occurring at some distance above the bed just
described, appears to be crowded with shells of Cyrena, but these are in a very
crushed and imperfect condition.

At Wadenhoe, just above the level of the river, we have sections illustrating
the extremely attenuated condition of the Lower Oolites. It is only in very
good sections that the exact limits between the Upper and Lower Estuarine
series can be traced, both being often greatly reduced in thickness ; wherever a
clear section, however, can be traced, the ironstone junction band is more or
less distinctly exposed, and the Upper or Great Oolite beds are found to repose
on an eroded surface of the Lower or Inferior Oolite beds.

The succession of beds seen at Wadenhoe is as follows :—

(1.) Cornbrash

(2.) Great Oolite clay | tracent in slopes above the pit.

(3.) Great Oolite limestone

(4.) a. White clays - - - 1 foot.
6. Yellow, sandy clay - - - I foot.
ce. Dark, laminated, sandy clay - - 1 foot 6 inches,
d, White clays, with vertical plant markings - 9 inches. |
e. Dark, carbonaceous clays - - 6 inches.
Jf. White clays, with vertical carbonaceous —

markings and ferruginous stains - - 2 feet.
(5.) Ironstone beds, to bottom of pit - - 8 feet.

A little below the level of this pit the Upper Lias Clay was dug. Possibly
we may regard a, b,c, and d@ as belonging to the Upper, and e and f to the
Lower Estuarine series. ;

Below Pilton and Stoke Doyle the Northampton Sands can be clearly traced,
but we get no good sections till we arrive at Oundle Wood, situated in a small
lateral valley west of the town of Oundle. The ironstone beds at this place
have been extensively quarried in ancient times. There are several large
mounds in this wood, some composed of masses of ore as brought from the pit,
and others of the same broken into small fragments, together with heaps of
calcined ore and of slag. From the remains of pottery and coins found at this
place it would appear that these workings were carried on by the Romans. In
a pit, opposite the boat-house on the lake, the ironstone rock, which here
contains Terebratula submazillata, Mor., and other shells, is covered by a
considerable thickness of freshwater sands and clays. At several points along
this valley, the ferruginous deposits of the springs probably indicate the presence
of the ironstone beds, sections of which are however very seldom seen along
this and the neighbouring valleys.

At Southwick the Northampton Sand is seen, and has been worked in ancient+
times; this is manifest from the large quantities of slag found there. The
ironstone is here overlaid by ferruginous sand with some seams of clay, the
whole being covered by beds of gravel composed of fragments of Oolite. The
ironstone beds at this point contain a few fossils, such as Terebratula,
Rhynchonella, and Avicula. The beds are much disturbed here by landslips.
Along the sides of this valley the Lincolnshire Oolite can be traced, like the
thin end of a wedge, coming in between the Upper and Lower Estuarine beds.

At Wood Newton brickyard we find the beds of the two estuarine series,
here separated only by the greatly attenuated rock of the Lincolnshire limestone,
very well exposed. Both the clays above and those below the limestone are dug
for brickmaking. By the aid of a well we are able to construct the following
section :— .

(1.) Clay (Upper Estuarine) - 3 to 4 feet.

(2.) Ironstone junction band - = - 0 to 1 foot.

(3.) Limestone (Lincolnshire Oolite) - - 15 inches.

(4.) a. White sand and cla
b. Brown sand - ‘| - - 16 to 18 feet,
e. Ironstone beds -

(5.)-Upper Lias Clay. - - - - at bottom.

At the foundatioris for the new bridge at Wood Newton, the ironstone bed
and the overlying sands and clays were well exposed, the whole resting on
the Upper Lias Clay. In the Wood Newton parish-pit and in the sides of the
brook between Wood Newton and Apethorpe, the white sands under the oolitic
100 GEOLOGY OF RUTLAND, &c.

limestone are exposed. At the Apethorpe “town-pit” beds of light-blue clay
and marl appear in the same position. Upon the side of the hill, on the right
bank of the Willow Brook, and opposite to the village of Kings Cliffe, a pit
shows the limestone with hard, quartzose, laminated beds exhibiting mammil-
lated surfaces at its base, and resting on the white sands with carbonaceous
markings and plant remains. ;

At Yarwell, on the west bank of the Nene, the Northampton Sand is evidently
thin ; it is composed principally of white sand, and its junction with the limestone
above and the clays below was seen. On the opposite side of the river, at
New Close Cover, the Lower Estuarine beds are dug in asmall pit, affording the
following section :—

3 oe
-) Brownish-yellow sand - - - inches to 1 foot.
(3.) Black band, entirely made up of car-
bonaceous matter showing vegetable

fibres - - - - - 3 inches.
(4.) Clayey sand of a grey colour with some
plant remains - - - 4 inches.

(5.) White sand.

North of Stibbington the ferruginous sands can be traced at the fish-ponds,
and the white sands have been found underlying the oolitic limestone in the
great ie south of Wansford. The same beds are seen underlying the Lincoln-
shire Oolite in the cutting between Wansford station and the Wansford or
Sibson tunnel, and here, as will be afterwards shown, we have a complete
series of the Great and Inferior Oolite beds exposed.

At Water Newton brickyard the sands and clays of the Lower Estuarine
series are dug under the beds of oolitic limestone which are here only of
insignificant thickness. Along the small tributary valleys in which are
situated Southorpe, Thornhaugh, Wittering, &c., the sands and ironstones of
the lower part of the Inferior Oolite can be traced, but they appear to be
generally very thin and afford no good sections. Along the valley of the Nene
eastward, the beds in question are almost always concealed by the thick deposits
of valley-gravel. At Milton Park and at Peterborough, wells have been sunk,
which passed from the Upper Estuarine clays directly into white sands of the -
Lower Estuarine, the Lincolnshire Oolite having entirely thinned out.

Inliers, The great plateau formed by the Lower Oolite beds is
frequently cut through by the numerous streams which intersect
it, so as to expose in the sides of narrow valleys all the strata

‘down to the Upper Lias Clay. This exposure of the lowest beds
of the Inferior Oolite is frequently aided by the numerous faults
which intersect the district, and throw the beds in question to
much higher levels than those which we might anticipate they
would occupy, from their general dip.

In the inlier at Pipwell, which is cut down to the Upper Lias
Clay in its western part, through an upthrow of the beds, we find
a number of exposures of the Northampton Sand. Near Pipwell
Upper Lodge the ironstone beds are dug in a small pit ; and half-
a-mile westward traces of an old reservoir are seen in the valley,
at a point where abundant springs issue at the junction of the
ironstone with the Upper Lias Clay. The Northampton Sand is
also well exposed in the deep gorges near the junction of the
two small streams above Pipwell Abbey.

At the inlier at Corby and Weldon there are many exposures
of the Northampton Sand, the succession of the beds exhibited at
a number of different points in road-cuttings, &c. being :—

(1.) Lincolnshire Oolite Limestone, becoming sandy at its base

and sometimes exhibiting traces of fissile stone (Colly-

weston Slate).
THE LOWER OOLITES. 101

(2.) Very variable beds of sand and clay with numerous plant
remains. (Lower Estuarine Series.)
(3.) Ironstone beds, with usual characters.

(4.) Upper Lias Clay.

The Northampton Sand here exhibits the usual very great
variation in thickness and mineral characters. Between Corby
and Little Weldon the same succession of beds is seen at several
points; near the latter place they suddenly disappear, the lime-
stone being let down against them by a fault.

The manner in which a rock of the impure shelly and oolitic
limestone of the Northampton Sand passes, often within very
short distances, into beds of white sand or ironstone is very
strikingly exemplified in this neighbourhood. In many places
the limestones are themselves very ferruginous and exhibit the
peculiar banding with thin seams of brown hematite, developed
along lines parallel to those of bedding and jointing, which is
so striking a feature in the Northampton Sand. Precisely
similar phenomena are exhibited in Yorkshire in the country
south and west of Malton, where the great estuarine series of
the. Lower Oolites, which form the north-east moorlands of
Yorkshire are greatly reduced in thickness, while in their midst
there are developed a number of, sometimes locally important but
always extremely inconstant beds of more or less sandy oolitic
and shelly limestone, precisely agreeing in character with those
of the Northampton Sand. The presence of these inconstant
calcareous rocks appears to be very characteristic of series of
strata, exhibiting other evidences of the alternations of freshwater
and marine conditions at the period of their deposition.

The small valley at Brigstock Parks exhibits the Inferior Oolite limestones
and sands considerably disturbed, and as‘already explained, unconformably
overlaid by the series of Great Oolite beds. Between Sudborough Lodge and
the Brigstock Park Lodges we find a pit opened in the summit of a small
anticlinal in the ironstone beds of the Northampton Sand.

About Little Oakley and Stanion the valley, cut through the Boulder Clay
and Great Oolite beds by Harper’s Brook, exposes the Inferior Oolite strata
along its sides similarly faulted and rolled, and unconformably overlaid by the
Great Oolite series. The ironstone beds at the base of the Northampton Sand
have frequently been dug in the wells and cisterns at the village of Stanion ;
while about Little Oakley there are numerous exposures of the white sands and.
clays of the upper part of the series, and the ferruginous rock of its lower part ;
they offer, however, no special features of interest at this place, and will be
noticed in connexion with the beds of the Lincolnshire Limestone in this inlier.
At Brigstock Mill, an interesting section in the brickyard and wells, to be here-
after fully described, exhibits the whole of the Lower Oolite series from the
Upper Estuarine series down to the Upper Lias, this place being near the

line of the easterly disappearance of the Tinodinshies limestone by attenuation.
The succession of the Northampton Sand beds at this place is given on page 191.
A long narrow inlier of the Northampton Sand is seen in the upper part of

the valley of the Willow Brook, near Dene, Bulwick, and Blatherwycke, but
there are seldom good exposures of the strata. At Dene brickyard we have
the following section :—

(1.) Marly limestone - - 1 to 2 feet.

(2.) Whitish, calcareous sands = - - - 1 foot 6 inches.

(3.) Hard, blue-hearted, sub-crystalline limestone - 1 foot 6 inches.

(4.) Brownish, calcareous sand, becoming indurated

into stone at its base - - - 2 feet.
Missing Page
Missing Page
104 GEOLOGY OF RUTLAND, &c.

also occur in the mass, which are ground up with the clay in the mill. This
admixture of the clay with fine sand is said to greatly improve its quality.
Mixed with a very small quantity of the white clay from Poole, Dorsetshire,
these clays of the Lower Estuarine Series make an excellent terra-cotta.

Some years ago, in a futile attempt to find coal at this point, a boring was
put down by the late Marquis of Exeter to the depth, it is said, of 500 feet,
Unfortunately, however, no accurate record was kept of the beds passed
through. From the information which I received, however, I infer that the
Lias formation was not penetrated, no red rocks having been reached;
if the information which I received can be relied upon, the Upper Lias Clay
would appear to be about 140 feet in thickness at this place.

Both the estuarine clays and sands, and the marine ironstones of the North-
ampton Sand are exposed at a number of points about Burleigh Park ; and
since the mapping of the area has been completed the quarrying of the latter
as an iron-ore has been commenced by the Marquis of Exeter. (See Mr.
Sharp’s Paper in the Quart. Journ, of the Geol. Soc., vol. xxix. p. 273.)

The light-coloured sands with ironstones at their base are seen at Wittering
and many other points along the sides of the valleys of Southorpe and Thorn-
haugh, the beds being thrown far above their normal position by the great
Stamford and Helpstone fault. =

At Ufford the white sands of the Lower Estuarine Series are found to be
highly micaceous, and to contain many thin layers of lignite and fragments of
wood. One of the pits at this point affords a very interesting section (Fig. 8).

Figure 8. Section of the Northampton Sand seen in a pit east of Ufford,
Northamptonshire.

(a.) Oolitic limestone.

(b.) Yellow, sandy limestone,
with marine shells.
(e.) Bed of lignite, 3 inches
thick.
' * Fragment of fossil wood.

 

 

(d.) Pale-purplish, micaceous
clays, with vertical,
carbonaceous remains
of plants, 3 ft.

 

(e.) White and fawn-coloured
sands, with vertical
plant remains, 3 ft.

 

 

 

 

 

 

 

 

 

 

(f.) Thin seams of lignite,
together, 4 inches
thick.

(g.) Bed of very fine white
sand, 1 ft. 6 in.

 

 

(h.) Yellow sands, becoming
more and more fer-
ruginous downwards,
dug to 4 ft.

(5) is similar to and corresponds ,with (a) of the section, Figure 9, on page 105.
THE LOWER OOLITES. 105

The vertical carbonaceous markings which occur in the beds (d) and (e),
appear to indicate that plants actually grew upon the spot, and were embedded
as they stood, by the quiet deposition of fine sediment around them. The beds
called “root-beds ” by Professor Morris,* which occur in another, but very
similar, formation, greatly resemble (d). The clay of (d) is very fine grained,
and the surfaces of its lamine are covered with scales of mica: in it the
carbonaceous matter is always preserved, while in the sands below (e) it is
a frequently removed, and the sides ‘of the empty tubes stained with oxide
of iron.

In descending through the lower beds of sand (h) we find them more and
more impregnated with oxide of iron, which exists as a coating around the
individual grains ; when this coating is removed by the action of acid a white
sand remains similar in every respect to that forming the bed (7). From the
statements of workmen it appears that this ferruginous character still increases
in going deeper, and that the bed which rests directly on the Lias Clay is a
thin band of the ordinary ferruginous rock of the Northampton Sand.

The section at Ufford lies about one mile to the west of that at Helpstone,
to be hereafter noticed, and on passing still farther towards the west and south
we find the thickness of the ferruginous rock to continually increase, until, at
no’ great distance, it is seen to constitute nearly the whole mass of the

‘Northampton Sand.

   

At the Helpstone brickyard the Northampton Sand, with the beds above and
below it, is bent into a sharp anticlinal fold; the great disturbance of the strata
at this point being connected with the fault so often referred to.

About a mile to the south-east and near Helpstone Heath Farm, where the
beds are also disturbed but in a much less violent manner than in the last-
mentioned section, we have a very instructive exposure of the Northampton
Sand formation.

In this section one of the most interesting aspects of the Northampton Sand
is well exhibited. It is represented below :—

Figure 9. Pit in the Northampton Sand between Ufford and Marholm (North-
amptonshire.)

Obliquely-laminated, fawn-coloured sand, | ft.

)

.) Purplish finely laminated clay, 3 in. : : aol ta
d.) Finely-laminated, fawn-coloured sands, with much oblique lamination,
5 ft. exposed.

 

* Quart. Journ. Geol. Soc., vol. ix., p. 380.
106 GEOLOGY OF RUTLAND, &C.

The bed (a.) forma the base of the oolitic limestone series, the beds of which, as
we pass downwards, are found to become more and more siliceous in character,
and to be not unfrequently interstratified with beds of sand. This stratum isa
very persistent one over a large area; it is a hard, usually blue, calcareous sand-
stone, well characterised by the mammillations of its under surface; when
finely laminated and capable of being rendered fissile by exposure to frost it
constitutes the well-known “ Collyweston Slate.” This rock is crowded with
marine fossils.

The sands below this bed are remarkable for the great amount of oblique
lamination which they present. The surfaces of the lamine of sand are
covered with fragments of carbonaceous matter, which appear in the section as
fine black lines beautifully marking the bedding. Besides these minute par-
ticles in the planes of bedding, larger patches of carbonaceous matter occur,
scattered through the mass, which are probably the vestiges of fragments. of
wood. Some of the beds of sand are crowded with shells, either whole or in
fragments, but these are so much decomposed as to be incapable of removal ; in
some of the layers there occur undoubted specimens of marine shells as Pinna
cuneata, Ostrea acuminata and Trigonia costata var. pullus Sow., in others,
numerous Cyrene.

The base of the sands is not seen in this pit, but in another in the vicinity,
where the beds are inclined, the white sands are found resting directly on the
Upper Lias Clay, without the intervention of any ferruginous rock. The total
thickness of the Northampton Sand at this place is rather more than twenty
feet.

In the extreme north of the area included within Sheet 64 two small inliers
of the Northampton Sand occur at Castle Bytham and Little Bytham, owing
to the streams having cut their valleys through the Lincolnshire Oolite into
the beds below. At neither of these localities, however, is there any clear section
of the strata.

Outliers. In the western part of the district which we are now
describing numerous outliers of Northampton Sand occur, usually
capping the hills or plateaux of the Lias Clay. Many of these
outliers are of very considerable area, one of them, that on which
the town of Uppingham is built, occupying a very considerable
proportion of the southern half of the county of Rutland. Not
a few of these patches of Northampton Sand owe their preserva-
tion to the action of faults, which have thrown the beds into a
position far below their normal level. Capping as they do the
long ridges between the deep and sinuous valleys cut by numerous
streams in the underlying Upper Lias Clay, these outliers of the
Northampton Sand are usually of very irregular form. They
give rise to the remarkably flat topped hills which are so cha-
racterestic of this district. (See Plate VII.)

The most southernly of the outliers in the district is that upon which the
villages of Dingley and Brampton are situated. Here the Northampton Sand .
is mostly covered with boulder clay; and the limits of the former are difficult
to trace, owing to the great extent to which the ironstone rock has in many
cases slipped over the subjacent Upper Lias Clay. __. cet

South of Dingley a pit exhibits the beds of the Northampton Sand dipping

~N. at an angle of 2°. Above them are seen calcareous beds of slaty structure
with a few traces of fossils (representative of the Collyweston Slate P) In the
ironsand itself were found fragments of Belemnites (rare) and Terebratula sub-
maswillata, Mor. Some other small exposures of the beds on this outlier occur,
ent no features of interest.
poe F the Welland at Neville-Holt another considerable outlier of North-
ampton Sand is preserved, and is in this instance capped by the fissile beds
representing the Collyweston Slate and the overlying oolitic limestones.
Large ironstone workings have been commenced on the south side of this
outlier. A trial hole is said to have proved a thickness of 15 feet of ironstone ;
el

 

 
 
 
 
 
THE LOWER OOLITES. 107

some of the lower beds, however, appear to have been too poor in iron to be
sent away for smelting and were used for building purposes.

The total thickness of the Northampton Sand foymation in the Neville-
Holt outlier appears to be about 20 feet. A boring to the depth of 100 feet
was put down in the Upper Lias Clay at Neville-Holt in the hope of finding
coal! The preservation of the considerable tract of Inferior Oolite at Neville-
Holt is evidently due to the fault which bounds the outlier on its northern
side and has produced a considerable subsidence of the beds. ;

To the west and east, respectively, of the considerable outlier just described,
there occur two small and somewhat obscurely exposed patches of the beds of
the Northampton Sand. The first of these caps the hill on which Slawston Mill
is built and gives rise to its peculiar and striking form (see Plate V.), the
other caps a less conspicuous hill lying east of the celebrated Neville-Holt Spa.

Above Hallaton-Ferns there occurs a small patch of the Ironstone-rock the
peculiar position of which can only be accounted for by regarding it as brought
to a much lower level by faults, and thus preserved when the surrounding
masses of the formation were removed by denudation. The beds, which are
well exposed in a pit, show considerable signs of disturbance and are capped
by a mass of Boulder Clay (Fig. 10).

Figure 10. Sketch of section in pit above Hallaton. Ferns, showing a small
outlying patch of the Northampton Sand capped by Boulder Clay.

    

we

A yi t
"574 "SS os
\nuy GAY

y io \ Vera, f
fase qe si Ms ie Yy can 4
3 TNs MANTA A RA ae Gltzs \

   

* Large boulder 18 inches long of the hard siliceous limestone (Pendle) of the
Inferior (Lincolnshire) Oolite.

On the north side of the Welland Valley, between Gretton and Uppingham,
three conspicuous hills, known as Bee Hill, Priestley Hill, and the Burrows, owe
their preservation and striking form to the patches of-the hard beds of the
Northampton Sand which cap them. The last mentioned of the three is
crowned with a small mass of the Lincolnshire Oolite limestone; and in all of
them the strata are more or less obscured by superincumbent drift. At Bee
Hill the rock capping the hill is nowhere well exposed ; while at Priestley Hill
the Northampton Sands are almost free from the covering of drift, but are not
displayed in any artificial openings. .At the hill known as the Burrows,
however, the strata are much more clearly displayed. In ‘one pit we find beds
of Northampton iron-ore of the usual character, alternating with white, sandy
clays ; the whole being covered by five or six feet of drift clay, full of boulders.
Strong springs arise at the base of the Northampton Sand. In a second pit
(near Lyddington Lodge) a similar alternation of ironstone beds with white,
sandy clays is also seen. The drift covering at this point is composed of very
coarse gravel.

As already stated, the little market-town of Uppingham is situated upon an
outlier of considerable size, which is, however, by the numerous streams
intersecting it, divided into numerous long spurs. At several points on this
108 GEOLOGY OF RUTLAND, &c.

outlier, as south of Uppingham, near Lyddington and at Glaston, hard beds
of a calcareous nature, approaching in Pinna those which are seen at Des-
borough and which make so conspicuous a feature in the country to the south-
wards, are seen at the base of the Northampton Sand series. At Uppingham
these calcareous beds are about two feet thick.

The lowest beds at Uppingham, as at many other points in the area, appear
to be considerably less ferruginous than those above them, and are extensively
quarried for building purposes. A large quarry near the town gave the
following section.

1. “ Bearing,” (ironstone rock with the usual characters) - - 8 ft

2. Hard building-stone, of a blue colour - - - - 8 ft.

3. Mass of concretions or pebbles embedded in a blue ironstone

matrix (very similar to the beds which occur at the base of the
Marlstone Rock-bed) - ; - - - - 6in,

4. Upper Lias Clay .

As illustrating the great variations in thickness within short distances of the
strata which compose the Northampton Sand, I may cite, for comparison
with the last, the following section - obtained in a well ‘at the town of

Uppingham. :
- 12 ft,

1. Sand and Clay - - - -
2. Good ironstone rock - - = _ - 5to6 ft.
3. “ Rock,”’ building stone - - - = - 3 ft.

4. Clay (Upper Lias) - - - - dug to 4 ft.
A stone-pit just outside Uppingham on the road to Stockerston illustrates
very admirably the gradual passage from the unweathered blue rock at the base,
up to the perfectly weathered, deep brown, “ cellular ” ironstone above, and the

transition upwards of this ironstone into loose sands (Fig. 11).
Figure 11. Stone pit near Uppingham, on the road to Stockerston.
= tel a Soil.
Clay.

 

Fine white sand

(with thin bands of clay)

gradually passing into .

 

 

 

 

brown sand,

sand rock,

cellular ironstone,

and finally into

hard, ferruginous rock.

Clay (Upper Lias.)

 

 

 

 

 
THE LOWER OOLITES. 109

This section is about 20 feet deep. At its base is seen the Upper Lias Clay,
and at its summit the light-blue, sandy clays of the Lower Estuarine Series.

The beds of Northampton Sand in the Uppingham outlier seldom yield
many fossils. At one of the pits above Lyddington I obtained, however,

Ammonites Murchisonz, Sow. var. subradiatus, Sow.
___ Pleurotomaria, sp. (cast.) :

Another pit, near the same village, exhibited at the base a hard, blue, calca-
reous rock, which is a water-bearing bed. Above this the beds are “ blue-
hearted,”’ each block, into which the mass is divided by the joints and bedding
planes, showing an irregular central mass of blue rock, surrounded by a varying
thickness of brown ferruginous material. As we pass upwards in the section,
the size of the central, unweathered nuclei diminishes, while that of the sur-
rounding weathered crusts is found to increase, till at last the former entirely
disappear. A large portion of the ironstone in this pit is not traversed by the
hard cakes of brown oxide of iron which form such a striking feature in most
of the beds of the Northamptonshire iron-ore. The rock here exhibits the
interesting oolitic structure which will be hereafter described, but instead of
the usual banded appearance displays sections of an uniform yellowish brown
tint, where it has been subjected to weathering operations.

At Seaton, a pit behind the church exposes beds of white sands and sandy
clays with many carbonaceous markings, and the outcrop of the ironstones
below can be traced at many points in the immediate vicinity.

_At Bisbrook, the line of junction of the Northampton Sand and the Upper
Lias is indicated by numerous springs. The lowest beds of the former series
were at one time dug at this place for lining ovens, a purpose for which they
are said to be admirably adapted.

At Glaston there occurs, at the base of the Northampton Sand, a very hard,
somewhat calcareous band, which is crowded with a shell which closely
resembles, if itis not actually identical with, the Rhynchonella cynocephala, Rich.

At Wardley, Ayston, Morcott, Stoke Dry, King’s Hill Lodge, and many
other points upon the skirts of the great Uppingham outlier, there occur
exposures of the ironstone beds of the Northampton Sand. None of these-
sections, however, present us with features of any novelty.

The villages of Ridlington and Preston are situated upon a long narrow out-
lier of the Northampton Sand, which is separated by a deep and narrow valley
from that last described. The hard rock of the ironstone gives rise to well
marked steep escarpments, but the highest portions of the outlier are capped
and obscured by drift deposits. A number of small sections are afforded at
different points, and there is evidence in the abundant furnace cinders that the
ironstones in this neighbourhood were formerly smelted.

Immediately to the westward of the last, two smaller outliers of the North-
ampton Sand occur, on the larger of which stands the farm-house, called on the
map Ridlington Lodge. These outliers afford several exposures of the ironstone
beds, which do not however present any features of interest. Another small
outlier lies to the north of the village of Preston.

Still further to the west a number of outliers of the Northampton Sand
evidently owe their preservation to the great Billesdon and Loddington fault.
These cap the prominent hills known as Whadborough Hill, Robin-a-Tiptoes,
see Plate VII., Barrow Hill, and the nameless eminences rising above the village
of Loddington and at Laund Wood. All of these afford more or less complete
sections of the ironstone rock, but in the three last mentioned the strata are
to a certain extent obscured by deposits of drift gravel and clay.

At Whadborough Hill hard calcareous beds occur near the base of the
Northampton Sand, and contain Terebratula submaxillata, Mor. and some other
shells. Beds of a somewhat similar character can also be traced upon Robin-
a-Tiptoes. From its elevation and striking form it might be anticipated that
the neighbouring hill called Colborough Hill would also be found capped by
the hard ironstone beds ;. but a careful examination of the summit failed to
detect any such rock in situ, so that we must infer that the Inferior Oolite
has been wholly removed from this eminence by denudation. __

Small pits in the ironstone beds have been opened in the outliers of Laund
Wood, Loddington and Barrow Hill, the position of which is indicated upon
the map. At the last mentioned locality the rocks show considerable. signs of
disturbance, owing to landslips.

32108. H
110 GEOLOGY OF RUTLAND, &c.

At Lyndon a small outlier of Northampton Sand, capped by the beds of the
Lincolnshire Oolite, occurs between the spurs which run out from the main
escarpment to Wing and Martinsthorpe. The preservation of this outlying
patch of Inferior Oolite rocks has evidently been brought about and its form
emi ed by the somewhat complicated series of faults which is found in

8 area.

By the same series of faults the beds which form the outliers of. Hambleton,
Normanton and Whitwell have been powerfully affected.

In Normanton Park there were several sections of the Northampton Sand
at the time the survey was made; one of these exposed a thickness of 8
feet of ironstone rock capped by the light-coloured sandy clays of the Lower
Estuarine Series.

The outlier at Hambleton is crossed by an East and West fault, which appears
to have a throw of about 20 feet. Through its agency the beds of the North-
ampton Sand have for a considerable distance been brought to the same level
as the Lincolnshire Oolite Limestone. At the time of the survey a number of
field drains afforded great facilities for determining the exact position of this
line of fracture. The ironstones and overlying sandy clays, which were well
exposed at a number of points, exhibit the usual features which we have already
described as characteristic of this formation.

_ South of Whitwell a small fault has let down the Northampton Sand, which
is in consequence found capping the hills of Upper Lias Clay. No clear sec-
tions are however presented at this point.

_ The last of these outliers of the Northampton Sand which we have to notice
is a singularly isolated one of very insignificant proportions. It is found cap-
ping the conspicuous eminence known as Ranksborough Hill, situated about
five miles to the north-west of Oakham. The beds of Northampton Sand are
here quite destitute of any covering of drift, and there can be no doubt that
the “ red-rock ” is here in situ, although but such a small portion of it has
escaped destruction by denudation. It is probable that the preservation of
this minute vestige of the formation, so far from the general line of its outcrop,
may have been in part due to its subsidence through faults; but'in the district
which surrounds it, composed of Lias Clays deeply buried under drift, the field-
geologist is destitute of the necessary data for determining the presence and
position of such dislocations of the strata. There are some indications which
would point to the conclusion that, beneath the thick masses of drift clay and
gravel crowning the very elevated ridge upon which the village of Cold-
Overton stands, beds of the ironstone rock may occur. But while the existence
of such an outlier of the Northampton Sand is, at best, very doubtful, its
limits are altogether unknown, and therefore no attempt has been made to
indicate it upon the map.

The Iron-Ore of the Northampton Sand.

Frequent allusion has already been made to this important
mineral production of the district now being described. The his-
tory of the working of these iron-ores in the Inferior Oolite of
the Midland district has been a somewhat remarkable one. There
is evidence that, at least as early as the period as that of the
occupation of the country by the Romans, the beds of brown
hydrated oxides of iron were known and extensively worked, We
have already noticed that in a wood near Oundle heaps of broken
ore, of the same calcined, and very large quantities of slag occur,
associated with which have been found Roman coins and pottery.
We have historical evidence that in medizval times, the district of
Rockingham forest vied with that of the Weald of Sussex and
Kent asa great iron producing district. The Norman Castle
of Rockingham is said to have been built for the protection of
the iron-furnaces in Rockingham Forest. In both of these areas
the presence of beds of tolerably rich iron-ore, in district
THE LOWER OOLITES. 111

abounding with timber, led to the erection of numerous furnaces
of the small kind then in use, and, the extensive production of iron.

Throughout nearly the whole of the district described in this
memoir enormous masses of slag, which are, of course, especially
conspicuous where. the land has been newly cleared for cultivation,
testify to the extent to which the manufacture of iron was carried on
in the area in ancient times. The slags are of a very dark, almost
black, colour and extremely heavy; they bear witness to the want
of skill of the ancient smelters and it is evident that only a compara-
tively small proportion of the iron contained in the ores was
extracted from them by the imperfect methods then in use.

The causes of the decline of the iron manufacture in this dis-
trict were the same as those which operated so powerfully in the
case of the Wealden district of the south of England. In the first
place, the enactment of rigorous laws to prevent the reckless de-
struction of timber-trees by the charcoal-burner operated power-
fully, by restricting the supplies of fuel. In the second place, the
discovery of the possibility of smelting iron-ores by means of coal
and coke caused the transference of the industry to the coal-
bearing districts, in which the ore and mineral fuel are found
in close association with one another.

For about two centuries the iron manufacture was thus wholly
banished from the district, and scarcely a tradition of its former
importance remained. With the introduction of railways into
this country, and the consequent very suddenly increased demand
for iron, new deposits containing iron-ores began to be sought
for, in order to supplement the supplies yielded by the coalfields.
At first this new demand appeared to be fully met by the open-
ing out of the extensive Liassic and Oolitic ironstone beds of
the Cleveland district, which have the great advantage of being
in close proximity to the Durham coalfield. Still increasing
demands for iron-ores of this class led to the re-opening of iron-
mines in the Northampton Sand, and although the competition
of the Cleveland and North Lincolnshire district, both more
favourably situated in relation to the fuel producing areas, must
have tended powerfully to retard the development of the in-
dustry in the midland district, yet the following table, kindly
supplied to me by Mr. Robert Hunt, F.R.S., Keeper of the
Mining Records, will show with what rapidity the working of
the iron-ores of the Northampton Sand formation has been
extended.

Annual produce and value of the iron-ores raised in Northamp-
tonshire from the year 1860 to 1872 :—

Tons. L£
1860 z - 95,664 23,416
1861 - - 113,139 28,535
1862 - - 116,718 31,940
1868 7 - 126,587 41,644
1864 2 - 885,787 84,761
1865 - - 364,349 96,137

H 2
112 GEOLOGY OF RUTLAND, &c.

Tons. £
1866 S 476,981 118,940
1867 - 416,765 104,191
1868 - - 449,116 112,279
1869 - - 540,259 135,065
1870 - - 887,020 177,404*
1871 - - 914,435 182,887*
1872 - - 1,174,211 234,842*
1873 - - 1,412,256 282,451*

The circumstances under which the working of the iron-ore of
the Northampton Sand was resumed in modern times are noticed
by Dr. Percy in the following terms :—-

** The introduction of the Northamptonshire ore is only of
recent date. Not long previous to the International Exhibition
of 1851, Colonel (now General) Arbuthnot called upon me in
Birmingham, where I then resided, and requested my opinion on
a specimen of the ore which he left with me. I found it to con-
tain a sensible quantity of sesquioxide of iron and a very large
amount of siliceous sand. I made no quantitative examination
of it; and, certainly, the specimen in question did not prepossess
me in its favour. However, I referred the Colonel to my friend,
Mr. 8. H. Blackwell of Dudley, who visited the locality of the
ore in order to examine it im situ. He obtained samples much
richer in iron than that which was placed in my hands. He
prosecuted inquiries on the subject with his usual energy, and
the result has been the discovery of an extensive deposit of
ore, which has since been smelted in large quantities in South
Staffordshire, Derbyshire, and South Wales.”

At a few points blast-furnaces have been erected for the smelt-
ing of these iron-ores at the locality in which they are raised.
The only place within the area of Sheet 64, at which any attempt
has been made to manufacture the iron upon the ‘spot, is at
Neville-Holt ; the works at this place have not, however, been
completed. But by far the larger portion of the ironstone of the
Northampton Sand is sent away to the coal-bearing districts ; the
highly siliceous ore of the oolites being found better adapted for
smelting in admixture with the calcareo-argillaceous ores of the
coal-measures than alone, or with the simple admixture of a
limestone flux.

Besides the ore of the Northampton Sand, the ironstone con-
tained in the Great Oolite Clays, the ‘junction-band” of the
Upper Estuarine series and the Marlstone Rock-bed, were also
worked in ancient times. An attempt to revive the working of
the first-mentioned of these deposits near Peterborough resulted

in failure. Of late years proposals have been made to open mines
in the Marlstone Rock-bed, which farther south, in Oxfordshire,
(Adderbury and King’s Sutton) yields a valuable ore.

 

*-The values in each of these years are estimated at four shillings per ton.
t Percy’s Metallurgy, Iron and Steel (1864), p. 225.

 
113

CHAPTER VI.

ORIGIN OF THE NORTHAMPTON SAND.

The formation described in the last. chapter presents the
geologist with many features of great interest. The remarkable
concentration of iron in the thick beds which compose it, is
accompanied by many striking peculiarities of physical and
microscopical structure. As in the district under description
many of these interesting features are very admirably illustrated,
the occasion was taken during the survey of the area to study
the chemical and microscopic peculiarities of the rocks composing
the several beds of the formation, in connexion with their position
and relations as cbserved in the field. The results of these
observations, with a discussion of their bearing upon the various
theories which have been put forward in explanation of the origin
of these remarkable rocks, are contained in the present
chapter.*

Every geological formation may be studied under two different
aspects ;—either it may be regarded in its relations as one member
of a series, and the record, more or less imperfect, of a period of
the earth’s history; or it may be viewed as the product of the
various forces, mechanical, chemical, and vital, which have ope-
rated in its original accumulation or its subsequent metamor-
phoses. In the former case we are called upon to investigate with
the field geologist the mutual relations of great rock masses,
their order of superposition, their conformity or unconformity,
and the nature and amount of their disturbances ; in the latter
we are led to study with the mineralogist and microscopist the
various details of their intimate and minute structure. In the
former case the most important aids to our inquiries will be
found in the remains of organised bodies contained in the beds,
and hence as our principal guide we must look to the naturalist;
in the datter the greatest assistance to our investigation will be
afforded by the crystallised minerals enclosed in the rock, and
therefore, for direction in our inquiries, our chief dependence must
be placed in the chemist. Hitherto the labours of geologists have
been chiefly devoted to the former class of researches, but the
latter offers subjects of at least equal interest and importance.

Every rock is more or less “metamorphic.” Ever since its
deposition it has undergone and it still is undergoing a constant
series of internal changes, the result of the action of various causes,
as heat, pressure, solution, the play of many chemical affinities,
and of crystallographic and other molecular forces,—-causes insigni-

 

* These observations were originally laid before the Geological Society of London
in the year 1869; but, it’ being found that, by the rules of the Geological Survey,
an account of the various sections referred to could not be published at that time, the
paper was withdrawn in order that it might make tis appearance in the present
Memoir.
114 GEOLOGY OF RUTLAND, &c.

ficant perhaps in themselves, but capable under the factor time of
producing the most wonderful transformations. The geologist is
called upon to unravel the complicated results, to pronounce what
portion of the phenomena presented by 4 rock is due to the forces
by which it was originally formed, and what must be referred to
subsequent change; to discriminate the successive stages of the
latter and to detect their various causes; in short, to trace the
history of a rock from its deposition to the present moment.

The object of this chapter is to examine the Northampton Sand
from the second of the points of view which we have indicated.
We propose to describe the various characters—petrological, litho-
logical, microscopical, and chemical—of the formation in question,
and to ‘attempt to base on a discussion of these, definite conclu-
sions with regard to the following points. Firstly, the conditions
under which the rocks composing it were originally deposited,
and, secondly, the changes which they have since undergone.

I1—GENERAL FEATURES OF THE NoRTHAMPTON SAND.

These have been somewhat fully illustrated by the local de-
scriptions of the preceding chapter. Especial attention may be
directed to the accounts given of the sections at Aldwinkle
railway-cutting (p. 98), Ufford (p. 104), that near Helpstone
Heath Farm (p. 105), one at Exton Park (p. 97), and that at Dene
brickyard (p. 102).

In the following remarks, the most interesting features of the
deposits of this formation, and especially such as appear to throw
light upon its mode of origin, are briefly noticed. ;

In some localities, as at Helpstone, Ufford, Aldwinkle, Kings-
thorpe, &c., the deposit is mainly or wholly compused of beds of
white sand, siliceous, calcareous, or micaceous, usually exhibiting
much oblique lamination, often more or less indurated, and
sometimes interstratified with beds of clay. Both the sands and
clays usually contain much carbonaceous matter, either in particles
lying between the laminz, in vertical stem-like markings, or
forming thin beds of lignite, each of which usually rests on a
seam of “ underclay.”

The mass of the beds is usually very destitute of fossils; but
thin seams occur crowded with shells, in some cases of marine in
others of brackish-water species, the animals of which evidently
lived and died upon the spot. When followed, either vertically
or horizontally, these beds of sand are frequently found to
graduate into the ordinary Northamptonshire iron-ore.

At Exton there occur in the midst of the white sands thin,
hard, and brittle amine of dark-brown hydrated peroxide of
iron, each of them being underlaid by a thin seam of clay.

Not unfrequently we -find, as at Dene and near Burton
Latimer, the formation in great part composed of beds of car-
bonaceous sandy clay, which from their dark colour have some-
times been mistaken for, and even mapped as, Upper Lias.
GENERAL FEATURES. 115

By far the most frequently occurring type of the Northampton
Sand, however, is that in which the upper portion of the formation
is composed of sands and clays similar to those which we have
been describing, and the dower portion by strata of greater or less
aggregate thickness of the well-known ironstone.

Everyone is acquainted with the great amount of change, both
physical and chemical, which many rocks undergo in consequence
of the passage through them of atmospheric water. Thus the
Cornbrash when dug under the Oxford Clay is an extremely
hard, dark-blue limestone, in which the planes of bedding are
scarcely visible, and joints, though present, so little open that the
rock scarcely admits of the passage of water through it, and it can
consequently only be quarried by blasting; but when the same
rock is dug at the surface its whole thickness is made up of a loose
rubbly brown limestone, the appearance of which in sections has
been, not inaptly, compared to that of a rough stone wall; each
of the separate fragments into which the bed is disintegrated is
often more or less thickly coated with a stalagmitic deposit.

Similarly, if we enter almost any quarry in an oolitic district
we shall find striking illustrations of the same kind of change.
The upper part of such a quarry will be found to be made up
of “rubble” or disintegrated rock ; below this the blocks of stone
will be seen to be solid, but soft, and throughout of a white or
brown colour. Lower still they will be found to have hard nuclei
of a blue colour, or in the language of quarrymen will be “ blue-
hearted ”; the lower we go, the Jarger shall we find these blue
centres to become, till at last the blocks will be seen to be through-
out of a blue coleur. If the same limestone be quarried under
beds of clay it will probably be found to be entirely of the
same blue colour.* :

We have been thus particular in adducing these instances,
because no geologist will hesitate for one moment in ascribing the
changes described to the weathering action of atmospheric water,
which, finding access to the rock by the planes of bedding and
jointing, traverses its substance, and acts chemically on its
materials, especially the compounds of iron.

Now, changes precisely similar in kind, though much greater
in degree (on account of the very large proportion of iron which
it contains), have in the case of the Northamptonshire iron-ore
resulted in some of the most marked and characteristic features
presented by that rock. As, however, the very obvious cause to
which we have referred has, in the case of the rock in question,
been neglected or ignored by some authors on the subject, in
favour of others, purely hypothetical, it may be necessary to
describe in some detail the facts, which are, I believe, sufficient to
place the subject altogether out of the region of controversy.

When quarried at the surface, the Northamptonshire iron-ore
is seen to be composed to some considerable depth of the hydrated

 

* See some interesting remarks on this subject and on the necessity of a
knowledge of it to those who seek for building-stonc, by Prof. Morris. Quart. Journ.
Geol. Soc., vol. ix., p. 329, note.
116 GEOLOGY OF RUTLAND, &c.

peroxide of iron only; weshall see hereafter that it is only the
superficial portion of the bed which is used as an ore, and hence
most of the quarries and pits present only this variety of the iron-
stone rock. But if the beds be followed vertically to some depth,
or horizontally some distance into the side of a hill, remarkable
changes in the nature of the rock will be found to occur.’ When
quarried at some depth from the surface each block will be found,
when broken, to contain a nucleus of compact, impure carbonate
of iron of a bluish or greenish-gray colour, and, as we go farther
from the surface, these nuclei will be found to gradually increase
in size till, in the end, the whole mass of each block is found to be
composed of the carbonated mineral. While the upper peroxidized
beds are easily traversed by water, the solid carbonated beds
below, on account of the closeness of their joints, are much less
pervious, and become “water-bearing.” These facts are per-
fectly familiar to the well-sinkers of the district, who find that
to obtain water it is always necessary to pass quite through the
“kale” (the soft weathered beds), but that copious springs will
be found in the “rock” (the solid unweathered beds), without
going down to the “blue bind” (the Upper Lias Clay); but that
nevertheless, to prevent a failure of water in times of great
drought, it is always safer to penetrate to the latter.-

When the Northamptonshire iron-ore is met with at the bottom
of very deep wells, it is, throughout its whole thickness, composed
of the hard, compact, gray carbonate, and this is also the case
when it is dug beneath beds of Boulder Clay.

In connexion with this gray, carbonated condition of .the rock,
there are two circumstances of great interest and importance

.which require remark :—firstly, that the fossils in it retain their
shelly substance, though the carbonate of lime is frequently
replaced by carbonate of iron, and are not, as in the weathered
rock, merely double casts; and secondly, that there occur in the
beds of lignite, vertical plant remains and fragments of car-
bonaceous matter.

In the gray, carbonated centres of blocks dug at some depth
in the weathered Northamptonshire iron-ore of some localities,
as at Holt, fossils similarly retaining their shells are found; in
these also the casts of vertical plant remains are very frequently
seen. In the upper beds such changes have taken place, owing to
the redistribution of the oxide of iron, that it would be in vain
to expect to be able to detect such traces in them.

The Northamptonshire iron-ore is generally almost destitute
of fossils throughout the greater part of its mass; occasional
beds however occur which are crowded with marine shells, pre-
served as we have already seen as double casts. These shells
present every appearance of having lived in the places where
they are found, and not of having been drifted; they belong
principally to the orders Lamellibranchiata and Brachiopoda,
but a few Glasteropoda also occur, as in the overlying limestone.
Cephalopoda are extremely rare, though specimens of Ammonites,
Belemnites, and Nautilus have been found. Occasionally seams
GENERAL FEATURES, 117

are found in the ironstone which appear to be crowded with shells

of Cyrena.

Near Stamford the Northamptonshire iron-ore is overlaid by

a thin bed of clay, with fine grains of white sand disseminated

through it, but without any other foreign admixture. In other

localities, as Holt and Desbro’, lenticular beds‘of a similar material
occur in the midst of the ironstone itself.

The most striking feature of the Northampton Sand may be
summarized as follows : —

(1.) The formation is usually composed of sand, sometimes
purely siliceous but at other times micaceous, carbona~
ceous, calcareous, argillaceous, or ferruginous.

(2.) In this formation there occur rapid alternations of evenly
stratified beds, with some exhibiting much oblique
lamination, and others indicating the existence of ter-
restrial surfaces.

(3.) The organic contents of the formation suggest the proxi-
mity of land at the time of its deposition, and also
indicate remarkably rapid transitions from marine to
brackish water and terrestrial conditions,

(4.) In this formation ferruginous beds are usually present,
but not unfrequently altogether absent.

(5.) These ironstones vary greatly in thickness, occasionally
constituting the whole of the formation, frequently
forming the greater part of it, not seldom being reduced
to very small proportions, and sometimes being wholly
wanting.

(6.) The ironstone when present always constitutes the lowest
portion of the formation and lies immediately upon the
Lias Clay.

(7.) The ironstone, when unweathered, consists ofa hard, solid,
compact or oolitic rock of a bluish or greenish-gray
colour, composed principally of carbonate of iron.

,

1].—Lrruo.oeicaL CHARACTERS OF THE NorTHAMPTON SAND.

The prevailing mineral characters of the clays and sands of
this formation have been sufficiently illustrated in the descriptions
of the typical sections before referred to; the ferruginous beds,
however, present some remarkable and highly interesting features
of rock structure, which it will be desirable to examine in some

-dittle detail.

The unweathered beds of ironstone consist of a mineral, com-
posed mainly of carbonate of iron (but containing disseminated
through it grains of quartz and siliceous oolitic concretions)
which is coloured, usually of a bluish or greenish tint, by minute
quantities of other ferrous compounds. The rock usually exhibits
only slight traces of the planes of bedding, and although it is
traversed by joints, yet these, as we have already seen, are so
little open that the stratum is almost constantly water-bearing,
and cannot be quarried without blasting. Of banding or concre-
118 GEOLOGY OF RUTLAND, &c.

tionary structure, with the exception of the minute oolitic features
to be hereafter described, this rock does not exhibit the slightest
trace. The different beds vary greatly in hardness, the oolitic
rock being much softer than the compact or granular.

But when we turn our attention to the weathered beds of iron-
stone, which are composed of hydrated peroxide of iron with
disseminated grains of quartz and minute quantities of a few
foreign materials, we find a remarkable contrast in many features
with the rock just described. Occasionally, as near Lyddington
in Rutland, beds of considerable thickness of the weathered iron-
stone are made up of an almost homogeneous rock, of yellowish
brown colour, friable texture, and oolitic structure; this is how-
ever exceptional, and the rock in question usually presents a
very marked and characteristic heterogeneous structure. In these
cases its mass is seen to be made up of two very different materials ;
that which forms the larger portion of the rock is' of a yellowish-
brown colour and soft earthy texture; the other portion is of a
dark-brown colour, compact, hard, and brittle; the latter contains
a considerably larger proportion of iron than the former. The
relative distribution of these two materials in the rock is also
a feature of very great importance. The hard, brown mineral
always occurs in thin plates of from one-third to one-tenth of an
inch in thickness; these plates form complete prismatic cells,
each of which encloses a mass of the light-coloured, earthy mineral,
and is itself often surrounded by another layer of the same
mineral, never more than one inch thick and usually much less.
The form of these cells, though presenting much irregularity,
usually approximates to a nearly rectangular prism, the relative
dimensions of which are subject to the greatest variations ;
occasional cells of other irregular polyhedral figures also occur,
but these are certainly exceptional. The absolute dimensions of
these cells also vary between wide limits in different beds, but
are tolerably uniform in the same beds, the length of one of the
sides may be a few lines only, or it may amount to several feet.
Sometimes these cells formed by the dark-brown mineral, are
arranged in a concentric manner, the intervals between them
being filled with the light-coloured variety; this structure prevails
in certain localities, and a very beautiful example of it may be
seen in a section at Easton; the examples of it are however, on
the whole, much less frequent than those of the non-concentric
cellular structure. The centres of the cells in both the varieties
may be occupied, as already explained, by larger or smaller nuclei
of the gray carbonated mineral. The inner surface of the hard
laminar material, forming -the walls of the cells, is always sharply
and clearly defined from the mass of the enclosed softer mineral,
and in fact an empty space of greater or less extent usually exists
between them ; in this latter case the hard and brittle walls of
the cells being unsustained are often fractured by the pressure of
the surrounding materials. The outer surface of the laminz, on
the other hand, almost always graduates to a greater or less extent
into the investing, light-coloured material. Frequently also, there
LITHOLOGICAL CHARACTERS. 119

isa marked gradation of density in the laminar material itself,
and in such cases the denser portion is always found to be that
nearest the interior of the cell.”

The form of the internal and well defined surfaces of the
lamine is extremely irregular, constantly tending towards mam-
millated and botryoidal characters, not unfrequently being ex-
tended into long finger-like projections, and sometimes being
further complicated by a secondary series of more or less regular
sculpture-like markings. This inner surface, though usually de-
tached from the enclosed mass of the soft mineral, is neverthe-
less frequently coated with an extremely thin layer of the latter,
and thus presents a bright yellow colour.

That portion of the bed of ironstone lying nearest to the
surface has, in addition to chemical disintegration, usually under-
gone a certain amount of mechanical denudation, by which means
a portion of the soft earthy material is carried away, and the hard
laminze being broken by mutual pressure, the result is a confused
mass of irregular fragments of the hard mineral, intermingled with
a larger or smaller proportion of the soft mineral. Thus a mass
is formed, which of course contains a larger per-centage of iron
than the undenuded rock, and it is this portion of the bed which,
to the depth of about six feet, is usually dug as an iron-ore.
Doubtless, if some ready mechanical means could be contrived for
separating the hard layers from the earthy portion of the rock,
its value as a source of iron would be greatly increased.

IIL—MicroscoricaL Cuaracters oF THE NorTHAMPTON
Sanp.

The ordinary sands and clays of this formation do not present
any microscopical features of particular interest. The former
consist principally of more or less rounded and waterworn frag-
ments of white quartz, the size of which is usually very uniform
in the same bed, but varies very considerably in different ones,
from a general diameter of from ;4, to 74, of an inch. In some
of the beds, as already observed, each of these grains is invested
with a coating, of greater or less thickness, of the hydrated
peroxide of iron. The calcareous sands contain, in addition to
the rounded quartz grains, fragments, usually angular, of carbonate
of lime, which by their minute structure are seen to be com-
minuted particles of shells. Of minute organisms either siliceous,
as diatomacee, or calcareous, as foraminifera, I have not been
able to detect any trace in this formation. The carbonaceous
fragments, which are so abundant in some of the beds, do not,
owing to the imperfect state of their preservation, present any
well defined histological structure under the microscope. In the

 

* _The peculiar distribution of the materials composing the Northamptonshire iron-
ore is very admirably illustrated in one of the beautiful plates which form part of
Mr. Maw’s interesting paper “On the distribution of Iron in Variegated Strata.”
Quart. Journ. Geol. Soe. vol. xxiv. (1868), Pl. xv. Fig. 37.
120 GEOLOGY OF RUTLAND, &c.

lower part of the limestones, however, which immediately overlie
the Northampton Sand, the plant-remains are better preserved,
and in many of the small fragments there found, the characteristic
venation of ferns can be easily distinguished ; occasionally, too,
larger specimens are preserved in the same beds, and in these the
disposition of the sori can often be observed, thus affording the
botanist safer materials for the construction and comparison of
species than is usually the case with fossil plants. Well preserved
masses of wood, both exogenous and endogenous, also frequently
occur in these beds, though these donot, of course, afford sufficiently
distinctive features for specific or even generic determination.
Some specimens of the upright plants in the clays and sands, which
were better preserved than is usually the case, appear to indicate
that these belong to the order of the Equisetacee ; the habits of
the fossil plants must certainly have been similar to that of some
recent members of that order. If this identification should prove
to be correct, the fact would be one of considerable interest, from
the abundance of plants of the same order in certain Yorkshire
beds, which will probably prove to be of the same age as the
Northampton Sand.

When we study microscopically the ironstone beds many
features of very great interest present themselves, which have
most important bearings on the problems of the mude of deposition
of the rock, and the causes of the changes which it has since
undergone.

I may first state that the most careful examination fails in
detecting any difference in structure between the gray masses in
the midst of the weathered blocks and the mass of the rock when
dug at a great depth and unweathered. So strikingly is this the
case that, on one occasion, having a large number of fragments
of rock illustrating the two conditions mentioned, from which
I was preparing sections for microscopical examination, I found
myself quite unable, they having become accidentally mixed, to
separate the two series; consequently the whole had to be thrown
away, and fresh specimens procured. ;

Notwithstanding their great differences in lithological and
chemical characters, the different varieties of the Northampton-
shire iron-ore,—namely, the gray carbonate, the light coloured
earthy peroxide, and the hard, dark coloured laminz,—the
microscopical features presented by them all are essentially the
same. In all, a slight examination is sufficient to show that there
is a considerable amount of variation in the intimate structure of
the rock from different localities, and of the different beds.in the
same locality; in some cases the whole mass is seen to be made
up of oolitic grains, varying in diameter from Jy to zpq of an inch ;
in others the structure of the rock is seen to be throughout
compact or granular; and in other cases again, and these are
by far the most frequent, we find a compact matrix, with oolitic
grains disseminated through it in greater or less abundance. a
nearly all cases there occur, scattered throughout the mass, rounded

or sub-angular grains of quartz.
MICROSCOPICAL CHARACTERS. 121

When fragments, not pulverized, of the Northamptonshire iron-
ore are digested in hydrochloric acid, a white mass is left nearly
equalling zz bulk the material acted upon. ‘This insoluble residue
under the microscope is seen to be made up of several constituents.
The principal of these are rounded or sub-angular grains of pure
white quartz, varying in diameter from +4, to s4, of an inch, and
rounded, siliceous, oolitic concretions of a pale-green colour,
from 34; to 71, of an inch in diameter. Besides these, we fre-
quently find in some specimens a number of scales of mica, and
in others black fragments, which disappear on the ignition of the
mass, and are thereby recognised as carbonaceous matter. The
quantity of the latter substance is in some samples very con-
siderable. Some of these facts concerning this insoluble portion
of the Northamptonshire ore have already been noticed by
Dr. Percy.*

Owing to the very different degrees of hardness of the various
constituents of the Northamptonshire iron-ore, there is considerable
difficulty in preparing good sections for microscopic examination.
After many trials of different methods, I have found that the
best plan for studying the internal structure of the rock is to
prepare a number of polished surfaces, and to etch these to
a greater or less extent with hydrochloric acid, by which means,
of course, the siliceous materials of the rock are seen standing
out in relief. In sections thus prepared we observe that the quartz
grains are scattered irregularly through the mass of ferruginous
matter in which the oolitic concretions are embedded. The
latter, when seen in section, present very different appearances.
Sometimes we find only a single outer coat of siliceous matter
enclosing several more or less decomposed grains of quartz; in
other cases the whole mass of the concretion is made up of con-
centric siliceous coats; and between these two extremes we may
observe every intermediate variety. The intervals between the
siliceous coats are filled either with carbonate or with hydrated-
peroxide of iron. The siliceous coats do not appear in any case to
be so compact or continuous, as to prevent the acid from penetrat-
ing and extracting the soluble material enclosed between them.

In the hard lamin of the weathered rock the oolitic concre-
tions can usually only be seen by making polished sections, but
in the light-coloured, earthy material they are usually visible,
even to the naked eye, and are in such a state of decomposition
that the several coats composing them may be successively broken
and removed with the point of a needle. The thin layer of a
bright yellow tint, which often adheres to the inner surfaces of
the dark brown laming, is easily seen, when viewed with a low
power, to be formed as follows :—The oolitic grains of the interior
soft mass have adhered to the investing, dark-coloured mineral,
and, owing to the friability of the former, the unattached portions
of these grains have been broken away, leaving fragments of one
or more of the coats still attached to the laminz.

 

* Metallurgy, Iron and Steel, pp. 225-6.
122 GEOLOGY. OF RUTLAND, &c.

IV.—Cuemica, CHaRActTERs oF THE NortHamMpPtTon SAND.

There have been already published a considerable number of
very accurate and detailed analyses of the N orthamptonshire
iron-ore.

In Dr. Perey’s work on the « Metallurgy of Iron and Steel,”*
there are .given no less than eight such analyses miade by
Messrs. Spiller, Riley, and Dick, and these have especial value,
as furnishing us with the exact composition of the portions of the
eS is are respectively soluble and insoluble in hydrochloric
acid.

To Mr. Maw we are indebted for the publication of two very
complete analyses by Mr. David Forbes, and of some more partial
ones by Dr. Voelcker.t *

“ Anazysis, by Mr. Joun Spiuuzr, of Northamptonshire Iron-ore from

Wellingborough. ‘
3 a. F
Sesquioxide of iron - - - 52°20 51°93
Protoxide of iron = - - ~ trace. _
Protoxide of manganese - - 0°51 _
Alumina - - - - 7°13 --
Lime - - - - 7°13 7°39
Magnesia - - - - 0°57 0°54
Potash - - 7 % eae —
Silica - - - - 1°60 1°77
Carbonic acid - - - 4°92 —
Phosphoric acid - - - 1°26 —_
Sulphuric acid - - _— _
Bisulphide of iron - - 0°03 _
hygroscopic _ —
Water 4 combined - = «1871-28
Organic matter - - Se oo
Ignited insoluble residue 13°55 13°59
100°27

Ignited insoluble residue.

 

 

Silica - - - 11°56 —
Alumiuas- - - 0°26 pe
Sesquioxide of iron - - 0°66 —
Lime - = - 0°33 —
Magnesia - - - - 0°11 =
Potash - - = a — =

12°92

Tron, total amount - - 87°00

“ This ore consists essentially of earthy hydrated sesquioxide of iron. It is
oolitic in structure and ochre-brown in colour. The insoluble residue con-
sisted almost entirely of siliceous oolitic concretions, but on dissolving these in
potash a small amount of residue was left, containing quartzose sand, scales of
mica, and minute spherical particles of magnetic oxide of iron. A trace of
copper was detected in a solution of 660 grains of the ore.”

 

* Pp. 208, 209, 225, and 226. ;
+ Quart. Journ. Geol. Soc., vol. xxiv., pp. 395-397.
CHEMIOAL CHARACTERS.

123

“ ANaLysis, by Mr. Epwarp Riuey, of Northamptonshire Tron-ore from

Wellingborough.

Sesquioxide of iron - 3 2
Protoxide of iron e =
Protoxide of manganese -
Alumina - - - - ot
jae c - -

agnesia - E e
Potash - =
Silica - - :
Carbonic acid
Phosphoric acid -
Sulphuric acid -
ae of iron —

roscopic

Water {oe
Organic matter -
Ignited insoluble residue -

Ignited insoluble residue.

Silica - - - - -
Alumina - - }

Sesquioxide of iron
Lime - -
Magnesia - : -
Potash - - - -

Tron, total amount

34°41
trace.
0°27
6°19
25°68
0°85
0:89
18°45
1°47
0°07
0°30

6°97
5°82
101°37

——

 

5°80
0°21
0°04
0°02
6°07
24°09

 

“This was similar to the last, but ochre-yellow in colour. The insoluble
residue for the most part consisted of siliceous oolitic concretions, and con-
tained also quartzose sand, mica, and small black particles of. magnetic

oxide of iron.”

“ AnNALysis, by Mr. Epwarp Ri.ey, of Northamptonshire Iron-ore from

 

Wellingborough.

a.
Sesquioxide of iron - - - 50°31
Protoxide ofiron - - - trace.
Protoxide of manganese = - - 0°51
Alumina - - - - 7°25
Lime - - - - 11°76
Magnesia - - - 0°62

Potash - - - - _
Silica - - - - 0°22
Carbonic acid. - - - 7°98
Phosphoric acid - - - 1°28

Sulphuric acid - - —=
eee of iron - - 0°17

roscopic - - —
Maier {see - - - 11°00

Organic matter - - - —_
Ignited insoluble residue - 9°33
100° 43

6.
50°48

0°45

11°87
0°60
0°35
7°80

11°07

9°34
124 GEOLOGY OF RUTLAND, &c¢.

Ignited insoluble residue.
Silica - -

 

 

é e 8°58 8°54
Alumina -: - - - 0°27 0°35
Sesquioxide of iron - - - 0°22 0°26
Lime - - “0°16 0°11
Magnesia = - - - trace. =
Potash - - i = 0-11* _

9°34
Tron, total amount - 35°37

‘This was in all respects similar to the last. A minute trace of a malleable
metal, apparently lead, was detected in the ore. Nearly the whole of the
silica, it will be perceived, existed in the form of oolitic concretions. The

insoluble residue contained quartzose sand, mica, and small particles of
magnetic oxide of iron.”

“ ANaLysIs, by Mr. AuLAN B. Dick, of Northamptonshire Iron-ore from

 

 

 

Hardingstone.
Sesquioxide of iron - - - - 74°12
Protoxide of iron - - - - —_
Protoxide of manganese - - - - 0°57
Alumina - - - - - 1°55
Lime - - - - - 0°76
Magnesia - - - - - - 0°18
Potash - - - —_—
Silica - - - - - 0°43
Carbonic acid = - - - - 0°57
Phosphoric acid - - - - 3°17
Sulphuric acid = - - - trace.
ro of iron — - - 0°06
‘oscopic - _
Water | eine - - 11°89
Organic matter - - - trace.
Ignited insoluble residue - - - - 7°15
100° 45
Ignited insoluble residue.
Silica = - - - - - - 5°60
Alumina - - - - 1°36
Sesquioxide of iron - - - - 0°20
Lime - - - - - _—
Magnesia - - - trace.
Potash - - - - - - undetermined.
7°16
Tron, total amount - - - 52°05
“« Awazysts of Northamptonshire Iron-ore from the East End Iron Works,
Wellingborough.
Sesquioxide of iron - - 2 - 76°00
Protoxide ofiron - - - - - trace.
Protoxide of manganese - 0°40
Alumina - - = = 2°30
Lime - - - - a = 0°41
Magnesia - - - - 2 2 0-11 } t
Potash - - - - - z et
Silica Sh - - - 3 e as
Carbonic acid - - - = 2 a4
Carried forward - si 79°29

 

 

* With traces of soda. + Estimated as carbonates.
CHEMICAL CHARACTERS. 125

Analysis of Northamptonshire Iron-ore—continued,
Brought forward - : 79°22
Phosphoric acid - - - 1°03
Sulphuric acid = -
Bisulphide of iron

 

hygroscopic i b 1°80
Wier] enna 12°40
Organic matter - - = ok,
Ignited insoluble residue - - 5°33
99°78

Insoluble residue consisted almost wholly of silica
with a trace of mica.
Tron, total amount - - 53°20
« This ore was ochre-brown in colour. The sample analysed was an average
of three specimens. No appreciable amount of sulphur was found in the ore.’

 Anatysis of Northamptonshire Iron-ore from the Heyford Iron Works,
near Weedon.

Sesquioxide of iron - - - - 56°20
Protoxide of iron - - - - trace.
Protoxide of manganese - - - - 0°20
Alumina - - - - - - 2°43
Lime - - - - - - 0°49
Magnesia - - - - - - 0°17
Potash - - - - - - _—
Silica - - - - - _
Carbonic acid = - - - - _
Phosphoric acid - - - - 0°84
Sulphuric acid = - - - - _
Bisulphide of iron - - - - _
hygroscopic - - - oS 1°16
Water combined. - - - - 9°74
Organic matter - - - - _—
Ignited insoluble residue - - - ~ 29°07
100° 30
The insoluble residue consisted of silica with a little mica.
Iron, total amount - - 39°34

“This ore was similar in appearance to the preceding. The sample analysed
was an average of two specimens. No appreciable amount of sulphur was
found in the ore.”

“ Anatysis, by Mr. ALuan B. Dick, of the inner and outer portions respec-
tively of a lump of Northamptonshire Iron-ore.
Inner portion. Outer portion.
38°

Sesquioxide of iron -

 

 

Protoxide of iron - - - 83°29 10°54
Protoxide of manganese = - - 1-11 0°69
Alumina - - - 4°62 12°35
Lime - - 0°50 trace.
Magnesia = - - - 7°96 4°13
Potash - - - - _ _—
‘Silica - - - - 1°99 1°96
Carbonic acid - - - 24°79 0°16
Phosphoric acid - - - 0°22 0°26
Sulphuric acid - - trace. trace.
Bisulphide of iron - - 0°13 0°13
hygroscopic - - _— —
Water { rehined . - 0°54 6-92
Organic matter - - - 0°08 0°19
Ignited insoluble residue - 24°09 24°61
99°32 99°98

 

 

 

* Estimated as carbonates.
32108. I
126 GEOLOGY OF RUTLAND, &C.

Ignited insoluble residue.

 

 

Silica, - = “ 5 17°50 21°28
Alumina - < ” 3°27 2°67
Sesquioxide of iron a 3°31 —
ime oe - “ trace. trace.
Magnesia = - - 0°81 0°22
Potash - a 2 0°20 0°38
25°09 24°55
Iron, total amount 28°28 34°83

** The inner portion, it will be observed, consists for the most part of
carbonate or protoxide of iron, and the outer portion of hydrated sesquioxide,
the latter having been clearly derived from the former by atmospheric action.
No metal precipitable by sulphuretted hydrogen was detected in a solution of
880 grains of the inner portion of the ore. On the contrary, extremely minute
traces of copper and lead were detected in a solution of 744 grains of the outer
portion of the ore, so that these metals appear to have been communicated
to the ore by water from without.”

“ Anatysis, by My. Davip Forgss, F.R.S., &c., of unweathered portions of

the Northamptonshire Iron-ore from the upper part of a section exposed at
Blisworth, Northamptonshire.

Specific gravity, 3°58.

Protoxide of iron - 49°58 = 79°9 carbonate of iron.
Sesquioxide of iron 5°67 ;
Bisulphide of iron 0°96 =iron, 0°45; sulphur, 0°51
Protoxide of manganese 0°16 ;
Alumina 1°56
Lime - 3°24 = 5°8 carbonate of lime.
Magnesia = - 0°46 = 1°0 carbonate of magnesia.
Carbonic acid - 34°64
Phosphoric acid - 0°44"
Silica - - - 2°16
Organic matter - trace.
Water of combination 1°56

100°43

 

“ ANALYSIS, by Mr. Davin Forsss, F.RS., &c., of unweathered portions of
the Northamptonshire Iron-ore from the lower part of the same section.

 

Protoxide of iron - - 40°93
Sesquioxide of iron - - 6°14
Protoxide of manganese - - 0°16
Alumina - - - - 8°08
Lime - - - 3°47
Magnesia - - - 2°21
Potash = - - 0°19
Sulpkur - - - - race.
abode acid - - - 22°32
Phosphoric acid - - - 1°99
Silica - - - - ~ 9°04
Water = - - - - - 4°92

99°72

“The specific gravity at 60° Fahrenheit was found to be 3°40]; and an
examination by the microscope showed it to consist almost entirely of two
mineral constituents, the one crystalline and colourless, being chiefly carbonate
of iron, and the other of a green colour, probably silicate of alumina and on.
Whether the green colour is due to it or to the presence of phosphate of iron
is not decided, but it appears probable that a green silicate does exist in the
mineral.” :

“1¢ may be roughly estimated to consist of—

80 per cent. of carbonate of iron.
7 per cent. of carbonates of lime and magnesia. ‘
113 per cent. of silicates of iron and alumina with phosphoric acid,
and 14 per cent, of water.”
CHEMICAL CHARACTERS. 127

“ Anaxysis, by Dr. Voricxer, F.R.S., of a friable portion of the
Northamptonshire Iron-gre, near Blisworth.

Protoxide of iron - s 7 - 7 0°875
Sesquioxide of iron 7 - 21°280
Phosphoric acid - - - - ‘1-030
Sulphuric acid - ‘oe - - 07219
Silica, lime, alumina, magnesia, &c. not separately
determined - = - S - 76°596
Carbonic acid = - - - - none.”

 

“ ANALysiIs of hard ferruginous cakes and layers, Northamptonshire lron-ore
deposit near Blisworth.

Protoxide of iron - - - - 1°352
Sesquioxide of iron - - - 76°538
Phosphoric acid - - - 0°020
Carbonic acid = - S - - - 0°014
Silica, alumina, lime, water, &c., not separately
determined : - - 22-076.”

 

From a comparison of the various analyses it appears that the
gray carbonated mineral in the Northamptonshire iron-ore con-
sists of from 60 to 80 per cent. of carbonate of iron, with from
10 to 25 per cent. of insoluble matter, principally sand and oolitic
siliceous concretions; besides these, and existing in smaller pro-
portions, we find the carbonates of the alkaline earths and alkalies,
water, carbonaceous matter, sulphur, and phosphorus. These
last two substances are, unfortunately for the value of the rock
as an iron-ore, always present, and frequently in considerable
quantity.

Carbonate of iron is a salt which when crystallized is trans-.
lucent and perfectly colourless, and in its amorphous forms is of
a pure white colour ; hence we are at once led to inquire what is
the nature of the colouring matter in the rock which we are
studying. The colours, as we have already seen, are various
shades of dull blue and green; the colouring matter, it is pro-
bable, bears only a very small proportion to the mass of the rock,
the blue colour being certainly not more intense than in man
limestones which weather almost perfectly white, and which when
analysed are found to contain only a very small per-centage of
iron. M. Ebelman has shown* that the cause of the blue colour
in many oolitic limestones is the existence of a small quantity of
sulphide of iron diffused through the mass, and I feel little doubt
that the blue colour exhibited by some varieties of the un-
weathered Northamptonshire ore is to be attributed to the same
cause. With regard to the green colour of other varieties there
is probably still Jess difficulty in deciding on its true origin; the
various protosalts of iron which, with the exception of the car-
bonate, are almost all of a pale green tint, at once suggest them-
selves, and especially the silicate and the phosphate. It is the
latter of these salts I am myself inclined to suggest as giving rise to
the colour in question, from the fact that in my various estimations
I have always found sulphur to be in excessin the blue varieties,

 

* Bull. Soe. Géol. de France, 2me Sér. Tom. IX., p. 221.
12
128 GEOLOGY OF RUTLAND, &C.

nd phosphorus in the green ones. This view receives some sup-
ee the analyses ge Mr. Forbes, which show the filling
results :—
Green variety.—Sulphur - trace. Phosphorus - 1°12
Blue a ” - 0°51 4 - 0:25

The skeletons of the oolitic concretions in the Northampton-

shire ore, which are insoluble in hydrochloric acid but are readily
dissolved by a solution of potash, appear to be composed of more
or less acid silicates of the alkaline earths, iron, and the alkalies,
It would also seein that there is contained in the rock some basic
silicates, as a small quantity of silicic acid is always found in the
Jiltrate after digestion in hydrochloric acid. The grains of sand
consist of almost pure silica, Besides the quartz grains and the
siliceous concretions, the insoluble residue contains scales of mica,
carbonaceous particles, both of which are occasionally present in
considerable quantities, and, according to Dr. Percy, grains of
magnetic oxide of iron.

In both the weathered varieties of the rock, the insoluble residue
appears to be identical with that which we have just been describ-
ing. The composition of the soluble portion is, however, very
ditferent, consisting mainly of hydrated peroxide instead of car-
bonate of iron ; alumina, lime, and magnesia are also present, but
in much smaller quantities than in the unweathered rock, The
relative proportions of the ingredients of the two varieties of the
weathered rock are strikingly different; in the light-coloured
earthy mineral the insoluble siliceous matter is in excess, and the
proportion of metallic iron seldom exceeds 20 per cent.; in the
hard and dark-coloured mineral forming the intersecting laminz,
on the other hand, the per-centage of iron frequently rises to
between 50 and 60, while that of the siliceous matter is pro-
portionately small. An interesting inquiry here presents itself as
to what are the relative proportions of these two varieties of
mineral in the mass of the ironstone rock. This is of course
subject to great variation, but by taking average examples and
following the method used in similar inquiries by Mr. Sorby,
namely, drawing to scale a map of a section and from this cutting
out the portions representing the two varieties and weighing
them separately on a delicate balance, I obtained the following
result :—In 100 parts of the rock there were 23 of the dark-
brown material and 77 of the light-coloured.

It will be observed that the brown rock would be formed from
the gray by the subtraction from the latter of carbonic acid and
a quantity of the alkaline earths and alkalies, and the addition
to it of oxygen, to peroxidize the iron, and water.

V.—ON THE CONDITIONS UNDER WHICH THE NORTHAMP-
TON SAND WAS DEPOSITED.

With reference to this portion of the subject a paper was read

at the meeting of the British Association in 1868.* Mr. Jecks,

 

* Colliery Guardian, vol. xvi. p. 197, and Rep. Brit, Assoc. for 1868. Trans. of
Sections, p. 69.
CONDITIONS OF DEPOSITION. 129

the author of that paper, suggested that the formation was de-
posited by large rivers which carried sand, mud, and a solution
of iron into the sea, and that, by oscillations of the land, truly
marine conditions were alternated with the estuarine.

With that part of the theory which refers the Northampton
Sand to the delta deposits of one or more great rivers, I am
perfectly ready to agree, believing that few geologists who have
examined the irregular manner in which these strata are accu-
mulated, their rapid variations in character both vertically and
horizontally, the oblique lamination of some of the beds, indi-
cating the action of currents constantly varying in force and
direction, the alternation of brackish water with marine conditions,
the abundance of the remains of plants, and the evidences of
actual land surfaces, in the intercalated beds of lignite and the
vertical vegetable remains, will be disposed to doubt that we
have here unequivocal evidence of the existence of estuarine
conditions.

When we consider the constant changes which take place in a

large delta ;—how, on the one hand, by the throwing up of sand
bars, tracts before covered by the sea are converted into lagoons
of brackish water, or on the other hand, in consequence of the
breaching of these bars by tidal action, the lagoons are put in
free communication with the sea, and again by means of the
silting up of lagoons land surfaces are formed capable of sup-
porting a rank growth of vegetation,—it will not, I think, be
difficult to account for the deposition of the sands and clays
constituting the Northampton Sand, without finding it necessary
to have recourse to the hypothesis of oscillations of level; at the
same time I am of course tar from denying that such a cause may
have operated to a certain extent.
* From the fact of the beds of the Northampton Sand having a
constant tendency to thin out towards the south-east, as Mr. Hull
has well shown,* it may be conjectured that the river or rivers
which deposited them flowed from the north-west, and this is
perhaps confirmed by the fact that the materials of which the
beds are composed are such as might be furnished by the degra-
dation of the carboniferous and other paleozoic rocks. It is of
course probable that in the Northampton Sand a formation only
averaging from 20 to 30 feet thick, we have only a very slight
vestige preserved of the large amount of material brought down
and deposited during the period.

Towards the close of the period, we find evidences of a gradual
passage into the marine conditions, under which the superincum-
bent limestones were deposited, these latter consisting almost
entirely of dead-shell banks and coral reefs. Above the lime-
stones we have indications of the return, probably after the lapse
of a very considerable period, to estuarine conditions, in the beds
so well exposed in the cuttings of the Great Northern Railway

 

* Quart. Journ. Geol. Soc., vol. xvi. p. 63.
130 GEOLOGY OF RUTLAND, &c

near Essendine, and so fully and clearly described by Professor
John Morris,* ¢ clearly described by Irotessoi

VI.—Moops or FoRMATION oF THE NORTHAMPTONSHIRE
Tron-Ore.

That portion of the theory of Mr. Jecks which deals with the
question of the origin of the iron in the rocks of this formation
is, like all the hypotheses which refer iron-ores to direct deposition,
beset with grave, I believe I may even say, insuperable difficulties.

The condition in which iron usually exists in solution in
nature is as ferrous carbonate, which is soluble to a very con-
siderable extent in water containing an excess of the acid. Thus
in chalybeate springs a very considerable per-centage of iron is
maintained in solution; but when these springs flow into a
running stream the iron, as is well known, is almost instantly
deposited as hydrated peroxide ; this is due to two causes, first,
the large exposure of the water to the atmosphere in the ever
varying surface o: the stream by which carbonic acid is given
off, and oxygen from the air absorbed, and second, the action
of living plants in the stream, which absorb carbonic acid and
give off oxygen ; by these means the very unstable ferrous [car-
bonate is rapidly decomposed, and the iron in the form of brown
oxide deposited on the plants and stones in the bed or on the
sides of the stream, I have on several occasions analysed the waters
of small brooks in coal measure districts, and have invariably
found that, although many springs which were strongly chalybeate
flowed into these streams, and their beds were in consequence
coated with thick deposits of peroxide, yet the quantity of iron
in solution in their waters was almost inappreciable. I do not
believe therefore that the water of any great river, or of the sea
can ever contain more than the minutest trace of iron in solution.
Now in the Northamptonshire iron-ore we are dealing with a
rock, not merely coloured by iron, but one which is a true iron-
stone, containing from 30 to 50 per cent. of the metal; a rock
which we cannot possibly conceive of as being deposited in an
open sea, or river. :

It may at first sight appear that in the Swedish lake ores, and in
the bog ores we have examples of the direct deposition of iron-ores,
which contradict the foregoing statements. ‘This is however not
the case, as the former class of ores are never deposited in‘ run-
ning waters, but only in shallow stagnant pools, among the roots
of plants ; while the accumulation of both kinds appears to be
due to the agency of organic beings.

We have already seen that the condition in which the iron
originally exists in the ironstone is as ferrous carbonate. For the
reasons I have already detailed, it is impossible to believe that
such an unstable salt could have been slowly accumulated to the
thickness of many yards in the sea or an open estuary without
undergoing decomposition.

* Quart. Journ. Geol. Soc., vol. ix. (1853), p. 317.
MODE OF FORMATION OF THE IRON-ORE. 131

The abundance of molluscan? remains in some of the beds of
ironstone, indicating as we have seen that the animals lived and
died upon the spot, precludes the idea that the médium in which
the beds were deposited could have been a strong solution of iron.

The fact that many of the shells in the unweathered rock are
more or less completely converted into carbonate of iron is, as
Mr. Sorby has shown in the case of the Cleveland ore, a strong
proof of the metamorphic character of the rock.

The existence of thin lenticular beds of white clay in the midst
of the ironstone in some localities, as Desbro’ and Neville-Holt,
is a very significant fact. If the strata were deposited in water
containing a large amount of iron in solution, the effect of a
temporary change from sandy to clayey characters in the sus-
pended matter, would be that we should have an argillaceous
ironstone intercalated among the arenaceous ones, and certainly
not that we should have a bed of perfectly white clay in the
midst of a mass of ferruginous strata. On the other hand by the
hypothesis that the iron was introduced after the other materials
of the rock were deposited and partly consolidated, this pheno-
menon is readily accounted for by the pervious character of the
sands and the imperviousness of the clay bands.

Again the theory of direct deposition affords no explanation of
the origin of the singular oolitic concretions, so characteristic of
the Northamptonshire iron-ore.

The foregoing considerations are, I believe, sufficient to lead
us to the conclusion that the hypothesis of the direct deposi-
tion of the Northamptonshire iron-ore is altogether untenable.
Mr. Sorby has shown* that the microscopic and chemical
features of the Cleveland iron-ore are such as to lead us to the
conclusion that it is an ordinary limestone altered by the perco-
lation through it of water containing carbonate of iron in solution.
The various facts which we have adduced in the present chapter
all appear to point towards the hypothesis that the iron-ore of
Northamptonshire is a similarly altered condition of the ordinary
white Northampton Sand,f and that this alteration has often take
place in a very local and capricious manner.

We have already described how in the iron-ore, when unwea-
thered, we find many of the characters of the non-ferruginous sands,
the abundance of plant remains (many of them vertical), the beds
of lignite, the general absence of fossils through the mass, the thin
zones crowded with mollusca, sometimes of marine and at others of
brackish-water species, and the similarity of a part of the insoluble
basis of the ironstone with the materials which compose the white
sands of the formation.

The peculiarities of the section at Exton which I have referred
to are also readily’explained by this hypothesis, when we remember

 

* Proc. Geol. and Polytec. Soc. W. Riding of Yorkshire for 1856.

{It might be- argued that the white sands are a bleached condition of the
ferruginous beds; but that the formner have not undergone a double process of
metamorphism is at once demonstrated by the state of preservation of their fossil
shells, which not unfrequently retain even their nacreous lustre.
132 GEOLOGY OF RUTLAND, &C.

that each of the thin laminz of ironstone rests upon a band of
clay ; the fact too that the Northamptonshire iron-ore, whatever
its thickness, always rests directly upon the Lias Clay is also in
the same way easily accounted for.

: It must be remembered that the action of the water contained
in the substance of rocks at great depths in the earth is very
different from, and much more intense than, that of the same agent
on the surface. Under the combined influences of heat and
pressure, water has been shown to possess solvent powers of which,
under ordinary conditions, it exhibits scarcely the faintest trace.
All geologists are now agreed that water, probably often in large
quantities, is contained in the substance of rocks deeply seated in
the earth; such water is probably the source of supply for most
hot and mineral springs, which in many if not in all cases, appear
to be connected with faults or other disturbances of the rocks
whence ‘they arise; these disturbances appear to have been the
means by which the passages have been opened through which the
waters reach the surface. I need scarcely refer to the part that
these subterranean waters are supposed to play in producing the
phenomena of volcanoes and earthquakes, by a large school of
geological theorists.

It would be easy to show, were it necessary, from the immense
amount of denudation which has taken place in the district, that
the beds of iron-ore now exposed to our observation must have
been long buried at great depths in the earth; during this period,
one of almost inconceivable duration, water containing carbonate
of iron would appear to have constantly penetrated the porous
sandy rock and thus gradually effected its metamorphosis into an
iron-ore. The action of this water would be twofold:—in the
first place it would deposit around the grains of sand and in all the
interstices of the rock, the dissolved carbonate of iron, and in the
second place, acting under the favourable conditions of great
pressure and high temperature, it would dissolve a portion of the
silica and other ingredients of the rock. Of the matter thus
dissolved, one portion appears to have been redeposited in new
combinations and, with the carbonate of iron, to have formed the
oolitie concretions, while the remainder was probably carried away
in solution.

That the theory which we have been describing is free from
difficulties we are far from affirming, but we nevertheless believe
that the difficulties which it may present are rather negative,
the result of our ignorance of chemical forces and processes, than
positive and opposed to laws which have been already well
established. It must be remembered how little has yet been done
in explaining the nature of the operations by which metallic com-

ounds, diffused through great masses of rock, are concentrated
and collected into beds and veins. The difficulty of such investi-
gations probably arises from the minuteness of the causes them-
selves, which nevertheless, by their constant action through periods
of time of almost inconceivable duration, have produced results
so stupendons in themselves and so beneficial to mankind. The
MODE OF FORMATION OF THE IRUN-ORE. 133

experimentalist, too, is constantly hampered by the circumstance
that, limited as is his control over the conditions of heat, pressure,
and the other physical forces, yet his command of the all-essential
requisite, time, is restricted within still more narrow bounds.

VII.—Causrs oF THE REDISTRIBUTION OF THE IRON IN THE
NORTHAMPTONSHIRE ORE.

We have already pointed out the principal circumstances con-
cerning the relative distribution of the carbonated iron-ore and
that in the condition of the hydrated peroxide, which lead us to
the conclusion that the latter is simply the weathered condition
of the former. As, however, a theory quite at variance with this
has been advanced in a very interesting paper published by
Mr. Maw,” it will be necessary to examine some of the phenomena
in a little more detail, and to enter on the inquiry of their bear-
ing on the two hypotheses. The author of the memoir just
referred to, supposes that originally the whole of the ironstone
beds of the Northampton Sand consisted of a nearly uniform
mixture of the carbonate and peroxide, and that by two processes
of “ segregation,” similar in kind but opposite in their modes of
action, the particles of carbonate moved towards a number of
nuclei, and thus formed detached nodules in the midst of the mass,
while the particles of oxide moving in an opposite direction were
accumulated into those hard cakes, which by “ mutual pressure ”
tended to assume that cellular arrangement so characteristic of
the rock.

In considering this theory several serious difficulties meet us at
the very outset.

First. How, on such an hypothesis, is the strikingly rectangularly
prismatic form of the cells to be accounted for? This structure is
most admirably illustrated in one of the beautiful plates accom-
panying Mr. Maw’s paper. “ Mutual pressure” would tend to
the production of cells of irregular polyhedral forms, which would
present in section the figures of irregular polygons, and certainly
not prisms with nearly rectangular sections. ‘That this cellular
structure is in some way connected with the jointing and bedding
of the rock will, we believe, be manifest to any geologist who is in
the habit of studying sections of the rock; this view is strikingly
confirmed by the fact that in some places, as at Easton, the direc-
tion of one set of the sides of the cells is found to exactly coincide
with that of the “master-joints” of the superincumbent lime-
stones.

Second. We might fairly, on the hypothesis of Mr. Maw, expect
to find in the central nodules of carbonate of iron some trace of
a concentric arrangement. But although I have had constant
opportunities of examining large numbers of these and have fre-
quently prepared polished sections of them, yet I have never been
able to detect even the slightest trace of any such structure.

 

* On the Disposition of Iron in Variegated Strata. Quart. Journ. Geol. Soc.
vol. xxiv., pp. 395-398.
134 GEOLOGY OF RUTLAND, &c.

That the whole of the Northamptonshire ore once existed in
the form of the gray carbonated mineral, and that the two varieties
of the brown peroxidized mineral are only altered conditions of
the original rock is, I believe, at once suggested by a study of
the general features of the formation, and strongly confirmed by
an examination of its lithological, microscopic, and chemical
characters. The cause of this alteration was none other than
the percolation of atmospheric water through the substance of
the rock, to which it had gained admission by the planes of
bedding and jointing. The competence of this cause to produce
the effects which we have assigned to it will scarcely be doubted
by those who have witnessed the great depth of some of the
** gossans,” which cover mineral veins, and which are admitted on
all hands to have been formed from the latter by weathering.

The distilled water which falls upon the earth in the form of
rain is, of course, free from solid matter in solution. During its
formation and fall through the atmosphere it dissolves a portion
of its ingredients, namely oxygen and nitrogen (the former being
the more soluble of the two) with traces of carbonic acid and.
ammonia. In the districts composed of the Northampton Sand
and the overlying oolite limestones, the rain which falls is almost
entirely and very rapidly absorbed; indeed the capacity of
absorption in these rocks appears to be practically unlimited, for
not only do many of the streams flowing over boulder clay
instantly disappear under ground -by means of swallow holes,
when they reach the junction of the clay and limestone or sand,
but it is a constant practice in the district when draining the
clays to carry the pipes not into a stream, but to an excavation in
the rock, and these artificial swallow-holes are found never to
fail in their object, even during the heaviest rainfalls. The Upper
Lias Clay or the unweathered “rock-bed” of the Northampton
Sand is, as we have already seen, the great water-bearing bed of the
district, and everywhere along the lines of junction, at the surface,
or wherever a well is sunk, very copious springs are poured out.

Let us now. inquire what is the chemical character of the water
of these springs. In the first place we may notice that, it is never
chalybeate; the few springs of this character in the district have
seldom any connexion with the Northampton Sand, but on the
other hand appear to be connected with the lines of fault. The
water of these springs, however, is very hard, and their hardness
is in a great measure of that kind know to chemists as temporary
hardness ; in other words, the water contains a large amount of
mineral matter, principally the carbonates of the alkaline earths
which are kept in solution by the presence of an excess of carbonic
acid. A very simple calculation would be sufficient to show the
enormous quantity of material which must every year be removed
from the substance of these rocks by the agency of springs. Now
the substances which are dissolved in the waters of these springs
are carbonic acid, carbonates of the alkaline earths and alkalies,
with minute quantities of alumina, silica, and iron, and these are
precisely the materials which, if abstracted from the grey car-
REDISTRIBUTION OF IRON IN THE ORE. 135

bonated mineral of the Northamptonshire ore, would bring it to
the peroxidized condition of the same rock, allowance being made
for the addition of oxygen and water which enters into it from
the atmosphere.

The action of the atmospheric water entering the rock by
means of the bedding and joint planes would have been as
follows :—Carbonate of iron is as we have seen rapidly decom-
-posed in the presence of free oxygen, hydrated peroxide of iron
being formed and carbonic acid set free, the last being of course
at once dissolved by the water. The carbonated water is now
in a condition to act on the soluble portions of the iron-ore,
which we have seen to consist of a small proportion of the
alkalies and a much larger proportion of the carbonates of the
alkaline earths, these it rapidly dissolves as well as minute
quantities of alumina and silica, while traces of the iron may
escape re-precipitation, and thus the hard waters of the springs be
formed. Proofs of the constant passage of water through the
rock of the Northamptonshire ore are seen in the numerous
‘surfaces covered with stalagmitic deposits and the empty double
casts of shells from which the materials of the shell substance have
evidently been dissolved.

But, besides the removal of the carbonic acid and certain
soluble materials from the rock, it has undergone another most
remarkable change, by the redistribution of the iron within it, and
the production thereby of the cellular structure. The accumu-
lation of oxide of iron, in lamine roughly parallel with the
bedding and jointing of the rock, is by no means peculiar to the
Northamptonshire ore, though perhaps in it carried to a greater
extent in it than in any other formation; similar phenomena are
exhibited by many rocks containing more or less iron, when
they become weathered, as the Marlstone Rock-bed, parts of the
Great Oolite, and the Cornbrash. From the study of a large
number of these cases, we are led to the conclusion that in all
of them the penetration of atmospheric water is the cause, con-
cerning the modus operandi of which we venture to make the
following suggestion :—

We have already seen that the light-coloured mineral contains
a much smaller, and the dark-coloured a much larger, per-centage
of iron than the normal condition of the carbonate, in which the
iron is evenly distributed throughout; and a moment’s consi-
deration is sufficient to convince us that the transfer of the iron
through the substance of the rock. could only have taken place
when the former was ina state of solution. Now, as the water
containing oxygen penetrates into the substance of the rock from
a joint or bedding plane, its first effect would be to part with its
oxygen and to take up a quantity of carbonic acid ; but carbonate
of iron being very soluble in water containing carbonic acid, the
liquid contained in the inner portion of the rock would soon
become strongly chalybeate; this liquid, passing outwards by
diffusion, would meet fresh water entering containing free oxygen,
and at the place where the two liquids came into contact we
136 GEOLOGY OF RUTLAND, &c.

should instantly have a precipitation of hydrated peroxide of iron.
This deposition of insoluble material would of course be liable
to take place in planes roughly parallel to those from which the
water acted, and when once such a barrier as this was commenced
in the midst of the rock, to however slight a degree, it would
constantly tend to increase, by retarding alike the outward passage
of the chalybeate water and the inward passage of the oxygenated
water. Thus, along the planes first marked out in the rock in
the manner we have described, a fresh precipitation of the oxide
of iron would continually take place, and these portions of the
rock would become dense, compact, hard, and dark-coloured, while
the remaining portions would by the removal of material be
rendered light, earthy, soft, and pale-coloured. It is evident that
if this operation were repeated a number of times, as it certainly
might be, we should have produced a concentric structure similar
to that which sometimes occurs in the Northamptonshire ore.
Again, it is well known that the hydrated oxide when precipitated
from a solution of iron tends to assume mamillated, botryoidal, and
other peculiar forms, and thus the similar characters, which we
have seen to be so frequently presented by the surfaces of the
hard lamine in the rock, are readily accounted for. The dark-
brown, glazed surfaces of the casts of the fossils in the weathered
ironstone rock may be similarly accounted for, when we consider
the tendency which there will be for water to accumulate in the
spaces left empty by the solution and removal of the substance of
the shells.

VIII.—Concrusions.

I will now give a brief recapitulation of the conclusions of the
present chapter, in the form of a sketch of what I conceive to
have been the history of the formation of the Northampton Sand.

We find, in what is now the Midland district of England, and
at a period separated by a long interval of time from that of the
last deposit in the area, the Upper Lias Clay, that a number of
considerable rivers, flowing through the palmozoic district lying
to the north-west, formed a great delta. Within the area of this
delta the usual alternations of marine, brackish-water, and terres-
trial conditions occurred, and more or less irregular accumula-
tions of sand or mud, in strata of small horizontal extent, took
place. Subsequently, and probably in consequence of the gradual
depression of the area, the conditions were changed, and in an
open sea of no great depth, by the abundant growth of coral
reefs and the accumulation of dead-shell banks during enormous
periods of time, the materials of the great deposits of the Lincoln-
shire Oolite limestone were formed. On a re-elevation of the
area the former estuarine conditions were also reproduced and
similar deposits, but of an argillaceous rather than an arenaceous
character, were formed. Confining our attention to the earlier of
these two estuarine series, that of the Northampton Sand, we ‘must
imagine the beds as being carried down to great depths in the
earth by the deposition upon them of the superincumbent strata.
CONCLUSIONS. 137

But at the same time another most important cause has come
into operation, namely, the passage through some portions of the
rock of subterranean water containing carbonate of iron in
solution. By this agent carbonate of iron was deposited in the
substance of the rock, while portions of the siliceous and other
materials were dissolved ; and these, entering into new combina-
tions, were in part re-deposited in the mass of the rock in the form
of oolitic grains, and in part, probably, carried away in solution
During the existence of the beds under a great pressure of over-
lying rocks, they would likewise become consolidated and jointed.
These metamorphic processes would probably take place with
extreme slowness, and may possibly still be going on, where the
rock remains deep seated in the earth; by their means portions,
greater or less, of the sandy strata, but. always those resting
immediately on the impervious Upper Lias Clay, would be gradually
converted into solid and jointed rock beds, composed principally
of carbonate of iron. The next stage in the course of alteration
in these rocks would commence when, by the action of denudation,
portions of them were brought again near to the surface, so as to
be traversed by the atmospheric waters, entering them as rain and
passing away from them as springs. The action of this water is,
as we have seen, to remove the carbonic acid and soluble salts,
to change the protoxide of iron into hydrated peroxide, and to
redistribute it in such a manner as to produce the remarkable
cellular structure of the rock, and also the mammillated, botryoidal,
and sculptured surfaces. Finally, by mechanical, as distinguished
from chemical, sub-aerial denudation, the beds of Northamptonshire
iron-ore nearest the surface are disintegrated and broken up, and
the softer and less ferruginous portions to some extent carried
away in suspension, and thus deposits, composed of the harder and
denser materials, formed, constituting the bed usually worked as
an iron-ore,

If the arguments and deductions brought forward in this chap-
ter be accepted, it will be seen that the formation and metamor-
phoses of this rock are alike principally due to one agent, water,
acting under various conditions. ‘The rain which falls upon the
surface of the land may be disposed of in one of four ways. First.
It may be returned, almost as soon as it falls, to the atmosphere by
eviuporation, without producing any effect on the rocks. Second.
It may produce direct mechanical erosion by flowing over the
surface and collecting into watercourses. Third. It may penetrate
into the rocks by their joints and fissures, and after effecting within
them chemical disintegration, thereby rendering them more suscep-
tible of mechanical degradation, reappear as springs to swell the
mechanical action of the portion before mentioned. Fourth. It
may penetrate the substance of the more deeply seated rock-beds
and, aided by heat and pressure, effect various metamorphoses
within them, probably also giving rise to the phenomena of
mineral and hot springs, earthquakes, and volcanoes.

It may fairly be objected that, in the foregoing remarks, we
have not succeeded in giving a complete explanation of all the
138 GEOLOGY OF RUTLAND, &c.

circumstances connected with the origin of the remarkable and
very interesting rock of the Northamptonshire ore. On the other
hand, as an important part of every inductive inquiry consists in
the examination of all possible hypotheses and the rejection of
those which are proved to be untenable, thus narrowing the range
of speculation within certain determined limits, we venture to hope
that the foregoing observations will prove to be a contribution
towards the solution of a problem of great difficulty and obscurity.
The questions of the original source of the iron, the mode of its
accumulation in subterranean water, of the nature and mode of
action of the molecular forces which produce mammillation and
other allied phenomena, and which certainly follow laws, it may be
more complex, but not less definite than those of erystallization,—
these are subjects which have scarcely yet been attacked by
geologists, but concerning which, in spite of their difficulty and
obscurity, the secrets will assuredly one day be wrung from nature,
by combining patient observation with persevering experiment.
CHAPTER VII.

LINCOLNSHIRE OOLITE LIMESTONE, WITH THE
COLLYWESTON SLATE.

This series of limestones was formerly considered as the equiva-
lent of the Bath Oolite, but is now, on conclusive stratigraphical
and paleontological evidence, referred to the Inferior Oolite. For
the grounds on which these strata have been removed from the
Great Oolite to the Inferior Oolite series, and the reasons for.
the nomenclature which I have proposed for the several members
of the Lower Oolites in the Midland district, I must refer to the
Introductory Essay to this Memoir (see pp. 1-40). Although the
formation extends northwards into Yorkshire, and southwards into
North-Northamptonshire, yet it attains its greatest thickness and
prominence in the county from which it takes its name. Its hori-
zontal extent is, however, by no means commensurate with its
great thickness and importance, for it is found to thin away rapidly
southwards, eastwards, and northwards; it should probably be
considered as the eastern portion of a great lenticular mass of
marine limestones intercalated between the Upper and Lower
Estuarine Series. : E

.The beds of the Lincolnshire Oolite display very various
characters in different localities. Two aspects which it assumes,
however, may be specially characterised.

The first of these we have called the “coralline facies” and it
is characterised by beds of slightly argillaceous limestone, of com-
pact, sub-crystalline, or but slightly oolitic texture, abounding with
corals, which are usually converted into masses of finely crystallized
carbonate of lime. The shells, which by their great abundance
specially characterise this facies, often occur in the form of casts only,
and consist of several species of Nerinwa, Natica Leckhamptonensis,
Lyc., Pholadomya fidicula, Sow., and P. Heraulti, Ag., Ceromya
Bajociana, VOrb., Pinna cuneata, Phil, Mytilus Sowerbyanus,
d’Orb., several species of Lima, and Terebratula submawillata, Mor.
The patches of limestone rock constituted in this manner afford
ample evidence of having once been coral reefs ;* near Castle
Bytham a pit is opened in a rock seen to be almost wholly made
up of corals. f . :

The other variety of the Lincolnshire Oolite, which we have'called
the “ shelly facies,” consists almost wholly of small shells or fragments
of shells, sometimes waterworn and at other times encrusted with
carbonate of lime. The shells belong to the genera Cerithium,
Trochus, Monodonta, Turbo, Nerinwa, Astarte, Lima, Ostrea, Pecten,
Trigonia, Terebratula Rhynchonella, &c.; and spines and plates of
Echinoderms, joints of Pentracrinites, and teeth of fishes also occur
abundantly in these strata, which exhibit much false bedding.
The Gasteropods are usually waterworn, and the specimens of

 

* Similar coral reefs in other portions of the oolitic series have been described by
Dr. Wrigut in an interesting memoir published in he Proceedings of the Cotteswold

Club.
140 GEOLOGY OF ‘RUTLAND, &C.

Conchifera and Brachiopoda usually consist of single valves often
broken and eroded. These beds it is clear were originally dead-
shell banks, accumulated under the influence of constantly varying
currents.

The rocks of the two facies of the Lincolnshire Oolite do not
maintain any constant relations with one another; at some places,
as Barnackand Weldon, beds of the shelly facies occur almost at
the base of the series, while at others, as about Geddington and
Stamford, the strata with the coralline facies occupy that position.
Sometimes, as at Ketton and Wansford, we find beds in the Lin-
colnshire Oolite entirely made up of fine oolitic grains, and these
constitute some of the most valuable freestones. Very rarely the
grains of which the rock is composed are very coarse, and it becomes
a pisolite. At some points, as near Little Bytham, the rock
assumes a very singular character, being filled with irregular
masses, each surrounded by a thin pellicle of carbonate of lime,
which when broken across are seen to be made up of the usual oolitic
grains. Sometimes, especially at the top of the series, the beds of
the Lincolnshire Oolite assume variegated tints, red and purple
being the predominant colours.

A striking feature in all the beds of the Lincolnshire Oolite is
the almost total absence of shells of the Cephalopoda, and in this
respect, as in many others, it resembles the freestone beds both of
the Great and the Inferior Oolites of the south-west of England;
all of these beds, indeed, were evidently deposited under very
similar conditions.

It is evident that the great mass of the Lincolnshire Oolite was
deposited under moderately deep-water conditions, but in its lower
part we find, in certain beds which indicate a gradual transition
between it and the estuarine series below, decided evidence of the
prevalence of littoral conditions. These lower beds of the limestone,
which are usually more or less arenaceous and alternate with beds of
sand, frequently, as about Cottingham, Morcott, and Wansford, con-
tain large quantities of wood with the remains of ferns and other
plants; Polypodites Lindley, Gépp (Pecopteris polypodioides, Lindl.
& Hutt.), and other species, which are found also in the Lower
Sandstone, Shale, and Coal of Yorkshire, characterise these beds.
Sometimes the sands which alternate with the lower beds of sandy
limestone are full of calcareous concretions, the associated limestones
exhibiting broad mammillated surfaces which give rise to the masses
known to quarrymen as “potlids”; occasionally, as at Dene, the
sands pass into a very hard siliceous rock full of plant-remains.

The lowest of these beds of sandy limestone frequently becomes
so fissile, when exposed to the action of frost, as to split under the
hammer into thin flags fit for roofing purposes. These constitute
the well-known Collyweston Slate. The surfaces of the Colly-
weston Slates exhibit ripple-markings, worm-tracks, and burrows,
and numerous plant-remains, all indicating the close proximity of
the shore; they yield numerous shells, among which may be
specially mentioned Gervillia acuta, Sow., Pinna cuneata, Phil., Tri-

onia compta, Lyc., Lucina Wrightii, Opp., Myacites Scarburgensis,
hil., sp., and Pterocera Bentley, Mor. and Lyc.; these beds, how-
ever, do not afford that abundance of interesting remains of insects,
crustaceans, fish, reptiles, and mammals which have made the
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 141

Stonesfield Slate so famous. The remarkably local character of
such slate beds in the Jurassic series has been already pointed out
in the Introductory Essay prefixed to this Memoir (see pp. 4, 6).

- AtStamford the Lincolnshire Oolite is about 80 feet thick, and
northwards it increases and acquires proportions probably exceed-
ing those of the Inferior Oolite of the Cotteswold Hills. In the
southern part of this sheet, at Geddington, it is only 123 feet thick,
and it thins out entirely a few miles further south near Harrington
and Maidwell. As we go eastward we also find it rapidly thinning
out, and at Water Newton Brickyard, Wansford ‘Tunnel, Wood
Newton, and near Cross Way Hands Lodge, and Stone-pit Field
Lodge. it is seen as a bed only a few feet in thickness separating
the Upper and Lower Estuarine Series; these a littlé further to the
east being found in actual contact.

The Lincolnshire Oolite of the district described in this Memoir
affords valuable building materials, both ragstones and freestones,
which are extensively dug at many places, as Ketton, Clipsham,
Casterton, Stamford, Weldon, Wansford, &c. The freestones are
of greatest value-when they are quarried under the clays of the
Upper Estuarine Series ; that of Ketton which, however, is only
three feet thick, is especially famous for its strength and dura-
bility. :

Te medieval times the well-known “ Barnack-rag ” was very
extensively worked and was carried by water to all parts of Lin-
colnshire and the fen country for the erection cf many noble Gothic
structures.* The limestones of the Lincolnshire Oolite are exten-
sively used for the manufacture of lime both for agricultural and
building purposes.

The Collyweston Slates were formerly dug at many places
within this sheet for roofing purposes, as at Kirby, Duddington,
Medbourn, &c. The demand for such materials has of late years,
however, greatly declined, owing to the competition of the Welsh
slate, and they are now only raised at Collyweston, and to a very
small extent near Dene.

The Lincolnshire Oolite forms a light and not very productive
soil, which is apt to be very treacherous in dry seasons; it is
usually of a red colour, owing to the comparative indestructibility
of the thin band of ironstone which lies upon it, and which we
shall presently describe.

In consulting the map described in this Memoir it must be con-
stantly remembered that the rocks indicated upon it are not in all
cases exposed at the surface. This is especially the case with the
Lincolnshire Oolite Limestone. The deposits of boulder clay,
sometimes attaining a thickness of over 200 feet, over large areas
wholly conceal the subjacent rocks. In these cases, in order to
preserve uniformity with the other portions of the Geological

 

* The working of this stone appears to have been almost entirely abandoned
before the beginning of the fifteenth century. At the village of Barnack a statue of
evident Roman workmanship bas been found carved out of the easily recognised
“rag”; in the beautiful parish-church the Saxon, Norman, Early English, and
Decorated portions are built of the same material, but in the fine mortuary chapel,
which is of Perpendicular age, stone from another locality has been employed.

32108. K
142 GEOLOGY OF RUTLAND, &C.

Survey Map of England, the probable outcrops of the strata have
been indicated by means of dotted lines. It can scarcely be doubted,
however, that, as in the portions of the area where the Jurassic

beds are fully exposed through the removal of the overlying.

boulder clay by denudation, the surface of the Lincolnshire Oolite
strata is diversified by outliers of the Great and Middle Oolite
beds, and by inliers of the several members of the Lias; while

curvatures and faultings of the strata have doubtless introduced.

complications among them, the details of which we are totally
destitute of the means of ascertaining. Hence, in those portions
of the map where the lines are dotted, it must be remembered that
it has been impossible to do more than to strike a balance of
probabilities as to the nature of the rocks underlying the superficial
deposits, after a careful examination of all the evidence which
could be procured.

The main fine of outcrop of the strata of the Lincolnshire
Oolite Limestone constitutes a band, with a varying breadth of
between three and four miles, crossing the area included within
Sheet 64 from north to south. In itssouthern half, or between the
valley of the Barford Brook and that of the Welland, the strike of
this great, band of calcareous strata is almost exactly S.W. and
N.E.; but to the northwards of the last-mentioned valley the
strata are affected by a series of powerful disturbances, to be more
fully described hereafter, and their strike becomes nearly due N.
and S. In its southern part this band of Inferior Oolite Lime-
stones is almost entirely concealed by the thick masses of boulder-
clay, which are only cut through in some of the deeper valleys
intersecting the district; in its northern portion, however, the
outcrop of the Lincolnshire Oolite Limestone within Sheet 64 is
much more fully exposed, the boulder clay constituting only a num-
ber of outlying patches. The difference in the appearance of the
tracts to the north and south of the Welland respectively, in the
former of which the Lincolnshire Oolite Limestone immediately
underlies the surface soil, while in the latter it is thickly covered by
boulder clay, is very striking. In the first case we have very light
soils of a bright red colour (due to the remarkable persistence of
the ferruginous masses of the “Ironstone junction band ” which
everywhere lies on the top of the Lincolnshire Limestone), while
in the second we find cold stiff clay lands, which until very recently
were almost everywhere covered by thick forests. The Ordnance
Map of this district is unfortunately very old, and the country
south of the Welland is represented as it was before the extensive
clearances of the forest land of recent years had taken place.
This has often"rendered the tracing of the outcrops of the various
beds a very difficult task. Scat :

Besides the exposures along the main line of outcrop stretching
from south to north in Sheet 64, the beds of the Lincolnshire
Limestone are displayed at many points to the eastward and the
westward of that band. In the Faemer case their appearance at
the surface is due to the removal by denudation of the overlying
rocks.along the lines of river valleys, those of the Nene, Gwash
and Glen, and their various tributaries. In the latter case, patches
of the Inferior Oolite Limestone survive as outliers of various
dimensions capping some of the higher hills of the district, their
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 143

preservation in these cases having been in many cases aided through
the strata being let down by faults, as an inspection of the map
will show.

In the south-eastern part of the area, namely in the valley of
the Nene about Oundle, the Lincolnshire Oolite Limestone is
found to have thinned out and wholly disappeared. Thus the
Upper Estuarine Series of the Great Oolite, in that neighbourhood,
comes to rest directly upon the Lower Estuarine series and the
ferruginous beds (Northampton Sand) of the Inferior Oolite without
the intervention of the calcareous rocks of the latter formation.
Northward, in the valley of the Nene about Stibbington, Castor,
and Water Newton, this easterly attenuation and disappearance of
the Lincolnshire Oolite can be well studied. Southwards, beyond
the limits of Sheet 64 (in 52 N.W.), the same great calcareous
formation is again seen thinning out and disappearing.

. The details which we have already given in the Introductory
Essay of this Memoir concerning the Lincolnshire Oolite Lime-
stone, in its range from North Northamptonshire to South York-
shire, enable us to conceive of this interesting formation as origi-
nally a great leuticular mass of calcareous rocks, the western half
of which has been wholly removed by denudation. Of the remain-
ing half of the great irregular “lens ” the thickest portion can be
traced in Mid- and South- Lincolnshire ; and as we pass northwards, .
southwards, and eastwards from this district, the strata are found
continually diminishing in thickness, and finally disappearing
altogether. ;

The paleontological evidence in favour of regarding the Lincoln-
shire Oolite as a, locally, very finely developed representative of the
Zone of Ammonites Sowerbyi, which in other parts of England is
only present in a rudimentary condition, has also been discussed in
the introductory portion of this Memoir.

The conclusion, therefore, to which we are led by the study of
the Lincolnshire Limestone is as follows:—During a portion of the
Jurassic period, well marked within the ancient life-province now
constituting Britain, Northern France, and Western Germany, by
the abundance of certain characteristic species (those of the Zone
of Ammonites Sowerbyi), local depression took place within an
area having a diameter of something like 90 miles, the amount of
depression being greatest within its centre. As a consequence of
this local depression there was slowly accumulated, by the growth
of coral reefs, and the action of marine currents sweeping small
shells and their fragments along the sea-bottom, a mass of cal-
careous strata, presenting many variations in its local characters,
and constituting the formation to which we have applied the name
of the “ Lincolnshire Oolite Limestone.” ;

There is evidence that the accumulation of this mass of cal-
careous strata was followed by upheaval, accompanied by some
local disturbances and even faulting of the rocks (see Introductory
Essay, pp. 33-38). It is also clear that, both previous to the for-
mation of this series of calcareous strata and subsequently to its
upheaval and partial denudation, estuarine characters prevailed
within the area of its deposition, and also far beyond those
limits.

K 2
144 GEOLOGY OF RUTLAND, &c.

In order to make more clear the fact of the thinning out of the
limestone strata of the Lincolnshire Oolite and the peculiar re-
lations of the Great Oolite Series and the Northampton Sands
which result from it, we have given in Plate II. two sections in
which the phenomena alluded to are illustrated. <A clear. per-
ception of the relations of the Lincolnshire Oolite to the other
strata of the district is absolutely necessary to anyone who
would understand the physical structure of the district included
within Sheet 64 of the Geological Survey. As supplying addi-
tional illustrations of the same subject I may direct attention
to Mr. Sharp’s admirable paper on the Lincolnshire Oolite Lime-
stone, forming the second part of his Memoir on -“ The Oolites
of Northamptonshire,” (see Quarterly Journal of the Geological
Society, vol, xxix. p. 225). The line of section between Rocking-
ham and Oundle given on Plate X. accompanying that Memon,
together with the numerous details concerning many very in-
teresting sections, cannot fail in their object of placing the true
relation of Lincolnshire Oolite to the beds, respectively below and
above it, altogether beyond controversy.

In describing the rocks of the Lincolnshire Oolite series, as
developed within Sheet 64, it will be most convenient to deal, in
the first place, with the sections of its strata which are displayed
along that band forming its main line of outcrop, which we have
already noticed as stretching throughout the district from Gedding-
ton and Rushton on the south to Thistleton and South Witham on
the north. We shall then proceed to notice the more or less isolated
exposures of the same rocks revealed to us by the denudation of
the overlying strata, to the eastward of the main line of outcrop ;
and, finally, we shall describe the several outlying patches, usually
occurring at high levels to the west of the same line. 4

Main line of Outcrop of the Lincolnshire Oolite—As already
noticed the Lincolnshire Oolite Limestone constitutes a band, having
a breadth of from three to four miles, which between Rushton and
Duddington has a general strike from S.W. to N.E., but from
Duddington northward strikes nearly from S.to N. This sudden
and marked change in the direction of the line of outcrop of the
strata is due, as we have seen, to the influence of great disturbances
and faulting of the strata along the line now occupied by the
valleys of the Welland, Chater, Gwash, and Nene. In the
southern part of this great band of calcareous rocks the boundaries
of the several members of the Jurassic series is unfortunately
rendered very obscure, by the prevalence and great thickness of the
overlying drift deposits.

The description of the extreme southern limits of the Lincoln-
shire Oolite, as seen in the more or less isolated patches of Old
(or Wold), Maidwell and Harrington, and at Glendon and Weekley
(see quarter-sheet 52, N.E.) does not come within the province of
the present Memoir. Some details on the subject will, however,
be found in the Introductory Essay prefixed to this Memoir
(Pp. 36-38), and in Mr. Sharp’s paper referred to above (pp. 229-234).

he Strata of this horizon are first encountered, in entering the
area of sheet 64 from the south, in the vicinity of the villages of
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 145

Geddington, Newton, and Rushton. The principal sections in this
neighbourhood are as follows :—

Limekiln at north-west angle of Weekley Hall Wood.
At this place there are very extensive stone-quarries.

(1.) Soil _ - - - - - - - 9 inches.
(2.) Rubble Oolite —- - - - - - 2 ft.
(Inferior Oolite.)

(3.) Hard, compact and sub-crystalline limestone, in places con-
taining scattered oolitic grains, with strong joints but
without clay partings, containing many specimens of 4 ft
Nerinza, but comparatively few other fossils; among :
the latter are, Natica Leckhamptonensis, Lyc., Lucina
Bellona, d’Orb., and Corals. This stone is underlain by
(4.) Well-stratified, calcareous sands of yellowish, brownish,
and greenish tints, containing small lenticular masses of
very sandy clay - - - - - - 4 ft.
These are probably the uppermost beds of the Lower Estuarine Series.
This bed is underlain, at the bottom of the pit, by darker brown ferru-
ginous sands.
The sands at this place are dug for building purposes.

Large pit immediately south of the former, the stone dug for road-metal.

(1.) Soil.
(2.) Boulder Clay of the usual character, consisting of light-blue

clay, containing many boulders, principally of chalk and

flint, grooved and striated - - - - Oto 6 ft.
(3.) Inferior Oolite, as in the last pit, but very hard and blue-

’ hearted (from being dug under the Boulder Clay); the bed

is divided into very large blocks by joint-planes, which

are often very much open and filled with Boulder Clay.
This rock consists of three courses, not separated ye clayey partings :—

in. :

The lst course . -2 0 1
» 2nd ,, - - -1 667 ft.
2 3rd ” > ma ~3 6
Underneath the beds of stone is a hard, sandy layer 3 inches thick, beneath
which is seen yellow sand, as in the last pit.
Tn the limestone in this pit the following fossils occur :—
Belemnites, sp. ?
Natica Leckhamptonensis, Lyc. (very abundant and sometimes very
large).
N me cingenda, Bronn, and other species.
Ostrea flabelloides, Lam. (O, Marshii, Sow.) var. (rave).
Modiola, sp. ?
Mytilus Sowerbianus, d’Orb.
Pinna cuneata, Bean. (not rare).
Lima, cardiiformis, Lye. and Mor.
bellula, Lye. and Mor. :
3» sp-? (Rodborough Hill Species).
» sp.? (the very large form).
Ceromya Bajociana, d’Ord.
Tancredia, sp. ? .
Pygaster semisulcatus, Phil.
At the limekiln opposite Geddington Grange we find Lincolnshire Oolite,
similar to that at Glendon, of which the bottom is not seen.
- South-west of Newton and on the opposite side of the valley are found
traces of old iron workings, with abundance of black slag of the usual character.
In a stone-pit on the road from Geddington to Grafton-under-Wood, imme-
diately above Geddington, there occurs an éxposure of the Lincolnshire Oolite,
presenting its coralline facies precisely similar to that seen at Glendon, and
displayed in a face about 6 feet in height.

Eee
146 GEOLOGY OF RUTLAND, &C.

In the irregular surface of the rubble which covers this rock, traces of the
“ ferruginous junction-band ” and the “ carbonaceous clays and sands of the
** Upper Estuarine series”’ are seen.
Pholadomya fidicula, Sow., occurs in the limestone here.
At the limekiln immediately south-east of the last (Mr. Bell’s pit), the
following section occurs :— 7
FE sat iow oneainon Sein 23
-) Pale bluish-white clay, with carbonaceous markings - 2to
(3.) Indurated, variegated, sandy clay (bright yellow, eis blue, oe
ash-coloured, pink, crimson, and greenish), occasionally
traversed by ironstone lamine - - - - 1 ft
(4.) Irregular ferruginous band - - - - 2in,
(5.) Ash-coloured sands with irregular clay seam: - - Sin.
(6.) Fine white clay with carbonaceous markings - - 3 to 6 in.
(7.) Band of ironstone nodules (ferruginous junction-band) _- 6 in,
tee wee beds belong to the Upper Estuarine Series of the Great
e).
(8.) Inferior (Lincolnshire) Oolite, consisting of—
a. Rubbly limestone - - -3 ft. 7
b. *Course of hard, somewhat oolitic, lime-
stone - - - - 1 ft.
c. Course of compact limestone  - - 2 ft.
ey x5 5 - - 2ft. Gin.
e. Three coursest of hard limestone, blue- :
hearted, 1 ft. each - - 3 ft. 12 ft. 6 in.
J. Course of very sandy limestone, mica-
ceous, hardens with drying, finely |

 

‘laminated, and containing many car-
bonaceous markings (equivalent of the
Collyweston Slate) - a 1 ft.

(9.) Yellow sand, top of the ‘‘ Lower Estuarine Series.”’

N.B.—In a. well at a cottage near, the “ red-rock ” (Northamptonshire Iron-
Ore) was reached.

Above and behind the church at Geddington there is an old pit opened in
the Lincolnshire Oolite Limestone. Another old stone-pit occurs ai the angle
of Newton Lane and the Avenue ; and here we find a compact, marly limestone
crowded with specimens of Nerinea (the Coralline facies of the Lincolnshire
Oolite). Near Geddington Grange there are two large stone-pits in the same
marly limestone rock containing an abundance of Nerineas, and along the
sides of Newton Lane, and on the road leading from Geddington to Rushton
there are several large pits in the same beds.

Near Rushton there occur the following sections :—

In a pit at the north-east corner of Rushton Park, is seen a rock 9 to 10 feet
thick (coralline facies) with the usual characters, the lower courses becoming more
and more sandy in character ; the lowest bed but one contains plant remains,
and the lowest bed of all consists of hard slabs of sandy limestone, having a
tendency to split into slates (equivalent of Collyweston Slates). This bed
rests on sands and clays of the “ Lower Estuarine Series ” (Northampton Sand).

In the valley crossing the road, one mile north of Rushton Hall the stream has
cut through the Boulder Clay and exposes the Inferior Oolite Limestone,
which here presents, for the first time in going northwards, the “ shelly facies”
of the Lincolnshire Oolite.

Passing northwards from Rushton we again find, at the limekiln half a.
mile north-east of the village, the beds of the Lincolnshire Oolite Limestone
_ consisting of about 12 feet of rock lying in regular courses; the stone here
is somewhat intermediate in character between that at Glendon (“coralline
facies ”) and that at Pipwell (“shelly facies ”’).

 

* In this bed occur numerous specimens of Pholadomya Heraultii, Ag., and Pinna
cuneata, Bean, in their natural positions. The courses of stone are separated by some-
what sandy partings.

+ The uppermost of. these three courses is almost entirely made up of Nerineai
they become sandier as we pass downwards.
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 147

The following fossils were seen here :—

Pholadomya fidicula, Sow.
Natica Leckhamptonensis, Lyc.
Pinna cuneata, Bean.

Ceromya Bajociana, d’Ord.

Northwards from Geddington we find a large stone-pit ‘with a lime-kiln
pends the road leading to Little Oakley. The following is the section presented
in this pit :—

(1.) Beds of white, compact, slightly oolitic stone  - - 6 to 8 ft.

(2.) Beds of hard, white, sub-crystalline limestone crowded

with Nerineas, and containing great masses of coral

converted into finely crystallized Calespar (Nail-head

and Dog’s tooth spar) —~—«- - - - 1 ft. 9 in.

(3.) Beds of coarse sandy limestone - - - - 2 ft.

Coarse, sandy, flaggy bed, covered with vermicular and

other markings, very inconstant (equivalent of Colly-

weston Slate) - ~ - -~ - - Oto 3 in,
Brown Sand. ;

The fossils obtained in this pit were as follows :—

Natica Leckhamptonensis, Lyc., large and abundant.
Alaria Phillipsii, d’Ord.

Actzonina glabra, Phil.

Nerinza, sp.? very abundant.

Chemnitzia Scarburgensis, Lyc. and Mor.
Pinna cuneata, Bean.

Gervillia acuta, Sow.

Pecten paradoxus, Miinst.

Hinnites abjectus, Phil.

Modiola Sowerbyana, d’Orb.

Cardium cognatum, Phil.

Large masses of Isastr@a and other corals, sometimes perforated by Litho-
domi, also occur in this pit.

Crossing the high ground between the Barford Brook and Harper’s Brook,
where the Jurassic strata are entirely concealed by the overlying Boulder Clay,
which here attains a thickness of probably not less than 200 feet, we reach a
series of fresh exposures of the beds of the Lincolnshire Oolite Limestone, in
the vicinity of the villages of Pipwell and Little Oakley.

At Pipwell Upper Lodge, and on the opposite side of the road to the farm-
buildings, traces of the outcrop of the Lincolnshire Oolite above the North-
ampton Sand, there exposed, were detected. .

Near Pipwell Abbey there are several large grass-grown quarries which
were evidently opened in the beds of the Lincolnshire Limestone. One of
these quarries had been used recently, and under the beds of the Upper Estua-
rine Series, capped by Boulder Clay, I found the shelly freestone presenting its
usual characters. The same stone is seen near the mansion of Pipwell Abbey
and in the bed of the stream which flows near it; the rock here yields the
usual fossils. . .

The following is the detailed section of the beds seen in the pit referred
to in the foregoing paragraph.

Old pit at Pipwell Abbey.
(1.) Boulder Clay - - - - - perhaps 15 or 16 ft
Upper Estuarine Series, the upper part not seen. .
(2.) Band of ash-coloured and drab clays . - 2in.
(3.) Coarse, brown sand becoming more ferruginous at :
its base - - - - 1 ft. 8 in,

(4.) Stiff, bluish-white clay with carbonaceous markings 10 in.
(5.) Brown sand - - . - + 10 in.
(6.) Variegated clay,—blue, yellow, brown, drab, and

greenish - = = - 2 ft.
(7.) Irregular band of Ironstone (ferruginous junction- __
band) - - ~ - - » 2in
Lincolnshire Oolite Limestone. 5
(4.) Decomposed oolitic rock = - - - 1 ft, 6 in.

(9.) Five courses of oolitic limestone seen - together 8 ft.
148 GEOLOGY OF RUTLAND, &C.

h deut (Fig. 12) represents the face of rock exhibited in a larg
ee ee ie the valley, one-third of a mile east of Pipwell Abbey.
This section is exposed on the south side of the quarry, the direction of its
face being nearly due east and west, its length 30 feet and its height 21 feet.

 
  

G

LLL
ZEAE

.

ZL
Zils

SEE
[27
PE

E

az

Seep

GZ
FS

So,

Fig. 12. Stone-pit in shelly beds of the Lincolnshire Oolite Limestone near Pipwell Abbey.
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 149

The beds of the Lincolnshire Oolite in this locality present, as is shown in
the drawing, the usual false-bedding so characteristic of the shelly facies of the
formation.

On the opposite side of the pit to that of which the sketch is taken, in holes
and pockets of the rubbly oolite, are seen the light-blue and variegated clays
of the Upper Estuarine |Series ; and similar indications of the ferruginous
“ junction-band ” exist, the whole being covered with rubble and soil.

The section seen here is as follows :—

(1.) Thin, rubbly, evenly-bedded, shelly oolitic limestone - 1 ft.

(2.) Harder false-bedded limestone of the same kind - 2ft.

(3.) Course of do., evenly: bedded oolitic limestone - - 1 ft.

(4.) a $5 false bedded 38 - - 2ft.

(5.) Three irregular courses of 55 - 2 ft. 6 in.

e) Very coarse false-bedded irregular course - - 1 ft.

( 2 ” ” ” ss 1 ft.

(8.) Bed of hard shelly ragstone - - - 1 ft. 6in

(9.) Softer oolitic bed - - - - lft.
(10.) eB - - - 1 ft.
CID) ee a8 - - - 1 ft. 6in
(12.) Hard ragstone bed - - ros 8 in.
(13.) Two soft freestone beds, each 1 ft. 3ins. - - 2ft. Gin.
(14.) Two hard. 9 9 - 2 ft. Gin.

(15.) White Clay (top of the Lower Estuarine Series).
N.B.—Possibly sandy beds occur at the base of the series.

The beds in the neighbourhood of Pipwell and Oakley exhibit signs of con-
siderable disturbance, and besides being traversed by the faults shown upon
the map, are evidently bent into long folds. :

Lower down the Hamers Brook the Lincolnshire Oolite Limestone is well .
exhibited again; but the whole of the strata here are affected by a very com-
plicated series of faults, as will be seen by an inspection of the map.

Very extensive quarries, known as Lord Cardigan’s pits, are seen in the east
side of the village of Stanion. The rock here exposed is a hard, shelly oolite,
and is found to rest, not on the usual white clays, but on “kale” (ferruginous
sandstone of the Northampton Sand).

To the west of the same village another quarry, known as the “town pit,”
presents the following section :—

(1.) Boulder Clay - - - - - 3to4 feet.

(2.) Oolite rubble, much mingled with clay and con-

taining fine crystallizations of Calcspar - 2 feet,
(3.) Beds of hard, crystalline, marly oolite used for
road-metal - - - - dug to the depth of 4 feet.

Under the beds of stone about 3 feet of brown, sand occurs, at the bottom
of which springs arise, indicating probably the presence of the compact iron-
stone rock of the Northampton Sand.

Between Stanion-and Brigstock the Lincolnshire Oolite Limestone is ex-
posed, and its relation to the beds above and _ below it are well illustrated in a
section, which will be described in detail in a later chapter.

At Brigstock- Mill there is a stone-pit in the same formation, here presented
ag a soft, shelly limestone with much false-bedding, many of its beds exhibiting
a reddish colour. Fossils are tolerably abundant in this pit, and consist for the
most part of small shells, both univalves and bivalves, usually more or less
encrusted with a deposit of carbonate of lime. 5 :

Between the Harper and Willow brooks the Jurassic strata are again wholly
concealed by the thick masses of Boulder Clay. On the outer escarpment,
however, at Stoke Albany, Wilbarston, Cottingham, and Rockingham, the
beds of the Lincolnshire Oolite are exposed by denudation below the great
superficial accumulations. They are also equally well seen along the sides of
the valleys formed by the Willow Brook and its tributaries, as about Corby,
Weldon, Dene, Bulwiek, Blatherwycke, &c.

The beds of the Inferior Oolite Limestone appear on the escarpment between
Stoke-Albany and Wilbarston from beneath the mantle of Boulder Clay which
overlaps the escarpment to the southwards. The strata here seem to be much
disturbed and dip in various directions. The beds are seen similarly in the
150 GEOLOGY OF RUTLAND, &C.

two pits at the south end of the village of Wilbarston, in one place having a
dip of no less than 10°. In the stone pits on the north side of the village of
Wilbarston the limestone beds of the Inferior Oolite are again seen to be
much disturbed; in one of the pits they dip E. at an angle of 15°, and in
another, the beds are in one place horizontal while at a short distance they
are inclined to the S.E. at an angle of 20°. It is possible, however, that this
appearance of local disturbance in the rocks is due to the fact of their exposure
on a steep escarpment, above a great thickness of Upper Lias Clay, &c., and
are to be referred to partial landslips rather than to subterranean movements.

On the left-hand side of the road leading from Cottingham to East Carlton,
there is a large pit in-the limestone of the Lincolnshire Oolite. Under 4 feet
of rubble we find about 20 feet of compact and oolitic limestone, lying in
distinct beds with clay partings. The upper beds are soft and white and
highly oolitic; the middle beds of the section harder, cream-coloured, and
slightly oolitic ; and the lower beds hard, crystalline, and blue-hearted.

In a pit below the church at Cottingham the strata of the Northampton
Sand and Lower Estuarine Series are seen lying below those of the Lincoln-
shire Oolite.

From the Lincolnshire Oolite limestone of this neighbourhood I ohtained,—

Polypodites Lindleyi, Gépp. (Pecopteris polypodioides, Lindl. &
ae (abundant in the lower beds, exhibiting the fructifica-
ion).

Ceromya Bajociana, d’Orb.

Pecten aratus, Waagen.

And other fossils.

In Rockingham Park several stone pits have been opened in the Lincoln-
shire Oolite. One of these exhibits about 5 feet of soft, somewhat fissile and
very oolitic limestone with a faint pinkish tint. A larger stone-pit in the
same park exhibits the following section :—-

(1.) Soil - - - - - - _ ~ Q inches.
(2.) Oolite, similar to that of last pit - - - 5 feet.
(3.) Softer, more marly, and compact oolite - . - 5 feet.
(4.) Hard, compact, marly oolite with Nerinea, &c. to bottom

of the pit - - - - - - 4 feet seen.
In the extensive stone pits at Snatchill Lodge, between Great Oakley and
Corby, we find the following sections at different points :— .
(1.) Boulder Clay, bluish, greenish, and brown. Mostly
of mottled colours, with boulders of all dimen-
sions, those of Ooliticand Cretaceous rocks pre-

dominating - - : - - 6 to 8 feet.
(2.) Oolite rubble, often contorted - - 0 to 3 feet.
(3.) Bed of hard, marly limestone of a drab colour (used

for road-metal) - - - - - 1 foot.
(4.) Whitish, calcareous sand - - : - 1ft. 6 in, to 2 feet.
(5.) Shelly limestone - - = - - 1 foot.
(6.) Soft, very oolitic, somewhat shelly limestone (used

asbuilding stone) - - - - 6 feet 6 inches.
(7.) Clay parting.
(8.) Two courses of hard, blue-hearted, sub-crystalline

limestone, used for road-metal, each course being
about 1 foot thick - - - 2 ft.
(9.) Blue clay, dug in making a drain - ~ 3 feet seen.
A second section obtained in the pits opposite to Snatchill Lodge was as
follows :—
(1.) Boulder Clay, of the usual characters, in places - ~ 6 ft. thick.
(2.) Bed of rubbly oolite - - - - - 2 ft.
(3.) Hard, compact, sub-crystalline limestone with a few

scattered oolitic grains, containing Nerinza, &c. - Jin,
(4.) Softer, sandier limestone - . : - 7 - 1 ft. Gin
(5.) Hard and coarsely oolitic limestone - - ~ 6 ft.
(6.) Softer, sandier limestone, with fewer oolitic grains ~ 2 ft.
(7.) Coarse, sandy, flaggy limestone - - : - Din.

(8.) Blue Clay.
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 151

It is evident that the beds exposed in these pits are those which con-
stitute the base of the Lincolnshire Oolite Series.

The beds of the Lincolnshire Oolite can be traced at several points in the
neighbourhood of the village of Corby. At the “ Mill-pit,’ between Corby
and Weldon, we have the following section :--

(1.) Boulder Clay - - - - - .1 to 3 feet.

(2.) Oolite rubble - - - - - - 2to3 feet.

(3.) Marly Oolites, becoming slaty at the bottom - - 6 to 8 feet.
(Dug for road metal.) ‘

In the great pits to the west of Great Weldon we find the section given

below :—
(1.) Boulder Clay, with boulders chiefly of Oolite, but with

some of Chalk and Lias - - -- & feet.
(2.) Soft, shelly, oolitic freestone ; this bed is but little used
for building purposes - - - 4 ft. Gin.

(3.) Hard, shelly ragstone - - - 2 to 3 feet.
(This bed is known as the ‘“‘ Weldon-rag.’’)
(4.) Beds of shelly freestone, harder than the top bed.
These form four courses, each from 2 to 3 feet in
thickness, the stone being known as the “ Weldon
Freestone” - - - - - - 10 feet.

At about § feet below the bottom of this pit another bed of hard “rag”
occurs in the midst of the shelly freestones.

Fine joints dividing the stone into large blocks traverse the stone in this pit
and render its quarrying easy.

The extensive “ hills and holes,” by which name the abandoned and grass-
grown quarries in this part of England are always known, testify to the
enormous quantities of Lincolnshire Limestone which in former times have
been raised in the neighbourhood of Weldon for building purposes.

At Great Weldon the shelly oolite of the Lincolnshire Oolite is seen in situ
in the bed of the stream which flows through the village. A little to the east
of the village a small road-side pit offers particularly favourable conditions
for the collection of the small shells, corals, fragments of echinoderms, &c. of
which the rock is almost wholly made up. These facilities are due to the soft,
crumbling, and weathered state of the stone, which here (as in the analogous
case at; Wakerley to be referred to in the sequel) enables the small organisms
to be removed with the point of a knife, or by simply crushing the stone. In
this pit at Weldon, the following species rewarded the patient search of Mr.
Richard Gibbs, the former fossil collector to the Survey.

Fossils from the Shelly Oolite of Weldon.

Actzonina glabra, Phil.

Natica cincta, Phil. ©

Nerineza cingenda, Bronn.

Eudesii, Lyc. and Mor.

— pseudo-cylindrica, Lyc.
——-- Stricklandi? Lyc. and Mor.
—— - Voltzii, Deslong.

—, sp.

Monodonta levigata, Sow.
Phasianella Pontonis, Lyc.
Myoconcha striatula, Sow.

—_— — crassa, Sow.

Mytilus lunularis, Lyc.

Cardium, sp.

Corbicella Bathonica, Lyc. and Mor.
Trigonia costata, var. pullus, Sow,
Ostrea flabelloides, Lam. (O. Marshii, Sow.), var.

 

 

 

 

——-, Sp.

P
Terebratula submaxillata, Mor.
Rhynchonella spinosa, Sow., var, Crossi, Walker.
Pseudodiadema depressa, dg. ~
Thecosmilia gregaria, M‘Coy.
152 GEOLOGY OF RUTLAND, &c.

At the angle of the road leading down from Great Weldon to Little W :
J : ; ; Bi eldon
the Junction of the shelly oolites with the light-blue clays, with plant-remains
belonging to the Lower Estuarine series, is exposed. :
It appears that at Weldon, as at Barnack, the base of Lincolnshire Oolite

wens wae :
bie ag gore by the shelly, and not by the compact and marly variety of

We have already seen that at several points the lowest beds of
the Lincolnshire Oolite Limestone present fissile characters, and
thus show a tendency to pass into those “slate-beds” which to the
northwards constitute, under the name of the Collyweston Slate, so
important a member of the formation. The most southerly points
at which such slate. beds have been worked for the purpose of
obtaining roofing materials, are at Kirby, and near Dene Lodge.

The extensive slate-pits at Kirby are now almost wholly abandoned, and but
few opportunities are afforded for studying the succession of beds here.

On the right-hand side of the road leading from Rockingham there is a
small pit in the marly or compact limestone, the beds being separated by clay
partings. In the upper part of the pit the beds become softer and more
oolitic. The total thickness of rock exposed here is from 12 to 14 feet.

On the opposite side of the road are the “ slate-pits,”” now no longer worked.
In the upper part of these pits the same beds of marly oolite as were noticed
in the pit last described are seen. These appear to have been underlaid by
sand, at the bottom of which the slates occurred. Thus the relations of the
slate beds at Kirby would appear to have been very similar to those of the
equivalent strata in some of the pits at Easton and Collyweston. The slates
appear to rest upon clay, and the pits are now full of water.

The best section I could obtain here was the following :—

(1.) Drift or Boulder Clay - - - - 3 feet.
(2.) Rubble oolite - - - - - 4 feet.
(3.) Thin-bedded oolite (weathered) - - - 4 feet.
(4.) Harder, thick-bedded limestone - - - 5 feet,

(5.) Sands, cream-coloured, and somewhat compacted- 4 feet to bottom.

In another part of the pits the sands are seen to a depth of 5 feet, and are
underlaid by 4 or 5 feet of hard limestone with clay partings. Under the last
seem to have come other beds of sand, then 2 or 3 feet of slate rock, and
finally clay.

The Kirby slate-pits, which belong to Lord Winchelsea, are now abandoned,
owing to several causes. The principal of these are as follows :—firstly, the
diminished demand for such materials as the “slates” of the Oolite series,
now that the increased means of communication afforded by railways offers
such facilities for procuring the lighter and more convenient Welsh slates ;
secondly, the exhaustion of the old pits; and, thirdly, the expense of opening
new ones to the required depth.

Near Dene Lodge, upon the border of Long Mantle Wood, there is a small
pit, at which, during the time when the survey of the district was made, small
quantities of “slate” were being raised and dressed in the same manner as is
still practised at Collyweston.

On the main escarpment in the neighbourhood we are now describing, the
outcrop of the Lincolnshire Oolite is concealed by the overlap of the Boulder
Clay between Rockingham and Gretton; but between the last-mentioned
village and Harringworth the beds of this formation again appear. In a pit
on the right-hand side of the road from Gretton to Harringworth, we find
2 feet of rubbly oolite resting on 6 feet of cream-coloured sand, full of intensely
hard siliceous concretionary masses with irregular rounded forms. The sands
at the base show a tendency to become ferruginous. A pit on the opposite
side of the road exhibits a somewhat similar section.

The Lincolnshire Oolite is well exposed in a number of pits in the vicinity
of Harringworth. Above the cross-roads towards Dene there are several large
quarries by the road-side,in which we find hard, somewhat shelly Oolite,
covered by much limestone rubble. The rock has here a pinkish tint.

At the brickyard and several other points near Dene, the lowest bed of the
Lincolnshire Oolite (representative of the Collyweston Slate) is an intensely
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 153

hard and very highly siliceous material, presenting mammillated surfaces, and
containing plant remains. It is so hard and compact as almost to resemble a
quartzite.

A large stone-pit at the angle of the road leading from Harringworth to
Dene yields the following section :—

(1.) Soil. - - - - - lft.
, (2.) Rubble oolite - - - - - - 2 ft.
(3.) White, calcareous sand - - - - - 1f. 9in.
(4.) Thin-bedded, soft, very oolitic limestone - - - 2 ft,
(5.) Brown, calcareous sand in places indurated into stone - 2 ft.
(6.) Bed of hard, compact rock, used for road-metal - - 1 ft. 6 in.
(7.) Several courses of hard, pinkish, shelly oolite, used for
building purposes - - - - - 5 ft.

Similar beds are exposed at Hollow Bottom and at several other points
between Harringworth and Dene.

The interesting section showing the relations of the Lincolnshire Oolite
to the beds below have already been noticed (see p. 101).

The beds of the Lincolnshire Oolite Limestone can be traced under the
strata of the Great Oolite series at Bulwick and Blatherwycke. At Laxton
there are quarries in the same rock; and at this place also a well was
sunk to the depth of 40 feet in the Oolitic Limestone, water being obtained
in the sands and clays below.

Over all the area already described the Lincolnshire Oolite is much obscured
by Boulder Clay ; but we have now-to notice the fine series of sections exposed
along the sides of the Welland and Chater, which, in the central part of the
area under description, cut completely across the line of outcrop of the
formation.

In the neighbourhood of Wakerley there are numerous quarries in the
Lincolnshire Oolite Limestone, from some of which stone is still procured,
while others are abandoned. Several such pits are seen between the “ Great
Wood” and the “Spinney.” At the northern corner of the former plantation
there is a large and deep quarry, exhibiting an admirable example of the
“shelly facies” of the Lincolnshire Oolite. Many of the beds are entirely
made up of drifted shells, usually of small size, the valves of the Brachiopods
and Conchifera almost always having their valves disunited, and the Gastero-
pods exhibiting equal signs of drifting in their broken spires and other marks
of attrition. Many of the shells are coated with a deposit of carbonate of
lime, and the beds exhibit much false-bedding. Owing to the softness of the
rock here, as in the analogous cases of Great; Weldon (already referred to) and
of Ponton, where Professor Morris procured so interesting a series of fossils
from the shelly beds of the Lincolnshire Oolite, this pit at Wakerley offers
peculiar facilities to the collector of fossils. The following species were
obtained here by the officers of the Geological Survey.

Fossils from Stone-pit near Wakerley.

Nerinza cingenda, Bronn.

——-— Cotteswoldiz, Lyc,
Voltzi, Deslong.
Vermicularia nodus, Phil.

—, 8p.

Trigonia tenuicosta, Fyc.

— denticulata, Lyc.
heemispherica, Lyc.
costata, Sow., var. pullus, Sow.
Opis gibbosus, Lyc. ‘
Neerciion Hirsonenisis, d’Arch.
Cardium Buckmani, Lye. and Mor.
Cucullea cucullata, Goldf.

Astarte, sp.

Arca rugosa, Lyc. and Mor.

—— Prattii, Lyc. and Mor.

— emula, Phil.

— cancellata, Sow.

 

 

 

 

 
154 GEOLOGY OF RUTLAND, Wo,

Ostrea, sp.
Pecten paradoxus, Miinst.

——-- lens, Sow.
Pteroperna plana, Mor. and Lye.
Lima cardiiformis, Sow,

—- gibbosa, Sow.
——- duplicata, Sow.
——- ovalis, Sow,
—~—- pectiniformis, Schloth.
——- Pontonis, Lye.-

7 punctata, Sow.
——- rudis, Sow.

, Gervillia acuta, ts
Hinnites abjectus, Phil.
———, velatus, Phil.
Terebratula submaxillata, Mor.
Cricopora Spiropora (straminea), Phil.
Cidaris Bouchardii, Wright.
Pseudodiadema depressa, Ag., sp.

 

————-, sp.
Pygaster semisulcatus, Phil.

Microsolena excelsa, Edw. and Haime.

Thamnastrea Defranciana, Edw. and Haime.

Thecosmilia gregaria, M‘Coy.

In the neighbourhood of Wakerley the relations of the Lincolnshire i
both to the beds above and below PY ae be studied. The white clays me
base of the Upper Estuarine series, which repose directly upon the Great Lime-
stone series, are here dug for commercial purposes; and in a pit above the
great escarpment the sands are seen at the base of the limestones. At this
latter point we find very hard mammillated beds which certainly represent the
Collyweston Slate, and contain—

Macrodon Hirsonensis, d’Arch.
Trigonia (casts).

Cardium (casts), &c.

Much wood and other plant remains.

Between Barrowden and Tixover the beds of the Lincolnshire Oolite appear
to come down to the level of the river Welland, which, in this part of its
course, crosses the outcrop of these strata. The lowest beds of the limestone
series here appear to be hard and cream-coloured; they are of a somewhat
sandy nature and alternate with beds of sand. These undoubtedly represent
the Collyweston Slate, which is so well developed a little farther to the east.

Near Morcott there are a number of quarries in the Lincolnshire Oolite,
one of which shows the following succession of beds:—_- .

(1.) White, oolitic limestone with some shells and echinoderms, and a few

plant remains.

(2.) Calcareous sands. .

(3.) Hard, blue, siliceous limestone, with few shells but many plant remains,

the latter sometimes well preserved (ferns, &c.)

(4.) Fine, white sands.

The rock of bed (1) is used for lime-burning; of (3) for road-metal; and of
(4) for mortar.

In the large pit near Morcott Mill beds of calcareous sand alternate with
courses of compact, marly limestone. At the base are hard beds of a blue
colour exhibiting a tendency to fissile characters. The strata about Morcott
exhibit signs of considerable disturbance. i

Between Tixover and Ketton the beds of the Lincolnshire Oolite can be
traced at many points, but no good sections of them are afforded.

At Duddington there are a number of old pits near the river which still bear
the name of “ the Slate-pits ; ” according to tradition slates similar to those of
Collyweston were once dug here, and their abandonment was due to their
being drowned by the waters of the Welland.

At Ketton the very extensive quarries offer to the geologists many neautiful
illustrations of the upper beds of the Inferior Oolite Limestone of the district and
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 155.

of the superposed Upper Estuarine Series. Thecompact and durable character
of the oolitic limestone of Ketton, as in the similar cases of the Casterton,
Clipsham, and Ancaster quarries, is doubtless due in great part, as was pointed
out by Professor Morris, to the fact of the rock being quarried under a con-
siderable thickness of clays which form the base of the Great Oolite series in
this district.
The following is the section exhibited by the quarries at Ketton :—
(1.) Upper Estuarine Clays (Great Oolite). In their lighter co-
loured bands these clays are crowded with Cyrena and
other shells; and in the dark coloured beds they contain
large fragments of wood and much carbonaceous matter -
(2.) “Junction-bed” full of ironstone nodules. This is of a
snuff-brown colour and earthy texture, and is full of white
decomposed fragments of a fibrous structure, apparently

the remains of shells and bones? -
(3.) “The Crash bed” - - - - - - 3 feet.
(4.) “ Grits” or “ top-rag ” harder than the “ bottom-rag ” 3 feet.
(5.) “ Bottom-rag ”’ - - - - - - 3 feet.
(6.) “ Freestone” - - - - 3 feet.

The “‘ Crash-bed ”’ (3) is a coarse oolite full of fragments of shells, which lie
on its planes of bedding. When first dug this rock is very soft, but by expo-
sure it acquires extreme hardness. It is of a purplish: red. colour, but varies
greatly in the depth of the tints which it exhibits. It is only used locally for
rough purposes, such as field walls, &c. A very interesting circumstance in
connexion with the “ Crash-bed ” is that its upper surface often exhibits the
vertical burrows of Lithodomi, indicating the long pause which ensued between
the deposition, and probably partial denudation of the Lincolnshire Oolite, and
the formation of the Estuarine strata which lie immediately above it. This
break in the succession of the Jurassic strata in the Midland district is at other
points even more strongly marked by actual unconformity between the Inferior
and Great Oolite Series (see Introductory Essay, pp. 33-38).

‘The “ grits” and “ rag-beds”’ (4) and (5) are hard limestones of oolitic struc-
ture, but not entirely made up of oolite grains. The stone fractures along
incipient crystalline or cleavage planes, often exhibiting surfaces with brilliant
lustre. As the rock is too hard to be easily dressed it is only used for local
purposes.

-The following species of fossils were collected at the Ketton quarries :—

" Pileopsis, sp. a
Nerinza pseudo-cylindrica, Lye.
Chemnitzia, sp.
Cyprina nuciformis, Lye.
Trigonia costata, Sow. Var pullas, Sow,
Lucina Wrightii, Oppel.
_—_—_, sp.
Unicardium, sp.
Pholadomya fidicula, Sow.
Perna quadrata, Sow. var.
Terebratula submaxillata, Mor.
Tsastrea Richardsoni, Edw. and Haime.

The celebrated Ketton freestone is a beautiful, oolitic limestone of good
colour, combining great freedom of working with remarkable powers of
resisting crushing force and wonderful durability. It is almost wholly made
up of very uniform oolitic grains, exhibits scarcely any trace of bedding planes,
and can be placed indifferently in any position in buildings without exhibiting
any tendency to weathering. yet . .

The Ketton freestone is highly valued by architects, and its employment is
frequently specified by them in cases where great strength is required in any
particular construction. The slight thickness of the bed, however, (only 3 feet)
and the large quantities of “ bearing” which require to be removed in order to
obtain it, renders it expensive and prevents its more general use. Hence for
general purposes the oolite of Ketton cannot compete with the cheaper
materials of Bath, Portland, and Ancaster. The number of men employed in
the Ketton quarries is about one hundred. :
156 GEOLOGY OF RUTLAND, &C.

In the cutting of the Syston and Peterborough Railway near Ketton (Geeston)
a good section was og ce which was examined when first opened and thus
described by Captain Ibbetson and Professor Morris :—

* Geeston (Railway Cutting).*

ft.
Rubbly oolite in shivers - . - - - 3
Compact marly limestone, Neringa and Ferns - - 25
Marly rock, very fossiliferous, Nerinea, Modiola plicata,
Ferns, and Isocardia concentrica, Pinna, Arca — ~ - 2
Sandy rock, with Lima, &e. - = - mt - 2
Crystalline ragstone, with Nerinea and patches of plants - 3
Compact, crystalline, oolitic ragstone - +. - 8
Concretionary bed - - - - - - 23
Slate beds - - - - - - - 3
Greenish clay - - 2

Ferruginous sand of inferior oolite at bottom.’”

On the opposite side of the river to Ketton, in the vicinity of the villages of
Collyweston and Easton, the lowest beds of the Lincolnshire Oolite have long
been extensively worked for the purpose of obtaining the once famous Colly-
weston slate. Excepting for ecclesiastical and other Gothic buildings (in
which the peculiar colour of the material is greatly admired and much affected
by some architects) and for strictly local purposes, there is now, however, but
little demand for the Collyweston slate. A considerable number of pits are
still worked in the district, but over a large area the “ slate-beds ” have been
wholly exhausted. On a future page we shall give a short account of the
methods pursued in quarrying and dressing the “slates” of Collyweston, once
a most important industry in this particular district, and which was also
extensively pursued at Kirby and some other points in the area which we are
describing.

As illustrating the general succession of the rocks among which the slates
are obtained, we may give the following section from a deep pit at Easton :—

(1.) Beds of oolitic limestone, varying greatly in hardness, &c,

Some of these beds are of sandy texture - -- 12 feet,

(2.) Beds of sand, with hard, siliceous, concretionary masses

lying in the planes of stratification, These sands are
sometimes indurated and present rounded and mammil-

lated surfaces - - - - - - 4 feet.
(3.) Bed of hard and partially oolitic limestone - - 2 ft. 6 in,
(4.) Bed of more or less indurated sand, with smaller con- :

cretionary masses than those of (2) - - - 1 ft. Gin,
(5.) Hard, blue-hearted, siliceous limestone - — = - 2 feet.
(6.) Finely laminated, calcareous sandstone beds, which weather

into “slates” - - - = - - 2 feet. —

(7.) Hard, flaggy, siliceous beds with mammillated surfaces

(* pot-lids,” &c.), “bastard-rock ” of the workmen ~- 6 inches.

(8.) Sands* - — - - - - - - 6 feet.

(9.) Ironstone beds of the Northampton Sand.

The “ slate-beds”’ (6) contained fine specimens of Lucina Wrightii, Oppel,
and other shells, LT Bene

In an adjoining pit the section is altogether similar in every respect, except
that the “ slate-bed ” is nearly 3 feet thick. /

The sands which underlie the “slate-bed ” at Easton and Collyweston is
said to be 6 feet thick. Underneath them lies the “ Red-rock ” (Northampton
Sand), but this bed is never bottomed here, as abundance of water is obtained
in it. Indeed during wet seasons the springs rise so rapidly that it is often
found impossible to get out the slates, : :

In another pit, at a short distance from that in which the section was taken,
the upper bed of sand (2) is between 5 and 6 feet thick and is dug for building
and foundry purposes, for which it is found to be well adapted.

 

* Brit. Ass. Rep., 1847, Proceedings of Sections, p. 128.
.

LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 157

The stone immediately above the Collyweston slate is often crowded with
specimens of Polypodites Lindleyi, Gépp (Pecuptonts polypodioides, Lindl. and
Hutt.), with some other ferns and plant remains. ‘

All the Inferior Oolite beds in the neighbourhood of Collyweston and Easton
are traversed by a series of master joints, having a very uniform direction of
40° W. of North (magnetic). Another set of joints cuts across the beds
almost at right angles to the master joints. By the jointed condition of these
rocks their quarrying is, of course, greatly facilitated

Although the “slate-beds”’ at the base of the Lincolnshire Oolite of the
Midland district have not yielded any of those beautiful mammalian, reptilian,
and insect remains, which have made the Stonesfield slate, constituting the
base of the Great Oolite Limestone in the south-west of England, so famous,
yet it presents a very similar association of generic forms to those found in the
latter beds. The species in the two sets of strata are, however, for the most
part distinct, and we are led to infer that while formed under very similar
conditions they are of widely separated age. In both the Stonesfield and
Collyweston slate, remains of fish, especially their palatal teeth, abound; in
both there occur the same genera of Mollusca, Gervillia, Trigonia, Lucina,
Alaria, &c., being especially abundant, while Brachiopods are rare ; and in both,
the fucoid markings, worm-tracks, ripple-marked surfaces, and evidently drifted
plant remains clearly indicate the shallowness of the sea in which they were
formed, and the proximity of the land.

The general nature of the fauna of the Collyweston slates is indicated by
the accompanying list of fossils collected by the Geological Survey.

Fossils of the Collyweston Slate,

Pterocera Bentleyi, Lyc. and Mor.
Alaria, sp. 4
Natica Leckhamptonensis, Lye..

 

, Sp.
Patella rugosa, Sow.
operculum of P
Arca cancellata, Sow.
Cuculleea cucullata, Goldf.

————, sp.
Cardium Hsia, Lye. and Mor.
cognatum, Phil.

—— Stricklandi, Lyc. and Mor.
Ceromya Bajociana, d’ Orb. :
Homomya crassiuscula, Lyc. and Mor.
Mytilus Sowerbyanus, d’Ord.

Lucina D’Orbignyana, Lye. and Mor.
Bellona, d@’ Orb.
despecta, Phil.
Wrightii, Oppel.
Astarte elegans, Sow.
excavata, Sow.
Trigonia compta, Lye.

hemispharica, Lye.
impressa? (var.) Sow.
Moretonis? Lyc. and Mor.
Myacites Scarburgensis, Phil.
equatus, Phil.

Modiola imbricata, Sow.

Pholadomya fidicula, Sow.

ovalis, Ag.

Heraulti, Ag.
, Sp.
Pinna cuneata, Bean.

Pecten demissus, Phil.
paradoxus, Miinst.
personatus, Miinst.

 

 

 

 

 

 

 

 

 

 

 

 

 

32108.
158 GEOLOGY OF RUTLAND, &c.

Pecten lens, Sow.
texturatus, Goldf,
, 8p.
Avicula, sp. -
Pteroperna plana, Lye.
——-— costatula, Desloug.
Lima interstincta, Phil.
—— spec. nov.
——- pectiniformis, Schloth.
Inoceramus obliquus, Lye.
Hinnites abjectus, Phil.
- velatus, Goldf.
-- tegulatus, Lye. and Mor.
Gervillia acuta, Sow.
monotis, Desloug.
Ostrea, sp.
Anomia, sp.
Tracts of Annelida,
Polypodites Lindleyi, Gépp.

Between Easton and Stamford the hard, siliceous rock forming the base of
the Lincolnshire Oolite and representing the Collyweston slate is exposed, At
several pene near the bed of the river Welland at Stamford, it has been
observed ; and here Mr, Sharp procured his interesting specimen of Astropec-
ton Cotteswoldia, var. Stamfordensis, Wright. A fragment of the same beautiful
starfish has recently been found at Collyweston.

In the immediate neighbourhood of Stamford the Lincolnshire Oolite is well
exposed in many pits. Here the nature and succession of the rocks have
been carefully studied, and their beautiful fossil contents have been assiduously
collected by Professor Morris, Mr. Bentley, and Mr. Sharp. In some cases
the sections exposed at the time when the district was surveyed were not so
clear as in former times, owing to the abandonment or partial filling up of
certain of the quarries,

As Mr. Sharp, whose long residence at Stamford and great geological attain-
ments admirably fit him for the task, -has recently brought together and
discussed the relations of the various beds seen in the several pits in the
vicinity of that town, I shall here quote his clear statement of the results
at which he has arrived (vide Quarterly Journal of the Geological Society,
vol. xxix. pp. 252-257) :—

* Returning towards Stamford—below the freestone bed of the ‘ Lings,’ is a
very close and brittle marly limestone, in which Rhynchonella Crossii, Walker,
occurs. Below this are the series of marly and crystalline beds of the Lincoln-
shire Limestone exposed in Tinkler’s and Squires’s quarries, having a thickness
of about 29 feet; some of them very fossiliferous, and containing zones of
coral. A particular bed (containing much coral, many Nerinee, and other
fossils), very crystalline, and taking a high polish, was formerly called the
‘ Stamford Marble,’ and was much used for chimney-pieces. The bed is still
present in the section, but its mineral conditions are so altered as to unfit it
for its former uses. In Squires’s quarry (which nearly adjoins Tinkler’s) a soft
marly bed is thickly developed, and yields a very fine cream-coloured stone,
easily worked, and (under the name of the ‘Stamford Stone’) much used for
chimney-pieces and for the interior carved work of churches. It contains
many fossils, often in fine condition; many examples of a large Natica and of
a very large Lima, and a beautifully preserved frond of a cycadaceous plant,
have been obtained.

 

 

 

 

 

 

“ Fossils from the Marly Bed of Squires’s Quarry.

Hinnites abjectus, Phil. sp.
Lima auedithopaic, Sow.
— Etheridgii, Wright.
—— impressa, Mor. & Lye.
—— proboscidea, Sow.
—— Pontonis, Lycett.
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE, 159

Lima Rodburgensis, Lycett, M.S.

——-, large sp. (allied to L. grandis, Rémer).
——, large sp.

Pecten aratus, Waagen.

arcuatus, Sow.

clathratus, Romer.

 

 

 

Arca, large sp. ?
Astarte elegans, Sow.
——— recondita, Phil.
Cardium Buckmani, Mor. & Lye.
—— subtrigonum, Mor, & Lye.
Ceromya Bajociana, d’Ord.
——— similis, Lycett.
Cucullea elongata, Sow.
Cypricardia Bathonica, d’Orb.
Cyprina Jurensis, Goldf., sp.
Loweana, Mor. & Lyc.
Lucina Bellona, d’Orb.
despecta, Phil.
Wrightii, Oppel.
Macrodon Hirsonensis, d’Orb., sp.
Modiola Sowerbyana, d@’Orb.
Myacites securiformis, Phil. sp.
Mytilus furcatus, Goldf.
Pholadomya Dewalquea, Lycett.
—— Heraulti, Ag.
———— lyrata, Sow.

ovalis, Sow.

ovulum, 4g.
———--, sp.?
Tancredia axiniformis, Phil.

 

 

 

 

Rhynchonella sub-tetraédra, Dav.
Terebratula perovalis, Sow.

 

Natica Leckhamptonensis, Lycett.
(like) Michelini, d’ Arch.
——, sp.?

Nerinza cingenda, Bronn.
Cotteswoldiz, Lycett.
Jonesii, Lycett.
Trochotoma obtusa, Mor. & Lyc.
——-- tabulata, Mor. & Lyc.
Turbo depauperatus, Lycett.

 

 

 

 

 

Belemnites acutus, Miller.

 

Clypeus Michelini, Wright.
Stomechinus germinans, Phil., large var.

 

Calamophyllia radiata, Lamzx. :
Latimeandra Flemingi, Edw. 6 Haime,
Thecosmilia gregaria, M‘Coy.

 

Hybodus (dorsal spine).
Strophodus magnus, Ag. (palates).
subreticulatus, Ag. (palates).

 

 

Frond of cycadaceous plant.
Ferns—

Pecopteris polypodioides, Lindley.

Wood.

L 2
160 GEOLOGY OF RUTLAND, &¢.

‘* Section in Lincolnshire Limestone, Tinkler’s Quarry, Stamford.

ft.in. ft. in.
1. Rubbly and broken limestone = - - - 4 0

2. Soft concretionary marly limestone, containing

Coral zones, with Perna, Lithodomus inclusus, &c. 3 6
3. Marly limestone in thin layers, shivered - - 40
4. Compact marly limestone, in thin and irregular

layers [I counted seven] - - 3 6

5. Very hard limestone, containing oolitic grains
sparsely distributed, occasionally very blue-
hearted - - - - - . =2 0 to 2 6

6. Earthy shale bed, in very thin Jamine, containing
numerous Pectens and other shells, with tests
beautifully preserved, but crushed by compression 1 6 to 2 0

7. ‘Stamford Marble ’—a very hard limestone, blue-
hearted, and containing much Coral, Nerinea
cingenda, N. triplicata, numerous other shells,
and teeth and palates of Pycnodus Bucklandi
and Strophodus magnus and S. subreticulatus—
formerly much more crystalline than in the
present section, and then, when polished, a
favourite material for chimney-pieces, &c., hence

its name—in two courses - - -1 0 tol
8. Very hard limestone, coarsely grained, in two |

courses - - - - - -2 6 to 3
9. Compact marly stone, rather hard - - 1

10. Compact marly stone, softer, and containing Ne-
rinee—in three courses - - - -3 0 to 3
11. Rather oolitic Limestone, a good building stone - 1

om AO n

« Fossils from Freestone and Shelly Beds near to Tinkler’s Quarry.

Arca pulchra, Sow.

Lima proboscidea, Sow. sp.

Pecten lens, Sow.

Pholadomya fidicula, Sow.

Serpula ?

Stomechinus germinans, Phil.
Strophodus magnus, Ag. (palates).

“ Fossils from Tinkler’s and neighbouring Quarries.

Avicula clathrata, Lycett.

echinata, Sow.

Gervillia acuta, Sow.

Lima bellula, Mor. & Lye.

—— Etheridgii, Wright.

— Pontonis, Lycett.

—— Rodburgensis, Lycett, M.S.
—~—, large sp. (allied to L. grandis, Rémer) ?
Ostrea flabelloides, T.am.

—-—, large flat species.

Pecten aratus, Waagen.

——— arcuatus, Sow.

—— clathratus, Romer.

demissus, Phil.

———- lens, Sow. (or large new sp. ?)
—— personatus, Miinst.

 

 

 

Arca Prattii, Mor. & Lye.
Astarte elegans, Sow.
—— minima, Phil.
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. I6L

Ceromya Bajociana, d’Ord.
similis, Mor. 4 Lyc.
Cyprina Jurensis, Goldf.
— Loweana, Mor. & Lye.
- trapeziformis, Romer.
Cypricardia Bathonica, d’Orb.
nuculiformis, Romer.

Goniomya V-scripta, Sow.
Lithodomus inclusus, Phil.
Lucina Bellona, d’Ord. ‘
Wrightii, Oppel.
Modiola Sars d’Orb,
Myacites calceiformis, Phil. sp.
decurtata, Phil. sp.
securiformis, Phil. sp.
Pholadomya Dewalquea, Lycett..
fidicula, Sow.
Heraulti, Ag.

— ovalis, Sow.

—, sp.?
——., sp. P
Tancredia axiniformis, Phil.
Trigonia costata, var. pullus, Sow.
sculpta, Lycett.
V-costata, Lycett.
, Sp. (new)? ~
Unicardium, sp. ?

 

 

 

 

 

 

 

 

 

 

 

 

 

Rhynchonella Crossii, Walker.
sub-decorata, Dav.
— sub-tetraédra, Dav.
Terebratula globata, Sow.
——-—- perovalis, Sow.
——_~——- pheroidalis, Sow.
—— sub-maxillata, Sow.

 

 

 

 

Actzonina, large species ?
Natica (Euspira) canaliculata, Mor. & Lye,
formosa, Mor. & Lyc.
—— grandis, Goldf.
——— Leckhamptonensis, Lycett.
Nerinza gracilis, Lycett.
— cingenda, Bronn.
—— Jonesii, Lycett.
Oppelii, Lycett.
triplicata, Bronn.
Phasianella elegans, Mor. & Lyc.
Pterocera, sp. ? (like ignobilis, Mor. & Lyc.).

 

 

 

 

 

Ammonites Murchisonz, Sow.*
subradiatus, Sow.
————— terebratus, Phil.
——_—— (large septa, very like species found in Ferruginous
beds at Duston).
Nautilus obesus, Sow.
polygonalis, Sow.
Belemnites Bessinus, d’Orb.

 

 

Serpula convoluta, Goldf.

 

 

* In the Museum of the Stamford Institution.
162 GEOLOGY OF RUTLAND, &c.

Galeropygus (Hypocl us) agariciformis, Forbes.
Holectypus temopheeout a

Pygaster semisuleatus, Phil.

Pentacrinus, sp, ?

 

Anabacia orbulites, Edw. & Haime.
Cladophyllia Babeana, Edw. & Haime.
Tsastrea limitata, Edw. & Haime,
Montlivaltia tenuilamellosa, Edw. & Haime,
Thamnastrea, sp. ?

Thecosmilia gregaria, M‘Coy.

 

Hybodus (large spine).
Pycnodus Bucklandi, 4g. (teeth),

 

Teleosaurus (tooth).

 

Pecopteris polypodioides, Lind. & Hutt.
Coniferous wood.

“ Professor Morris, in his well-known Paper on the Lincolnshire Oolites,
published in the Society’s Journal for 1853, gives, on page 336, the following
as a foot note :— é

“At Tinkler’s quarry and the adjoining lands near Stamford, a typical
series of the whole district may be observed. In a higher part of the hill, the
stratified and bituminous clays, with the ferruginous band, may be observed,
overlying the freestones (Ketton and Casterton); the lower parts of the free-
stones from the top of the quarry; below which—
ft. in.

1. Compact oolitic rock, few shells - - - - 20
2. Concretionary compact marly oolite, full of shells, and
zones of corals, the bottom more compact, the upper
part marly, and decomposes more rapidly, containing

shells in great abundance _—s- - - - 4 0
3. Compact hard shelly oolitic rock, Nerinea, &. - - 26
4. Compact oolitic rock, somewhat crystalline - - 16
5. Shaly bed, irregular laminated, fragments of plants and
many compressed shells, Lucina, Pecten, &c.  - - 20
6. ‘ Stamford Marble,’-—very compact, marly limestone, full
of shells and corals, Nerinea abundant - - - 26
7. Indurated, somewhat marly rock - - . - 3 0
8. Compact rock - - - - - - 16
9. Compact, marly, coarse grained, oolitic rock - - 26
10, Fine-grained, oolitic rock - - - ~ - 1 0
11. Cream-coloured marly rock*; with Nerinea abundant, Lima -

Terebratula, Isocardia (Ceromya), Modiola, Lucina, &e. 1
12, Coarse oolitic rock = - - - - 2Qfeet to 26 0
 * Probably resting on the sands with slaty beds, which have been found in
sinking lower down the hill, overlying the ferruginous rock, which covers the
Upper Lias.’ - :
tP This series, thus noted by Professor Morris 20 years ago, may still be
considered, so far as it goes, to be ‘typical’ of the district ; but, as might
be expected, the then section in ‘inkler’s quarry does not exactly agree with
that now exposed ; which, of course, is at some distance from the former site.
A comparison will exhibit differences, and yet a remarkable coincidence.
Although entirely different sets of figures represent the various thicknesses
of the beds of the two sections, these figures, when summed up, give total
thicknesses for the two sections almost identical. Thus, the section recently
measured by me exposes a thickness of about 29 feet, to which may be added
the further thickness of 20 feet penetrated by the well, giving a total thickness
of 49 feet. Professor Morris’s measured and estimated thicknesses amount
together to 50 feet; the difference being only one foot.

 

* This represents the marly bed, the “Stamford Stone,” of Squires’s quarry.
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 1638

“The coincidence seems to me very significant. However variable and dis-
crepant the rate of deposition at the two points during the passage of time
represented by the whole thickness of beds, the aggregate amount of deposit
at both points only differed in the proportions of 49 to 50.

«The measurements of the beds of the Lincolnshire Limestone exposed at
Simpson’s quarry, on the ‘ Lings,’ in Tinkler’s quarry, and in the well, give
65 feet as the total thickness of the formation here.

“A well at Torkington’s brick-pit (half a mile to the east) pierces through a
thickness of 74 feet of the same beds; this about tallies with the thickness
pierced by a well sunk by Mr. Browning the architect, at a somewhat lower
level in North Street, allowing for a diminution of thickness at the top.

«Some excavations were recently made, at a lower level than Tinkler’s quarry,
near to the Scotgate entrance to Stamford; which exhibited the Slate beds
reposing on the Lower Estuarine Sands,

“ For the foundations and cellars of the houses of the Rock Terrace, hard by,
excavations were made in the Ferruginous beds of the Northampton Sand ;
so that the surface of the Upper Lias Clay cannot be many feet below the
level of the street at this point.

“ To the east and north-east of Stamford, the various bed are considerably
depressed. On the road to Uffington, immediately north of the bridge which
passes over the Stamford and Essendine Railway, and abutting upon the deep
cutting here, is Mr. Eldret’s quarry; in which is a fine section, exposing a
thickness exceeding 30 feet of beds of the Lincolnshire Limestone.

“The floor of this quarry is only a few feet higher than the level of the
Welland river at this point, although the base of the limestone has not been
reached.

‘This is a very good typical section of the middle beds of the formation ;
which here has thickened considerably. It consists of a series of fifteen dis-
tinct beds of limestone, of varying character: some are oolitic (one being a
true ‘freestone’), and these are in an unusual position, at the bottom of the
section, while others, and by far the greater part, are marly, and devoid of oolitic
grains; some are soft, like the Squires’s-pit ‘Stamford Stone,’ while others
are hard, and sometimes crystalline and blue-hearted; some are very fossili-
ferous, while others are slightly so, and some apparently bare of fossils. In
my detailed notes of this section, I have recorded the peculiar names by which
the several beds are identified by the quarrymen.

“ Section at Eldret’s Quarry, with Quarrymen’s Terms.
ft.
. ‘ Rammel] ’—broken stone, about - - - -4
* Clinkers ’—compact marly whitish stone, very good for
lime-burning : has a glistening fracture - -
. © Pendle *—hard, flaggy limestone, rather oolitic, deeper in
colour than the last, in thin layers - - -
. ‘Shelly Course ’—composed wholly of shells with corals,
very hard, (‘Stamford Marble’?) — - -
. ‘ Bullymong "—soft white marly limestone, containing
numerous fossils (like the ‘Stamford Stone ’ of Squires’s
uarry), more compact and harder towards the bottom - 4
. ‘Blue Limestone ’—hard compact stone, blue-hearted,
good rubble walling-stone - - - - 4
- 0
-)

oo fF & Ne
oo Oo OF

6

7. Course of cream-coloured clay - - -

8. Hard limestone, with oolitic grains -

9. * Bastard Freestone "—an oolitic limestone, in two courses 3
10. Hard and compact marly course - - - - 0
11. Soft white marly limestone (like the ‘Stamford Stone’ of

Squires’s quarry), in four courses of different thickness - 5
12. ‘ Caley ’ oolitic bed (like some of the upper beds at Colly-
weston) - - - - - - -
13. ‘ Bastard Freestone,’ containing concretionary masses of
very hard limestone - - = :
14, ‘ Freestone ’—a good oolitic freestone - - -1
15. Limestone—thickness not ascertained.”

Bn COC OO NCONWNR O&O
164 GEOLOGY OF RUTLAND, &c.

At Stamford the effects of the great Tinwell and Walton fault
are first encountered, as will be seen by a reference to the map.
Owing to this great dislocation, and the cross faults in connexion
with it, the several strata in the vicinity of the town are found
occupying peculiar, and at first sight apparently anomalous, posi-
tions. For an account of the exposures of the beds obtained
during the construction of the railway and other works in the

vicinity of the town, I again quote Mr. Sharp’s admirable
Memoir :—

“‘ At Stamford Bridge, the Upper Lias Clay is only just up to the level of
the bed of the river; and in ascending the hill from this point through St.
Martin’s, will be pee over in succession—the ferruginous beds of the
Northampton Sand, the Lower Estuarine sands and clays, the Collyweston
Slate and Lincolnshire Limestone beds, and the Upper Estuarine Clays; then
again, in reiterated sequence, a great thickness of Upper Lias Clay, the fer-
ruginous beds (worked for ironstone at the top of the hill), the Lower Estua-
rine beds, the Collyweston Slate, and further on the rock beds’ of the Lincoln-
shire Limestone. So that the Collyweston Slate occurs both at the foot and
at the top of the escarpment, with a difference of level of some 150 feet.

“ A cross fault has divided the sunken mass; for, in a section at the back
of the Midland Railway Station (levelled out of the side of the hill), the
Lincolnshire Limestone is seen in lateral juxtaposition with the ferruginous
beds of the Northampton Sand. From an excavation in the station-yard I
obtained, from a calcareous band in the latter, fragments of a zone containing
numerous bivalves, the hollows of which being filled with calcite offer a
ee contrast to the ferruginous matrix—an effect exactly paralleled by
the Astarte-elegans zone in ironstone quarries at Harlestone, near North-
ampton.

“The railway passes, by a tunnel under St. Martin’s, through the subsided
mass of Lincoinshire Limestone, the beds of which have preserved their hori-
zontal position, with little apparent disturbance. At the east end of the
tunnel, the railway (very little above the level of the river) passes over beds of
the Collyweston Slate; from which, at this point, in 1853, I obtained the
beautiful and unique Astropecten Cotteswoldie, var. Stamfordensis, described,
named, and figured, by Dr. Wright, in his Monograph upon the Asteroidea,
published in the volume of the Paleontographical Society for 1862.”

“ Sr, Marrin’s, STAMFORD.

“On the summit of the hill south of and over-looking Stamford, are the
Marquis of Exeter’s excavations for ironstone, just within the Burghley Park
Wall. ; ,

“At the top of the section, in patches, answering to the surface contour,
appears the Collyweston Slate, weathered into slate from lying so near the
surface: beneath this are the Lower Estuarine sands and clays, having a
thickness of from 6 to 7 feet, the lowest band containing vertical plant
markings: immediately under these, is the ‘ Best Black ? ironstone (cellular),
then the ‘Second,’ together from 4 to 5 feet in thickness: a calcareous band
of 6 inches comes in here; and below it succeed—the ‘ Bottom ironstone (so
called), also cellular, 2 feet; a green ferruginous bed, 13 foot; and a thin
ferruginous band, ‘full of water,’ and containmg small pebble-like nodules
(as in the same bed in different ironstone quarries about Northampton)
9 inches; and under all the Upper Lias. As far as I have been able to ascer-
tain, no fossils have been found in these beds.

“* Section at Burghley Park Ironstone Quarry.
ft. in, ft. in.

1. Soil and rubble, with patches of Collyweston Slate ae

at bottom - -
co te ah pre

LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE, 165

ft. in. ft. in.
2. Lower Estuarine series—
a, Sand, pale yellow, becoming redder towards the
bottom -. - - - - 5 0
6. Blue clay, with vertical plant-markings - - 16
3. Ferruginous beds— . — 66
a. © Best black’ ironstone, cellular - - 20
b. * Second,’ less cellular, and more sandy - 20
c. Calcareous band —=~—s- - - - 0 6
d. § Bottom’ ironstone, cellular - - - 20
e. Green ferruginous stone, about - - - 1 6
f. Thin red ferruginous band, with pebble-like
nodules (as at Duston and Kingsthorpe) - 09
— 8 9

(The last two beds were ‘ full of water ’).
4. Upper Lias Clay.

“Within a few hundred yards to the west, are Lumby’s Terra-cotta Works,
A band in the Lower Estuarine Clays supplies an excellent material (mixed
with some other ingredients) for this manufacture, and a very durable cream-
coloured terra-cotta is produced. Similarclay is found at other places in the
same bed, and is largely used in the well-known terra-cotta works of Mr.
Blashfield of Stamford.

‘© At a quarter of a mile further south, on the roadside opposite Whincup’s
Farm, is the old stone quarry of the abolished Trustees of the Great North
Road. The Lincolnshire Limestone is here seen in section to the depth of
18 feet : it is divided into eight distinct beds, varying in mineral condition ;
some are marly and others oolitic, those near the bottom having much of the
character of Barnack Rag, being coarsely oolitic, and containing numerous
small shells.

‘* Section in the Lincolnshire Limestone in the Old-Road Pit, near Whincup’s
Farm.

1. Rubble and broken limestone - - _ S
2. Compact cream-coloured marly ‘limestone, in thin layers
much broken - - - = < 2
3. Soft white marly limestone, surfaces and angles rounded by
weathering (Lima bellula, Mor. and Lye.) - . -
4, Hard cream-coloured limestone, rather oolitic -
5. Oolitic limestone, like the ‘ cale’ of Collyweston -
6 - =
7
8

. Soft crumbling’ caley’ oolite -

. ‘Rag’ bed—coarse oolite, containing numerous shells,
Lucine Wrightii, Oppel, Opis, &c. - = =

. Hard oolitic stone, not bottomed - = é is

be phwhd wo He
AR AOR O OF

“ WHITTERING.

* A mile south of Whincup’s Farm the road descends a small valley, crosses
the White Water brook upon the Upper Lias, and, after passing for a mile
over various beds of the Lincolnshire {limestone traverses the area of the old
* Whittering Pendle’ quarries. These were very shallow, and, having fallen into
disuse, the old familiar pits have long since been levelled down and ploughed
over, The ‘ Whittering Pendle,’ although it has been considered identical with
the Collyweston Slate, is very different in its mineral character, being very hard,
crystalline, and sometimes almost cherty intexture. It was excavated in large
irregular slabs, varying in thickness from one inch to two inches, and was
used, without being squared, for the door-slabs and rough floors of cottages,
for back-kitchens, &c.

“The fossils gathered from this bed are generally characteristic of the
Lincolnshire Limestone; but I must particularly notice a specimen taken by
myself from the section neal? thirty years ago, and labelled as a Coral during
all that time, but which last July was identified by Professor Phillips, F.R.S.,
as the spadix or fruit of Aroides Stutterdi, Carruth., an Arum-like plant, only
previously known, I believe, as occurring in the Stonesfield Slate, and
described by Mr. Carruthers in the ‘ Geological Magazine’ for April 1867.
- 166 GEOLOGY OF RUTLAND, &C.

“ Fossils from the ‘ Whittering Pendle.
Gervillia, sp. ?
Hinnites afreotaini Phil.
—— velatus, Goldf. sp.
Lima cardiiformis, Sow.
—— impressa, Mor. & Lye.
—— Pontonis, Lycett.
Pecten aratus (?), Waagen.
——— lens (?), Sow. (or new sp. 2).
———— personatus, Goldf.
Perna quadrata, Phil.
rugosa, Goldf.
Pteroperna, sp. ?

 

 

Lucina Bellona, d’Orb.

—— Wrightii, Oppel.
Macrodon Hirsonensis, d’Arch. sp.
Modiola, sp. ?

 

Belemnites Bessinus, d’Orb.

 

Aroides Stutterdi, Carruth. (spadix).

Owing to the series of faults already alluded to, the beds of the
Lincolnshire Oolite are found considerably to the eastward of their
main line of outcrop, and are exposed in more or less isolated
sections at many points along the tributaries of the River Nene.
The peculiarities presented by the beds at these their most
easternly exposures, and where they are rapidly becoming atte-
nuated preparatory to their final disappearance altogether in this
direction, will be described in the sequel.

To the west of Stamford the beds of the Lincolnshire Oolite are seen to be
considerably disturbed in the neighbourhood of Wilds’ Ford, where, as will be
seen by a reference to the map, a fault intersects the strata.

At astone-pit between this last-mentioned point and Stamford, and at a
distance of about one mile west of the latter town, the following species were
obtained by the fossil-collector of the Survey :—

Natica Leckhamptonensis, Lye.
Nerinza pseudo-cylindrica, d’Orb.
-, Sp.
Astarte, sp.
Ceromya Bajociana, d’ Orb.
Lucina Bellona, d’Orb.
Modiola imbricata.
Macrodon Hirsonensis, d’Arch.
Myoconcha crassa, Sow,
Mytilus Sowerbyanus.
Pholadomya fidicula, Sow.
—_——-—, ovalis, Sow.
——_-——,, Heraulti, Ag.
——, reticosta.
Lima cardiiformis, Lyc. & Mor.
— bellula, Lyc. & Mor.
—— punctata, Sow.
ectiniformis, Schloth.
—— Pontonis, Lye.
Pecten lens, Sow.
Pinna cuneata, Beau.
Terebratula sub-maxillata, Dav.
Thamnastrea Lyelli, Edw. & Haine.

Passing again to the outer escarpment of the main line of outcrop we find

many exposures of the beds which we are describing. The effect of the series

 

 

 
LINCOLNSHIRE OOLITE AND GOLLYWESTON SLATE. 167

of north and south faults which intersect the strata between Tickencote and
Blatherwycke are sufficiently illustrated by the map, and need not he farther
alluded to here. Near these faults the strata are often much disturbed, as
ped be seen at Ketton Station and in the railway-cutting to the eastward
of it.

In a railway-cutting east of Luffenham Station the lowest beds of the Lin-
colnshire Oolite are exposed. The courses of limestone are here seen to be
interstratified with beds of white or yellow sand, such as are so frequently
found occurring towards the base of the limestone series. Some of the lime-
stone beds are laminated and pass into coarse slates.

In the churchyard of North Luffenham the graves are opened through a bed
of slaty rock into the white sands below.

In the South Luffenham cutting of the London and North-western Railway,
the oolitic limestone, the Northampton Sand (ferruginous rock with usual
characteristics, but only 3 or 4 feet thick), and the Upper Lias Clay are all
seen.

About Edith Weston, and again at Whitwell and Barnsdale, the beds of the
Lincolnshire Oolite are exposed at a number of points near the escarp-
ment: the strata are here affected by a number of small faults. In the
stone pits above Whitwell and in those of the lime-kilns at Barnsdale Hill we
find the lower beds of the Lincolnshire Oolite, consisting of hard compact beds
of oolitic limestone with flaggy beds at their base, underlaid by sand.

A pit formerly existing at this place is thus noticed by Professor Morris
and Captain Ibbetson :—“*At Edith-Weston a species of Lingula, near to,
if not identical with, L. Beanii (Phillips), occurs in great abundance, indi-
cating like the recent congeners its gregarious habits, and there mixed up with
numerous fragments of the Pecopteris polypodioides in fructification.”

To the eastward, in the neighbourhood of Normanton, there are many expo-
sures of the Lincolnshire Oolite. Extensive quarries exist near Normanton
Lodge, and in the excavations for a large tank in front of Normanton Hall I
saw the freestone beds resting on the representative of the Collyweston Slate,
and this in tarn on the Northampton Sand.

Over an extensive area stretching to the northern limits of Sheet 64 the Lin-
colnshire Oolite forms a great plateau capped by numerous outliers of the beds
of the Great Oolite. Quarries in the former beds are numerous in this district,
but seldom offer any features of interest. This district is but little obscured
by Boulder a

At Tixover the quarries of oolitic limestone have yielded many fragments of
Trichites; at Pickworth in the same rock a very large Pecten (undescribed),
with a diameter of seven inches, was found; and the same beds of the Lincoln-
shire Oolite at Little Bytham have yielded a fine ‘Ammonite (A. polyacanthus,
Waagen). The extreme rarity of Ammonites, and indeed of all Cephalopods
in the Lincolnshire Oolite, has already been noticed; Stamford and Little
yileradt are the only localities within Sheet 64 at which these shells have been

etected.

At Clipsham Quarries the beds of the Lincolnshire Oolite are extensively
wrought for building purposes. The stone is quarried from beneath a consider-
able thickness of the Estuarine Clays forming the base of the Great Oolite series.
The sections are similar to those of Ketton and Stamford brickyard (Torking-
ton’s pit) but not so complete. The ironstone junction-bed is present, but
does not seem to be so persistent as is usually the case. The Clipsham sections,
are, however, somewhat obscure.

The Clipsham freestone which, like that of Ketton and Weldon, is associated
with other beds of more or less coarse shelly rag, is an oolitic limestone similar
to that of Ketton, but less even in grain, and with a few shells scattered through
its mass. Its characters more closely resemble those of the extensively worked
stone of the same age abotit Ancaster.

At the cross-roads between Greetham and Thistleton there are extensive
quarries, exhibiting the Lincolnshire Oolite as a compact, sub-crystalline lime-
stone presenting many of the shells, &c. characteristic of the coralline facies of
the formation.

 

* Rep. Brit. Ass., 1847, ‘I'rans. of Sec., p. 131.
168 GEOLOGY OF RUTLAND, &c.

In the neighbourhood of Little Bytham the similar beds fof the marly or
compact variety of the Lincolnshire Oolite are found in some pits to be almost
entirely made up of corals, the interiors of which are nearly always filled with
beautifully crystallised calespar. Near the same place we find the peculiar
concretions surrounding and enclosing a number of oolitic grains already
alluded to. ‘These concretions might at first sight be mistaken for pebbles,
but an examination of their internal structure will soon disabuse the mind of
this idea. The pit in which they occur presents the following section :—

Pit between Little Bytham and Witham, half-a-mile from the former place.

(1.) Rubble and ‘soil.
(2.) Beds of oolitic limestone, with usual

characters = - - 5 feet.
(3.) Beds of oolitic limestone, full of the
irregular concretions - - 5 or 6 feet to bottom of pit. |

This pit is clearly near the top of the Lincolnshire Oolite, for the Upper
Estuarine Clays are seen let down in pockets at the top of the pit.

From Barnsdale northwards to the extreme limits of the sheet, the beds of
the Lincolnshire Oolite Limestone do not extend to the outer escarpment, which
is entirely formed of the Northampton Sand. The strata of the first-mentioned
formation do not here afford any sections of particular interest to the geologist,
and the line of their junction with the underlying rocks is in places concealed
by Boulder Clay. -

In a pit in the oolitic limestone east of Market Overton the beds exhibit
evidences of a disturbance which is probably of an entirely local character,
and not in any way due to subterranean movement on the large scale. The
appearances presented by this section are represented in the woodcut (Fig. 13).
Many of the beds here, as is usual in this rock, exhibit, much oblique lamina-
tion. :

Fig. 13. Section in Lincolnshire Oolite Limestone East of Market Overton.

 

The appearances presented in this section are oe of explanation on the
hypothesis that subterranean streams of water, such as certainly occur in the
district and notably between Thisleton and South Witham, have dissolved out
channels or great subterranean tunnels in the calcareous rock. The formation
of such caverns would, in many cases, be followed by subsidences of the super-
incumbent strata into them, and thus effects similar to the “creeps” of coal-
mining ‘districts might be produced near the surface. The depression is filled
with Boulder Clay, which is denuded away from all the area around. This
indicates that the subsidence took ‘place before that denudation was com-

plete.

Aah
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 169

Inliers, &c. of the Lincolnshire Oolite.

Besides the exposures already described along the main line of
outcrop, the beds of the Lincolnshire Limestone make their appear-
ance to the eastward, usually in more or less isolated sections, along
the lines of the numerous brooks which have cut for themselves
valleys through the Boulder Clay and subjacent oolites, and
empty themselves into the Nene and Welland. In some cases
these patches of Inferior Oolite Limestone are completely isolated,
and exist as inliers in the midst of the Boulder Clay or the beds
of the Great Oolite series; in other cases their connexion with
the main portion of the outcrop of these beds in the district,
along the band which we have already described, can be traced.
It will be convenient to describe all these more easternly expo-
sures of the formation together, as there are a number of
features which are common to them all. Owing to the easternly
attenuation of the formation which we have had occasion to notice
so frequently, the Lincolnshire Oolite in the localities which we are
now about to notice is of far inferior thickness to that which it
presents along the line of escarpment to the westward; and in
some places we find it with altogether insignificant proportions,
and actually see it disappearing altogether, thus permitting the
estuarine beds of the Great Oolite to repose directly upon those
of the Inferior Oolite. Among the most interesting exhibitions of
the easternly part of the Lincolnshire Oolite in this district the
following may be noticed. It must be borne in mind that the effect
- of the faults which traverse the district has been such as to place
the beds in a favourable position for their exposure at the surface
by denudation.

On the extreme southern limit of Sheet 64 an interesting inlier of the Infe-
rior Oolite (Northampton Sand and Lincolnshire Oolite) occurs, which has
been already noticed (see Introductory Essay, pp. 36, 38, and fig. 3). The Infe-
rior Oolite strata show considerable signs of disturbance which appears to have
taken place before the deposition upon them of the beds of the Great Oolite
series.

Further to the north two other small inliers of the Lincolnshire Oolite simi-
larly occur, in the midst of the same tract of country composed of Great Oolite
rocks, and for the most part deeply covered with drift. The small patches of
strata exhibit beds greatly disturbed and faulted, and as in the last instance
their exhibition at the surface is due to the cutting of a deep valley in the
overlying beds by small streams. ;

Along the valley of the Nene from Aldwinkle to Perio Mill, con-
siderably to the north of Oundle, the limestone of the Lincolnshire
Oolite seriesis altogether absent ; the Upper Estuarine series (Great
Oolite) resting directly upon the Northampton Sand. It is in the
small lateral valley in which the village of Southwick is situated
that we first find traces of the great calcareous formation of the
district.

At Cross-Way-Hands Lodge, at the bottom of the valley just alluded to,
there is a pit in the shelly, oolitic freestone, which is seen to the depth of
12 or 14 feet, with the usual characters and fossils. At the cottages near, a
well was sunk to the depth of 30 feet, before water was obtained. The lime-
stone beds can be traced eastwards along the sides of the same valley to
Stonepit Field Lodge.

At the last-mentioned locality we find the attenuated representative of the
lower part of the Lincolnshire Oolite (Collyweston Slate) on the point of
170 GEOLOGY OF RUTLAND, &c.

disappearing. The section here exhibits a. thickness of 12 to 14 feet of ve
hard, slaty sandstone, calcareous in places, containing irregular masses a
oe sods of iron, and presenting many mammillated surfaces (“ pot-lids,”

c.) The fossils in this rock are few and badly preserved ; among them occur—

Gervillia acuta, Sow.

Pecten vagans, Sow.

Pteroperna (plana P, Lye. and Mor.)

Several bivalves ‘and univalves too imperfect for identification.
Wood and plant remains,

In the valley in which the villages of King’s Cliffe, Apethorpe, and Wood-
Newton are situated, we find another series of exposures of the Lincolnshire
Oolite Limestone; the beds, as in the previous case, thinning out and dis-
appearing as we follow them to the eastwards.

The slipping of the heds of limestone at King’s Cliffe over the subjacent
beds has given rise to some picturesque features upon a small scale. A house
at King’s Cliffe on the left bank of the Willow Brook is built in an old stone-
quarry ; the face of rock forms the back of the house, and the hard siliceous
beds representing the Collyweston slate form its floor. The sands of the
Lower Estuarine Series are seen below the rock.

A pit on the left hand side of the road leading from King’s Cliffe to Spa
Lodge is opened in the oolitic limestone; the rock is here traversed by large
fissures (“pipes”’) which are filled with the white, marly and sandy clays of
the Upper Estuarine Series, here seen covering the oolitic limestone rock.
These fissures, which vary from 1 to 5 or 6 feet in width, coincide in
direction with the joint planes of the beds, and in all cases show on their
sides signs of the solvent action by which they have been formed. In some
cases the sides of these fissures are covered with beautiful deposits of stalag-
mite.

On the side of the hill on the right bank of the Willow Brook and opposite
to Cliff, there is a pit showing the lower beds of the limestone resting on the
sands below. The basement bed of the Lincolnshire Oolite is a hard, quartzose
rock, of more or less laminated structure, with mammillated surfaces beneath,
at the junction of the limestone and sand.

On the surfaces of the flags obtained from these pits, which can sometimes
be raised of considerable size and are used for rustic bridges, peculiarly shaped
concretionary masses are sometimes found. One concretion of this character,
found on a slab near King’s Cliffe, has attracted much attention in the
neighbourhood from the popular belief that it is a “fossil carrot.” Small
recesses or caverns are sometimes formed by the weathering out of the sands
from beneath the hard rock; one of these is known in the district as “the
Robber’s Cave.” .

In the very shelly beds of the Lincolnshire Oolite exposed at some points
near King’s Cliffe many specimens of the drifted fossils, of which they are
wholly made up, can be procured. An interesting collection of these shells
made by the Rev. Miles J. Berkley, F.R.S., &c., during his residence at this
place was obligingly presented by him to the Geological Survey. .

Along the line of the Willow Brook, between King’s Cliffe and Fotheringhay,
a good section of the beds of the district can be made out. Near King’s Cliffe
the Lincolnshire Oolite’consists of hard, compact, marly rock ; and on the road
from King’s Cliffe to Apethorpe this rock is found passing into soft, shelly
oolite.

The following fossils were obtained from the Lincolnshire Oolite in the
neighbourhood of King’s Cliffe :—

Belemnites acutus, Mill.
Pleurotomaria sulcata, Sow.
» 8p.
Phasianella Pontonis, Lyc.
—_—_—_——- striata, Sow.
Natica, Leckhamptonensis, Lyc.
Trigonia Moretonis, Mor. and Lyc.
— tenuicosta, Lyc.
Pholadomya fidicula, Sow.
- Heraulti, Ag.

 

 

 

 

—_—_—
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 171

Myacites Scarburgensis, Phil.

— securiformis, Phil.

— decurtatus, Phil.

Mytilus Sowerbyanus, d’Ord.

— lunularis, Lyc.

Lucina Bellona, d’Orb.

Wrightii, Oppell.
d’Orbignyana, Mor. and Lyc.
Cyprina nuciformis, Lyc.

Ceromya Bajociana, d’Orb.

Cucullea cucullata, Goldf.

Cardium Buckmani, Lyc. and Mor.
—, Sp.

Arca rugosa, Lyc. and Mor.

Hinnites abjectus, Phil.

Pteroperna plana, Lye.

Pecten demissus, Phil.

lens, Sow.

—— articulatus, Sow.

Gryphza minima, Phil.

Ostrea flabelloides, Lam. (O. Marshii, Sow.) var.
Lima Pontonis, Lye.

—- mals Lyc. and Mor.

—- grandis, Lyc.?

Sera ect Schioth.

—- punctata, Sow.

—--, sp.

Terebratula submaxillata, Mor.
————-— perovalis, Sow.
Rhynchonella varians, Sow.

—— spinosa, Sow., var. Crossi, Walker.
Serpula intestinalis, Phil.

plicatilis, Goldf.

-, sp.

Pygaster semisulcatus, Phil. sp.
Pseudodiadema depressa, 4g. sp.
Galeropygus agariciformis, Forbes.
Thamnastrea Lyelli, Edw. and Haime.

The Wood-Newton “ parish-pit ” is opened in the oolitic limestone of the
. Lincolnshire Oolite, which is here hard and somewhat laminated in structure.
In the bed of the stream below white and brownish sands are seen. The
strata here exhibit signs of disturbance.

Opposite to Wood-Newton the bed which rests immediately upon the sands
of the Lower Estuarine Series is a very hard, fine-grained, calcareous sand-
stone. This rock contains sufficient carbonate of lime to break along cleav-
age planes with a brilliant lustre.

In the well at Wood-Newton brickyard the following section was
obtained :—

(1.) Clay (Upper Estuarine Series) of white and light-blue

colour and sandy character, with whitish concre-

 

 

 

 

 

 

 

 

 

 

 

tionary nodules, but no fossils = - - - 3 to 8 feet.
(2.) Ironstone junction-band.
(3.) Stone, as described above (Lincolnshire Oolite) - 1 ff, din,

(4.) White sands, becoming ferruginous below, and rest-
ing on rock in which water was obtained (North-
ampton Sand) - - - - - 17 feet exposed.

At this point it is evident that the attenuated representative of the Lincoln-
shire Oolite is on the point of disappearing. °

In the cleared space between the Walk of Sulehay, Spires Wood, and Ring
Haw, there is a large pit with a limekiln, opened in the beds of the Inferior
172 GEOLOGY OF RUTLAND, &C.

Oolite Limestone. The beds are here generally compact, or somewhat sandy,
and only occasionally oolitic. The white clays of the Upper Estuarine Series,
which rest on the limestones, are well seen in the fields around.

On the road from Ring Haw to Yarwell there is another pit in beds of
suet ie white, sandy, and but rarely oolitic limestone, here dug for
road-metal.

To the south-east of the town of Stamford the beds of the
Lincolnshire Oolite are well displayed over a very considerable
area, owing in part to the great displacement which the beds of
the formation have undergone by the faults which traverse the
district, and its extensive denudation by the Rivers Welland and
Nene (the valleys of which are here closely approximated) and
their tributaries. In this area we are able to study the easterly
attenuation and disappearance of the formation in the valley of the
Nene; but in that of the Welland the effect of the great fault
has been to throw down a higher series of beds along the lower
part of the course of that river, before it reaches the fens. Hence
the sections presented along these two valleys, which are only a
few miles apart, offer many striking points of contrast, as will be
seen by an inspection of the map.

In Burleigh Park the Lincolnshire Oolite can be seen both in the low
grounds in front of the mansion, where a large excavation, made to receive
the drainage, exposed an instructive section, and in the high grounds behind
it, where it is found overlying the Northampton Sand, and with that forma-
tion constituting the summit of a steep escarpment, the lower slopes of which
are formed by fie clays of the Upper Lias. Nothing can be more striking
than the effects of the Great Tinwell and Walton fault at this point, the
fault, as will be seen from the map, passing through the midst of the park.

Over the high ground constituting Wittering Heath the limestone of the
Lincolnshire Oolite forms the surface rock. Here the nature of the light,
stony soil, of a deep red colour, which these limestones afford is very well
illustrated. Some portions of this area have not long been brought under
cultivation.

In the neighbourhood of Barnack the very extensive “hills and holes”
show what enormous quantities of the celebrated ‘“ Barnack-rag” were
quarried in former times. Indeed almost all the beautiful ecclesiastical edifices
of the Norman, Transition, Early English, Geometric, and Decorated periods
in North Northamptonshire and South Lincolnshire, and especially those of
the adjoining Fenland, appear to have been constructed of stone derived from
these extensive quarries, around which a very considerable population of
quarrymen appears in early times to have been established. Far earlier, even
in Roman times, the value of this building material seems to have been recog-
nised ; but before the Perpendicular period (15th century) the use of the stone
appears to have been abandoned, probably from the exhaustion of the quarries.
The excavations of the “hills and holes”’ of Barnack, now filled up and grass-
grown, are continued in Walcot Park, where some of the pits still remain
open. Several pits in the Lincolnshire Oolite are still worked near Barnack,
but in none of them is a rock of exceptionally fine quality found; and the
general opinion that the Barnack-rag (a freestone of excellent quality almost
made up of small shells and other drifted organisms, and containing a few
scattered oolitic grains) is now wholly exhausted is probably the correct one.
It is only necessary to study some of the beautiful Gothic edifices constructed
of this stone to see how freely it was capable of working under the chisel, how
suitable it was for buildings with elaborate mouldings and florid decorations,
and how its durability so well adapted it for preserving the triumphs of
medizval workmanship, even when exposed in the open air to a rigorous

imate.
not the sections now exposed at Barnack the following may be noticed as

typical.
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 173

Pit in Lincolnshire Oolite Limestone near Barnack.,

(1.) Soil.
(2.) Rubble oolite.
(3.) Rock, made up of small shells and fragments of shells,

echinoderms, corals, &c.; plates and spines of
Cidaris, with joints of Pentacrinus, and many speci-
mens of the minute variety of Rhynchonella spinosa

(R. Crossi, Walker) abound - - - - 4 feet seen.
(4.) Ordinary white, oolitic limestone, not shelly —- - & feet.
(5.) Beds of yellow and white sand containing hard siliceous

concretions - - Base not seen.

The bed (3) is regarded as part of the celebrated bed of the ‘‘ Barnack-
rag,” which it greatly resembles. It is here exposed near the surface, and is
consequently of little value.

It is not certain whether the bed (5) is to be regarded as representing
the higher part of the Northampton Sand, or the base of the Lincolnshire
Oolite, i.e., the beds in which, at certain points, the Collyweston Slates make
their appearance.

It is interesting to notice that the shelly facies of the Lincolnshire Oolite
occurs at Barnack near the base of the series. At many points in this
neighbourhood sandy beds occur intercalated in the lower part of the
series (Collyweston Slate). At Wittering Heath, as we have already seen,
these arenaceous beds are indurated into the beautiful, hard, siliceo-calcareous
rock known as “ Pendle.”

At Southorpe, and along the railway line between Stamford and Wansford,
there are a number of exposures of the Lincolnshire Oolite limestone, and
of the sands intercalated in the lower part of the series and immediately
underlying it.

About Ufford and Helpstone Heath there are many pits in the lower beds
of the Lincolnshire Oolite, and nowhere, perhaps, can its relations to the
underlying sands of the Lower Estuarine Series be better studied. (Vide
woodcuts, Figs. 8 and 9, pp. 104, 105.)

About Wansford we find many interesting exposures of the
Lincolnshire Oolite, and from this point eastward we can clearly
trace the gradual thinning-out and final disappearance of the for-
mation in the vicinity of Water Newton and Castor.

South of the village of Wansford the extensive pits near Wansford Mill
afford us a good section of the great limestone series, presenting its ordinary
characters.

In the ‘“‘ Wood-pit” at Stibbington the upper surface. of the oolitic lime-
stone is seen to be very irregular; but this is, in part at least, due to the per-
colation of water with carbonic acid which has dissolved the upper portions
of the surface of the limestone, and thus let down the superjacent clays, &c.
into the holes and pockets (“ pipes”) thus formed.

The following fossils were collected in this neighbourhood by the late Dr.
Porter, of Peterborough, principally from the “ Wood-pit” at Stibbington :—

Acteonina glabra, Phil., sp.
Pleurotomaria, sp.
Monodonta levigata, Sow., sp.°
Patella rugosa, Sow.
Phasianella, sp.
Trochus Gomondii, Mor. & Lye.
spiratus, d’Arch.
Turbo Phillipsii, Mor. & Lye.
gemmatus, Lye.
—-, sp.
Cerithium Beani, Phil.
————-- cingenda, Phil.
Nerinza Voltzi, Desh.
—, 8p.
Modiola imbricata, Sow.
Mytilus lunularis, Lye.
32108. M

 

 

 
174 GEOLOGY OF RUTLAND, &c.

Arca Prattii, Mor. & Lye.
igonia, soem Lye.

ucina d’Orbignyana, Lye. & Mor.
Astarte alesaun: i a
minima, Phil.
—, sp.
Opis lunulatus, Sow.
—— similis, Lye. & Mor.
Gryphzea, sp.
Ostrea Marshii, Sow. (labelloides, Lam.). °-
——-- Sowerby, Lyc. 8 Mor.
—~--, sp.
Pecten lens, Sow.
——-- vagans, Sow.
Avicula, sp.
Gervillia acuta, Phil.
Pteroperna costatula’(?), Desh.
—— plana, Mor. & Lyc.
Lima bellula, Lye. & Mor.
—— duplicata, Sow.
Terebratula maxillata, Sow.
—- perovalis, Sow.

 

 

 

 

eta ne.

Rhynchonella spinosa, Schloth.

——-—, sp.

Serpula plicatilis, Goldf.

Vermicularia nodus, Phil.

Acrosalenia hemicidaroides, Wr.
~ spinosa, Ag.

 

—_———--, sp.
Holectypus a ressus, Leske.
Pentacrinus Miilleri, Aust.
Pseudodiadema depressa, Ag.
Otopteris graphica, (Bean. MS.) Leckenby.

Under the sandy, whitish and bluish clays, with irregular plant-beds, we
find in this pit the “junction-band,”’ a layer of nodules of more or less
compact or earthy brown ironstone. This is underlaid in many places by a
bed of white marl, the product of the decomposition of the beds of iimestone,
and containing apparently waterworn fragments of compact limestone rock,
the beds below being very oolitic.

Near the Sibson railway-tunnel there are several very interesting sections
exposed in old stone“pits. In the cutting at the west end of the tunnel itself
we can trace a most interesting section, exhibiting both the top of the
attenuated Lincolnshire Oolite with the overlying beds of the Great Oolite,
and also the sandy beds forming the base of the former formation. The top
of the oolitic limestone, and its junction with the Upper Estuarine Series, pre-
sents us with similar appearances to those which are afforded by the “ Wood-
pit.”

The beds of the Lincolnshire Oolite are again well exposed at the opposite
or eastern end of the Sibson tunnel.

In Water-Newton brickyard we find, beneath the sands and clays of the
Upper Estuarine Series, 4 feet of beautifully fine-grained oolitic limestone,
with the “‘junction-bed ” of nodular ironstone lying on the top of it. Below
the limestone bed, which forms two courses, we find other stratified clays and
sands, with a plant bed about 6 inches thick in the higher part of the series.
At this place it is evident that we have the insignificant representative of the
Lincolnshire Oolite separating the two estuarine series, belonging to the
Great and Inferior Oolite respectively.

On the opposite side of the river, near Castor, traces of the Lincolnshire
Oolite were found; but the country here is greatly obscured by great masses
of valley gravel. Further east, as innumerable sections show, the Lincoln-
shire Oolite is altogether absent, and the Upper Estuarine Series rests directly
on the Northampton Sand.
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 175

North of Stamford the rivers Glen and Gwash with a number of
tributary brooks, have removed over considerable tracts portions
of the beds of the Great Oolite Series, and thus exposed the beds
of the Lincolnshire Oolite. This district is characterised by the
broad flat plateaux constituted by the beds of the great calcareous
formation of the district, and everywhere giving rise to a red soil,
upon which stand numerous outliers, exhibiting that peculiar
tabular outline which the geological student soon learns to associate
with the rapidly alternating beds of limestone and clay so abun-
dant in the Oolitic Series. These characteristic features of the
scenery of the district are well illustrated in several of the plates.

It was in this district that Professor Morris, taking advantage
of the fine sections afforded by the construction of the main line
of the Great Northern Railway, carefully studied and described in
the year 1853 the interesting succession of strata in this area, and
thus called the attention of geologists to the remarkable differences
which exist between the sections of the Lower Oolites in the Mid-
land district, and those of the Cotteswold and Yorkshire areas
respectively.

By far the best sections in the area just referred to, namely, that
lying eastward of the main line of outcrop of the Lincolnshire
Oolite, and in the tracts around the scattered outliers of the Great
Oolite, are those afforded by the cuttings on the main line of the
Great Northern Railway, and in the branch line between Essen-
dine and ‘Stamford. 5

In the cuttings between Stamford and Essendine, to the northwards of the
latter place, and at Carlby, Aunby, Careby, Little Bytham, and Creeton, very
beautiful illustrations are afforded of the characters presented by the beds of
the Lincolnshire Oolite and of their relations to the overlying beds of the
Great Oolite series. These features have been sufficiently described in the
country to the southwards, and as these sections are but a repetition of many
already given in this Memoir it will not be necessary to notice them in detail,
more especially when it is remembered that all their more interesting features
were pointed out by Professor Morris so long ago as 1853, when the fresh
state of the cuttings offered facilities for their study which do not now exist.
Mr. Sharp has also added some interesting notes upon the same district in his
recently published memoir. ;

The following account of such of the fine sections along the main line of the
Great Northern Railway as present exposures of the beds of the Lincolnshire
Oolite is extracted from Professor Morris’ valuable paper (Quart. Journ. Geol.
Soc. vol. ix (1853), pp. 328-330).

“The Counthorpe cutting is a continuation of the same series of beds, but
increased in thickness and varying in character, in descending order :—

Mottled clay with bands of Oysters - - - - 3
Dark bituminous clay - - - - - 1
Compact, sandy, and occasionally soft shelly rock, with verti-
cal remains of plants; the shells are not numerous, com-
prising the genera Natica, Modiola, Trigonia S =
Stratified dark green and brown shelly clays - - -
Stratified dark clays with layers of shells, not broken, and
indicating the beds to have been deposited under quiet
conditions; the shells are Avicula, Cytherea, Pecten, Lima,
Ostrea, Terebratula, Lingula, and probably Cyrena -
Mottled and dark clays - - - - 4
Bituminous band - - - 7 - - 6
Stiff brown and greyish clays; no shells; numerous vertical 0%
plant-markings = - - - - - - f

Oo
176 GEOLOGY OF RUTLAND, &c.

ft.
White and yellow clays - - - - - 3
Ferruginous band = - = 1

Oolite, fine-grained and pinkish, the blocks occasionally
with blue centres*; some of the beds coarser, and con-
taining small shells, as Cerithium and Nerinea, from - 12t0 13

Two small sections of the oolite occur between this and Creeton cutting,
which latter exhibits the following descending series :—
ft.

Irregular laminated grey and green sands and clays, with layers
full of shells in parts - - - - -
Soft sandy rock full of shells, as Modiola, Ostrea, Pecten -
pee and dark green clays, with occasional shelly
ayers - 7 ze si .
Gare clays, in some parts finely bituminous (6 inches), at
ase - - - - - - -
Greenish sandy rock with vertical plant-markings - -
Various coloured clays, green, grey, brown, without shells - 10
Ferruginous band - - - - - -
Oolitic rock, thick-hedded and horizontal, with occasional
false-bedding at the upper part; inclination of oblique
lamine 30° N.

“The Little Bytham cutting presents a similar section, the beds varying some-
what in character (i.e. less fossiliferous) and thickness, especially towards the
upper part; the sandy rock with Modiola is wanting, but the clays are full
of small Oysters and much thicker; the total thickness of clays is about
30 feet overlying the oolitet ; the latter was quarried to some depth below the
level of the line and presented the following :—

ft.
Pinkish oolitic rock, obliquely laminated (45°), the thicker
layers being separated by seams of clay with crystallised
ypsum = - : “. - - - - 1
Oolitic rock - - - - - - ~ 4
Compact oolite with fragments of shells - - - 5
Compact marly rock with Nerinea and Lucina - - 38
Compact oolite rock, about - - - - m

There is one point in connexion with this district which it may
be necessary to call attention to here. The long series of dee
cuttings along these railway lines enable us to perceive that the
whole of the strata are bent into very slight synclinal and anticlinal
folds, which do not however interfere with the general south-
easterly dip of the beds of the district. Although the want of
continuous sections in other parts of the area does not enable us
to recognise so clearly this phenomenon of the incipient folding of
the strata, yet I am convinced, from the manner in which outliers
and inliers of the various strata make their appearance over the
whole district, that the features so clearly traceable in the tract just
described are by no means confined to it, but are equally present
in the whole of the Jurassic formations of the Midland counties.

 

«* From some recent experiments it would appear that the blue colour of the oolite
may be due to the presence of sulphuret of iron ; see a paper by M. Ebelman, Bull.
Géol. Soc. France, 2 ser. tom. ix., p. 221.

+ The clays which here cover the oolite (and the observation applies to the whole
district) have materially tended to its preservation as a solid rock, in preventing the
ordinary effects of atmospheric action, which, when the surface is not so covered,
causes it to split up into shivers and renders the upper part comparatively useless as
a building material. This observation may be useful to those who have occasion to
search for or avail themselves of the building-stone of the district.”
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 177

Mr. Hull arrived at precisely similar conclusions concerning the
slight or incipient folding of the Jurassie rocks during his survey
of the Cotteswold Hills.*

Outliers of the Lincolnshire Oolite.

To the west of the main line of outcrop of the formation there
occur a number of outliers of the calcareous rocks of the Inferior
Oolite, capping the beds of the Northampton Sand and Upper Lias
Clay. The outliers of the limestone beds of the Inferior Oolite
are not so numerous as those of the ferruginous and sandy beds
which lie below them, for it is evident that in many cases the relics
of the former have been removed by denudation, while those of the
latter remain. The escape from destruction by denudation of
many of the outlying patches of Inferior Oolite strata in the district
can, In many cases, be traced to the influence of faults or synclinal
flexures in letting down the portions of the strata below the level of
the main masses around them.

At Stoke-Albany we find a portion of the Lincolnshire Oolite, which we have
represented on the map as doubtfully connected with the masses forming the
main outcrop of the beds on the great escarpment. As, however, the relations
of this mass of strata are here obscured by the Boulder-Clay, it is possible
that it is in reality an outlier. :

In the interesting outlier of Inferior Oolite strata at Neville-Holt, the North-
ampton Sand already described, (pp. 106-107) is capped by beds of the Lincoln-
shire Oolite, the whole of the strata evidently owing their preservation to the
fault indicated upon the map. ‘The base of the limestone series here is
evidently formed by sandy limestones, sometimes exhibiting a fissile character.
There is no pit in these beds now open, but they can be traced in the allotment
grounds on the western side of the hill. There can be no doubt that these
beds really represent the Collyweston Slate. Several pits are seen on the top
of Neville-Holt Hill, exhibiting the oolitic limestone with its usual characters.
The stone is for the most part of the compact and marly varieties (coralline
facies), and at one point, where it is quarried for building purposes, it contains
numerous specimens of Brachiopoda. I obtained here—

Terebratula submaxillata, Mor. (of all ages).
——————- perovalis, Sow. (adults only),
Pteroperna costatula? Mor. and Lyc.

Between Lyddington and Seaton the eminence known as “the Barrows ”
is capped by beds of limestone, evidently belonging to the Lincolnshire Oolite,
and which yielded—

Ceromya Bajociana, d’Ord.

Ostrea flabelloides, Lam. (O. Marshii, Sow.) var.
Avicula, sp.

Pecten lens, Sow.

The beds were exposed in a drain-cutting, but the masses of drift which
overlap them renders it impossible to define on the map the exact limits of
this little outlier. : ;

Above the village of Seaton there is an outlier of the Lincolnshire Oolite of
very considerable size. Here the beds are well exhibited in a number of large
quarries. Near Seaton Church there is a pit exhibiting the basement beds of
the formation, consisting of slaty or flaggy calcareous and micaceous sandstone,
the equivalent of the Collyweston slate. A little farther to the north we find
pits in which the ordinary beds of the Lincolnshire Oolite are dug to the
depth of 10 feet without reaching the slaty beds at their base.

At Bisbrook there is a very small outlier of the bottom or slaty beds of the
Lincolnshire Oolite. The rock can be traced near the church, and was formerly
dug for road-metal, but it is said to have constituted only a band of a few

 

* Quart. Journ. Geol. Soc., vol. xi (1855), p. 483.
178 GEOLOGY OF RUTLAND, &C.

inches in thickness, with sands above and below it. This band seems to have
been entirely worked out, and now only small quantities of the slaty rock are
collected from the surfaces of the fields for the purpose of mending the roads.
A little to the west of the village the Linoalndhive Limestone with the slaty
beds at its base was exposed in a number of holes opened in different parts of
the fields, but which are now all closed. The slaty beds at the base of the
series were found to rest directly upon white, calcareous sands, and these on the
light-blue, sandy clays of the Lower Estuarine Series.
From the rock forming the small outlier at Bisbrook I collected the following
species of fossils :—
‘ Gervillia acuta, Sow.

Pinna cuneata, Phil. fey abundant.

Numerous small bivalves.

Trigonia compta? Lyc.

Pecten paradoxus, Goldf.

Mytilus Sowerbyanus, d@’Ord.

Homomya crassiuscula, Lyc. and Mor.

Ceromya Bajociana, d’Orb.

Cardium cognatum, Phil.

Cucullea cucullata, Goldf.

The lower slaty rock here splits up into thin plates after being weathered ;
it shows the peculiar siliceous mammillatious appearances with “ potlids,” &c.,
and has below it the white sands with siliceous concretions. Thus it will be seen
that alike, in its characters and relations, this rock presents a perfect identity ~
with the Collyweston slate. Some of the slabs of the flaggy rock at Bisbrook
are covered with fucoid P markings and tracks of various kinds. Other slabs
of the stone exhibit great numbers of specimens of Gervillia acuta, Sow.

Further north we find two other outliers of the Lincolnshire Oolite, one of
considerable size, on the northern edge of which the village of Pilton is built,
and a much smaller one to the westward on which a part of the village of
Wing stands.

To the west of Pilton there are pits opened in the limestone strata, exhibiting
in their upper parts soft, white, oolitic limestone which is used for lime-burning.
Below this we find hard, slaty, arenaceous limestone, the evident equivalent of
the Collyweston slate, containing many of the usual fossils of that rock,
which is used for building purposes and road-metal.

Between Pilton and Morcott there are other limekilns, the pits in connexion
with which are opened in the white oolitic beds, the slaty beds at the base not
being reached here. At this place I found the largest specimen of Ceromya
Bajociana, d’Orb., which has ever come under my notice; it was 63 inches in
length and 4% inches in breadth. Among other fossils, were obtained here
the following characteristic forms :— a

Pygaster semisulcatus, Phil. sp., abundant.
Galeropygus agariciformis, Forbes, sp., abundant.
Ceromya Bajociana, d’Ord., very abundant.
Natica Leckhamptonensis, Lyc.

Pinna cuneata, Phil.

Mytilus Sowerbyanus, @’ Ord.

Lima, spec. nov.

On the small outlier at Wing there are traces of old stone-pits, but none
have been opened for the last 30 years. One place retains the name of “ Stone-
pit-field garden.” The stone dug here is said to have been very hard and
white, and admirably adapted for mending the roads, for which purpose it was
quarried. The pits appear to have been quite exhausted of all the good stone
before they were abandoned; but from fragments lying about, and from the
materials employed in the walls and buildings in the village, I inferred that
the stone dug was, in part at least, the hard and fissile siliceous limestone at
the base of the series, the equivalent-of the Collyweston slate.

At Lyndon Park another small outlier of the Lincolnshire Oolite evidently
owes its preservation to the agency of the.great fault which bounds it on ita
western side. Here a number of old stone-pits enable us to determine that
the rock exposed consisted of the lower hard flaggy-beds at the base of the
limestone series.
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE, 179

_ To the action of similar faults must be referred the preservation of the out-
liers at Manton and Martinsthorpe. At the former place, in a pit near the
mill occupying one of the highest points in the district, the white limestone was
formerly dug under Boulder Clay and was found to rest on beds of white sand.
Other old stone-pits occur behind Manton Lodge, but the Boulder Clay which
overlaps the whole of this high ground renders the exact limits of this outlier
very obscure. To the west of the village of Lyndon a pit shows what may be
regarded as a spur stretching from this outlier of the Lincolnshire Oolite,
— oer spur evidently extended to the high ground above Manton

mnel, :

The evidence of the existence of an outlier of the formation at Martinsthorpe
is found in two small pits near the church; but the boundaries assigned to
this outlier upon the map are purely conjectural.

The outlier between Hambleton and Normanton, near Armley Wood, could
be accurately studied at the time when the survey of the district was made,
in consequence of the opening of a large number of field-drains upon the hill
which it caps. By the aid of these it became clearly apparent that a small
fault has here let down the Lincolnshire Limestone against the Northampton
Sand, as is shown on the map, and thus led to the preservation of the small
patch of the former.

The most northernly of the outliers of the Lincolnshire Oolite in this district,
that above Market Overton, is a small patch of the calcareous strata, separated
by denudation from the great mass of the formation which appears a little to
the eastwards. Several quarries have been opened in this outlying mass of
limestone strata which exhibits considerable signs of disturbance.

-

Building Stones, &c. of the Lincolnshire Oolite.

At many points within the limits of Sheet 64 the limestones of
the Inferior Oolite are dug for lime-burning, the compact marly
or sub-crystalline varieties being most highly esteemed for this
purpose. The lime procured from this source is largely employed
both for agricultural and building purposes.

Where the ironstone of the Northampton Sand is smelted upon
the spot, the limestone of the superjacent Lincolnshire Oolite
affords a valuable flux for use in the blast furnaces. It is thus
employed at Glendon and Holt.

The fine sand which alternates with the limestones at the base
of the series, are, like the similar material at the top of the North-
ampton Sand below it, dug for making mortar. The sand-pits from
which such material is obtained are distinguished in the district as
“ mortar-pits.” ;

But it is for its building stones and fissile rock capable of being
employed as roofing material that the Lincolnshire Oolite principally
calls for the notice of the economic geologist. ci

By far the greater part of the quarries in the district meet only
a local demand for building materials; from a few, however, the
stone is sent to a very considerable distance, while about Ancaster,
in the district to the northwards, very large quantities of material
are raised in extensive quarries employing a large number of
men, and sent to all parts of the country. The most important
quarries, which have more than a local interest, within the limits of
Sheet 64 are those of Ketton, Barnack, Little Casterton, Stamford,
Weldon, and Clipsham. :

In the year 1839 a valuable report was presented to Parliament
as “the Result of an Inquiry, undertaken under the authority of
the Lords Commissioners of Her Majesty’s Treasury, by Charles
Barry, Esquire, H. T. De la Beche, Esquire, F,R.S. and F.G.S.,
180 GEOLOGY OF RUTLAND, &c.

William Smith, Esquire, D.C.L. and F.G.S., and Mr. Charles H
Smith, with reference to the selection of stone for building the
new Houses of Parliament.” In this interesting work we find a
number of notices of some of the building stones quarried within
the limits of Sheet 64.
: In the introduction to this report it is stated that “many build-
ings constructed of a material similar to the Oolite of Ancaster,
such as Newark and Grantham churches and other edifices in-
various parts of Lincolnshire, have scarcely yielded to the effects of
atmospheric influences.” And again “the churches of Stamford,
Ketton, Colleyweston, Kettering, and other places in that part
of the country attest the durability of the Shelly Oolite termed
Barnack Rag, with the exception of those portions of some of them
for which the stone has been ill selected.” As further evidence of
the value of the building-stones obtained from the beds of the
Lincolnshire Oolite we may call attention to the especially favour-
able notice of the Ketton Oolite in this report.
The following are the accounts given of the stone of some of the

principal quarries in the Lincolnshire Limestone within the limits
of Sheet 64:—

Barnack Mill—The rock is described as a Shelly Oolite of a
light whitish-brown colour, consisting of carbonate of lime, compact
and _oolitic, with shells, often in fragments, the rock being coarsely
laminated in the planes of the beds. The thickness of freestone is
said to be 4 feet, and of common wall-stone 6 feet, and the size
of the blocks procurable to reach 30 feet. The quarry is said to
have been opened four years since (1835) and to be a continuation
of the old quarries in the vicinity, which are very extensive. The
stone from this quarry is reported as being used for troughs and
cisterns which are perfectly impervious.

Among the buildings in which the stone of Barnack is known
or reported to have been employed the following are enumerated :
Burleigh House, Peterborough Cathedral, Croyland Abbey, Boston,
Spalding, Holbeach, and Moulton churches, and the greater pro-
portion of the churches in Lincolnshire and Cambridge.

Ketton.—The stone is stated to be an oolite of a dark cream
colour, consisting of oolitic grains of a moderate size slightly
cemented by carbonate of lime. The workable bed of stone is said
to be 4 feet thick and to form sometimes one and at other times
two courses, and the size of the blocks that can be procured is said
to reach 100 feet. The following general remarks are added on
the Ketton quarries. ‘The Rag Beds” (lying above the Freestone)
“ are of a white tint and the grains are cemented with highly
crystallized carbonate of lime ; the Crash” (above the Rag) “is of
a dark brown colour, very coarse, full of shells, distinct ova, and
very ferruginous. The ova in the freestone beds are slightly
attached or cemented together, consequently the stone is very
absorbent. Ketton Rag weighs 155 lbs. 10 oz. per cubic foot.”
(The weight of the Ketton Freestone is given as only 128 lbs..5 oz.
per cubic foot.)

“This and the neighbouring quarries, many of which are out of
work, are of great antiquity. Joints 2 to 7 feet apart. Beds dip
slightly.”
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 181

Of the localities in which the Ketton stone is known or reported
to have been employed the following are mentioned: “Cambridge,
Bedford, Bury Saint Edmunds, Stamford, London, &c. ; many of the
ancient and modern buildings at Cambridge, also in the modern works
at Peterborough and Ely Cathedrals; also St. Dunstan’s Church,
Fleet Street, London.”

As illustrating the general chemical composition of the lime-
stones of the Lincolnshire Oolite, we may quote the following
analyses by Daniel and Wheatstone from the same report :—

Oolite of Oolite

Ancaster. Ketton.
Silica - - - 00 0:0
Carbonate of lime - - 93°59 92°17
Carbonate of magnesia 2°90 4°10
Tron, Alumina 7 - 0°80 0°90
Water and Joss - - 271 2°83
Bitumen zs = A trace A trace.

The “crushing weight” for Ketton Rag is stated in this report
to be higher than that of any other stone reported upon. For a
two inch cube the “crushing weight” required was 321 cwt., and
the especial remark is made that “among Oolites the Ketton Rag
is greatly distinguished from all the rest by its great cohesive
strength and its high specific gravity.” For similar cubes of the
Ketton, Ancaster, and Barnack freestones the crushing weights
were 91, 83, and 65 cwt. respectively.

The following table, extracted from the report, illustrates the
density and absorbent powers of several varieties of the limestone
of the Lincolnshire Oolite :— :

 

 

; ‘ . A Bulk of water
Specific gravit; Specific gravity

— : of che ary Tf the solid absorbed ; total

specimens. particles, bulk considered
as unity.
Ancaster 2°182 2°687 0-180
Barnack - 2°090 2° 623 0-204
Ketton Freestone - 2°045 2°706 0° 244
Ketton Rags - 2°490 2-692 0°075
Haydor - - 2°040 2°691 0:241

 

 

In those beds of the Lincolnshire Oolite in which the rock is
made up either of shell-detritus or distinct oolitic grains, or of a
mixture of these, with only a slight cementing matrix of carbonate
of lime, we have useful freestones. Where, on the other hand, the
materials of the shelly or oolitic varieties of the rock are cemented
by crystallized carbonate of lime, or where the rock itself is
compact or sub-crystalline (as in the “coralline facies” of the
formation) the material can no longer be dressed for ashlar work,
but often constitutes a very valuable “ ragstone.”

Specimens of the building stones obtained from the most im-
portant quarries in the Lincolnshire Oolite are exhibited upon the
ground floor of the Museum of Practical Geology, Jermyn Street,

London.
182 GEOLOGY OF RUTLAND, &o,

As next in importance to the building stones of the Lincolnshire
Oolite we must notice the fissile rock (Collyweston slate) which,
as we have already seen, is procured from the lowest beds of the
formation and has been largely employed as a roofing material.

We have already noticed how the quarrying of this material has
declined of late years owing to the comparatively greater lightness,
cheapness, durability, and convenience of Welsh slates, now ren-
dered, by the improved railway communication of the district,
everywhere available.

The beauty of the Collyweston slate and the manner in which
its colour harmonizes with that of the stone employed in the walls
of many ecclesiastical edifices, prevents the total abandonment of
the industry, and many Gothic architects, and notably Sir Gilbert
Scott among others, continue to employ the material in the con-
struction of modern churches. Hence a number of quarries, all in
the parish of Collyweston, still remain open. At the period of the
Geological Survey of the district, as already mentioned, a little
pit was still open between Dene and Rockingham, from which small
quantities of slate were raised for local purposes.

The Collyweston Slates have been dug over a considerable area
in Sheet 64, old pits being traceable from Wothorp near Stamford
to the western side of Collyweston, a distance of more than three
miles. At the first of these places they are said, by tradition, to
have been met with much nearer the surface than in the present
workings, and this statement is confirmed by the geological relations
of the beds in this neighbourhood. ‘The valuable fissile character
of the beds is merely a local accident; and in some directions the
bed of stone has been followed and found to become non-fissile and
in consequence worthless for roofing purposes. There is only a
single bed of stone (the lowest limestone of the series) which is
used for making roofing slates. This varies greatly in thickness,
being often not more than 6 inches thick, but sometimes swelling
out to 18 inches, and in rare cases to 3 feet ; while, not unfre-
quently, the bed is altogether absent and its place represented
by sand. Rounded mammillated surfaces, like the “pot-lids” of
Stonesfield, abound in these beds. .

The slates are worked either in open quarries or by drifts
(locally called “fox-holes”) carried for a great distance under
ground, in which the men work by the light of candles. The upper
beds of rock are removed by means of blasting, but the slate rock
itself cannot be thus worked,’ for though the blocks of slate rock
when so removed appear to be quite uninjured, yet, when weathered,
they are found to be completely shivered and consequently rapidly
fall into fragments. ‘The slate rock is therefore entirely quarried by
means of wedges and picks, which, on account of the confined spaces
in which they have to be used, are made single sided. The quarrying

of the rock is facilitated by the very marked jointing of the beds,

a set of master-joints traversing the rocks with a strike 40° W.
of N. (magnetic), while another set of joints, less pronounced,
intersect the beds nearly at right angles. en ak
During the spring of the year the water in the pits rises so
rapidly that it is impossible to get the slates out. ; ;
The slates are usually dug during about six or eight weeks in
December and January. The blocks of stone are laid out on the
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 183

grass, preferably in a horizontal position. It is necessary that the
water of the quarry shall not evaporate before the blocks are
frosted, and they are constantly kept watered, if necessary, until as
late as March. The weather most favourable to the production
of the slates is a rapid succession of sharp frosts and thaws. If the
blocks are once allowed to become dry they lose their fissile quali-
ties, and are said to be “stocked.” Such blocks are broken up for
road-metal, for which they afford a very good material. The lime-
stone beds above the slate rock are burnt for lime.

The slates are cleaved at any time after they are frosted. Three
kinds of tools are used by the Collyweston slaters. The “cliving
hammer,” a heavy hammer with broad chisel-edge for splitting up
the frosted blocks. The “batting hammer” or “dressing-
hammer,” a lighter tool for trimming the surfaces of the slates and
chipping them to the required form and size. The “bill and
helve,” the former consisting of an old file sharpened and in-
serted into the latter in a very primitive manner. This tool is used
for making the holes in the slates for the passage of the wooden
pegs, by means of which the slates are fastened to the rafters of the
toof. These holes are made by resting the slate on the batting
hammer and cutting the hole with the bill.

The slates are sold by the “ thousand,” which is a stack usually
containing about 700 slates of various sizes, the larger ones being
usually placed on the outside of the stack. The slates when sold
on the spot fetch from 23s. to 45s. per thousand. Many of the
Collyweston slaters accept contracts for slating, and go to various
parts of England for the purpose of executing their contracts.

The land at Collyweston is generally held by slaters by copyhold,
the slaters paying 6s. 8d. per “pit” to the lord of the manor (a
“pit” is 16 square yards) with an extra charge of 1s. 6d. per pit to the
measurer. A few workings are rented of the lord of the manor,
the slaters paying 30s. per pit with an additional 1s. 6d. for the
measurer. These payments are made every year at the annual
“‘slaters’ feast” held in January.

The manner in which the slates are placed on the roof is as
follows:—The largest are laid on nearest the wall plate, and the size
of the slates is made gradually to diminish in approaching the ridge.
The ridge itself is covered by tiles of a yellowish white tint, made
at Whittlesea, and harmonising well in colour with the slates them-
selves. The larger slates are, in the ordinary way, fixed to the
rafters of the roof by means of wooden pegs driven through a hole
in the upper part of each slate. But roofs are often covered with
small slates which are fixed by mortar.

On the ground floor of the Museum of Practical Geology at
Jermyn Street, London, specimens of the “slates” made at Colly-
weston, and of the various tools employed by the workmen are exhi-
bited.

Origin of the Oolitic Structure of the Rocks.

Believing that the time is not yet come for a full discussion of
this interesting question, I shall not in this place attempt to do
more than to call attention to the facts which, in the district de-
scribed in this Memoir, appear to throw some light upon the subject.
Some valuable remarks upon the subject will be found in the late
184 GEOLOGY OF RUTLAND, &c.

Professor Phillips’ “Geology of Oxford and the Valley of the
Thames,” pp. 394-397.

The oolitic structure as is well known is not confined to rocks of
any particular age. It is found alike in certain of the beds of the
Silurian, the Carboniferous, and the Permian formations, as well asin
Tertiary, and even more recent deposits. In England, however, it
is so commonly found in limestones of Jurassic age that the struc-
ture has come to be regarded as almost characteristic of the rocks
of that period. Within the limits of Sheet 64 the oolitic structure
is scarcely in a single instance exhibited by any limestone of the
Great Oolite period, butit is so constantly presented, in more or less
marked degree, by the beds of the Inferior Oolite, that, within the
area specified, the structure may be regarded as characteristic of
the rocks of the latter age.

In many cases, as is well illustrated by Professor Phillips and
other writers on the subject, the concentric coats of which the
oolitic grains are made up are seen to be wrapped round some
object embedded in the limestone, as a Foraminifer, or a fragment
of the test of a mollusc or echinoderm, or a grain of sand. But
there aré many cases in which the closest microscopical examination
fails to detect avy distinct object, either organic or inorganic, in the
centre of-the grains of the oolite.

The size of the oolitic grains varies very greatly in different
examples and transitions are found to the coarsest pisolites. Many
varieties in the size of the oolitic grains might be instanced from
the beds of the Lincolnshire Limestone ; but the rocks of this
formation only very rarely assumes the pisolitic character. ‘The in-
teresting features presented by it at Little Bytham have been already
noticed.

Sometimes, as in the case of the Ketton Freestone, the rock is
almost entirely made up of beautifully globular and uniform grains
of oolitic structure. In many other cases we find a compact or
sub-crystalline matrix through which oolitic grains are more or less
sparsely scattered.

It was suggested by the late Sir Henry De la Beche that grains
of sand or fragments of shells or other organisms might, when rolled
in water containing much calcareous matter, receive successive
coatings of carbonate of lime and thus build up a rock of oolitic
structure ; and he adduced some interesting observations of his own
made at Jamaica in favour of this suggestion.

That such deposition of carbonate of lime around nuclei con-
stituted by shells, &c. does sometimes take place, all geologists
will admit. Indeed, we have some pretty examples of the action in
the country described in the foregoing pages ; for we have seen that
the small organisms constituting the mass of the shelly oolites of the
Lincoinshire Limestone are thus often found encrusted. We may
even go farther, and admit that this operation may proceed to such
an extent as to produce a pisolitic or oolitic structure in the rock
built up from such materials.

But it is nevertheless clear, as was suggested by Professor Phil-
lips, that, in the majority of instances, the oolitic structure has
been developed in the rock subsequently to its deposition. In some
cases oolitic grains are found formed in the midst of the sub-
stance of shells or other included calcareous organism in the rock ;
LINCOLNSHIRE OOLITE AND COLLYWESTON SLATE. 185

and. the facts which we have adduced in Chapter VI., concerning
the structure of ironstones in this and other districts, show that
the oolitic structure is a phenomenon of too wide occurrence, and
is exhibited in connexion with too great a variety of conditions of
deposition in the rock masses in which it is displayed, to be capable
of universal explanation in the way suggested by De la Beche.

That the chemical actions set up in the calcareous mass, saturated
as it must be with percolating water, and exposed, by the accumula-
tion of superincumbent strata, to elevated temperature and enormous
pressure, may produce the oolitic structure in limestones, and similar
forms in dolomitic and other rocks, we can scarcely doubt, when
all the facts of the case are taken into account.

In connexion with this subject it may be well to recall attenticn
to the fact that the various tints presented by the several lime-
stones, clays, sandstones, and ironstones of the Jurassic series appear
to be entirely due to the effects of weathering. When dug at
great depths or otherwise obtained at points where they have not
been exposed to atmospheric influences, all these rocks exhibit an
almost uniform deep-blue tint, which is apparently communicated
to them by a diffusion through their substance of small quantities
of sulphide of iron.

 
186

CHAPTER VIII.

THE GREAT OOLITE.

The Great Oolite is, in this district, represented by a series of
beds of remarkably uniform character, which occupy a very con-
siderable area within it and give rise to some of its most distinctive
features. The formation is made up of four members; two of
these consist mainly of calcareous materials, and were evidently
accumulated under purely marine conditions, while, alternating
with them, there occur deposits of argillaceous character, in which
we seem to have proofs of a rapid succession of marine, brackish-
water, fresh-water, and terrestrial conditions, such as could scarcely
occur except within the delta of one or more great rivers.

These four members of the Great Oolite Series are as follows,
enumerating them in ascending order:—The “Upper Estuarine
Series,” consisting of white and variegated clays, with shelly-bands,
irregular beds of limestone, “beef” or “bacon ” beds, lignite and
plant seams, and some sandy and ferruginous strata; the “ Great
Oolite Limestone,” consisting of alternating beds of compact marly
limestone and mar! or clay, the whole crowded with marine fossils;
the “ Great Oolite Clays,” an argillaceous stratum, frequently
variegated, with irregular, sandy, ferruginous, or shelly-bands
interspersed through it ; and the “ Cornbrash ” or shelly limestone
with some subordinate argillaceous beds included in it.

As explained in the Introductory Essay accompanying this
Memoir the formations in the south-west of England, of which
these deposits appear to be the equivalents, are the following :—The
Upper Estuarine Series is on the same geological horizon as the
Stonesfield Slate; the Great Oolite Limestones are merely a
continuation of the great calcareous formation which, under the
name of the Upper Zone of the Great Oolite, is so familiar to all
students of the geology of the south-western districts of England ;
the Great Oolite Clays may be regarded as representing the Forest
Marble and Bradford Clay, while the Cornbrash of the district under
description is clearly part of the same remarkably uniform and very
distinct stratum, which, throughout nearly the whole of the Jurassic
districts of England, maintains such constant and distinctive
characters.

Between the district under consideration and Oxfordshire, the
members of the Great Oolite Series become more or less attenuated
and changeable in character, the argillaceous members, however,
suffering much more in this respect than the calcareous. North-
wards, in North Lincolnshire, the Great Oolite Series again
undergoes much diminution in thickness ; but in this case the
calcareous beds are those which we find soonest affected. First, the
Great Oolite Limestone becomes greatly attenuated, then reduced
to one or two inconstant bands, and finally it disappears, allowing
the Great Oolite Clays and the Upper Estuarine Series to come
into direct apposition. Still farther north the Cornbrash loses its
well marked characters, and, no longer presenting its characteristic
fauna, but being reduced to a few oyster beds, at last dies out
THE GREAT OOLITE. 187

altogether. Finally, in South Yorkshire, all the members of the
Great Oolite Series are found to be altogether wanting, and the
representative of the Oxfordian rests directly on that of the Inferior
Oolite. In North Yorkshire the only representative of the Great
Oolite Series appears to be the thin limestone bands with associated
clays, known as the “Cornbrash of Scarborough,” which must not
be confounded with the Cornbrash of the rest of England, with
which it happens to present some points of mineralogical re-
semblance.

It is not‘easy in every case to distinguish, at first sight, the several
divisions of the Great Oolite Series; the two calcareous and the
two argillaceous members of the formation being particularly liable
to be confounded with one another. It may therefore be well, at.
the outset, to state the chief points by means of which the discrimi-
nation of the limestones may be effected. .The argillaceous members
can, of course, in all cases be recognised by their relations to the
calcareous, when these have been correctly identified.

In the first. place it may be well to state that the limestones of
the Great Oolite Series are, within. the limits of Sheet 64, clearly
distinguished from those of the Inferior Oolite Series in the same
area (the Lincolnshire Oolite) by the almost total absence in them
of the Oolitic character. Indeed, only at one or two points near
Oundle and Stanion have I found any examples of the Oolitic
structure in the limestones of the Great Oolite age. The fossils of
the Lincolnshire Oolite, too, are so distinct as a whole from those
of the Great Oolite Series, that, although there are a number of
species common to both formations, there is rarely the slightest
danger of the limestones of the two series being confounded.

With the Cornbrash and the Great Oolite Limestone, however,
the case is quite the reverse, and much care is sometimes required,
in order to avoid being misled by the mineralogical resemblances
and general identity in the fauna of these two sets of calcareous
strata.

Asa general rule the Cornbrash limestone is distinguished by
its finer grain, its reddish-brown colour, and its peculiar wall-like
bedding as seen in weathered faces of rock; while the Great
Oolite limestone is coarser in grain, of a whitish colour, and
weathers out in more solid blocks with broad faces.

The soil formed by the Cornbrash has usually a‘ reddish hue
(like that to which the Lincolnshire Oolite gives rise), while that of
the Great Oolite limestone has more commonly a black colour.
These differences of physical character in the two limestones cannot,
however, in every case be relied uponas certain tests; for in some
localities the Great Oolite limestone presents the brown colour, the
mode of weathering, and the red _ soil usually characteristic of the
Cornbrash ; while, on the other hand, the Cornbrash occasionally
assumes the characters of the Great Oolite Limestone.

It is to the fossils, then, that we must look for the principal
assistance in discriminating these two limestones ; and, fortunately,
there are certain species eminently characteristic of either of them.
The chief of these we now proceed to notice. In both the
Cornbrash and the Great Oolite Limestone, beds made up of oysters
are by no means uncommon ; but, while in the former the species
188 GEOLOGY OF RUTLAND, &Cc.

thus occurring in great aggregations is the massive, strongly plicated
O. Marshii, Sow., in the latter we find, under like circumstances, the
two minute and smooth species 0. Sowerbyi, Lye. and Mor., and
O. subrugulosa, Lyc. and Mor. Everywhere, indeed, in this area
the easily recognised O. Marshii may be regarded as characteristic
of the Cornbrash, while the equally well marked 0. subrugulosa
may be regarded as distinctive of the Great Oolite. In the Corn-
brash, the Echinoderm LZchinobrissus clunicularis, Lihwyd, is
abundant, while the Clypeus Miilleri, Wright, is rare; in the Great
Oolite, however, the former is rare and the latter very abundant.
Again, in the Cornbrash Avicula echinata, Sow., Gervilia aviculoides.,
Sow., and Terebratula obovata, Sow., are very abundant, while in the
Great Oolite they are rare; and Terebratula mazillata, Sow., Rhyn-
chonella concinna, Sow., and Homomya gibbosa, Sow., which are com-
paratively rarely seen in the Cornbrash, occur in vast numbers in
the Great Oolite. In the distribution of the Cephalopods we have
another distinguishing feature in the two beds; for, while in the
Great Oolite, Ammonites are almost wholly unknown and Nautili
tolerably abundant, in the Cornbrash, shells of the latter group
very seldom occur, while Ammonites macrocephalus, Schloth, and
A. Herveyi, Sow. abound and A. discus, Sow. is also occasionally
found. Belemnites are excessively rare in both deposits. There are
a number of species, however, such as Pholadomya deltoidea, Sow.,
Myacites decurtatus, Phil., M. securiformis, Phil. Echinobrissus orbi-
cularis, Phil., Holectypus depressus, Leske, &c. which appear to be
equally abundant in both of the limestones. Asa general rule it
may be stated that the Cornbrash presents a much greater number
and variety of species than the Great Oolite.

It must be clearly borne in mind, however, that the characters
here enunciated as distinctive of the two limestones of the Great
Oolite Series can only be regarded as such within the limits
described in this Memoir; for as we trace the beds over larger areas
we find them losing their typical character. ‘I'hus the Cornbrash
‘near its northern limits and before its final disappearance, presents
beds of small oysters (O. Sowerbyi, Mor. and Lyc.), like the Great
Oolite limestone farther to the south. ;

These two series of limestones, each resting on a mass of clays,
give rise to the formation, through denudation, of a number of
outliers scattered over the plateau formed by the limestone of the
Lincolnshire Oolite. The tabular and sometimes terraced forms
presented by the hills composed of these Great Oolite strata are
eminently characteristic of the scenery of the district we are
describing, and forcibly recall the forms assumed in the Cotteswold
area by the hills, formed by the hard rocks of the Lower Zone of
the Great Oolite resting on the subjacent softer materials of the
Pre care proceed to describe in detail each of the members
of the Great Oolite Series exhibited in Sheet 64.

Ture Urrer EstuarinE SERieEs.

is, the lowest division of the Great Oolite, consists of clays,
bocatnaly very sandy, of various colours, light-blue being the pre-
valent one, but bright tints of green, purple, &c. being not uncommon.
THE GREAT OOLITE. 189

Interstratified with the clays are bands of sandy stone, with vertical
plant-markings and layers of shells, sometimes marine, as Phola-
domya, Modiola, Ostrea, Newra, &c., at other times fresh-water,
as Cyrena Unio, &c. Beds full of small calcareous concretions
and bands of “beef” or fibrous carbonate of lime also frequently
occur, and the sections sometimes closely resemble those of the
Purbeck series. In its lower part this series consists usually, but not
always, of white clays passing into sands. At the base of these clays
there is always found a thin band of nodular ironstone, seldom much
more than one foot in thickness; this “ironstone junction-band ”
is everywhere conspicuous, and marks the limit between the Great
and Inferior Oolite Series in the district. There is very decided
evidence of a break, accompanied by slight unconformity, between
these two series in the Midland area. All the characters presented
by the beds of the Upper Estuarine Series point to the conclusion
that they were accumulated under an alternation of marine and
fresh-water conditions, such as takes place in the estuaries of rivers.

These beds, which probably never exceed 30 feet in thickness
and are often much less, were well exposed in the cuttings of the
Great Northern Railway described by Prof. Morris in 1853. They
are also exhibited at the top of some of the great quarries in the
Lincolnshire Oolite, as at Ketton, Clipsham, and Casterton. The
clays are admirably adapted for brick-making, for which purpose
they are dug at Stamford, Great Oakley, Water Newton, Wood
Newton, between Stanion and Brigstock, and between Pilton and
Luffenham. In the lower part of the series at Little Bytham,
clays are dug from which are made bricks of singular hardness and
durability ; and at Wakerley, in the same position, a good fire-clay
occurs, which is used at Stamford for muffles, and also in the
manufacture of terra-cotta.

These beds form a cold, stiff land, which, even when well drained,
gives rise to a but very unkindly soil. Consequently, the tracts
occupied by these beds are often left waste, and constitute some of
the few heaths and commons in'this highly cultivated district ; among
these may be instanced Ailsworth, Helpstone, and Luffenham
Heaths.

The clays of the Upper Estuarine Series do not cover any very
extensive areas within the limits of Sheet 64. On the contrary,
they usually constitute the short and somewhat steep slopes
between the tabular masses formed by the limestones of the Great
and Inferior Oolite respectively ; and _in fact, their mode of occur-
rence is very similar to that of the Fuller’s Earth in the Cotteswold
Hills. Where, however, these clays do cover any considerable area,
they are almost always obscured by drift, while in the steep slopes
between the two limestone series clear and valuable sections are
often afforded to us. Lying, as they do, upon a great mass of lime-
stones (the Lincolnshire Oolite), the sandy clays of the Upper
Estuarine Series are often found let down into “ pipes,” in conse-
quence of the removal of the calcareous rock by subterranean waters,
usually along lines of jointing. Thus, patches of these strata are
sometimes seen at considerable distances from their proper lines
of outcrop ; but such “ outliers,” are of course, on too small a scale
to be represented upon the map.

32108. N
190 GEOLOGY OF RUTLAND, &c.

The outcrop of the Upper Estuarine Series in Sheet 64 may, in
the southern part of the area, be followed along the eastern side
of the band of calcareous rocks constituted by the Lincolnshire
Oolite as already described, and which rises on its western side into
the great escarpment. Along the eastern side of the valleys formed
by the Harper, and Willow brooks an almost continuous outcrop
may be traced in the ridge leading from the plateaux formed by
the Great Oolite Limestone to those constituted by the Lincolnshire
Oolite Limestone. And on the western side of the same valleys a
number of outliers, usually capped by the limestones of the Great
Oolite, exhibit the same beds ; these outliers being separated from
one another by the denuding action of the numerous small tributary
streams which flow into the two brooks we have mentioned.

The valleys formed by the Nene and Welland, with the com-
plicated ramifications formed by their numerous affluents, give
rise to very frequent exposures of the beds of the Upper Estuarine
Series in the eastern and central parts of the area, as may be
seen by a glance at the map.

Lastly, the two branches of the river Glen exhibit, in the sides of
their ramifying valleys, an equally complicated series of outcrops in
the northern part of the district: and here also, numerous outlying
patches of Great Oolite strata diversify the surface of the great
plateau of Inferior Oolite Limestone lying to the westward.

Commencing with the southern part of the great line of outcrop, we have
several exposures of the basement beds of the Great Oolite Series in the
neighbourhood of Geddington. These have, however, been sufficiently illus-
trated by us in describing the characters and relations of the Lincolnshire
Limestone in this locality. (See pp. 145-6.) _

In the pits about Pipwell Abbey, Pipwell Lodge, and between Pipwell and
Oakley, numerous indications and partial exposures of the beds of the Upper
Estuarine Series were detected, some of which have been already referred to.
In the abandoned stone-pit at Pipwell Lodge, the light-blue clays were exposed
to a depth of 4 feet, and appeared to contain plant remains in situ.

At Great Oakley the beds of the Upper Estuarine Series are dug for brick-
making, but, at the time the district was surveyed, there was not, unfortu-
nels any clear exposure of the strata. The succession of beds here was as

ollows :-—

(1.) Alternations of fcetid limestone, with Ostrea and other marine shells,

and bands of clay also full of oysters. (Great Oolite Limestone.) -

(2.) Light-blue, sandy clays, with thin bands of laminated, highly pyritous
sandstone of a grey colour, exhibiting plant markings and shells of Cyrena.
ae oF also contain carbonaceous and shelly bands. (Upper Estuarine

eries.

The Inferior Oolite below is not reached here.

By the form of the ground and some small exposures, the same beds can be
traced in Great Oakley Park; while at Little Oakley they suddenly appear at
a much higher level, owing to the action of a fault. In the greatly disturbed
district between Little Oakley and Stanion, although there is no difficulty in
tracing its outcrop, we find no clear sections of the Upper Estuarine Series.

In the brook a little to the east of Little Oakley, the white clays at the base
of the Upper Estuarine Series are seen resting on the beds of the shelly facies
of the Inferior Oolite, the ironstone junction-band intervening. The upper
5 feet of the Inferior Oolite is reduced to a disintegrated mass by weathering ;
while the lower 7 or 8 feet consist of hard, shelly rag. The beds dip 3° to the
south-east.

At Little Oakley, 20 yards on the east side of the road from Geddington,
Hayper’s Brook, which has been to a great extent flowing underground,
reappears at the surface, the shelly Inferior Oolite being seen in the bed of the
stream. This marks the junction of the Upper Estuarine Series with the
Inferior Oolite.
THE GREAT OOLITR. 191

At Little Oakley stone-pit the beds of the Inferior Oolite (shelly facies) di
10° to 12° W.N.W. At the north-western part of the pit, f or é feet 2 its
white clays, with the ferruginous junction-band of the Upper Estuarine Series
are seen. The upper part of the stone is much disintegrated, and, where not
covered with clay, is worn into large “ sand-pipes ” which are filled by portions
of the Upper Estuarine Series and the Boulder Clay. The higher beds of
limestone consist of the soft shelly freestone, and the lower ones of the hard
shelly ragstone, but great nodular masses of the latter exist in the midst of
blocks of the former.

At the excavations at the brickyard and limekiln at Brigstock Mill between
Stanion and Brigstock (“ Lord Lyveden’s pits”) we can trace out the fol-
lowing interesting section. The beds here have evidently undergone conside-
rable disturbance, and the section is not equally clear in every part.

ft. in.
(1.) Soil.
(2.) Oyster beds (A. Sowerbyi, Lyc. and Mor, &c.) - 10
(3.) Blue clay - - - - - - 6 0
(4.) Ferruginous band - - - - - 0 6
(5.) White and mottled, sandy clay - - - 20
(6.) Sandy clays, whitish above and greenish below, full of
compressed shells (Modiola plicata, Sow. of allages)- 3 6
(7.) Dark mottled clays full of carbonaceous markings and
plant remains - - - - more than 5 0
(8.) Whitish, mottled, sandy clay - - - - 4 6
(9.) Line of concentric, ferruginous nodules - - 0 6
(10.) Irregularly bedded, sandy limestone - - - 2 0?
(11.) Hard, marly limestone - - - - 6 0
(Coralline facies of the Lincolnshire Oolite.)
(12.) Sandy limestone passing downwards into calcareous
sand - - - - - - 12 to i 0
- - - 6

(13.) Clay - - -
(14.) Ironstone rock (Northampton sand).

The beds (12), (13), and (14) were seen in a well. If, as seems probable, (2)
represents the bottom bed of the great Oolite Limestone, then the Upper
Estuarine Series here is about 22 feet thick, and the Lincolnshire Limestone,
at this point evidently approaching its line of easternly attenuation and dis-
appearance, not much more than 20 feet. The difference in characters pre-
sented by the Lincolnshire Limestone at localities within short distances of
one another, namely, in the great pits at Stanion and in that at Brigstock Mill,
has already been noticed. The section of the Upper Estuarine Series exposed
at this point is one of the most’ complete and interesting in this part of the
area.

Between Dene-Thorpe, and Weldon there is an old pit, in which white
and blue, clayey and sandy beds are seen, lying upon the shelly oolite of the
Lincolnshire Limestone. ‘These beds resemble those described in the last
mentioned locality, but there is no clear section. ;

About one-fourth of a mile south of Dene-Thorpe, and at some height
above the stream the light-blue clays of the Upper Estuarine Series are again
exposed.

above Dene and by the side of the road leading to Bulwick we find the
limestones of the Great Oolite resting on a series of clays, which in their lower
portion are of a whitish or light-blue colour. :

In the road-cutting immediately above Bulwick we can trace the following
succession of beds.

.(1.) Marly limestone. .

(2.) Marl beds crowded with Rhynchonella concinna, Sow. sp.,
Ostrea, &c.

(3.) Whitish clays.

(4.) Blue clays.

(1) and (2) evidently constitute the base of the Great Oolite limestone, and
(3) and (4) the top of the Upper Estuarine Series. At the bottom of the hill,
beds of compact limestone (coralline facies of the Lincolnshire Oolite) appear
clearly underlying the clays of the Upper Estuarine beds of the Great oe

N
192 GEOLOGY OF RUTLAND, Sc.

In the road between Bulwick and Blatherwycke whitish and bluish clays of
the same age are again seen underlying the Great Oolite Limestones.

In the spurs overlooking the valley at Fineshade and Duddington the clays
of the Upper Estuarine series give rise to a well marked feature in the contour
of the ground, and, at a few points, sections of their peculiar and characteristic
beds may be observed. :

At the limekiln near the corner of Collyweston and Hornstock Woods there is
(Fig 14)” afforded by a clay-pit, of strata which are of considerable interest.

ig. 14,

Fig. 14, Clay-pit at Lime-kiln, corner of Collyweston and Hornstock Woods.

te PB oe = SISSY Se?’ = at ra ce
SE ge ee ef ape TP a8 a
a es, rey 6 2 SSN y N72 L/S g
Dr Dae PR eo.
me eT NY ype x = foo
: oe =

   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

a. Soil,

b. Upper Estuarine Series (lower part).
c, d, e. Ironstone and Marl (junction-bed).

Jf Lincolnshire Oolite Limestone.

The section seen here is as follows :—

ft. in,
(1.) Soil - - - - ic Z 24.2
(2.) Marly clays, white, light-blue, and mottled, somewhat
laminated and “ dicey ” - - - about 4 6
(3.) Nodular, ferruginous, sandy bed - ep Oa be
(4.) White marl - ” - - - -41 6
(5.) Nodular, ferruginous, sandy bed - - «
(6.) Laminated, sandy beds, passing down into sandy, oolitic
ae at the bottom of the pit (Lincolnshire Lime-
stone).
There are several points of some interest in connexion with this section.
In the first place the “ironstone junction-band” at the base is double, this
being however merely a local variation. And, secondly, the character of the
THE GREAT OOLITE. 193

lower, white, sandy, and argillaceous beds of the Upper Estuarine Series is
such, as to forcibly suggest that they may have originated in the denudation of
limestone beds like those on which they repose; the soluble calcareous consti-
tuents having apparently been removed, and the remaining fine grained
materials sorted in moving water. A similar origin has been assigned to other
fire-clays of analogous character. The only trace of organism detected in
these clays consist of a few fragments of carbonaceous material.

If we now turn our attention to the basin of the Nene, we find in
the numerous ramifying valleys connected with that river-basin, a
series of sections of the Upper Estuarine Series, along a line
parallel to those of the outer escarpment which we have hitherto
been describing. Here, however, the Lincolnshire Limestone is
absent, at least in the southern part of the basin, having dis-
appeared through its easternly attenuation; and thus we find the
Upper Estuarine Series of the Great Oolite resting immediately
upon the Lower Estuarine Series of the Inferior Oolite (North-
ampton Sand) as is the case in the whole of the country to the
south-west, namely, in South Northamptonshire and North Oxford-
shire. For fuller illustrations of the relations of these beds I must,
however, refer to the Introductory Essay to this Memoir and to the
sections (Plate IJ.). In this area it is not always easy to define
accurately the limits of the Upper and Lower Estuarine Series.

In the Tichmarsh cutting of the Northampton and Peterborough Railway
the base of the Upper Estuarine Series, consisting of a mass of clays about
5 or 6 feet thick, is seen resting directly upon the sandy, and here non-ferru-
ginous beds of the Northampton Sand. This section is, however, just beyond
the southern limits of Sheet 64.

South of the village of Wadenhoe, there is a pit exhibiting the following
interesting section :—

Tronstone Pit at Wadenhoe.

i
B

(1.) Soil and rubble of Great Oolite - 7 -
(2.) White clays - - -
(3.) Yellow, sandy clay - -
(4.) Dark, laminated, carbonaceous clay
(5.) White clays with vertical plant-markings
(6.) Dark, carbonaceous clays - - - -
(7.) White clays, with vertical carbonaceous markings an
ferruginous stains -
(8.) Ironstone beds to the bottom - - -

A little below the level of this pit the Upper Lias Clay was dug.

The Great Oolite and Cornbrash are seen in the high ground above the pit.

If, as seems probable, the beds (2) to (7) inclusive represent the Upper
Estuarine Series, this formation has become greatly attenuated and is not more
than 8 feet in thickness. The Northampton Sand also is evidently very poorly
represented, and we have thus an illustration of the fact, that all the members
of the Jurassic series partake in a greater or less degree of that easternly attenu-
ation, which, in the case of the Lincolnshire Oolite, is so marked in degree
and so productive of complexity in the relations of the beds. .

In the foundations of an engine-house on the south side of the bridge near
Lilford Hall the beds of the Upper Estuarine Series were well exposed, and
seem to consist of sandy beds at the top, underlaid by about 6 feet of light
coloured (bluish and greenish) fresh-water clays. y

In the ornamental water near the Lodge of Lilford Park the following
succession of beds was seen.

a

coo Aweaocoe

1 faa eos 1 1
TN CORFE OD

ft. in.
(1.) Great Oolite Limestone (with clay partings) - 5 0
(2.) Cla - - 10

Yy : 5 =
(3.) White and light-brown sand passing down into—
(4.) Light-blue clay, of which the base was not seen.
194 GEOLOGY OF RUTLAND, &C.

The Upper Estuarine Clays of the Great Oolite were exposed in several
cuttings on the Northampton and Peterborough Railway, both to the north
and south of the town of Oundle.

In the lateral valleys west of Oundle several sections of the same beds are
exposed, especially near Oundle Wood and on the road between Oundle and
Glapthorne. They can also be traced at several points in the immediate
vicinity of the village of Lower Benefield. In this neighbourhood it seems
probable that, as at some other points, the nodular ironstone of the “ junction-
band,” at the base of the Great Oolite series, has in former times been dug for
the purpose of smelting.

Around the valleys at Glapthorne and Southwick, clays of the Upper
Estuarine series can be easily traced; but the only point where they present
any feature of marked interest is on the side of the road east of How
Wood, north of Southwick, where a plant or “root-bed,” is seen, like that
described at Danes’ Hill, &c. by Professor Morais.

‘ear Cross- Way-Hand Lodge the succession of beds could be clearly traced
at the time of the survey in a series of field-drains. Below the Great Oolite
Limestone and Clays the fresh-water, sandy clays were well exposed, and only
found to be separated by a comparatively thin bed of stone (the Lincolnshire
Limestone) from the ferruginous sands of the Lower Estuarine Series (North-
ampton Sand) which are exposed a little lower down the stream. We are
here evidently near the thin end of the wedge constituted by the Lincolnshire
Oolite, and as we trace the strata further to the north and west, the thickness
of this important series of marine limestones is found continually to increase,
and the two estuarine deposits to be separated by greater thicknesses of
calcareous rock.

The Upper Estuarine Series, as already noticed, is seen at Wood Newton
(p. 171), and also at several points near Apethorpe. And at various pits in the
neighbourhood of King’s Cliffe the clays of the Upper Estuarine Series with the
persistent “ironstone junction-band ” at its base is exposed, being often let
down into “ pipes” or “ pockets” in the irregularly eroded surfaces of the
Lincolnshire Limestone.

In the woods of the Bedford Purlieus, now to a great extent cleared, the
beds of Estuarine Clay can be traced below the Great Oolite. At several of the
farm-buildings erected in the area, the same beds were reached in wells.

The strata of the Upper Estuarine Series, on the eastern side of the Nene
valley, though exposed at many points, appear to be generally thin and destitute
of any features of geological interest till we reach the neighbourhood of Wans-
ford, where we find a number of valuable sections.

In this neighbourhood, as seen at Yarwell and other points, the upper part
of the series we are describing often consists of sands instead of clays.

In the “ wood-pit ” at Stibbington, we have a good section of the fresh-water
clays and sands, the shelly oolite beds being quarried beneath them. Here
the upper surface of the Oolitic limestone displays great irregularity, but this ap-
pearance is, in part at least, due to the percolation of surface waters, which have
dissolved the upper surface of the limestone, and let down the superjacent clays
into holes and “ pockets.”?’ Under the sandy, whitish and blueish clays, with
irregular plant-beds, we find the “junction-band,” a layer of nodules of more .
or less compact or earthy, brown ironstone. This is underlaid in many places
by a bed of white marl probably the product of the decomposition of the lime-
stone and containing apparently waterworn fragments of compact limestone,
the beds below being highly oolitic. This would seem to indicate that a
considerable amount of denudation of the Inferior Oolite limestone preceded,
at this point, the deposition of the earliest beds of the Great Oolite series.

The strata of the Upper Estuarine Series were well exposed in making the
Sibson tunnel on the Northampton and Peterborough Railway, and sections
of them may still be traced at either end of it in the deep cuttings. At the
western end of the tunnel, near Wansford station, the whole series of beds,
from the Great Oolite Limestone (here underlaid by a considerable thickness
of freshwater sands and clays, with the ferruginous nodular junction band at
their base), down to the thin representative of the Lincolnshire Limestone and
Northampton Sand, may be seen,
THE GREAT OOLITE. 195

At the other end of the tunnel the beds of the Upper Estuarine are again
seen, but more obscurely. They appear here to present, at their base, features
similar to those we have described as occurring in the Stibbington pit.

As already noticed (page 174) the Upper Estuarine Series (its relations to
the Inferior Oolite beds below being well illustrated) is exposed in the section
at Water Newton brickyard.

The beds we are describing can be traced up the line of the Billing Brook,
till we reach the fault shown upon the map, and by means of which the Great
aye strata are suddenly cut off, and thrown against those of the Oxford

ay.

In the district to the northward, between the valleys of the Nene and the Wel-
land, we find a number of interesting exposures of the strata of this age. They
are seen at Bainton Heath surmounted by the Great Oolite Limestone; while
at Ufford a well, sunk through the last-mentioned strata, reached beds of green
clay crowded with Cyrena and other shells. At Castor Hanglands Wood a
considerable thickness of white, sandy clay, forming the base of the Upper
Estuarine Series, is seen at the top of the limestone quarries, where the
Lincolnshire Limestone has been proved to the thickness of 20 feet. On the
top of the hill between Helpstone brickyard and Oxey Wood, we find the
following section :—

ft. in.
(1.) Light-blue, sandy clay, with some carbonaceous markings 5 to 6 0
(2.) Band of nodular, sandy ironstone, “ junction-band ” - 16
(3.) Hard and compact, argillaceous limestone, of a blue colour,
weathering brown, with large smooth joint-planes - 6 to8 0
(Lincolnshire Oolite.) to bottom.

The beds in this pit show great signs of disturbance, being in immediate
proximity to the anticlinal roll so well exhibited in Helpstone brickyard, and
also to the great Tinwell and Walton fault.

About Milton Park several wells and other sections show that the clays
of the Upper Estuarine Series rest immediately upon the sands of Lower
Estuarine age, the Lincolnshire Limestone being here altogether absent.

From Stamford northward to the farthest limits of the map, which
this Memoir is especially designed to illustrate, as well as beyond
that line, the beds at the base of the Great Oolite Series are well
exposed in a number of railway-cuttings on the main-line of the
Great Northern Railway. It was by the examination of these
sections in their fresh state that Professor Morzis was enabled to
give those admirably clear descriptions of these argillaceous strata,
which first called the attention of geologists to the fact that we have
in the Midland district formations which cannot be exactly identi-
fied either with those of the south-west of England or of Yorkshire,
These interesting estuarine strata were, however, in the first in-
stance, supposed to be on the horizon of the Forest Marble, and
not on that of the Stonesfield Slate, which is now recognised to be
their true position.

As the sections on the line of the Great Northern Railway are
now for the most part turfed up and rendered much more obscure
than they were when studied by Professor Morxis, I shall quote
the excellent observations of that geologist upon the subject.*

“The Careby cutting (denuded in the centre) extends for three-quarters of
a mile, and exposes the lower bituminous and brown clays overlying the oolite
of 15 feet thickness; it is thick-bedded and blue in its centre, sometimes
obliquely laminated and shelly, with zones of marly concretions; the shells

are chiefly Lima, Pecten, Ostrea, Terebratula, and a few corals; some of the
beds exhibit a bored surface.

 

* Quart. Journ. Geol, Soc., vol. ix., pp. 330, 331.
GEOLOGY OF RUTLAND, &c.

196

s; and crossing the valley
exhibits a good

y
g (Fig. 15),

he lower cla
viz. :—

Danes’ Hill cuttin

poses ti

“A small section again ex

traversed by the river Glen,
typical section of the superincumbent clays,

 
  

*(Ayavoog [eorBojoay ayy Jo [OUNOD oy} pur sito Jossayorg Jo uoIsrmad £q poqzosut st ainSy sty)

( “ysequiog -
ae - “KEI 81100 yeouy -
“s0120g O4T[00 3varE) 81D pus ouoysoury (ou0z reddy) °a31]00 ywary °
“pued SNOUIUININE
‘pogyuyg }
L *saHeg eulrenjsy reddQ -g
*aH[0Q JOMeyUyT *auO\seUNIT] ONTOO eITYsU[OoUry -p

oVs

OB ttaeneennenee

"YOUT | 09 4995 OST “BTWOG TeoJeA “sure ZF “yySueT]

hompny wsay2soNT 7oaiE) ay] fo auy WNT ay} UO ‘auysupooury ‘Gusng YyT seung. ay] us pasodxa uoyoag ‘cl buy

feet.
~2to3

33
2

arly rock

ie

atches, with the characteristic fossils -
shells

and

“ Cornbrash in p:
act sandy
Marly rock, full of

Comp:
THE GREAT OOLITE. 197

feet.

Oyster-bed, compact at bottom and soft at top, full of oysters

flatly arranged, and a few other shells, Perna, &c. - - 8
Clay and soft marly rock, very irregular - - - 4
Clay enclosing mex rock - - - - - 4
Green sandy clay, Pholadomya, &c.  - - - oe |
Bituminous clay - - - - - - 02
Coneretionary sand and lime rock - - - - OF
Shelly clays, Nezra, &c. - - - - - s
Black and green clays (no shells) - - - -
Shelly and sandy clays, bituminous at_base, with fragments of

plants horizontally disposed - - - -
Grey sandy and marly rock, upper part (9 inches) less shelly

than lower, with vertical plant markings (root or stem-bed)- 2
Shaly clay = - - - - - - 1
Bituminous clay - - - - - WU
Green clays - - - - - 33
Greyish and dark clays, finely laminated - - 4

* At the southern end these lower clays are about 15 feet thick between the
root-bed and the ferruginous band, upon which latter they repose, and below
which the oolite extends a few yards only into this cutting. It may be re-
marked, that the beds exhibit a synclinal dip towards the centre, at the angle
of which a small fault is visible, giving to the position of the stem bed in this
section an irregularity, and somewhat affecting the parallelism of it in regard
to the other sections.

“ The Aunby cutting, the contour of which is very irregular, although not
exposing so complete a series as the last, still presents some differences, more
especially observable in the arrangement of the plant-bed, which in this section
exhibits a different mode of accumulation, being here replaced by two distinct
bituminous layers, each of which has its accompanying root-bed; the upper
bituminous clay attaining a thickness of 2 feet, with lignite and impure coal ;
the lower is about 3 inches, and, with its accompanying root-bed, thins out
towards the north end of the cutting. The following is the series about the
middle of the cutting :—

Grey and whitish clays, with markings of plants at base
Sandy and shelly clays - - -
Dark clays -
Green clays, finely laminated - - -
Bituminous clays with lignite and coal -
Grey sandy clay with vertical plant markings
Bituminous clay - - - -
Grey clay with stems -
White and grey clays - - -
Ferruginous band - = 2

The oolite extends along the base of the cutting.”
Inliers.—The only inlier, of any importance, of the beds of the

Upper Estuarine Series is that of the Brigstock Parks, on the

extreme southern limit of the area. The interesting relations of

the beds here, with the proofs of unconformity exhibited between
the Great and Inferior Oolite Series, have been already noticed

(page 38). Two sections at this place exhibit clearly the characters

of the upper and lower portions respectively of the Upper Estuarine

Series.

1 ' '
ehh anwoe
g

vie

2 in.

i |
peptouer

RINT bO ©
Nie

Section in road-cutting at Stone-pit-Quarter. ft. in.

(1.) Bottom bed of Great Oolite, consisting of hard, white,
marly limestone with many shells - - thickness variable.
C) Light-coloured stratified clays with Oysters -
(3.) Variegated clays, ash coloured, bluish, and greenish -
(4.) Irregular thin band of marl, with fraginents of very thin
shells (Modiola imbricata, &c.) - -
(5.) Lighter coloured marly clays - - -
Connexion with next section not seen.

conn
enoso
198 GEOLOGY OF RUTLAND, &c.

Pit at the north-east angle of Old Head Wood.

ft. in.
(1.) Soil, Boulder Clay, and Gravel - - = - 24
(2.) Dark-coloured, carbonaceous clay - - - - 10
(3.) White, sandy clay, with traces of vertical, carbonaceous

markings - - - - - - 7 6

(4.) The nodular ironstone ‘‘junction band ” well seen here - variable
(5.) Soft, somewhat rubbly oolite, about - - -
(6.) Hard, compact oolite with Nerinea and Corals (Lin-

colnshire Limestone, coralline faces) - . - 56 0
(6.) Brown sand, becoming paler going downwards.
The beds in this pit dip S. 17°.
The difference in level between the bottom of the Great Oolite and the top
of the Inferior Oolite is about 30 ft.
There are several small faults in this pit, each of only a few inches throw.

Outliers.— West of the main line of outcrop of the Great Oolite
strata a number of outliers occur, for the most part only separated
from it by the narrow valleys of the numerous streams, which
traverse and furrow the surface of the Great Oolite plateau. It
will be only necessary to notice such of these as present sections of
some completeness, novelty, or interest. Some of these outliers
consist only of the Upper Estuarine Clays, and in such cases are
almost always obscured by drift; others are surmounted by higher
beds of the Great Oolite series.

The series of outliers, extending from Weldon to Wakerley, are largely
concealed by drift, and present no sections of value till we reach the Great
Wood south of the latter village. Here the lowest beds of the series, consist-
ing of white fire-clay, have been rather extensively dug and conveyed to
Stamford for the purposes of being made into muffles and also for the manu-
facture, in admixture with other clays, of terra-cotta.

The Wakerley clays are dug. immediately below the peaty soil of the wood
to the depth of 6 feet being found to rest directly on the oolitic rocks of
the Lincolnshire Limestone; and they appear to be here of tolerably uniform
character throughout. A pit ata slightly lower level showed only 4 feet of
white fire-clay lying upon the limestone.

The large outlier of the Great Oolite east of Luffenham presents us with no
good sections of the Upper Estuarine Clays; but their outcrop can‘be readily
traced, and the “cold and hungry ” nature of the soil formed from the white
clays at the base of the series is very evident at Luffenham Heath,

The next outlier to the north has been encroached upon by the great exca-
vations of the Ketton quarries. Here, above the ‘‘ Crash-bed ” of the
Lincolnshire Limestone, we have the “ ironstone junction-band ”’ surmounted
by a great thickness of clays, the lighter coloured portions of which are seen
to be almost wholly made up of Cyrena and other shells, while the darker
portions abound with carbonaceous matter, and sometimes contain large
masses of wood. ; ;

North of Stamford we have sections in the Upper Estuarine beds at Little
Casterton quarries, and the brickyard near the town, known as Torkington’s
pit. In the Little Casterton quarries the junction of the clays at the base of
the Great Oolite series with the Lincolnshire Limestone is well seen. The
surface of the oolitic rock is very irregular; the ironstone junction-band is
present, sometimes exhibiting a thickness of several feet, and it is immediately
overlaid by the usual white clays. In some of the pits the whole thickness of
the Upper Estuarine beds is displayed, but the sections cannot be accurately
measured. ;

Their succession appears to be as follows :—

Section at Little Casterton Quarries.
(1.) Limestone full of shells of Ostrea subrugulosa, Lyc. and Mor. (Great

Oolite Limestone). 5
(2.) Light-coloured clays, crowded with shells of Cyrena, &c.
(3.) Dark-coloured “bituminous clays,” with much wood and many plant

remains,
THE GREAT OOLITE. 199

(4.) White, sandy clays.
(5.) Ironstone “ junction bed.”
(6.) Lincolnshire Limestone, proved to 50 feet in depth.
In the brickyard at Stamford (Torkington’s pit) I obtained in 1869 the
following section ; the pit is now closed (December 1874).

Section at Torkington’s Pit, Stamford.

ft
(1.) Soil - - - : = 5 = 1
(2.) Oyster beds of Great Oolite Limestone - - - 3
(3.) Dark-coloured, nearly black, carbonaceous and ferrugi-
nous clay, without shells - - - - 3
(4.) Grey clays, with shells - - - - - 38
(5.) Clays of a tea-green colour, sometimes passing to a bright
green, and crowded with shells - - - - 56
(6.) Black, carbonaceous bed, without shells - - 1 to 2
(7.) Green clay (without shells but with masses of jet) - 2
(8.) “Skerry,” a hard gritty clay used for making fire-bricks.
It resembles in texture the “‘root-beds” but has no ver-
tical plant remains - - - - -
(9.) Grey clay, blackish in places (but makes fine white bricks
and is esteemed the best clay in the pit) - -
(10.) White clays, very sandy in places - -
(11.) Light reddish-brown clay, full of wood -
(12.) Ironstone junction-band - -
(13.) Limestone (Lincolnshire Oolite) - -
(14.) Sands and ironstone of the Northampton Sand.

In the “ Skerry ” (8) and the clays below it iron-pyrites abounds. The total
thickness of the Upper Estuarine Series here is 27 feet.

The upper clays burn into a red brick, the “skerry”’ into a fire-brick,
and the grey clays (9) into a fine white brick.

On the small outlier of the Upper Estuarine clays nearly covered by the
“ spinney ” called Tickencote Launde, there is an old stone-pit in the wood,
which exhibits oolitic limestone covered by only 5 or 6 feet of whitish clay.
There are also in this wood very numerous swallow holes, such as so commonly‘
occur along the line of junction of the Upper Estuarine Clays with the
Lincolnshire Limestone.

The other extensive outliers of Great Oolite strata to the northward do not
present us with any interesting section of the estuarine beds, constituting the
base of the series, till we reach the Clipsham quarries. Here the Oolitic
Limestone is quarried under a considerable thickness of the overlying Es-
tuarine clays, the section presented being similar to those of Ketton quarries
and the Stamford brick-pit, but not so complete as in the latter. The iron-
stone junction-band is present, but does not seem to be so constant as is
usually the case; the section is, however, somewhat obscure.

At Little Bytham, at the adamantine clinker works beside the Great
Northern Railway, the clays of the Upper Estuarine Series are extensively dug
for the purpose of making bricks of peculiarly excellent quality, which, from
the ringing sound which they give when struck together, are known as “clinker
bricks.” We have here a very interesting section exposed.

Section at the “ Clinker Works” and Railway Cutting, Little Bytham.

SOM Om OD

et oT o

coocooco f

- 74

ft. in.
(1.) Soil - - si . 3 2 - 06
(2.) Tea-green clays - - - - - 12
(3.) Brown, sandy clay - - - - - 10
(4.) Greenish clay, full of soft, white, carbonate of lime - 10
(5.) Variegated blue and brown, sandy clay - - - 16
(6.) Blue clay - - - - - - 0 6
(7.) Blue and brown, sandy clay, similar to (5) - - 1 6
(8.) Bed of indurated sand with fossils - - - 0 6
(9.) Blue clay, slightly mottled - - - - 0 4
(10.) Brown and blue mottled, stiff clay, with lumps of soft
carbonate of lime - - - - - 04
200 GEOLOGY OF RUTLAND, &c.

e

WS SAW AWNWNWH © GOB

(11.) Tea-green clay, ferruginous at the bottom - -
(12.) Dull tea-green clays - - -
(13.) Lighter-coloured tea-green clays, with seams of comminu-
ted shells and carbonaceous markings - - -
(14.) Brown sand, full of shells, and containing carbonaceous
markings ~ - - - - - -
( iB Black clay - : - - - -
(16.) Lighter-coloured and more compact clay -
(17.) Greenish, compact clay, with ferruginous markings -
(18.) Tea-green clays with ferruginous markings - -
(19.) Dark-blue, compact clay with ferruginous markings = -
(20.) Dark-blue, compact clay, becoming ferruginous at the
bottom, with vertical plant markings - : -
(21.): Brown, ferruginous clay (representative of junction-bed)
(22.) Rubbly limestone (Inferior Oolite) - - -

The following were seen in the Railway Cutting :-—

(23.) False-bedded oolitic limestone - - 4
(24.). Sandy bed, full of oolitic grains - - - - 0
(25.) Compact, blue-hearted, oolitic limestone, slightly false-

bedded - - - - - 5 6

The interesting appearances presented by this exposure of strata, an un-
usually fine one for the district, are illustrated in Plate VIII., in which both the
section seen in the railway-cutting, and that in the adjoining clay-pits are
represented. :

It is to Professor Morris that geologists are indebted for first
pointing out the peculiar estuarine conditions of which the beds
we have been describing afford such satisfactory evidence. Having
the opportunity of examining the freshly-opened cuttings on the
railway, he collected, under the most favourable circumstances,
the fresh-water fossils of the beds. These, unfortunately, are
usually badly preserved and often so obscure as to be indetermin-
able. The marine shells of the series appear to be identical with
those of the Great Oolite Limestones above, into which formation
the beds we are describing insensibly merge. The only fresh-
water fossils which have been found capable of identification are
Oyrena Cunninghami, Forbes, with several species of the same
genus, Unio, one or more species, and Paludina.

As an illustration of the great variability in thickness in the
several members of this formation, we quote the following table
from Professor Morris’ Memoir

* «Tas.e exhibiting the varying THickNEss of the Cuays in the different

Reon BOF ORSO bp eeS

 

 

sections :—
os : > sat, | Counthorpe
« Danes’ | Little
‘Essendine.| Aunby. ‘ | Creeton. 0
_ Hill. | Bytham. Swayficld.
ft. ft. ft. ft. ft. ft.
Oyster-bed and marly
rock - - - 11 _ 16 8 ; 5
Clays between the above 16
and the stem-bed - 9 20 6 10 4
Stem-bed - at 38 2 3 14 5
Clays below the stem-
bed - : : 4 7 15 104 10 14
Iron-band - present 1 1 1 1
Oolitic rock = - — _ — 10 8 13”

 

 

 

 

 

 

 

* Quart. Journ, Geol. Soc., vol. ix., p. 838.
WNVHLAGT ZILITT LV SW4OM MONE CNV ONILIAD AVMUVE FHL LV
G@ITTOO DSTRSNIOONTI (NY SHITWSS ANTEVOLSH Wadd AHL dO NOLLOYS

ae

 

 

d arpa “THA 221
THE GREAT OOLITR. 201

The beds of the Upper Estuarine Series are not of great c i
importance. The clays contain just such a valuable: ailtniate of
siliceous matter in a finely divided state as to adapt them for the
manufacture, in some cases, of fire-bricks, and in others of tile-ware
of Recuar ne and soundness.

t Wakerley, as we have already noticed, the white

the base of this formation are dug nther extensively by gal
known makers of terra-cotta, Messrs. Blaskfiéld of Stamford. It
is an excellent fire-clay, and is said often not to contain more
than 15 per cent. of alumina ; it is, however, largely made up of
finely divided quartz, with a considerable quantity of carbonate of
lime, the latter sometimes in small oolitic grains, and at other times
even occurring in the forms of lumps of oolitic limestone, which
are- occasionally of considerable size. The muffle-tiles made of
these Wakerley clays are said to withstand the severest heat for a
longer time than the celebrated Stourbridge Clay. For pillars of
terra-cotta, which are required to sustain a considerable weight, and
at the same time to endure a considerable amount of heat (as, for
instance, the columns employed in the construction of hospitals
and other large buildings, which also serve as flues for conducting
hot air), the Wakerley clay forms an excellent “body.” For the
finer classes of white and ornamental terra-cotta ware the Wakerley
clays are of no use, as the roots and vegetable matters which abound
in them (the masses being penetrated in every direction by the
roots of trees) gives the material made from them, when burnt, an
unpleasant yellowish tint.

The red ware at Stamford is usually made of a mixture of clays.
These are as follows:—The weathered Upper Lias of the valley of
the Welland, which is of a dull brown colour, and full of selenite
formed by the decomposition of nodules of iron-pyrites; the un-
weathered clays of the same formation, which are dug at greater
depths at Stamford, and the similar Lias Clay from Manton tunnel ;
and, lastly, the lighter Oxford Clay from the London Road,
Peterborough, which is of a more sandy texture, and is found to
prevent the other materials with which it is mixed from shrinking
and cracking. These several materials are well crushed and ground
together, and for the finer moulded work a proportion of pounded
felspar, kaolin, or other ingredients according to circumstances, are
added.

For these details concerning the economic characteristics of the
several clays of the district I am indebted to Mr. Blashfield of
Stamford. ;

‘Great Oorirr Limestonss, &c., Upper Zone.

This series of beds, which graduates alike into that which we
have just described below it, and into the argillaceous series above,
consists of alternate beds of white limestone and marly clay, with
seams made up of the shells of small oysters (0. Sowerbyi, Mor. &
Lye., and O. subrugulosa, Mor. & Lyc.). Sometimes the limestones
consist of comminuted shells and then split up into thin flags like the
Forest Marble of the South of England, for which they have been
mistaken. Beds of this character are seen at Castor, Alwalton, &c.
More usually the limestones are soft, white, and marly, abounding
in casts of shells; those of the Myade being especially abundant.
202 GEOLOGY OF RUTLAND, &c.

The limestones at the bottom of the series sometimes attain to a
considerable thickness, and very occasionally, as near Brigstock and
Stanion, exhibit traces of oolitic grains ; but, as a general rule,
the Great Oolite of this district is everywhere distinguished from
the Inferior by the total absence of oolitic structure. When dug
under a considerable thickness of clay, all the beds are blue and
of great hardness. Occasionally these beds become somewhat
ferruginous, and are’ then, in their general aspect, scarcely distin-
guishable from the Cornbrash.

A large proportion of the species of fossils in these beds occur
also in the Cornbrash, but not afew of the species found in the
latter are wanting in the Great Oolite Limestones. A few species
by their great abundance serve everywhere to characterise the
Great Oolite Limestones ; among these we may especially mention
Ostrea Sowerbyi, Mor. & Lyc., O. subrugulosa, Mor. & Lyc., Clypeus
Miilleri, Wright, and Homomya gibbosa, Sow., sp. In some places,
as at Bottlebridge, near Peterborough, palatal teeth and dorsal
spines of fishes (Strophodus, Pycnodus, Hybodus, Asteracanthus, Sc.)
occur in considerable abundance with the bones of Saurians, in-
cluding the gigantic Cetiosaurus ; at others the stone contains large
numbers of corals, Zsastrwa being the prevailing genus.

These limestones, marls, and shelly rocks which constitute the
Upper Zone of the Great Oolite, maintain a remarkable uni-
formity of character over a large part of England; stretching
southwards as far as Gloucestershire, and northwards from the
district we are describing into Mid-Lincolnshire, where they appear
to thin out and disappear finally. :

The beds of limestone are used locally for building purposes
and occasionally for road-metal. The compact, marly beds are
especially valued and everywhere largely dug for lime burning.
Hard, blue, shelly beds of this series were formerly quarried for
ornamental purposes, and were known as “ Alwalton Marble.” This
material is employed in the Early English portions of Peterborough
Cathedral as a substitute for the celebrated Purbeck Marble in the
small clustered columns which characterise that style.

Except where ferruginous, these beds form a dark coloured soil,
which, from its admixture of clay and limestone, is celebrated for
its fertility.

Extent.—The limestones of the Great Oolite almost always cover
the beds of the Upper Estuarine Series, and in fact the preserva-
tion of the soft strata of the latter formation has been evidently
due to the presence of the hard, superincumbent rocks, Con-
sequently the remarks upon the general range and extent of the
beds of the Upper Estuarine Series in this area apply almost
equally well to those of the Great Oolite Limestone. Occupying,
however, generally higher levels, the outcrops of the Great Oolite
Limestone to the westward are more obscured by Boulder Clay and
other drift deposits, than those of the subjacent formation. Hence
it is where the beds of the limestone series are exposed at lower
levels, as along the valleys of the Nene and Welland, that the best
sections are found. It will therefore be well to reverse the order of
description which we adopted in the case of the Upper Estuarine
Series, and to notice, firstly, the numerous clear and unmistakeable
sections exposed along the great lines of the river valleys to the
THE GREAT OOLITE. 203

eastward, and then to turn our attention to the less satisfactory
exhibitions of the same strata where exposed at their highest levels
towards the great western escarpment of the district.

_ Although the general uniformity of character in this formation
is very marked, not only within the district which we are now
describing, but also far to the northwards and southwards, yet
there are many local variations in the characters of its beds and
in the general assemblage and facies of its fossils, which seem to
indicate numerous changes in the depth and other conditions of the
seas in which the beds were deposited. The graduation of the strata
of the Great Oolite Limestone series downwards into the Upper
Estuarine Series, and upwards into the Great Oolite Clays is
most perfect. Indeed, as in the south-west of England the three
members of the Great Oolite Series, namely, the Lower Zone,
the Upper Zone, and the Forest Marble, are connected by the
most intimate ties, so the beds, which in the Midland area seem to
be their almost exact representatives, are linked together by equally
unmistakeable gradations.

Commencing with the valley of the Nene, where the southern limit of Sheet
64 crosses it, we find at Wadenhoe a section of the limestones of the Great
Oolite, and are able to trace the relations of the various beds between the
Cornbrash above and the Upper Lias Clay below.

At this place the following shells, among others, were obtained from the
Great Oolite Limestone.

Arca Pratti, Lyc. & Mor.

Lima pectiniformis, Schloth.
interstincta, Phil.
—-—— duplicata, Sow.
Hinnites abjectus, Phil.
Pecten demissus, Phil.
Pteroperna gibbosa, Lye.
— plana, Lye.

Ostrea gregaria, Sow. var.

Northward, near Pilton Lodge, the limestones of the Great Oolite are dug
below the superjacent clays, and, in consequence of being thus protected from
atmospheric influences, the rock is of great hardness. There are several sec-
tions of the Great Oolite Limestone in Lilford Park, presenting, however, no
features of special interest. Near the bridge in this park, the junction of the
marine beds of the Great Oolite Limestone with the estuarine strata below was
well exposed in an artificial opening. In the ornamental water, near the
lodge in this park, the bottom and more solid rocks of the Great Oolite Lime-
stone to the depth of 5 feet, with only some insignificant clay partings, was
seen resting directly on the Upper Estuarine Sands and Clays.

As a general rule, the lower beds of the Great Oolite Limestone are more
solid and compact, while its upper portion consists of alternations of marls or
clays, limestone beds and oyster bands, and it thus graduates upwards into
the clays with shelly bands above it. : oe ;

West of Lilford Lodge, we find a pit of considerable size in the Great Oolite,
affording us the following section :—

Section in pit west of Lilford Lodge.

 

 

ft. in.
iy Fe igreaiaed mon 2 kOe 2 0
2.) Bluish-green and mottled clay - - - -
) E (Base of Great Oolite Clays).
(3.) Clayey band crowded with oysters s é - 10
(4.) Stony band almost made up of oysters, thick-\ pom 9in.tol 3
ness irregular - - -j

(5.) Bed of compact stone, very hard, and entirely made up of
comminuted shells. (This bed greatly resembles the
Forest Marble of Dorsetshire)  - - - -
204 GEOLOGY OF RUTLAND, &c.

f. in.

(6.) Soft, white, slightly oolitic rock, becoming marly at its
base, and crowded with oysters - - - - 2 0

(7.) Stone, entirely composed of comminuted shells, very
irregularly bedded, and with little or no clay in its part- iG

ings - - . 5 = e
(8.) Somewhat softer, marly bed, full of oysters, &c., irregular :«

in thickness, but averaging - - -
(9.) Beds of hard stone, like (7), base not seen—to bottom 9
of pit - - - - - - -
This pit was formerly dug somewhat lower, but no good stone was found
under the bed (9), which rests on a marly band with oysters. It is uncertain
whether the clays and sands of the Upper Estuarine Series were reached. The
Great Oolite Limestone in this area is probably about 20 feet in thickness.
The Great Oolite Limestone is exposed at several points near Stoke Doyle,
and its junction with the clays below is marked by the occurrence of powerful
springs.
South of Oundle, the beds of the Great Oolite Limestone are exposed in a
number of cuttings on the Northampton and Peterborough Railway, Near
Barnwell we obtained the following section :—

Section in railway-cutting, near Barnwell, on the Northampton and Peterborough

Railway.
ft. in.
(1.) Great Oolite Clays, blue and mottled, with a thin band
of ferruginous nodules at the base. The junction of this
bed with the Cornbrash is not seen in this cutting, Thick-
ness seen - 5 9

(2.) Bed of laminated, sandy limestone, with bands of white
marl and thin layers of “beef”? (fibrous carbonate of
lime). There are but few fossils in this bed except the
ubiquitous Modiola imbricata, Sow., and Ostrea subrugu-
losa, Lyc. and Mor. - - - - - 18

(3.) Beds of hard (“ Forest-Marble ”-like) limestone, entirely
composed of comminuted shells, with a few specimens of
Ostrea subrugulosa, Lyc. and Mor. - - -

(4.) White, marly limestone, full of shells, Modiola imbricata,
Sow., Ostrea subrugulosa, Lyc. and Mor., Pholadomya
deltoidea, Sow., Pteroperna plana, Lyc. and Mor., Myacites
decurtatus, Phil., Cardium striatulum, Sow., Cardium sp. 1 6

(5.) Beds of hard (“ Forest-Marble-like”’) stone, composed of
comminuted shells, in two courses, with a clay band
between them. In other places this clay-band increases
toa thick bed of white marl, full of oysters and other.
shells - - - - - - - 7 0

(6.) Bed of white marl, becoming, in places, hard and nodular,
and containing shells - - - - - 3 0

This is the lowest bed exposed in the railway-cuttings.

Near the town of Oundle we find a number of extensive pits in the Great
Oolite Limestone, and in one of these, long since-closed, was obtained a number
of specimens of the beautiful star-fish called Ophiurella Griesbachii, Wright.

The following species were also obtained here :—

Modiola imbricata, Sow,

Lima semicircularis, Goldf.
Ostrea subrugulosa, Lye. & Mor.
—~-— Sowerbyi, Lyc. & Mor.

One mile to the westward of the same place the following species were col-
lected by Mr. Ricuarp Gipss :—

Fossils from a pit in the Great Oolite 1 mile west of Oundle.
Nautilus Baberi, Lyc. & Mor.
Natica neritoidea, Lyc. & Mor.
Nerinza funiculus, Desi.
Anatina undulata, Sow.
THE GREAT OOLITE, 205

Corbicella Bathonica, Lye. 8 Mor.
Cyprina trapeziformis, Rém.
Cypricardia Bathonica, d’Ord.
- nuculiformis, Rom.
ppenne Loweana, Lye. & Mor.
odiola imbricata, Sow.
— furcata, Goldf.
Myacites calceiformis, Phil.
—~- securiformis, Phil.
Mytilus sublevis, Sow.
Lucina crassa, Sow.
Bellona, d’Orb.
Pholadomya deltoidea, Sow.
———— Heraulti, Ag.
Trigonia costata, Park.
Hinnites abjectus, Phil.
Perna quadrata, Sow.
Pinna ampla, Sow.
Rhynchonella concinna, Sow.
————- varians, Schloth.
Terebratula globata, Sow.
————— maxillata, Sow.
Echinobrissus clunicularis, Lihwyd.
— sinuatus, Leske.

Ina large pit near the town, the limestone of the Great Oolite is thick-
bedded and crowded with fossils; at some points the rock exhibits pink and
variegated tints. In the great stone-pit at Oundle Union the oyster beds are
well seen, lying above the thick-bedded limestones which are quarried for
building stone. In the valleys west of Oundle the oyster beds and underlying
rag-stone of the Great Oolite Limestones are exposed in a number of pits.
The former beds are known locally as “hurr,” and are often dug for con-
structing artificial rock-work. Where covered by the ferruginous gravel of
the pre-glacial series (derived from the Northampton Sand, see p. 243), these
beds have often acquired, by the percolation of Chalybeate waters, a deep
brown colour and great induration. ;

One of the most interesting pits in which these characters are displayed lies
to the north-east of Benefield, where we find the following succession of beds.

 

 

 

 

 

Section in stone-pit north-east of Benefield,

(1.) Sandy gravel, containing small, irregular pebbles of brown
oxide of iron, derived from the Northampton Sand (pre-
glacial beds).
(2.) Breccia of argillaceous limestone and clay, full of Great
Oolite fossils.
(3.) “ Hurr” beds almost wholly made up of small oyster
shells, and in their upper part indurated and stained of a
dark brown colour by oxide of iron.
4.) Bed of blue clay—1 foot thick.
i Beds of good stone to bottom. ; :
Another peculiarity of the Great Oolite Limestone, as seen in the neigh-
bourhood of Oundle, is well displayed in a pit between Upper and Lower
Benefield. Here the bottom beds of the series, which can be raised in very
large slabs and blocks, exhibit much false-bedding and are crowded with shells ;
they also contain fragments usually subangular of a compact limestone
possibly derived from the Lincolnshire Limestone and indicating the denudation
which those beds suffered prior to, and during, the deposition of the Great Oolite.
Ata pit in this neighbourhood the following fossils were collected by Mr.
RIcHARD GIBBS :— -

Fossils from Great Oolite at Upper Benefield 4 miles N.W. of Oundle.

’ Strophodus magnus, 4g.
Arca emula, Lye. & Mor.
Lucina despecta, Phil.

32108. oO
206 GEOLOGY OF RUTLAND, SC.

Modiola imbricata, Sow.
Myoconcha crassa, Sow.
Trigonia Moretonis, Lyc. § Mor.
Tancredia extensa, Lyc.
Lima pectiniformis, Schloth.
as caplet Sow.
strea Sowerbyi, Lyc. & Mor.

: eiheatioae igo. & Mor.
Pecten lens, Sow.
demissus, Phil.
—— clathratus, Rom.
sp.
Anomia, sp.
Acrosalenia hemicidaroides, Wright.
Pygaster semisulcatus, Phil.

In the road from Glapthorne to Southwick, although the beds of the Great
Oolite limestone are themselves concealed, their position is clear, the clays
above them and the sandy, estuarine beds below being well exposed: while
in the numerous spurs about these villages many small exposures of the
Great Oolite Limestone may be detected. In the railway-cuttings north of
Oundle, by Cotterstock, Tansor, &c. the beds are so much obscured by the
valley gravels that the sections are of little value.

The following fossils were collected in this neighbourhood :—

 

 

 

Fossils from a pit in the Great Oolite 1 mile west of Glapthorn.

Cypricardia rostrata, Sow.
Modiola imbricata, Sow.

Trigonia costata, Sow.

——-—- Moretonis, Lyc. §- Mor.
Ostrea Sowerbyi, Lyc. & Mor.
Plicatula tuberculosa, Lye. & Mor.
Perna. quadrata, Sow. 7

North-west of Cross-Way-Hands Lodge there are two pits in the oyster beds
and the white limestone below them belonging to the Great Oolite Limestones.
Over the great drift-covered tract, formerly clothed with woods and known as
the Walk of Morehay, there are but few exposures until we approach the
valley of the Willow Brook. At several points on the edge of Morehay Lawn
the limestones and oyster beds of the Great Oolite are seen directly covered by
Boulder Clay. But the geological structure of this district is rendered very
obscure, by the thickness of the Boulder Clay and through the great tracts of
woodland which still remain uncleared.

Descending into the valley of the Willow Brook we find near Apethorpe
Lodge several exposures of the beds of the Great Oolite Limestone. A well
sunk to the depth of 30 feet passed, in its upper part, through blue clay with
stones (Boulder Clay) and reached the thin shelly and stony beds with
white marly bands between them, at the top of the Great Oolite. In these
water was obtained, and in consequence the well was not carried lower. In
the brook below the reservoir we find, beneath the gravel, the bituminous
clays below the Great Oolite Limestone, while north of the farm-buildings the
hard limestones forming the base of the series which we are now describing
are seen in the sides of an old stone-quarry at present used as a saw-pit.

West of the same farm-buildings a stone-pit still in use affords the following

section :—

ft. in.
(1.) Soil - - - - - - - 10
(2.) Irregular stony band full of comminuted shells ~ 0 4
(3.) Marly band full of oysters, &c. - - - 0 6
(4.) Stony and somewhat sandy band - - - 0 8
(5.) White marl - - - - - - 0 8
(6.) Light-blue, laminated clay - - = - 0 3
7.) White marl with oysters, &c. - - - 1 8
% Beds of hard, white limestone, bottom not seen - 3 0
THE GREAT OOLITE. 207

Precisely similar sections may be observed in several small stone-pits on the
opposite side of the valley to Morehay Lawn.

The “ town-pit ” of Apethorpe is opened in the lowest hard bed of the white
limestone. It is here about 16 inches thick, and is overlaid by hard, cemented,
limestone rubble. It is underlaid by a bed of marl, and that in turn rests
on a bed of stone 4 inches in thickness. Below this we find a great mass of
light-blue clay belonging to the Upper Estuarine Series. Along the line of
the valley by King’s Cliffe, Apethorpe and Wood Newton to Fotheringhay a
number of small-pits occur by means of which the general succession of the
Great Oolite beds may be traced. :

On the north side of the valley of the Willow Brook, we find another
extensive tract, like the Walk of Morehay, covered with wood and greatly
obscured by drift. This is known ag the Westhay Woods, the Bedford
Purlieus, and the Walk of Sulehay.

On the slopes leading up to Westhay Lodge, the Great Oolite Limestones
(oyster-beds, &c.) are seen directly overlapped. by the, Boulder Clay. On the
Bedford Purlieus the beds of Great Oolite Limestones are exposed in some
small openings, and are also reached in two of the wells dug on parts of the
old forest-land which, at the time of the survey of the district, were being
cleared and laid out in farms in this old forest tract. The same beds were passed.
through in a well at Cross Leas in the same district.

Returning to the valley of the Nene, we find the Great Oolite Limestones
underlying the pre-glacial gravels at Ring Haw Wood. About Elton there are
several exposures of the Great Oolite strata, and between that village and
Holborn Lodge a well 72 feet deep yielded the following succession of beds :—

(1.) Cornbrash - ' = 8 feet seen.
(2.) Clays (of Great Oolite) - - - 14 to 15 ft.
(3.) Shaley rock (oyster-bands) [ (Great Oolite Lime- | 5 feet.

(4.) Hard rock (limestones) stones.) 4 to 5 feet.

(5.) Indurated sand and clay (Upper Estuarine series) 30 to 40 feet.
(6.) Rock (Lincolnshire Limestone.) .

In the last bed water was obtained.. What is most remarkable in this
section is the thinness of the Great Oolite Limestone, another example of the
tendency of its beds to south-easternly attenuation. A somewhat similar section
was found in a well nearer to Elton. ;

At either end of the Sibson tunnel on the None and Peterborough
Railway, the whole succession of beds of the Great Oolite is well exposed ;
the beds of the Limestone series ‘presenting their usual character and
succession. : get ge Se

At Bainton Heath and between this place and Southorpe the strata of the
Great Oolite Limestone, and their relations to the clays above, and the estu-
arine beds below, can be well observed. At Ufford, a well was sunk through
the hard limestone rock of the Great Oolite, which required blasting, into
the green clays with Cyrena (Upper Estuarine Series) below it. .

At Helpstone, a number of large pits have been opened in the Great Oolite
Limestone, the stone being extensively quarried for road-metal, which is sent
to considerable distances in the Fenland. lia large stone-pit, containing a
limekiln, above Helpstone, we have the following section :— ed

eo ee a . in.

(1.) Soil, &e. - - - - - 20
(2.) Oyster beds, with bands of clay between them _—- 3.0
(3.) Thick mass of very hard, dark-blue limestone, with :

many shells - ‘! -' = ~~ to bottom of pit.

A well here, commencing at the top of the oyster beds, and dug to the
aol of 12 feet, just reached the top of the clays of the Upper Estuarine

eries. ‘

A similar succession of beds is seen in two other large pits at this place.
The lowest rock, to the thickness of two feet, is here found to be soft and
worthless for road-metal and is not taken out. In the rock here I found—

Pholadomya deltoidea, Sow.
Trigonia Moretonis, Mor. & Lyc.
Clypeus Miilleri, Wright,

and other fossils.

Oo 2
208 GEOLOGY OF RUTLAND, &C.

At Oxey Wood and several other points in the neighbourhood the oyster-
beds and limestones of the Great Oolite are exposed.
Above Ailsworth there are good sections in the marly, white limestone of the

Great Oolite. The oyster-beds are here seen overlying the limestone, and in
the latter fossils are abundant, including— ae :

Pholadomya deltoidea, Sow. Very abundant.
Homomya gibbosa, 4g. Abundant.
Terebratula maxillata, Sow, (Adult forms.)
Rhynchonella concinna, Sow.
Clypeus Miilleri, Wright,
: Holectypus, sp.
At Ailsworth Heath traces of an old pit in the Great Oolite Limestone are
seen,

_Near this place the following fossils were collected from the Great Oolite
Limestone :—
Fossils from stone-pit near Ailsworth.
Strophodus magnus, Ag.
Monodonta, sp.
Natica globosa, Lyc. & Mor.
Nerinza funiculus, Desi.
——- Voltzii, Desi.
Anatina undulata, Sow.
Arca, Pratii, Lyc. & Mor.
Ceromya concentrica, Sow.
—--— plicata, Ag.
Cardium, sp.
Cucullea Goldfussii, Rom.
Cypricardia Bathonica, d’Orb.
————— rostrata, Sow.
Cyprina nuciformis, Lyc.
Loweana, Lyc. & Mor.
Homomya Vezelayi, d’Arch.
Isocardia tenera, Sow.
Lucina Bellona, d’Orb.
Modiola furcata, Goldf.
imbricata, Sow.
Myacites calceiformis, Phil.

- securiformis, Phil.
Pholadomya deltoidea, Sow.
———_—_—- Heraulti, Ag.
Trigonia Moretonis, Lye. & Mor.
Avicula echinata, Sow.

Lima duplicata, Sow.
Ostrea subrugulosa, Lyc. § Mor.
Gervillia aviculoides, Sow.
Terebratula maxillata, Sow.
—— ornithocephala, Sow.
submaxillata, P Mor.
4 globata, Sow.
Rhynchonella concinna, Sow.
——— varians, Schloth.
Serpula, sp.
Echinobrissus sinuatus, Leske. .

At Castor the oyster beds of the series are seen, and on Castor Heath the
rocks of the Great Oolite Limestone assume the form known as Alwalton
Marble, greatly resembling some of the flaggy beds of the Forest Marble of
the south of England. The oyster beds and limestones of the Great Oolite
can also be traced along the sides of the Billing Brook, till they are cut off by
the fault already referred to.

The beds of the Great Oolite Limestone, which are seen at several
points about Water Newton, can be traced between that point and Alwalton,
at which latter place they are well exposed in the railway-cuttings and old
‘ marble-pits.” The steep escarpment of the Alwalton Lynch is formed by

 

 

 

 

 
THE GREAT OOLITE. 209

the limestones and oyster beds of the Great Oolite, overlying the variegated
sandy clays of the Upper Estuarine Series. The beds are well seen in the
road leading from the village down to the Nene.

The Alwalton Marble was formerly dug all along the Alwalton Lynch, but
the whole of the pits are now closed. The hard, blue, shelly limestone was
found to take an excellent polish, but does not appear to have been very
durable.

About Milton Park a number of wells showed the beds of the Great Oolite
Limestone to vary from 10 to 20 feet in thickness. There is a small'pit in the
oyster beds in Thorpe Park. ;
i a Orton, near Peterborough, a well gave the following succession of

eds :—
(1.) Cornbrash.

(2.) Great Oolite clays - - - - 13 to 14 feet.
(3.) Great Oolite Limestones - - - - 17 feet.
(4.) Upper and Lower Estuarine Series - - 39 feet.

(5.) Ironstone rock (Northampton Sand).

In the admirable exposures of the Great Oolite in the railway-cuttings at
Bottlebridge, near Orton, the late Dr. Porter collected large numbers of very
interesting fossils.

North of the valley of the Welland the outcrop of the beds of the Great
Oolite Limestone can be traced in the district traversed by the line of the
main line of the Great Northern Railway, in the cuttings of which, and in
those of the Essendine and Stamford Branch Railway, we find some interest-
ing exposures of the beds.

The Belmesthorpe cutting on the last-mentioned railway not only furnishes
an excellent section of the beds of the Great Oolite Limestone, but enabled
the former collector of the Survey, Mr. Ricuarp G1BBs, to obtain an interest-
ing series of its characteristic fossils. North of Essendine, about which place
there are numerous exposures of the limestones and oyster beds, we find rocks
exposed in this formation which yield a greater variety of fossils than is
usually found in the beds of this age. At this point large masses of coral
(Isastrea) are very abundant in the Great Oolite Limestones.

The fossils collected at Belmesthorpe were as follows :—

Fossils from the Great Oolite in the Railway-cutting at Belmesthorpe.

Nautilus Baberi, Lyc. & Mor.
Natica globosa, Lyc. & Mor.
Cardium, sp.

Corbicella Bathonica, Lyc. § Mor.
Cyprina nuciformis, Lye.
Loweana, Lyc. & Mor.
Cypricardia rostrata, Sow.
Bathonica, d’Orb.
Isocardia tenera, Sow.

Myacites calceiformis, Phil.
securiformis, Phil.
Modiola imbricata, Sow.
Pholadomya Heraulti, Ag.
Trigonia costata, Sow.

— Moretonis, Lyc. & Mor.
Gervillia monotis, Desi.

Lima puncturata, Sow.
cardiiformis, Lyc. 8 Mor.
Ostrea Sowerbyi, Lyc. & Mor.

— subrugulosa, Lyc. & Mor.
Pecten demissus, Phil.

Perna quadrata, Sow.
Pteroperna costatula, Des!.
Terebratula perovalis, Sow.

On the road from Essendine to Toft there are numerous small pits, exhibit-
ing the oyster-beds and limestones of the Great Oolite with their usual

characters.

 

 

 

 

 

 

 

 
210 GEOLOGY OF RUTLAND, &c.

In the Dane’s Hill cutting of the Great Northern Railway the lowest bed of
the Great Oolite Limestone presents some interesting characters, which are
worthy of remark. It constitutes a mass about 3 feet’ thick, the upper layer
of which contains many long cylindrical spines of echinoderms, especially of
Acrosalenia. The bed is of a brown colour, and somewhat sandy character,
Its analogue does not appear to exist in the Belmesthorpe cutting of the
Stamford and Essendine Railway, where we have an equally clear section;
but it seems to be represented by a white compact limestone.

At Essendine cutting, on the main line of the Great Northern Railway, a
good section was exposed during its construction, which was thus desenibed by
Professor Morris :—*

“With the Essendine cutting, now to be described, the argillaceous and
shelly series terminate, as far at least as the Railway sections are concerned.
In descending order, and with a view of rendering the peculiar characters and
affinities of these beds more intelligible, the physical features and organic
contents will be more fully detailed. Observing the same order of arrange-
ment, we commence with the upper beds (1,) which are full of Oysters, with
occasional patches of Serpule, 3 to 5 feet; the rock (2) immediately below
the oyster-bed is sandy and marly, becoming occasionally very compact,
calcareous, and bluish, and sometimes shaly, from 10 to 12 feet,t in the marly
portion the fossils are very abundant, as—

Cardium.
Modiola imbricata.
Trigonia Moretonis.

ore

nicardium varicosum (Sow., sp.)
Pholadomya lirata.
Terebratula maxillata.
Pecten annulatus.

Lima cardioides.
interstincta.

Ostrea Bathonica.

Perna quadrata.

Natica.

Turbo tuberculatus.
Phasianella cincta.
Nautilus.

Acrosalema hemicidaroides.

 

3. Green and irregular sandy clays, fossiliferous, with layers of
Neera and Pholadomya, abundant - - - -
4, Marly, sandy and slaty rock, with Avicula and other shells -
5. Dark green and bituminous, shelly clays, with Cytherea
Neera, and Cyrena ~ - - - -
Bituminous band - - : - - -
6. Compact, sandy and marly rock full of Cardium, Cytherea,
Neera_- - - - - :
Variegated clays, bituminous, &c.; these beds contain azone -
of dark clays, with Cyrena Cunninghami, C. (sp.?), and a
species of Mactra - - - - : -
3. Thracia, abundant.
Modiola.
Pecten lens, rare.
Nezra Ibbetsoni.
Pholadomya acuticosta.
Lingula.
Terebratula obsoleta.
Anomia.
Gryphza nana.

too op

po oF
we

 

* Quart. Journ, Geol. Soc., vol. ix. pp. 331, 332.
t ‘« The more solid portions of this bed have been recognised by Mr. PRESTWICH,
as being of frequent occurrence in the boulder clay of Norfolk and Suffolk.”
“RVMTIVYE RMTHIMON IVEEOD THL AO |NIZIND ANIGNGSSa AHL NI NHHS
SAVIO ENIMVAIST Uaddn ONIATUPGNA HHL ALIA ENOLSHWIT GIITOO IvaN® SHL 40 NOLLOUS

 

 

 

 

 

 
THE GREAT OOLITE. 211

4. Avicula and Modiola, much compressed.

5. Newra.
Anomia,
Mactra.
Cerithium.

6. Cardium.
Modiola.
Neera.

Anomia.

Pinna.

Ostrea.

Astarte cuneata,
Cyprina.

“Some fine saurian remains, obtained from this cutting, were presented by
Mr. Reynolds to the Museum of Practical Geology. Among these remains,
which have been determined by Professor Owmn, were the tympanic bone of
Cetiosaurus longus, the metatarsal bone of Cet. brevis, a fibula, and a fragment
of a large vertebra.”’

The appearances presented by the Great Oolite Limestone and the under-
lying clays of the Upper Estuarine Series are represented in Plate IX.

The fossils collected by the officers of the Geological Survey in the Dane’s
Hill cutting are the following :—

Fossils from the Dane’s Hill Cutting.

Arca emula, Phil.

Cardium Stricklandi, Lye. & Mor.

— subtrigonum, Lyc. & Mor.

sp.

’ Ceromya concentrica, Sow.
Cucullea Goldfussii, Rom.
Cypricardia Bathonica, d’Ord.
——— rostrata, Sow.
Cyprina Loweana, Lyc. & Mor.

nuculiformis, Rom.
Tsocardia tenera, Sow.
Lucina Bellona, d’Orb.
Modiola imbricata, Sow.
Pholadomya deltoidea, Sow.
—————_ Heraulti, Ag.
Macrodon Hirsonensis, d’Arch.
Trigonia costata, Park.
Moretonis, Lyc. & Mor.
Anomia, sp.
Gervillia aviculoides, Sow.
, Sp.
Ostrea Sowerbyi, Lyc. & Mor.
Pecten demissus, Phil.
Pteroperna costatula, Desi.
———-, sp.
Perna quadrata, Sow.
Rhynchonella concinna, Sow.
Terebratula maxillata, Sow.
Serpula, sp.
Cidaris, sp.” :

Near Careby Mill we have the following section :—

 

 

 

 

 

Pit in Great Oolite north-east of Careby Mill.

ft. i
(1.) Soil - = 7 i = a 4,
(2.) Clay - - - - - - 26
(3.) Oyster beds (0. subrugulosa, &e.)  - :

4.) Hard, compact, blue limestone, in courses
(5.) Clay (to the bottom of the pit).
212 GEOLOGY OF RUTLAND, &c.

In the neighbourhood of Witham-on-the-Hill there are many pits exhibitin
: : : a
the beds of the Great Oolite Series, among which we may notice the following
as yielding interesting sections :—

Pit between Witham-on-the-Hill and Manthorpe. Stone dug for road-metac.

- ft. in.
(1.) Soil - - : « = 7 - 09
(2.) Oyster bed - i ra ea = - 0.9
ie Dark coloured, stiff clay - = - - 20
4.) Oyster bed with layers of “Beef” - - - 0 9
(5.) Marly parting.
(6.) Oyster bed with layers of “Beef”  - - - 10
(7.) Marly parting,
(8.) Oyster bed with “Beef” = - = zs - 1 6
(9.) Oyster beds - - 2 ‘ - - 13
(10.) Marly parting. ;
(11.) Bed of hard, solid, blue-hearted limestone, crowded
with shells, especially—
Modiola imbricata, Sow.
Perna rugosa, Sow.
Pteroperna plana, Mor. & Lyc.
Lima duplicata, Sow.
pagers eae, Sow.
strea subrugulosa, Mor. Cc.
Strophodus ey. oe
Pit a little to the north of the former.— ft. in.
C ) Soil - - - - - - - 1 0
2.) Oyster bed - - - - - - 09
(3.) Bed of stone- -  - - - - - 0 4
(4.) White, marly oyster bed - - - - 10
(5.) Drab, sandy oyster bed - - - - 0 6
(6.) White, marly stone - - - - - 2 0
(7.) Sandy oyster bed = - - - - - 1:0
(8.) Hard limestone - - - - - 0 6
(9.) Mottled clay, containing many vertical plant-mark-
ings and some great masses of carbonised wood - 4 0
(10.) Soft, sandy stone, with many vertical plant-markings 1 6

N.B.—These lower sandy beds exhibit many ripple-marked surfaces. Beds
(9) and (10) probably belong to the Upper Estuarine Series.

As already remarked, the beds of the Great Oolite Limestone
where they outcrop towards their western limits are much more
covered with Boulder Clay, and yield fewer illustrative sections than
in the valleys of the Nene and Welland. Numerous outliers of
the strata exist here, but, owing to the great prevalence of drift, the
beds are seldom well exposed in them.

Tmmediately souta of the limits of Sheet 64 the strata of the Limestone
series are well seen about Grafton Underwood, and between that place and
Sudborough, exactly on the edge of the area we are describing, there is a pit
opened in a bed of white limestone made up of fragments of shells embedded

in a marly paste and containing numerous fossils. This is probably the
bottom bed of the series.

By the roadside, half a mile east of Sudborough Church, a pit in the Great
Oolite Limestone exhibits a thick bed of rock, somewhat oolitic (as in the Duke
of Buccleugh’s pit at Geddington Chase) and covered by an oyster-bed, with
the usual characters, about | foot thick. Above the oyster-beds there isa
considerable thickness of variegated clays with stony bands, representing the
Great Oolite Clays. The beds in this pit, which are just beyond the limits of
Sheet 64, appear to be much disiualiel

Some of the beds of limestone in this neighbourhood are coarsely flaggy.
They consist of a shelly limestone, like the Forest Marble of the south of
England, but have diffused through their masses a few oolitic grains.
THE GREAT OOLITE. 213

The relations of the Great Oolite Limestone to the clays above and to
the estuarine strata below it is well seen at many places about here.

At the northern end of Geddington Chase, and not far from the village of
Stanion, we find the following very interesting section in the Great Oolite :—

Section in Duke of Buccleugh’s pit at Geddington Chase.

ft. in.

(1.) Soil - - - - - - 0 6
(2.) Boulder Clay, containing boulders of quartzite, coal
measure sandstone, a few flints, but little or no
chalk. Near its base traces of a gravel composed

of Northampton Sand detritus are seen - - 3 0
(3.) Variegated (greenish, bluish, and purplish) clay, in

some places quite denuded away - - Otol 0

(4.) Pale greenish white marl, full of irregular, concre-
tionary, hard, sub-crystalline, calcareous nodules,
also of a pale greenish-white colour (weathering

white; comparable with that at Ailsworth) - 0 6
(5.) Green and variegated clay with carbonaceous mark-
ings - - - - - - 0 6
(6.) Grey, foetid, somewhat sandy, limestone - - 0 4
(7.) Laminated, marly parting - - - - 0 2
(8.) Extremely hard, sub-crystalline, drab limestone - 1 6
(9.) Marly parting - - - - - 0 2
(10.) Marly bed abounding in “Beef” - - - 0 6
(11.) Variegated, dark, carbonaceous clays, finely stratified 2 0
(12.) Finely-laminated marl with “ Beef ”’ - - 0 3
(13.) Hard, white, shelly limestone with many shells and
an oyster-bed at the bottom, with O. subrugulosa,
Mor. & Lyc. - - - - - 0 6
(14.) Marly bed crowded with O. Sowerbyi, Mor. & Lyc. O 2
(15.) Clay like bed (11) - - - - - 10
(16.) Beds of hard limestone with few traces of marly
partings. . The limestone is sometimes compact
and full of oysters, at others made up of com-
minuted shells, and becomes in places very oolitic,
thus simulating the characters of the Inferior
Oolite. Near the bottom there are traces ap-
parently of pebbles of compact oolite (like those
seen at Benefield). This limestone contains wood
Ostrea Sowerbyi, Mor. & Lyc., Echinobrissus clu-
nucularis, Lihwyd, & E. sp. - - - 6 0
the bottom
not seen.

The beds in this pit show considerable signs of disturbance and dip S.W. 9°.

Beds (2) to (12) probably belong to the Great Oolite Clays, the remainder
to the Great Oolite Limestones.

About Brigstock and Stanion both the limestones and oyster-beds of the
Great Oolite are exposed at many points. Westward, about Great and Little
Oakley and at Pipwell; they are also seen, but do not furnish any very good
sections. ‘The best is that afforded by the Great Oakley brickyard, where we
have 6 feet of Great Oolite Limestone, consisting of alternate courses, each
about 1 foot thick, of Forest Marble-like stone, and marly oyster bands, con-
taining Ostrea subrugulosa, Mor. & Lyc., and O. Sowerbyi, Mor. & Lyc. Under
the rock occur black, carbonaceous clays and, still lower, light, variegated clays,
both belonging to the Upper Estuarine Series.

Outliers.—N orthwards, both in the outer line of outcrop and in
the numerous outliers at Weldon, Dene, Bulwick, Blatherwycke,
Laxton, Wakerley, Duddington, Barrowden, Ketton, Stamford,
Ryhall, Pickworth, Aunby, Holywell, Clipsham, Little Bytham, &c.,
we find many exposures presenting repetitions of the characters
which we have already so fully illustrated ; but deep or continuous
214 GEOLOGY OF RUTLAND, &c.

sections seldom occur. We have already remarked upon the general
uniformity in character of the beds of this formation over large
areas.

The position of the beds of the Great Oolite Limestone, above
the clays of the Upper Estuarine Series, causes the spurs and
outliers composed of these formations to assume a very marked
tabular outline, which is sufficiently pronounced to give a dis-
tinctive character to the scenery of this district; as is illustrated
in several of the plates in this volume.

The marly limestones of the Great Oolite are highly esteemed
for burning into lime, both for building and agricultural purposes,
and it is thus very largely employed wherever it occurs. The more
solid beds are frequently used locally for building stone, and ata
few points, as at Oundle and Geddington Chase, it is susceptible of
being wrought as a freestone. As a general rule, however, the
limestones of the Great Oolite of this district cannot compete with
those of the Inferior Oolite for building and architectural purposes,
though they are preferred to the latter as a source for lime.

The beds of the Great Oolite Limestone in this area give rise
to the formation of a soil usually of a black colour, but occasionally,
from accidental circumstances, of the same red tint as that of the
Cornbrash and Lincolnshire Limestone. Owing to the admixture
of calcareous and argillaceous materials in them, the soils of this
series are considered to be of much higher value than those of
either of the other two limestones of the district, which are much
lighter in character and in seasons of drought are apt to prove very
treacherous to the farmer.

Tur Great OowitE Crays.

This is a series of variegated, blue, green, yellow, and purplish
clays, often containing bands of irregular whitish or pale-green
calcareous concretions, and, not unfrequently, ironstone in the
form of septaria or in branch-like concretions.. These beds are
very variable in thickness, attaining a maximum of from 20 to 30
feet. They are usually very barren of fossils, but such as do
occur show that their affinities are with the Great Oolite Lime-
stones below. Occasionally thin seams are found almost entirely
made up of the shells of a small Placunopsis (P- socialis, Mor. &
Lyc.), and, much more rarely, bands with Ostrea Sowerbyi, Mor.
& Lye., and O. subrugulosa, Mor. & Lye. It is not improbable
that these beds are, in part at least, of estuarine character. They
are now mapped separately for the first time; for though they
occur far to the southward of this area, yet they are often reduced
to such insignificant proportions that they have not been separated
on the Survey Maps from the rest of the Great Oolite.

Occurring, as these clays do, between the hard rocks of the
Cornbrash and Great Oolite Limestones, they give rise to a steep
slope between two plateaux ; in the same manner as is the case with
the Upper Estuarine clays lying between the Great and Inferior
Oolite Limestones ; the constant appearance of this feature is very
characteristic of the scenery in a great part of the country in-
cluded in Sheet 64.
THE GREAT OOLITE. 215

In former times the ironstones of these beds were frequently dug
and smelted; and some years ago a considerable quantity was
raised at Bottlebridge, near Overton Longville, on the estate of
the Marquis of Huntley ; but the quantity of material requiring
to be removed to obtain the ore led to the abandonment of the
workings. At New England, near Peterborough, and at Bedford
Purlieus, the clays are dug for brick-making. *

Extent.—Although this argillaceous formation certainly exists in
the country to the southwards, and sometimes indeed presents a
considerable thickness of strata united with features of great geo-
logical interest, yet it has been found impossible by the officers
of the Geological Survey, so inconstant is it in thickness, and so
irregular and variable in its mode of occurrence in that district, to
map it as a distinct series. Throughout Sheet 64, however, its
characters having acquired greater uniformity, and its presence
being so persistent, it has been thought advisable to represent its
outcrop on the map by a distinct colour. This was felt to be the
more necessary, as its mineral characters, so different from those of
the Great Oolite Limestones below it, and the Cornbrash above,
and the consequent peculiarities of the soil which it produces,
taken in connexion with the marked features in the contours of the
district which the occurrence of a series of soft clays between the
two limestone deposits, have caused us to attach an importance to
it beyond what its thickness or paleontological characters would
at first sight seem to warrant.

In carrying the geological lines northward from the typical
district of the Cotteswold Hills, the surveyors found it impossible
to define the limits of the Forest Marble beyond the neighbour-
hood of Banbury. In the whole of the South Midland district,
though the two well-marked and persistent limestone series of the
Upper Zone of the Great Oolite and the Cornbrash are often sepa-
rated by beds, occasionally of some thickness, of clay, sand, or
ironstone, yet these are so inconstant in character, and so irregular
in thickness, that it has been thought advisable rather to include
them with the formation lying below it, than to attempt a separa-
tion of them as indicating a strict horizon.

As shown by Professor Puitiirs, the Forest Marble towards its
northern limits occasionally assumes Estuarine characters, contain-
ing Cyrena and other fresh-water shells. In the Great Oolite Lime-
stone, which may perhaps be regarded as a more northern expansion
of the Forest Marble, and certainly occupies the position of that
formation relatively to the persistent members of the Great Oolite,
the estuarine characters of the strata appear to be even more
pronounced.

In the case of the clays of the Great Oolite, the beds of which
are seldom of any economic value, it is very seldom that we obtain
any clear sections. Sometimes its lower beds are seen at the top
of pits opened in the Great Oolite Limestones, and occasionally
quarries in the Cornbrash expose its upper members. ‘These, with
a few railway-cuttings, occasional field-drains and wells, and one or
two pits in which its clays have been dug for brick-making or its
ferruginous bands for ironstone, afford almost the only means which
we have of studying the characters and succession of the beds which
216 GEOLOGY OF RUTLAND, &c.

compose this formation. The general line of its outcrop, however,
1s very clearly defined, owing to its difference of character from
the limestone strata which lie respectively above and below it.

At Wadenhoe the position of the clays of the Great Oolite is very clearly
defined, though it is evidently quite thin, and throughout the south-eastern
part of the area, in the valley of the Nene, so insignificant do these beds
here appear to pe, that no attempt has been made to represent them, as a
distinct formation, on the map. Ina pit at Pilton Lodge, however, the clays
are well exposed, and are seen lying on the top of the Great Oolite Limestones.

As illustrating the thinness of all the beds of the Great Oolite Series here,
I may cite the following estimate of them which I made near this point :—

Cornbrash.
Clays - - - - - - - 6 feet.
Great Oolite limestone - - - - 15 feet.

Clays of Upper Estuarine Series,

The clays of the Great Oolite are seen near Lilford Lodge in Lilford Park, and
again near Barnwell Castle, and in the Barnwell railway-cutting (see p. 204).
At all these places they appear to consist of dark-bluish and greenish mottled
clays, in some places crowded with carbonaceous markings. At some points
light-blue, more or less sandy clays, greatly resembling those of the Upper
Estuarine Series, appear in their midst.

At Oundle the thick beds of the Great Oolite Limestone are in places seen
to be covered with masses of blue clays: and at some points in this neighbour-
hood nodular bands of ironstone occur in these clays.

: in a pit west of Oundle we find the following interesting succession of
eds :—
(1.) Cornbrash rubble.
(2.) ge of very stiff clay, dark-blue, greenish, and mottled, about 12
eet.
(3.) Ferruginous band.
(4.) Clay bed, containing large crystals of selenite.
(5.) Oyster beds.
(6.) Thick beds of hard stone dug to a considerable depth.

The beds (2), (3), and (4) evidently belong to the Great Oolite Clays.

In the valleys leading up from Oundle to Church Field Farm and Benefield,
the clays of the Great Oolite can be traced at a number of points; and near
Oundle Wood the nodular ironstones which it contains appear to have been
worked by the Romans and smelted.

North-east of Benefield the clays of the Great Oolite assume locally a some-
what sandy character; they are stained with oxide of iron, and contain some
of the common Cornbrash and Great Oolite fossils in certain marine bands,

In the valley between Upper and Lower Benefield we find a pit affording a
very interesting section of the higher beds of the Great Oolite Series, as
follows :—

ft. in.

(1.) Soil, “loess,” and river gravel - - - -3 0

(2.) Cornbrash rubble - - - - : 720

(3.) Variegated clay (with a band of ironstone nodules at its oe
ase - - - - - - -

(4.) Oyster beds, in places becoming ferruginous - -2 0

5.) Clay band - - - - 010

t Hard and coarse Forest-Marble-like limestone; the lowest
bed, which comes out in large slabs, exhibits much false ‘
bedding, is crowded with shells, and contains fragments,

; aoe angular, of compact limestone - - -

.) Clay. :

Th biveat Oolite clays are here evidently very thin and insignificant, and
hence no attempt has been made to separate them on the map in this part of
the district.

On the road between Southwick and Glapthorn the Cornbrash is hidden by
drift, but the sandy and ferruginous beds, at its base helonging to the Great
Oolite Clays, were well exposed in a deep road-cutting at the time of the survey
of the district.
THE GREAT OOLITE. 217

As we go northwards towards the central portion of Sheet 64, the clays of
the Great Oolite, though greatly obscured by drift deposits, evidently begin to
acquire greater thickness and importance, and it has been found possible to
represent their outcrop on the map. Below Calvey Wood, on the Walk of
Morehay, the clays are seen below the Cornbrash, and are found to contain
numerous branch-like concretions of brown oxide of iron, like those of the
equivalent beds at New England, near Peterborough. .

On Bedford Purlieus a pit known as “the Duke’s brickyard ” was opened
in the clays of the Great Oolite. They here seem to offer the usual characters,
but the state of the pit was such at the time of the survey of the district
as to preclude the possibility of my obtaining any clear section of the beds.
The presence of the Great Oolite clays was proved in several wells opened on
the Bedford Purlieus; and between Elton and Holborn Lodge, on the opposite
side of the Nene valley, a well indicated a thickness of 14 to 15 feet for this
formation (see ante, page 207).

The Great Oolite clays were exposed in the deep railway-cuttings at Wansford
tunnel ; and a little to the southwards I saw some excellent exposures of them
in a number of field-drains. They here consist of a series of very stiff, bluish,
and occasionally greenish clays, of varying depth of tint, and containing
numerous masses of white, argillaceous, shelly (concretionary ?) limestone, which
weather to a white colour on their exterior. These yield a few marine fossils of
Great Oolite species. Towards their base the beds are almost wholly com-
posed of these shelly and sub-crystalline limestone masses. The shells in them
appear to be always fragmentary, and for the most part indeterminable. Above
these are beds of clay, crowded with small shells, including Placunopsis socialis,
Lyc. & Mor. in great abundance, with Terebratule and Ostree. The indu-
rated and calcareous condition of the lower beds of the Great Oolite clays may
be observed at a number of points in this district. :

At the east end of Sutton Wood also, a series of field-drains afforded good
exposures of the Great Oolite clays. They were found to consist of light-green
and light-blue clays, very tenaceous in character, and containing irregular
fragments of compact, argillaceous limestone. These concretions sometimes
contain crystalline centres, and exhibit on fracture a pale greenish colour. No
fossils were seen in them at this place.

At a well near some new cottages at the western end of the village of Help-
stone, I found the following section :—

(1.) “ Bearing ”’ of soil and clay.

(2.) Base of Cornbrash.

(3.) Blue clay (Great Oolite Clays), 13 feet.

(4.) Ferruginous rock, yielding an abundance of water, which was, how-
ever, unfit for drinking purposes.

The wells sunk at various points round Milton Park show the Great Oolite
Clays to have here a thickness of from 15 to 30 feet, and to be very variable in
character. The beds were generally light or dark-blue in colour, somewhat
sandy, and contained balls of ironstone,

At the railway-cutting near Overton Longville, at a place called Bottle-
bridge (St. Botolph’s Bridge), the clays of the Great Oolite were exposed
between the Cornbrash and Great Oolite Limestones. At this place the late
Marquis of Huntley commenced digging the ironstone-balls, which form four
bands in the midst of the dark-blue clays. The ironstone in the upper bands
was soft and of a dark-brown colour, owing to weathering action, but in the
lower bands were of a gréenish-white colour, and unoxidized, and every
gradation between these two varieties occurred. The ironstone is said to have
been cf good quality, and between 100 and 200 tons of it were sent to
Wellingborough to be smelted. Its exploitation was soon abandoned, owing
to the quantity of material which had to be removed to obtain the nodules of
ironstone.

-[ was informed by the late Dr. PortEr that in an excavation for the New
England Gasworks, near Peterborough, the clays of the Great Oolite were
found tv have a thickness of 22 feet. At New England, near Peterborough, a

brickyard has been opened in the clays beneath the Cornbrash. The succession
of beds here is as follows :—
218 GEOLOGY OF RUTLAND, &c.

(1.) Brick-earth, full of terrestrial and fresh-water shells ; very
variable in thickness - - - - - lto3.ft.
(2.) Gravel - < < = a = - Oto4 ft
(3.) Cornbrash.
(4.) Mottled, greenish, and bluish clays, with bands of iron-
stone nodules, and thin, stony bands crowded with
marine shells.

The ironstone nodules in this pit when broken are often found to have their
cavities filled with water.

At Orton, near Peterborough, the thickness of the clays of the Great Oolite
was found, in a well, to be only 13 or 14 feet.

North of the valley of the Welland, the clays of the Great Oolite were ex-
posed in a number of field-drains at Firewards Thorns. Farther north, the
beds may be traced at many places between the limestones of the Cornbrash
and the Great Oolite, everywhere giving rise to a marked feature in the surface
contours, but not presented to study in any open sections.

The only point on the main line of the Great Northern Railway where the
Great Oolite Clays were exposed is the Banthorpe cutting, -which is thus
described by Professor Morris :—

“The upper part of the Banthorpe cutting (next in order) consists of about
7 to 9 feet of Cornbrash rock, containing the characteristic fossils, and
overlying a dark tenacious clay, sometimes laminated with shelly layers, below
which, and forming the base of the line, is 7 feet of compact shelly bluish
oe occasionally sandy, and becoming shaly, full of Ostrea, Gervillia, and

vicula.”’ ;

Along the western line of its outcrop, and in the-numerous outliers of the
Great Oolite Series, we find but few interesting exposures of the argillaceous
strata we are describing. At the great pit at Geddington Chase, already fully
described (vide page 123), the formation can be admirably studied. It is in
this place seen to consist of variegated and carbonaceous clays, with band of
argillaceous limestone, and fibrous carbonate of lime. (“beef”). It here greatly
resembles, as do also the Upper Estuarine beds, the strata of the Purbeck and
Punfield series. . 8 3

The clays of the Great Oolite Series are not of great importance
in an economic point of view. As we have already seen they are
employed for brickmaking at Bedford Purlieus and at New England
near Peterborough, while at several localities in ancient times, and
at Bottlebridge, near Overton Longville, in recent years, small
quantities of the ironstone bands have been raised for smelting. _

The beds of this formation give rise to a cold and wet soil,
very similar in character to that of the lower beds of the Upper
Estuarine Series. Fortunately, however, they do not occupy any
considerable areas in the district, but form only the short slopes
between the Cornbrash and Great Oolite limestones ; and even in
these, the unkindly nature of the soil is usually somewhat tempered
by the downwash from the overlying strata. Some of the tracts
occupied by the beds of this division-of the series have only recently

been brought under drainage and cultivation.

Tue CorNBRASH.

This, the highest member of the Lower Oolites, presents well
marked characters, which it retains throughout a great part of
England. In the district described in the present Memoir it never
exceeds 15 feet in thickness and is often much less. It consists of
a somewhat ferruginous limestone usually very fossiliferous. When
dug under a considerable thickness of clay this rock is of a blue
colour, exceedingly hard, and can only be quarried by blasting;
but when it has been weathered it breaks up into flat masses of
a light brown colour, each of which is usually coated with stalag-
THE GREAT OOLITE. 219

mite; in this condition the appearance of the rock in section
has been not inaptly compared to that of a loose stone wall or
field-dike. Some of the beds of the Cornbrash are often of a
softer and sandier texture, and from these the fossils are most
readily extracted. At the top of the Cornbrash and at its junction
with the Middle Oolite we usually find an oyster-bed composed
of the great O. Marshii, Sow., an oyster which never occurs in the
Great Oolite Limestone below. The various forms of Ammonites
Herveyi, Sow., and A. macrocephalus, Schloth., are also very abundant
in and characteristic of the Cornbrash; while another Ammonite,
A. discus, Sow., also occurs in it, but is exceedingly rare. Many
species, especially those of the Myade, abound equally in the
Cornbrash and the Great Oolite, but some forms by their
great abundance serve to characterise the Cornbrash ; such are
Lchinobrissus clunucularis, Lihwyd sp., E. orbicularis, Phil. sp.,
and Holectypus depressus, Leske, among Echinoderms; Terebratula
obovata, Sow., and 7. lagenalis, Schloth., among: the Brachiopoda ;
and Avicula echinata, Sow., and Gervillia aviculoides, Sow., among
the Conchifera.

The Cornbrash is found cropping out along the sides of many
of the valleys and also as outliers capping certain hills. To the
north and west of Peterborough it covers a considerable area, rising
gradually from the level of the Fen till it forms the high ground
of Castor Heath. At Stilton, on the edge of the Fen, a small patch
of Cornbrash is brought in by a fault, and occurs as an inlier.

The Cornbrash does not yield a good building-stone, but it is occa-
sionally used for rough walling ; I have found that in Peterborough
Cathedral all the coarse work, which is out of sight, is constructed
of Cornbrash, on which formation the edifice stands. On account
of its hardness the Cornbrash is everywhere much sought after as
a material for mending the roads, and it is occasionally, though
very rarely, burnt for lime. The rock, from its ferruginous
character, makes a red soil; but in this district it does not enjoy
.the reputation among agriculturists which it has in the South of
England, and to which it is indebted for the name it bears. It
seems to be rather to the contrast afforded by the more kindly soil of
the Cornbrash in the south-western parts of England as compared
with the light and treacherous coverings of the other limestone
formations of the Oolitic series, and the cold intractable clays
which alternate with them, that the great agricultural reputation
to which the former stratum owes its designation is due.

Extent.—We have already remarked upon the uniformity of the
characters and fossil contents of the Cornbrash limestone from
Dorsetshire and the Cotteswold Hills, along the whole line of its
strike, till it disappears in North Lincolnshire. We have also seen
that the so-called Cornbrash of Yorkshire is not a stratum con-
tinuous with that with which we are dealing, and does not perhaps
represent precisely the same geological horizon. |

Owing to the great number, variety, and beauty of their fossils,
the thin limestone beds of the Cornbrash have attracted much
attention from geologists. Lists of the species found in this forma-
tion, as developed in the Cotteswold Hills, have been published by
Professor Buckman and Drs. Wricut and Lycert. The fauna of
the same beds in Oxfordshire has been illustrated by Professor
220 GEOLOGY OF RUTLAND, &c.

Puitiips, who has also given a catalogue of the species. “As a
considerable tract of country intervenes between the area to which
the list of Professor Pixs refer, and those included in the de-
scriptions of this Memoir, I avail myself of the opportunity of giving
a very complete list of the fossils of the Cornbrash as developed in
the neighbourhood of Rushden in south Northamptonshire. The
rock in the neighbourhood of Rushden is remarkably fossiliferous,
and during many years the pits at this place were subject to very
diligent search by the Rev. A. W. GrizsBacu, to whom geologists are
indebted for the discovery of a great number of interesting new
forms. To Mr. G. SHarmany, the present Assistant-palzontologist
of the Geological Survey, I am indebted for the following list of
species collected at Rushden, and now in his collection, which
will be useful for comparison with those of the northern and
southern areas respectively.

Fossils from the Cornbrash of Rushden, Northamptonshire.
Anabacia orbulites, D’Ord., E. and H.
Alecto gracilis.
Cellepora, sp.
Diastopora Taraniinen’ diluviana, Milne-Edw.
Millepora straminea, Phil.
Pentacrinus, sp. ,
Pseudodiadema pentagonum, McCoy.
Acrosalenia spinosa, Agass.
Stomechinus intermedius, Agass.
Pedina rotata, Wright.
Holectypus depressus, Leske.
Echinobrissus clunicularis, Likwyd.

quadratus, Wright.

orbicularis, Phil,

Clypeus Miilleri, Wright.

Pygurus Michelini, Cotteau. ;

Goniomya literata, Sow., Mor, & Lyc.

Myacites, sp.

_ - securiformis, Phil.

Gresslya peregrina, Phil.

Quenstedtia levigata, Phil.

Unicardium impressum, Lyc. & Mor.

Astarte elegans, Sow.

Pholadomya Murchisoni, Sow.

—— Heraulti, Ag.

——, sp.

Ceromya concentrica, Sow.

Isocardia, sp.

Cardium dissimile, Phil.

—— citrinoideum, Phil.

Trigonia clavellata, Sow,

costata, Sow.

pullus, Sow.

elongata, Sow.

——-— impressa, Sow.

—~—— tuherculosa, Lyc.

Cypricardia Bathonica, D’Ord.

Avicula echinata, Sow.

——— Miinsteri, Goldf.

Lucina rotundata, Rémer (?).

Mytilus cuneatus, Sow.

——— imbricatus, Sow.

——— Lonsdalii, Mor.

——— Sowerbyanus, D’Orb,

Gervillia aviculoides, Sow.

 

 

 

 

 

 

 

 

 

 

 
THE GREAT OOLITE. 221

Lima pectiniformis, Schloth.

— rigidula, Phil.

— ovalis, Sow.

—— duplicata, Sow.

—— gibbosa, Sow.

—— sp.

Hinnites abjectus, Phil.

Pecten lens, Sow., Mor. 8 Lye.
arcuatus, Sow., Mor. & Lyc.
anisopleurus, Buv.

-—— peregrinus, Mor.

Pecten demissus, Phil.

retiferus, Mor.
Ostrea Marshii, Sow. (0. flabelloides, Lam.).

 

 

 

 

sp.

Chemnitzia vittata, Phil.

Natica, sp.

Pleurotomaria granulata, Sow.

Serpula, sp.

Terebratula intermedia, Sow.
ornithocephala, Sow.

— obovata, Sow.

Bentleyi, Mor.
——-- cardium, Lam.
Rhynchonella morierei, Dav.
concinna, Sow.
Ammonites discus, Sow.

— Herveyi, Sow.
—————- macrocephalus, Schloth.
Nautilus, sp.

Plesiosaurus (paddle bone).

Fish (palatal teeth, several forms).
Astacus rostratus, Phil.

‘Wood.

The Cornbrash, forming as it does the highest portion of the Great
Oolite series, follows in its outcrop the same general lines as those of
the other members of that formation in the district which we are
describing. It is, however, even more obscured by the overlapping
masses of Boulder Clay and drift than the subjacent formations. In-
deed it may be regarded as certain that the extent of country occupied
by the rocks of the Cornbrash is considerably less than that repre-
sented on the map as belonging to it. This arises from the fact that,
being the last deposited bed before the great mass of argillaceous
strata of the Oxford Clay, it is frequently recognised outcropping
from below the drifts, in positions where we should be able to detect
no traces whatever of softer rocks. Some of the great outliers of
Cornbrash are almost certainly capped, to a greater or less extent,
by beds of the Oxfordian series, but as no positive evidence of the
presence of these, and much less of their extent and boundaries,
could be obtained in these drift-buried districts, no attempt has
been made to represent them. In one case, however, namely, that
of the outlier between Fineshade and Kings Cliffe, recent excava-
tions for a railway have furnished Mr. Monckton of Fineshade
and Mr. Suarp of Dallington, as the latter gentleman has kindly
informed me, with proofs of the undoubted existence of a mass of
Oxfordian beds lying upon the Cornbrash.

Excepting near Sudborough, the outer line of the outcrop of the Corn-

brash is entirely concealed by an enormous mass of Boulder Clay, in many
places probably not less than 200 feet thick. Hence, as indicated by the

32108. Pp

 

 
222 GEOLOGY OF RUTLAND, &c.

dotted lines, this part of its range on the map is purely hypothetical. Where,
however, the beds appear at a lower level and are exposed along the sides of
the valley of the Nene and its tributaries, we have a number of interesting
sections, which serve to sufficiently illustrate the characters and fossils of the
formation in the district.

Immediately to the south of the limits of Sheet 64, between Thorpe, and
Wigsthorpe, the Cornbrash is dug at a place known as “ Stone-pit-field.”
About Achurch and above Wadenhoe the outcrop of the beds can be clearly
traced although no good sections of them are exposed. ,

Ata reservoir behind a farm-house at Lilford, the base of the Combrash
was seen resting on the variegated clays of the Great Oolite. At Lilford
Lodge there is a pit which exposes the rock, with its usual petrological
characters and yielding the following fossils :—

Avicula echinata, Sow.
Td Myacites decurtatus, Phil.

In a pitin the Gouilrasts, south of the village of Barnwell All Saints, we
find the following section :—

ft. in.

(1.) Soil with pebbles = - - - 20

& TS Eee - - - - - lto2 0

-) Oxford Clay ? (very irregular - Otol 0

(4.) Sandy limestone _ - ee y - - 13

(5.) Hard compact limestone - - - 1 6
to bottom.

(5.) is a very hard, blue-hearted limestone which contains the usual fossils ;
it is seen again in the bed of the stream at this place.

Another pit in the Cornbrash is seen south of Barnwell Station, the rock
here contains specimens of Ostrea Marshii, Sow., of great size.

At various points around the town of Oundle, and especially in the sides of
the tributary valleys which are connected with that of the Nene, we find a
considerable number of exposures of the Cornbrash beds, but nowhere affording
sections of sufficient completeness or interest to call for their detailed de-
scription in this Memoir. The following list of the fossils collected at the
various pits in this immediate neighbourhood will give a sufficiently clear
idea of the general character of the Cornbrash fauna in the southern part of
our district.

List of fossils collected from the Cornbrash in the neighbourhood of Oundle.

Ammonites Herveyi, Sow. (small and rare).

Trigonia elongata, Sow. (abundant and characteristic).
— sp. (casts of a probably new species).
———— Moretonis, Lyc. & Mor. var.

Goniomya literata, Sow. (abundant).

Isocardia tenera, Sow. (abundant).

 

——— sp.
Bisladomys deltoidea, Sow. (abundant).

Rei lyrata, Sow.

Myacites decurtatus, Phil. sp.

: - securiformis, Phil, sp. } very abundant,

Modiola imbricata, Sow.

Lima rigidula, Phil. (abundant),

Pecten lens, Sow.

vagans, Sow.

inzequicostatus, Phib.

Wollastonensis, Lyc.

clathratus? Sow. eer
Avicula echinata, Sow. (very abundant and highly characteristic)
——W— Braamburiensis? Sow.

Gryphza mina, Phil. sei
Ostrea Marshii, Sow. (O. flabelloides, Lam.) (abundant and characteristic).
acuminata, Sow. (rare).

- Sowerbyi, Mor. & Lyc. (rare).

Terebratula obovata, Sow. (common).

varieties passing into T. digona? Sow. (very abundant).

 

 

 

 

 

 

 

 
THE GREAT OOLITE. 223

Terebratula ornithocephala, Sow., many varieties (very abundant).
—-, maxillata, Sow. (rather rare and never large),
Bentleyi, Dav. (rare).
Rhynchonella concinna, Sow. sp.
Echinobrissus clunicularis, Llhwyd.
—————- orbicularis, Phil.
Holectypus depressus, Lam.

In the valley by Church Field Lodge the beds of the Cornbrash are fairly
well exposed and yielded the following fossils :—

Fossils from the Cornbrash, at Churchfield Lodge near Oundle,

Astarte, sp.
Tsocardia tenera, Sow.
Lucina, sp. ;
Modiola imbricata, Sow.
Myacites securiformis, Phil.
_Pholadomya deltoidea, Sow.
Myacites decurtatus, Phil.
Trigonia elongata, Sow.
- Moretonis, Lyc. & Mor.
~———, sp.
Avicula a hinges Sow.
: Gervillia aviculoides, Sow.
Pecten demissus, Phil.
vagans, Sow.
Ostrea Marshii, Sow. (O. flabelloides, Lam.)
Terebratula obovata, Sow.
Echinobrissus clunicularis, Lihwyd.
Acrosalenia, sp.

Near Polebrook the Cornbrash is dug under the Oxford Clay, and conse-
quently the rock, instead of presenting its usual reddish-brown colour and
rubbly character, is very hard and compact, and of a dark-blue colour. Its
identity, indeed, might at first sight seem doubtful, but for its geological
relations and the following fossils which it yields :—

Trigonia elongata, Sow.
Modiola Sowerbyana, D’Ord.
Lima rigidula, Phil.
Avicula echinata, Sow.
Pecten (several species).
Ostrea Marshii, Sow. (O. flabelloides, Lam.)
Echinobrissus clunicularis, Lihwyd, &c.
Near the same place Mr. Ricuarp GrBBs collected the following fossils :—

 

 

 

Fossils from a pit in the Cornbrash at the Cross-Roads half a mile west of Pole-
brook.

Chemnitzia, sp.

Gresslya peregrina, Phil.
Lithodomus inclusus, Phil.
Myacites decurtatus, Phil.

- securiformis, Phil.
Pholadomya deltoidea, Sow.
Avicula echinata, Sow. _

Pecten demissus, Phil.

vagans, Sow.

Serpula, sp. :
Echinobrissus clunicularis, Lihwyd.
orbicularis, Phil.

On the opposite, or western, side of the Nene valley the Cornbrash is
exposed in a number of small pits, &c. about Liveden, being here, however,
much obscured by drift.

Between Ashton and Elton the Cornbrash outcrop can be clearly traced at
a number of points, but the beds are here much obscured by the valley gravels.

Pp 2

 

 

 

 
224 GEOLOGY OF RUTLAND, &c.

Good stone for road-inetal was formerly dug below the gravels at the entrance
to the village of Warmington. There were also at one time extensive pits on
the south side of the same village, where Cornbrash with its usual characters
and fossils was dug under a thickness of 14 or 15 feet of gravel. The stone
is still well seen at the side of the road, and at the time of the survey was
exposed, together with the clays beneath it, in a number of field-drains.
At several other points in the neighbourhood, the Cornbrash has. also been
quarried under a considerable depth of gravels. There is a pit in the rock
opposite to Elton Church.

: On the opposite side of the Nene valley the Cornbrash with its usual fossils
is well exposed on the south side of Cotterstock Wood. About Glapthorne,
Southwick, and Benefield the rock can be traced at many points in the lateral
valleys of the district, outcropping from below the drift, but good sections are
rare.

The valley of the Billing Brook-exposes the Cornbrash and the estuarine (?)
sandy clays beneath it at several points: and about Water Newton Lodge the
formation is admirably displayed. The rock is here crowded with the usual
fossils, and I found in it a specimen of Ammonites discus, Sow., which is so rare
a species that only one other example of it came under my notice during the
survey of the whole district.

Between the valleys of the Nene and Welland, from Wansford to Peter-
borough, the Cornbrash covers a very considerable area. Indeed, there is
perhaps no tract of equal extent occupied by the beds of this formation in the
whole country. The genera] agricultural poverty of the Cornbrash in this
area is shown by the fact that this large district occupied by it remained till
quite recently in the condition of an ‘open heath, and even now considerable
portions of it have not yet been enclosed. Everywhere over the tract the red
character of the soil formed by the Cornbrash is very conspicuous and striking.
One small outlier of Oxford Clay, greatly obscured by drift, occurs capping the
Cornbrash of this extensive tract, which is cut off and, to some extent, bounded
on its northern side by the Great Tinwell and Walton Fault. To the eastward,
the Cornbrash is found gradually dipping under the clays of the Oxfordian or
Middle Oolite Series, which to so great an extent underlie and constitute the
foundation of the Fenland. .

Between Chesterton and Peterborough, on the south side of the Nene valley,
many exposures of the Cornbrash are seen about Alwalton, Overton Water-
ville, Overton Longville, and Woodstone, the beds here, however, offer no
features of interest.

At Ailsworth Heath the Cornbrash rock is seen, crowded with the usual
fossils, and among these I found a specimen of the rare Ammonites discus of
Sowerby, 24 inches in diameter, and some exceedingly large examples of Lima
pectiniformis, Schloth. (L. proboscidea, Sow.). About Helpstone the Corn-
brash is thrown down by the great fault, and in consequence itis found
occurring in very unexpected situations, and often exhibiting signs of con-
siderable disturbance. On the west side of Rice Wood there is a pit containing
a limekiln; but though the rock exhibits its usual characters, the fossils were,
for the usually prolific Cornbrash, extremely rare. The following species
were, however, collected by me :— ;

Belemnites, sp.

Goniomya v-'scripta, Sow.

Myacites decurtatus, Phil.

Avicula echinata, Sow.

Ostrea Marshii, Sow. (O. flabelloides, Lam.)
Terebratula obovata, Sow. (several varieties).

At the western part of Helpstone we find several pits in the Cornbrash, the
rocks being covered with clay and consequently very hard and durable. We
have here the following section :— en

. in.
1.) Clay (drift or reconstructed Oxford Clay) - - 40
2.) Soft, sandy layer full of specimens of Ostrea Marshii, Sow.
3.) Hard, compact or shelly, blue limestone - - 5or6 0
4.) Soft, sandy bed of limestone, resting on indurated, blue
clay.
THE GREAT OOLITE. 225

The bed (2) seems to be tolerably persistent wherever the top of the Corn-
brash is exposed, which is not very frequently the case. The existence of
oyster beds with the large plicated oyster, forms, as we have already seen, a
striking contrast between the Cornbash and the Great Oolite Limestone; in which
latter, beds of the little O. Sowerbyi, Lyc. & Mor., and O. subrugulosa, Lyc.,
abound, while O. Marshii is unknown. That these variations in distribution
of species are due to differences of condition, rather than to changes of fauna,
is shown by the fact that the normal form of O. Marshii occurs in the rag-
stones of the Inferior Oolite, while varieties of it are found in the freestones of
the same formation in the Cotteswolds and in those of the Lincolnshire
Limestone.

The fossils in these pits about Helpstone are numerous, and include very
large specimens of Ammonites macrocephalus, Schloth.,in which, as is the
habit ofthe species, the exterior ribs and tubercles entirely disappear from the
outer whorls in the adult stage, so as to give the shells the appearance of vast
Nautili, for which they have been frequently mistaken. Some univalves, forms
which are usually rather rare in this formation, also occur in the Cornbrash
at this place.

In the opening at the side of Hilly Wood, close to the great fault, and where,
in consequence, the beds are seen to be greatly disturbed, the bed of Ostrea
Marshii, before referred to, is well seen lying on the top of the Cornbrash
limestone. The beds here generally dip to the north (or away from the up-
throw of the great fault), the average amount of their inclination being 15°;
this is, however, very variable, and in one place is seen amounting to 65°, while
not far off the beds are vertical. The beds of the Cornbrash are also exposed
at several other points around Hilly Wood. There is also a good pit in the
Cornbrash, here exhibiting its usual characters and fossils, near Lawn Wood.

A pit on the south-west of Helpstone gave the following section :—

ft. in.
(i.) Soil and gravel - - - - - 2 0
(2.) Oxford clay (trace) - - - - - 0 Oto9
(3.) Sandy bed, crowded with Ostrea Marshii, Sow.
Variable in thickness, up to - - = '} 0
(4.) Clay parting - - - - -
(5.) Stone beds of the Cornbrash - - - - 3 seen.

In some of the Cornbrash pits about Helpstone large quantities of fossil
wood occur; these are evidently fragments of drift timber, and sae mea
exhibit serpulz, and other marine shells attached to them. Here, too, 1 found
a remarkably fine specimen of Ammonites macrocephalus, Schloth., having a
diameter of 1 foot 6 inches, and a thickness of over 8 inches. The outer
surface, as in all adult examples of this species, was quite smooth and destitute
of ornamentation, and the masses of oysters and serpula with which it was
covered indicated that it had long drifted on the sea-bottom. ,

South-east of Helpstone the beds of Cornbrash are again brought in by a
lateral fracture connected with the Great Tinwell and Walton Fault. Here,
however, the beds, which are capped by the Oxfordian clays, are much obscured
by Boulder Clay and gravel, and can for the most part be traced only by the
aid of field- and other drains. In a field near Woodcroft, however, there is a
pit (with a limekiln) opened in the beds of the Cornbrash which here exhibits
its usual characters. The wells at Woodcroft obtain their supply of water from
the Cornbrash, or, in one case, from the Great Oolite Limestones below. Un-
fortunately, however, no record of the section observed in this latter case was
preserved.

About Walton, and especially in the cuttings of the Great Northern Railway
between that place and Peterborough, the Cornbrash limestone is well exposed.
In this district, as indeed is almost everywhere the case when exposures of the
ootitic beds over a considerable area are seen, we find numerous proofs that the
strata are bent into a number of exceedingly gentle synclinal and anticlinal
curves, which, though not sufficiently pronounced to interfere with the general
dip of the strata, have exercised a most important influence in determining the
preservation of the several outliers, spurs, and inliers of the various rocks from
denudation.

About Peterborough the Cornbrash is exposed at a great number of points,
and its fossils have been collected by Mr. Bentley and the late Dr. Porter.
226 GEOLOGY OF RUTLAND, &c.

At Dogsthorpe the lowest beds of the Oxford Clay (those representing the
Kellaways) are dug for brickmaking, and through the kindness of the owner of
the pit, Mr. Thomas Parker, I was enabled to examine the junction of these
beds with the Cornbrash. We have here the following section.—
t. in,
(1.) Soil and gravel - - - - 3 0
(2.) Sandy clay and sandy rock - - - - 8 0
(3.) Hard, blue, “dicey” clay with Nucula nuda, Phil.

Corbula, sp. Ammonites Herveyi, Sow., &c. The

lowest hed of this clay is crowded with Rhyncho-

nella and other fossils - - a - 7 0
(4.) Hard, blue, Cornbrash rock with Avicula echinata,

Sow., Ostrea, sp.

In the following list I have given the names of the species which have been
derived from the very numerous openings in the Cornbrash, in the immediate
vicinity. of Peterborough.

At the point where the Stamford and Wansford Branch Railway crosses the
Syston and Peterborough Branch of the Midland Railway, not far from the
Uffington and Helpstone station of the latter, we find a good section of the
Cornbrash exposed. The Ostrea Marshii bed at its top is here well represented,
and this is covered by the light-coloured, sandy clay, representing the Kellaways,
which is seen to extend for some distance along the sides of the railway. At
this place the Cornbrash is crowded with the usual fossils, including Ammonites
macrocephalus, Schloth. (in every stage of growth), We also find the following
species :—

Belemnites ?

Pholadomya deltoidea, Sow.
Goniomya v- scripta, Sow.
Lima pectiniformis, Schloth.
Pecten (several species), dc.

Near Uffington Lodge a pit in the Cornbrash exhibits very numerous
specimens of fossils; we here find (often of great size) Ammonites macroce-
phalus, Schloth.

Homomya gibbosa, Ag.
Trigonia elongata, Sow.
—, Sp.
Pinna tetragona, Phil.
Avicula echinata, Sow.
Ostrea Marshii, Sow. (O. flabelloides, Lam.)
Terebratula obovata, Sow.
and the forms approximating closely to T. digona, Sow. or

The gregarious habit of Avicula echinata is well illustrated at this section.

To the northwards, in the neighbourhood of Belmesthorpe and Uffington
Wood, the rock of the Cornbrash forms the surface over a considerable area,
and several small pits have been opened in it, the positions of which are shown
upon the map. Near Brown’s Oak and Banthorpe the cuttings of the main-
line of the Great Northern Railway afford some interesting sections of the
formation. The latter of these is thus noticed by Professor Morris :*¥—

“In the Casewick cutting the Cornbrash, which isa grey, slightly compact _
and crystalline, shelly, and thin-bedded rock, occurs throughout the base of
the cutting ; its fossil contents are—

Pholadomya, sp.
Panopea calceiformis, Phil., sp.
Modiola bipartita, Phil.
Gervillia aviculoides, Sow.
Goniomya litterata, Sow., sp.
Lima rigida, Sow.
Ostrea Marshii, Sow. (O. flabelloides, Lam.)
Pecten demissus, Phil.
-- lens, Sow.

 

 

 

* Quart. Journ, Geol. Soc., vol. ix. p. 332.
THE GREAT OOLITE. 227

Terebratula Bentleyi, Mor.

—— obovata, Sow.

Diastopora (Berenicea) diluviana, Milne.-Edw.
Serpula, two species.

Portion of a jaw of Chimera.”

Still further north, the Essendine and Bourne branch of the Great Northern
Railway crosses the outcrop of the beds of the Cornbrash, but does not expose
any particularly good sections. About Wilsthorpe, Braceborough, and Great-
ford, however, the Cornbrash occupies a considerable area and is exposed in a
number of pits. The rock here presents a noteworthy peculiarity; the flat
rubbly fragments of which it is made up, being all coated with a deposit of
white stalagmitic carbonate of lime, which gives them the appearance, when
viewed at a little distance, of having been whitewashed. ‘he fossils found in
these pits are those which everywhere characterise the Cornbrash, and the beds
here are seen to dip directly under the fens, being overlapped by the deposits
of the Fenland gravels.

Above Manthorpe the top of the Cornbrash, with the bed crowded with
Ostrea Marshii, Sow., is well seen. At Lound a pit occurs which affords the
following section :—

 

Pit in the Cornbrash at Lound dug for road-metal,

ft. in
Boulder Clay —- - - - - - 3 0
Trace of Oxford clay in place (?) - - - 0 0
Bed of laminated stone full of Ostrea Marshii, Sow., and
other species, and Ostrea (large flat species) - - 09
Bed of soft, sandy stone - - - - - 0 6
Bed of hard, whitish stone crowded with fossils (Lima
pectiniformis, Scholth, L. punctata, Sow. &c.) - 0 9
Light-brown, sandy clay - - - - - q :

Hard, blue-hearted stone - - - -
Rubbly Cornbrash at bottom.
Ammonites macrocephalus, Schloth (very large specimens).
Ostrza Marshii, Sow. (very abundant).
Modiola imbricata, Sow.
Gervillia aviculoides, Sow.
Lima punctata, Sow.
pectiniformis, Schloth.
Pecten lens, Sow.
demissus, Phil.
Hinnites gradus, Phil.
Cypricardia Bathonica, Mor. & Lye.
Pholadomya deltoidea, Sow. (abundant).
Goniomya v- scripta, Sow.
Myacites securiformis, Phil.
Perna rugosa, var quadrata, Mor. & Lye.
Terebratula obovata, Sow.
—maxillata, Sow.
Terebratula lagenalis, Sow.
Rhynchonella concinna, Sow., sp.
Serpula, sp.

Northwards from this point to Bourn and Edenham, where the Cornbrash is
well developed and has yielded some interesting fossils (the original specimen
of the Terebratula Bentleyi, Mor. was found at Handthorpe near Bourn) we
find several interesting exposures of the formation. The interesting sections
about Bourn will be described in the explanation of Sheet 70 of the Survey map.

The fossils found in the various Cornbrash pits, in the immediate vicinity of
Bourn, were as follows :—
Fossils from Cornbrash of Bourn.

Ichthyosaurus (vertebra).
Nautilus Baberi, Lyc. & Mor. (?)

 

 
228 GEOLOGY OF RUTLAND, &c.

Ammonites Herveyi, Sow.
“-——= macrocephalus, Schloth.
Cardium cognatum, Phil.
Goniomya y-scripta, Sow.
Gresslya, peregrina, Phil.
Modiola imbricata, Sow.
Myacites decurtatus, Phil.
—- calceiformis, Phil.
Pholadomya deltoidea, Sow.
Trigonia costata, Sow.
Gervillia aviculoides, Sow.
Lima pectiniformis, Schioth.
—— rigidula, Phil.
Ostrea Marshii, Sow. (O. flabelloides, Lam.).
Pecten demissus, Phil,
lens, Sow.
sp.

Discina, sp.

Terebratula lagenalis, Schloth.

obovata, Sow.

Serpula, sp.

Echinobrissus orbicularis, Phil.

Outliers—As already remarked, many of the outliers of the
Cornbrash are greatly obscured by the drift deposits which lie
upon them, and often overlap their edges. The general position
and limits of these outliers being indicated upon the map, it will

only be necessary to notice in detail such of them as afford inte-
resting sections.

The outlier shown on the map at Brigstock Parks was proved by some deep
wells which, passing through the drift, reached the Oxford Clay, and as this
formation is everywhere in the district underlaid by Cornbrash, we have repre-
sented it here; but the outlines of the mass are purely hypothetical.

The two outliers of the Walk of Morehay only exhibit the Cornbrash along
their eastern margins, where, by the dip, their beds are brought to a lower level.
The most southern of these two outliers is capped by a mass of Oxford Clay
and Kellaways Sand, the extent of which is doubtful. It is not improhable
that the northern outlier is similarly capped, but of this we have no actual

roof.

P In the case of the outlier between Fineshade and King’s Cliffe, however, the
recently constructed trial-shafts for a railway have exposed the Oxford Clay
and representative of the Kellaways resting upon the Cornbrash (see p. 221).
On the eastern side of this outlier the Cornbrash is exposed at Cliffe Parks,
where it covers a considerable area, At the nope part of the Cadges Wood
its beds are well exposed in a ditch-cutting, and I collected here—

Ostrea Marshii, Sow. (O. flabelloides, Lam.), large and abundant.

Ammonites Herveyi, Sow.

Pholadomya deltoidea, Sow.

Myacites decurtatus, Phil.

Lima rigidula, Phil.

Lucina, sp.

Terebratula maxillata, Sow.

The Cornbrash is again seen north of Blatherwycke Mill, and on the western
side of the same outlier we can trace the formation capping a number of spurs
between Blatherwycke and Duddington. The succession of beds is here clearly
seen to he as follows :—

(1.) “Kale,” forming top of spurs (Cornbrash).
(2.) Stiff, blue clay (clays of Great Oolite).
(3) Beds of limestone (Great Oolite).
(4.) acd ae of clays in sides of valley (Upper Estuarine
eries).
(5.) Oolitic rock, forming “red land ” of the plateau (Lincoln-
shire Limestone).

 

 

 

 
THE GREAT OOLITE. 229

In their higher portions these ridges are much obscured by the masses of
pre-glacial gravel, which are in turn overlapped by the Boulder Clay. Above
Duddington the Cornbrash is seen and at once recognised by its lithological
characters, and the presence in it of—

Ostrea Marshii, Sow.
Ammonites Herveyi, Sow.
And the common Cornbrash Echinoderms.

The effect of the great north and south fault upon the Cornbrash in this
outlier is very strikingly seen in tracing the outcrop of the beds.

At the outlier of Bedford Purlieus many exposures of the Cornbrash occur,
but no good sections. Over a great part of its area the outlier is greatly
obscured by drift, and its surface has only been recently cleared of woods.

The outlier of Barrowden Hay and Luffenham Heath, the limits of which
can be clearly defined on its eastern side, is also much covered with drift on
its western. It does not afford any instructive sections.

North of Stamford a small outlier of Cornbrash occurs on the highest point
of the plateau lying north of the town, and known as the “ Stamford open
field.” In the earlier edition of Sheet 64 this outlier was not represented,
there being at that time no sufficient evidence of its existence. Iam indebted
to Mr. Sharp for calling my attention to a number of trial holes for stone,
which were opened during the recent enclosure of this tract. From these trial
holes, many of which failed in reaching beds of solid stone, it appears that a
number of small fragments, vestiges of an outlier of Cornbrash, still exist at
the top of this hill. None of these fragments of the cap of Cornbrash exceeded
4 feet in thickness, and so irregular and uncertain is the mode of occurrence of
the rock, that its limits can only be represented on the map by a dotted line. It
yields, however, Ostrea Marshii, Sow., and several other characteristic Cornbrash
fossils, and its identity with that formation is therefore beyond doubt. It is
underlaid by a thick mass of clays, with some shelly bands (clays of the
Great Oolite). Indeed a very excellent section of the whole of the beds from
the Cornbrash to the Upper Lias can be traced at the town of Stamford.
This section has been admirably illustrated by Mr. SHarp.

It will not be necessary to describe in detail the various outliers to the
northwards, some of which are of quite insignificant proportions, though others
cover considerable areas. The small outliers at Firewards Thorns, south-
west of Essendine, exhibits only the bottom bed of the Cornbrash, the clays
immediately below it being crowded with Ostrea subrugulosa, Lyc. & Mor.
In a small outlier to the north, the limestone rock has been wholly removed,
and only the clays below it remain; but in one to the west a considerable
thickness of the Cornbrash rock is exposed.

A very extensive outlier of the Cornbrash occurs between Careby Lings
and Monk’s Wood; and numerous smaller ones south of the latter place, at
Dogsight, and Holywell Lodge. In the latter of these the Great Oolite Clays
below were well exposed in a number of field-drains. _

The manner in which slight foldings of the strata have contributed to the
preservation of these outlying patches has been already explained, and is well
illustrated in the cuttings on the main line of the Great Northern Railway
which were so clearly described by Professor Morris. :

At Clipsham, however, we find an outlier of Cornbrash, considerably to the
westward of all those which we have been describing to the north of the
Welland, and which evidently owes its preservation to the action of a fault.
The rock here presents the usual characters of the Cornbrash and contains
Ammonites Herveyi, Sow. and Pholadomya deltoidea, Sow. var. :

The great outlier which occupies a great part of Grimsthorpe Park is much
obscured by drift, but the beds are exposed in some of the cuttings of the
Edenham and Little Bytham Railway.

Inliers—Several inliers of Cornbrash, seén at the bottom of the
valleys cut in the overlying Oxfordian clays, occur within the
limits of Sheet 64. The most important of these is the interesting
patch of rock near Stilton in Huntingdonshire, where several pits
have been opened in it to obtain road-metal. A glance at the
map will show at what a considerable distance this exposure of the
230 GEOLOGY OF RUTLAND, &C.

Cornbrash rock lies from any other exhibition of the same bed ; and
a careful study of the ground indicates that its appearance at this
singular and unexpected locality is, in part, due to a considerable
fault, which here traverses the beds. The area covered by this
inlier is not great, but the patch of rocks is of very great interest
indeed, from the number of interesting species of fossils which
it has yielded, but still more from the mode in which these are
found preserved at this locality. The fossils of the Cornbrash, and
especially those with thin and delicate shells, such as the Myade.
usually occur as internal casts only, but at Stilton these delicate
shells, often retaining their pearly nacre, are found very beautifully
preserved. At this point Mr. Benrixy has recently found very
beautiful specimens of the rare and interesting ‘Brachiopods
Terebratule Bentleyi, Mor. and Terebratula coarctata, Park., the
latter species having been formerly supposed to be peculiar to the
Bradford Clay of the Bath area. The Cornbrash rock in this inlier
is of a paler colour and less ferruginous character than is usually
the case with it.

The following fossils have been collected from the rocks of the Cornbrash in
this interesting inlier :—

Fossils from the Cornbrash of Stilton, Huntingdonshire.

Ichthyosaurus, sp.

Plesiosaurus, sp.

Teleosaurus, sp.

Strophodus magnus, Ag.
————-—- subreticulatus, Ag.
Pycnodus Bucklandi, Ag.
Asteracanthus verrucosus, Ag.
Ammonites Herveyi, Sow.

-- macrocephalus, Schloth.
———-- modiolaris, Lihwyd.
Chemnitzia simplex, Lyc. & Mor.
Cardium cognatum, Phil.
Cypricardia cordata, Lyc.
Goniomya v-scripta, Sow.
Homomya crassiuscula, Lye. & Mor.
— gibbosa, Sow.
Isocardia tenera, Sow.

Lucina striatula, Buv.

Modiola gibbosa, Sow.

—~—— imbricata, Sow.
———- Lonsdalei, Lye. & Mor.
——- Sowerbyana, @’Orb.
Myacites calceiformis, Phil.
———— decurtatus, Phil.
recurvus, Phil.
securiformis, Phil.
—--— sinistra, Ag.
Pholadomya acuticosta, Sow.
—— deltoidea, Sow.
— lyrata, Sow.
————— Phillipsia, Mor.
Trigonia Scarburgensis, Lyc.
Anomia semistriata, Bean.
Avicula echinata, Sow.

Lima duplicata, Sow.

—— impressa, Lyc. § Mor.
—— leviuscula, Sow.

—~— pectiniformis, Schioth.

 

 

 

 

 

 
 
 

 

ALITOO

@YIHS NICONLT

IVaue® fH AM Oe

 

 

“MaYd YAIMCHLSWSO

 
THE GREAT OOLITE. 231

Lima rigida, Sow.
—— rigidula, Phil.
Pecten anisopleurus, Buv.
—— articulatus, Schloth.
annulatus, Sow.
—-- demissus, Phil.
- inequicostatus, Phil.
lens, Sow.
—-- Michelensis, Buv.
vagans, Sow.
Rhynchonella concinna, Sow.
———-- Moorei, Dav.’
obsoleta, Sow.
— varians, Schloth.
Terebratula Bentleyi, Mor.
coarctata, Park.
intermedia, Sow.
lagenalis, Schloth.
———— sublagenalis, Dav.
—_—_—- maxillata, Sow.
—- — obovata, Sow.
orinthocephala, Sow.
Glyphza rostrata, Phil.
Serpula intestinalis, Phi.
—-- squamosa, Bean.
—--— tetragona, Sow.
Clypeus Milleri, Wright.
Echinobrissus clunicularis, Lihwyd.
orbicularis, Phil.
Holectypus depressus, Leske.

At Kate’s Bridge the Cornbrash is again exposed as an inlier in the midst
of the great spread of Oxford clay. There is, however, no reason for supposing
that the exposure of the former beds at this point is contributed to by a
fault. The fossils found in the Cornbrash in a well at this place were—

Echinobrissus clunicularis, Lihwyd.
Holectypus depressus, Leske.
Isocardia tenera, Sow. :
Where exposed at the surface, the Cornbrash rock of this inlier presents its

usual characters.

Near Thurlby Wood a number of extensive pits are opened in the Cornbrash
exposed in an inlier contiguous to, and almost continuous with, that of Kate’s
Bridge. The characters of the rock and the species of fossils here found are
those which usually distinguish the Cornbrash.

The Cornbrash is not a rock of any great economic value. Its
peculiar bedding renders it quite unfit for a building stone, though
it is frequently locally employed in rough constructions and for
field-dikes. It is also occasionally quarried for lime-burning in
the district, but for this purpose is by no means so highly esteemed
as the subjacent Great Oolite. As a road-metal, however, it
possesses deservedly a high reputation among limestones ; and for
this purpose it is very extensively quarried, and occasionally
conveyed to considerable distances.

The small esteem in which throughout the Midland district the
Cornbrash is held by agriculturists has already been noticed.

The low tabular hills, which characterise the scenery of the
districts occupied by the alternations of the clays and limestones
constituting the Great Oolite Series are illustrated in Plate X.

 

 

 

 

 

 

 

——=:

 

 

 

 

 

——.

 

 
232

CHAPTER IX.
THE MIDDLE OOLITES.

This division of the Jurassic series is only partially exposed within
the limits of Sheet 64, being represented by the lower portion of the
Oxford Clay with the sandy beds representing the Kellaways Rock
at its base. _ Like the Lias, this formation consists almost wholly
of clays, which are usually concealed by a thick covering of glacial
clay and gravel. The Oxford Clay was evidently a deep sea
deposit and, like the Lias, exhibits evidence that during its forma-
tion the fauna gradually underwent very considerable changes,
especially in the species of Cephalopoda. We will now describe
the succession of its principal beds as represented in this district.

a. Kellaways Sands, Sandstones, and Clays.——These beds, which
lie directly upon the Cornbrash, consist of an alternation of clays
usually light-coloured, very arenaceous, and sometimes pyritous,
with irregular beds of whitish sand. ‘The latter are not un-
frequently cemented by calcareous matter into a friable rock, in
which case they are usually full of fossils. ‘These fossils belong to
the species which characterise the Kellaways rock of Yorkshire
and Wilts; Gryphea bilobata, Sow., Avicula inequivalvis, Sow.,
(A. expansa, Phil.), and Belemnites Oweni, Pratt, being among
the most abundant forms. These beds were first detected in this
district by Professor Morris, who saw them exposed in the Case-
wick cutting of the Great Northern Railway. Although such
sandy beds are everywhere in this district found at the base of
the Oxfordian, and indeed extend, though perhaps not un-
interruptedly, through the country from Yorkshire to Wiltshire,
yet they are so variable in thickness and mineral character that
it has not been considered advisable to attempt their separation
from the Oxford Clay upon the map; the places where they are
well seen, however, are indicated by the symbol KEL. The
Kellaways beds form a link between the Cornbrash, which was
accumulated in rather shallow water, and the Oxford Clay, which
was a deep sea deposit; they contain many of the species found
in each of these formations, with a few which are peculiar.

The Kellaways beds are dug for brick-making at Oundle,
Southwick, Benefield, Dogsthorpe, Uffington, Kate’s Bridge, and
Warmington ; and it is said that the bricks made from them are
much superior in quality to those manufactured from the Oxford
Clay, especially in respect to the amount of heat which they will
bear. The sandy nature of these beds gives a peculiar character
to the soil upon them ; causing it to exhibit a whitish colour and
a dryness very different from that of the Oxford Clay above.

b. Clays with Nucula.—These are laminated, blue shales crowded
with compressed Ammonites and the little Nucula nuda, Phil.
They are seen at many points, and are dug for brick-making at
Haddon, Eyebury, and Holme.
THE MIDDLE OOLITES. 233

e. Clays with Belemnites Oweni—Consisting of dark-blue clays
abounding with Belemnites Oweni, Pratt, which often attains to a
gigantic size. Gryphea dilatata, Sow., appears to commence in
these beds, which yield abundantly the bones of saurians and fish,
and great masses of wood converted into jet. These beds are
exposed in the brickyards at Standground, Fletton, Woodstone,
Sudborough, Conington, Luddington, and Great Gidding.

d. Clays with Belemnites hastatus—These blue clays contain
many of the fossils which are found in the last, but are character-
ised by the appearance, in great numbers, of the little Belemnites
hastatus, Blain. They are dug at Werrington, Ramsey, and
Eyebury.

e. Clays with Ammonites of the yroup of the Ornati.— These are
dark-blue clays containing great flattened nodules of iron-pyrites,
with numerous Ammonites fossilized by the same mineral. The
most abundant species in these beds are Ammonites ornatus,
Schloth, 4m. Duncani, Sow., Am. Bakerie, Sow., Am. athleta,
Phil., with Terebratula impressa, Von Buch. These beds are
dug in the brickyards about Whittlesey, and also in those at
Thorney, and Eye Green.

Sf. Clays with Ammonites of the group of the Cordati.—These are
exposed only at the Forty-foot-Bridge brickyards, which are just
upon the eastern limits of this sheet.

Main Line Outcrop of the Middle Oolites in the District—In
Sheet 64 the Oxfordian strata constitute a band of country,
immediately bordering the Fenland, which rises into numerous
swelling hills, usually of no great elevation. Throughout this
tract the Secondary deposits are greatly obscured by the superin-
cumbent Boulder Clay and gravels; the land formed by the Middle
Oolite is in the main devoted to grazing purposes, but some con-
siderable areas of it have been brought under the plough, while
others remain as woodland. A few exposures of the Oxfordian
strata also occur in the Fenland, to the east of this main line of
outcrop ; and again in outlying patches capping the Lower
Oolites to the west of it.

Immediately to the south of the limits of sheet 64, the beds of the Oxford
Clay were well exposed in the Wigsthorpe cutting of the Northampton and
Peterborough Railway. This cutting was examined by Professor Morris and
Captain Ibbetson at a time when the beds were well exposed, and they described
the section in the following terms :—‘ The Oxford Clay is well seen in the
Wigsthorp cutting, near Thorpe Aychurch, and is marked by zones of Septaria,
frequently containing fossils. Am. Konigii, &c., the lower part of the section
being thin slaty clays full of Ammonites Jason or Elizabethe much compressed,
Belemnites, Avieula, and numerous bivalves.’”’*

In a well at the same place, which extended to the depth of 30 feet, I also
saw a good section of the same beds consisting of dark blue clays abounding
with Gryphea dilatata, Sow., and many Ammonites and Belemnites which were
too imperfect for identification.

At Sudborough brickyard beds near the base of the Oxford Clay are dug.

They yield abundantly very large specimens of Belemnites Puzosianus, d’Orb ;
Ammonites and saurian remains also occur at this place.

 

* See Morris and Ibbetson, notice of the geology of the neighbourhood of Stamford and
Peterborough, Brit. Ass, Rep. for 1847, Trans. of sect., p. 127.
234 GEOLOGY OF RUTLAND, &C.

At the reservoir constructed for the supply of Lilford Hall, on the south-
west side of the park, the Oxford Clay was just reached in one corner of the
excavation under a great mass of boulder clay : the beds exposed. here are
evidently low down in the Oxfordian series, and consist of dark blue clay full
of crushed specimens of Ammonites, with many examples of Nucula nuda, Phil.

Near Barnwell railway-station, the lower beds of the Oxford Clay were
exhibited in a number of drains, at the time of the survey.

_ At Oundle brickyard the lowest beds of the Middle Oolite, consisting of
light-coloured, somewhat sandy clay, with bands of hard, sandy and ferruginous
rock, are well seen. The bands of sand-rock which alternate with the clays
are seldom more than 7 or 8 inches in thickness, and often thin out altogether
within very short distances. They are often so crowded with fossils that the
abundance of carbonate of lime does great injury to the bricks during their
burning. The clay here is said to form an inferior kind of fire-brick capable
of withstanding a considerable degree of heat. On sinking through the clay
at this place, it is said that ferruginous beds were found from which strongly
chalybeate springs arose. I am uncertain whether these beds are to be regarded
as the Cornbrash, or to belong to one of the sandy ferruginous beds of the same
kind as those exposed in the pit. It is evident from the fossils which they con-
tain, that the rocks exposed in the Oundle brickyard are the representative of
the Kellaways.

At Benefield brickyard the same series of beds is exposed, consisting of
light-blue clay with very irregular and inconstant bands of sandy rock, con-
taining Serpula, Belemnites, Gryphea, Avicula, and other shells. They were
also exposed in some other artificial openings in the neighbourhood. The
rapidity with which the surface water soaks away over the areas, throughout
which these sandy beds representing the Kellaways outcrop, causes their soil to
present a remarkable contrast with that of the districts occupied by the stiff
and impervious clays of the higher portions of the Oxford Clay. The light-
sania sandy soils formed by the former rocks, constituting what is locally
known as “‘drummy land,” can easily be traced, over many miles of country
in this district, at the limits of the Oxford Clay and Cornbrash formations.

At the brickyard of Ashton, lying on the opposite side of the Nene valley
to that of Oundle, Oxfordian strata, probably a little higher in the series
than those of Oundle and Benefield, are worked. These consist of dark-blue
clays containing Nucula nuda, Phil., many fragments of Belemnites, crushed
Ammonites and large quantities of wood converted into jet. These beds are
doubtless the same as those exposed at Wigsthorpe and Lilford which we have
before noticed. .

At the Warmington brickyard no good section was exposed, but the beds
worked are evidently of the same sandy character as those which, throughout
the district, immediately overlie the Cornbrash, and by their fossil contents are
shown to represent the Kellaways. The Cornbrash is reached under the Ox-
fordian beds by wells sunk at a number of points in the neighbourhood of this pit.

The very considerable tract of Oxfordian strata lying between the Nene
valley and the Fenland is almost entirely obscured by the great drift deposits
(boulder clay and gravel), which are, indeed, seldom cut through by the valleys
so as to expose the subjacent rocks. Consequently, exposures of these {latter
are exceedingly rare in the district. ; ;

At Luddington brickyard we find, under a thickness of 5 or 6 feet of drift,
Oxford Clay of a light-blue colour which is dug to the depth of 30 feet. It
contains Gryphea dilatata, Sow., Belemnites Puzosianus, d@’Orb, and, some-
what rarely, Ammonites. Le

At the Great Gidding brickyard, which is just beyond the southern limit of
Sheet 64, similar beds of Oxford Clay, of a light colour, are found. Specimens
of Serpule were the only fossils which I detected at this spot. :

Along the course of the Billing Brook I found several exposures of light-
coloured and sandy clays belonging to the Oxfordian series. These are
exposed in consequence of the thick drift deposits of the area being cut through
by the deep valley in which this stream flows. 5

Along the road between Elton and Haddon the Oxford Clay was well seen in
some deep drains. It consisted of light-coloured, very tenaceous, clay, in which
fossils were only sparingly distributed. Specimens of Belemnites Puzosianus,
d’Orb, and fragments of wood were, however, not rare.
THE MIDDLE OOLITES. 235

Near Haddon Church a well sunk at the new parsonage penetrated the
Oxford Clay to a depth of more than 30 feet, but no water was obtained.
The clay brought up was dark coloured and highly laminated. It contained
many fossils, including :

Belemnites Puzosianus, d’Orb.
Ammonites ornatus, Schloth.

A other species (indeterminable).
Nucula nuda, Phil.

The fossils were all crushed and very imperfectly preserved. At Haddon
brickyard similar clays with Nucula nuda and Belemnites were dug. The
brickyard at Morborne is now abandoned, and I could obtain no information
concerning the beds and fossils formerly exposed in it.

A little to the south of Fletton the Oxford Clay was exhibited in a number
of field-drains. The beds here contained great numbers of Nucula nuda,
Phil., which were however very badly preserved.

In the neighbourhood of Peterborough the various beds forming the lower
part of the Oxfordian series are well exposed.

At Dogsthorpe the brick pits exhibit light and dark-blue clays, often mottled,
becoming in some places very sandy and passing in others into light-brown
sands which are somewhat indurated. The sandy rock here does not appear
to form regular beds in the clay, but to constitute nests and irregular lenticular
masses. I am indebted to the owner of these pits, Mr. Thomas Parker (who
had preserved a considerable number of fossils and rendered me important
aid in the examination of the district) for making an experimental sinking
through the lower beds in the pits, whereby the following section was exposed :—

(1.) Soil and Gravel - - -

(2.) Sandy Clay with stony bands

(3.) Hard blue “ dicey ” clay - : -
(4.) Cornbrash limestone.

In (2) the clays appeared to be totally destitute of fossils, but in the sandy
stone, great; numbers of specimens of Gryphee bilobata, Sow., and Belemnites
Puzosianus, d’Orb, including individuals of all ages, occurred. :

The clays (3) had at their base a band crowded with fossils including
Ammonites Herveyi, Sow., Nucula nuda, Phil., Corbula sp., and Rhynchoneila sp.

The Cornbrash limestone (4) was identified, both by its petrological charac-
ters and by its containing Avicula echinata, Sow., and Ostrea Sowerbyi, Lyc.
and Mor. The bricks made from the sandy clays of Dogsthorpe are said to
be capable, like those of Oundle and Benefield, of withstanding a very con-
siderable degree of heat.

At Standground, Fletton, and Woodstone, near Peterborough, dark-blue
clays containing large quantities of fossil wood, which, by their fossils, are
shown to belong to a rather higher portion of the Oxfordian series than those
just described, are dug for brick-making. From these pits the late Dr. Porter,
of Peterborough, obtained a number of very interesting fossils. These
include :—

Belemnites Puzosianus, d’Ord. (extremely abundant.)
Ammonites Bakeriz, Sow.
convolutus ornatus, Quenst.
macrocephalus, Schloth.
heterophyllus ornatus? Quenst.
hecticus, Rein.
‘3 arduenensis, d’Ord.
Rhynchonella varians, Schoth.
with very many bones of Saurians, and spines and teeth of fish.

Among these, are especially worthy of notice, large portions of the skeleton
of Steneosaurus, the teeth of Strophodus reticulatus, Ag., and the dorsal spines
of Asteracanthus verrucosus, Eg. The last-mentioned fossils sometimes attain
to very large proportions, specimens 12 inches in length, with a girth in their
thickest part of five inches, and a thickness of two inches, having been found.
Some fragments have also occurred indicating even greater dimensions than
these.

The very large quantities of wood, either converted into jet or mineralized by
pyrites, is ‘a specially noteworthy circumstance at these localities near Peter-

NOP

”

3b

”
236 GEOLOGY OF RUTLAND, &C.

borough. This wood sometimes occurs in masses of great size; it is evidently
drift-timber, which, floating in the open sea, became water-logged and sunk
to the bottom, there to be buried in the fine clays in association with the
numerous marine animals of the Oxfordian period.

By the great Stamford and Helpstone fault the line of outcrop
of the Middle Oolites, like that of the Lower Oolites, is subjected
to great displacement, and the strata appear far to the westward
of the positions at which their occurrence might be anticipated,

Between Marholme and Woodcroft the beds of sandy stone, representing
the Kellaways, and the overlying blie clays were exhibited in a number of
field drains,

At the westernmost of the two mills at Werrington a brickyard exhibits
beds of Oxford Clay, overlaid by thick masses of Boulder Clay with patches
of gravel at its base. The Oxford Clay here yielded,—

Ammonites Duncani, Sow.

Belemnites Puzosianus, d’Ord.

Icthyosaurus sp. (Vertebre and other bones.)
Plesiosaurus sp. (Ditto.

In the clay-pit at the east end of the village of Werrington the clays yield
rather numerous fossils, including, besides some Ammonites and vertebrate
remains which were not determined,—

Belemnites hastatus, Blainv. (very abundant).
5 Puzosianus, @’Orb. (rare).

Gryphea dilatata, Sow.

Nucula nuda, Phil.

Serpula vertebralis, Sow. (abundant).

Omitting the special mention of many small and obscure sections, we have,
in the Casewick cutting of the Great Northern Railway, as described by
Professor Morris in 1853, some very interesting and instructive sections of the
lowest beds of the Oxfordian series. This interesting section is now, however,
almost wholly concealed in consequence of the sides of the cutting being
turfed up. . : ;

This section (see Fig. 18, page 244) is described by Professor Morris, as fol-
lows:—

“ Resting upon this bed” (the Cornbash) “is the equivalent of the Oxford
clay, consisting of 10 feet of dark laminated unctuous clay, with gray-brown
sandy ferruginous clay; the dark clay contained Ammonites Herveyi abun-
dantly, as well as Modiola bipartita, Trigonia clavellata, Thracia, depressa,
Nucula nuda, Phil., and Saurian bones. The brown sandy clay, which passed
into ferruginous rock, contained many well preserved fossils, the most abun-
dant being,— ;

Gryphea bilobata, Sow. (in every stage of growth).
Belemnites Oweni, Pratt (Puzosianus P d’Orb).
Ammonites Calloviensis, Sow.
Nautilus sp.
Pholadomya acuticosta, Sow.
Panopea peregrina, Phil. sp.
Lima rigidula, Phil.
Avicula expansa, Phil.
Pecten demissus, Phil.
» lens? Sow.

‘ These fossils would indicate that the ferruginous rock and gray sand were
the equivalent of the Kellaways rock, which has not been previously noticed
in this district,””*

Throughout the remainder of the outcrop of the Oxfordian
beds to the northward, within the area now being described,
there are few good sections. At all points, however, where the
strata are sufficiently free from drift, the outcrop of the sandy

 

* Quart. Journ. Geol. Soc., vol. ix. (1853), p. 333.
THE MIDDLE OOLITES. 237

beds, representing the Kellaways, can be readily recognised by
the distinctive characters of the soil which they form.-

At Kate’s Bridge four miles south of Bourne there are two pits in the
Kellaways strata. In one of these, the thickness of clay overlying the
Cornbrash rock is only 6 feet, the beds consisting of light-blue sandy clay
containing Belemnites, Gryphea, Avicula, and other shells.

At Bourne we have, in a brickyard, the following section of the same beds :—

ft. in.
(1.) Soil - - = 5 = = = T 6
(2.) Clay eon sandy and yellow below - - - | 6
(3.) Light-blue and yellow mottled sand - - 2 0
(4.) Light-coloured, laminated clay - - - - 2 6
(5.) Sandy rock (very irregular) - - - - 4 0
(6.) Light-blue clay - - - - - 8to9 0
(7.) Cornbrash P - - - - - -
The bed (5).contained,—

Belemnites Oweni, Pratt (Puzosianus? d’Orb.)
Avicula expansa, Phil. :
Gryphza bilobata, Sow.

Wood.

The Oxford Clay appears to constitute the substratum of that
portion of the Fens included within Sheet 64. The process of
‘elaying the land (that is, digging deep trenches through the
superficial peat and silt into. the clay beds below, and spreading
portions of these latter over the surface) occasionally affords fair
exposures of the strata and fossils of the dark-blue Oxfordian
Clays. Ata few points, however, the rock, met with under these
circumstances, is the Boulder Clay ; patches of which appear to
have escaped the wide-spread marine denudation, which has
produced the plain of. the Fenland. Besides these local and
temporary exposures of the Middle Oolite strata within the
Fenland, we have a few brickyards which afford sections of the
same strata within this area,

South of Bury a brickyard in the Oxford Clay exhibits a section of dark-
blue clays containing much pyrites, which yield the following fossils :— %
Gryphee dilatata, Sow. (abundant).
Belemnites Puzosianus, d’Orb. (rare).
55 hastatus, Blainv.
Ammonites Lambertii, Sow.
% cordatus, Sow. ;

With imperfect specimens of both bivalves and univalves, and some bones
of Saurians. : .
_ At Ramsey, near the railway station, the Oxford Clay was formerly largely
dug and burnt as a substitute for gravel, a use to which the clays of this
formation are frequently applied. : : :

At Ramsey Heights there are several brickyards still’ open, the clay used
being that of the Middle Oolite (lacally termed“ Galt”). At one of these,
the bricks made are burned with peat. Neither of the clay pits at these
brickyards, however, afford any sections of special interest to the geologist.

At Forty-foot-Bridge there are two clay pits opened in the Oxford Clay.
In one of these, a band of hard rock, 8 or 10 inches in thickness, is found at
a depth of 15 feet. The clays at this place are crowded with Ammonites
Lambertit Sow. (many varieties): Belemnites hastatus, Blainv., is also very
abundant, while Belemnites Puzosianus, d’Orb, is rare. Gryphea dilatata, Sow.,
occurs in moderate abundance. ms :

At Conington brickyard blue clays of the Oxfordian series are dug, which
yield abundant specimens of Belemnites Puzosianus, d’Orb, and, somewhat
rarely, examples of Gryphea dilatata, Sow. Similar clays are dug at the
Holme brickyard. ;

32108. Q
238

GEOLOGY OF RUTLAND, &C.

A cutting on the main line of the Great Northern Railway, between Farcett '
and Yaxley, exposes a considerable thickness of light-blue Boulder Clay full
of chalk detritus, with some irregular gravelly beds intercalated in it. At the
bottom of this drift occur the dark-blue Oxfordian Clays-containing very
large septaria and yielding many fossils, among which were,—

elemnites Puzosianus, d’Orb.
55 hastatus, Blainv.
Ammonites excavatus, Sow.
»  athleta, Phil.
‘ 93 Duncani, Sow.
a? cordatus, Sow.
Gryphea dilatata, Sow. (very large).
Serpula vertebralis, Sow.
» Sp.

And a number of bivalves too imperfectly preserved for identification.

In the nea neonEog’ of Whittlesea there are several brickyards in which
the beds of the Oxford Clay are exposed in good sections. ;

To the North-west of Whittlesea the clays are dug in a very extensive pit;
théy are of a deep-blue colour and contain much pyrites and wood. The
fossils are often, indeed so thickly encrusted with pyrites that it is impossible to
determine their species. Among them are,—

Belemnites Puzosianus,. d@’ Orb.
# hastatus, Blainv.
Ammonites athleta, Phil. :
Pr (several other species).’
Gryphza dilatata (very abundant).
Serpula sp. : / :

The large clay-pits at the town of Whittlesea have yielded great numbers
of beautiful specimens of Ammonites, especially those belonging to the Ornatus
group, including— ,

Animonites Duncani, Sow. z
» 3 +» _ (variety).
55 _Elizabethe, Pratt.

os Comptoni, Prati.

e ornatus, Schioth.

3 Jason, Rein.

s Bakerize, Sow.

wy cordatus, Sow. (variety).-

es tatricus, Pusch. (young). =
is Constantii, d’ Orb. ; ,
3 plicatilis, Sow. -

Belemnites, bones of Saurians, and specimens of Gryphea dilatata, Sow., also
abound in these pits. i : :
At Eastrea brickyard, clays, probably somewhat higher in the Oxfordian
series, are exposed; these yield,— ;
Belemnites Puzosianus, d’Orb (very rare).
ag hastatus, Blainv. 28
Ammonites Lambertii, Sow.
Rhynchonella varians, Sow.
Saurian remains.

At the brickyard at Eyebury a number of interesting vertebrate remains
have been collected by Mr. Leeds. Some of these are now in the Oxford
Museum. The clays at this place have yielded a considerable number of
specimens of Terebratula impressa, Von Buch.

Near Eye several pits opened in the Oxfordian strata expose beds of blue
clay with Gryphea dilatata, Sow., and numerous Belemnites and Ammonites.

At Eye Green a thin ferruginous stony seam occurs in the midst of the
Oxford Clay. At this place there are found in the clays great numbers of
Ammonites in all stages of growth, including many varieties of Ammonites Jason,
Rein., and A. ornatus, Schloth: Belemnites Puzosianys, d’Orb, is very rare here,
while B. gracilis, Phiil.,is abundant. Terebratula impressa, Von Buch, also
occurs at this locality,
THE MIDDLE OOLITES. 239

At Thorney there is an excellent section of the Oxford Clay, it being here
dug to a considerable depth. Ammonites of the Ornati and Armati groups
are abundant, but the specimens are usually encrusted with pyrites. Gryphaa.
dilatata, Sow., occurs in prodigious numbers, but Belemnites Puzosianus, d’Orb,
is very rare,

Outliers.—The outliers of Oxford Clay are almost always thickly
covered with drift. Their boundaries are usually indicated by
dotted lines upon the map, and in very few instances have any
instructive sections been obtained in them. Under these circum-

-stances it will be unnecessary to notice them in detail; the only
sections observed were a8 follows :— ;

At Brigstock Parks a deep well, at one of the farmhouses, afforded unmis-

“takeable evidence that, under the thick covering of Boulder Clay, the Oxford
Clay occurs in situ. The extent and boundaries of this outlying patch are
_however purely hypothetical. aah oft

At Southwick there is a brickyard exhibiting the lowest strata of the
Oxfordian series, which here consist of the light-coloured, sandy clays, and
stony beds, representing the Kellaways Rock. These contain ~

Belemnites Puzosianus, d’Orbd.
Avicula expansa, Phil.
Gryphza bilobata, Sow.
As may be inferred from the aecount given of the formation in
the preceding pages, the various clays of the Oxfordian series are
_ extensively dug, for brick and tile-making, at many points within
this area. . The materials thus produced vary greatly in quality, at
different places, owing to the great range of differences in mineral
character which the clays from the several horizons in, this forma-
tion present when compared with one another. The most con-
spicuous of these differences, and that which has the greatest effect
in determining the characters of the materials manufactured from
the clays, consists in the proportion and quality of the sand
occurring in admixture with the plastic mass. ee geese

As the Oxford Clay is so frequently covered with drift within this
area, it exerts but a comparatively small direct influence on the
nature of the soils. ° :

 
240

. CHAPTER X. .
THE POST TERTIARY DEPOSITS. |

These deposits, as already pointed out, are of far later ‘date
than those we have been describing, and lie indifferently and un-
conformably upon the whole of them. Their classification and
nomenclature is in a much more unsettled and unsatisfactory con-
dition than that of the Jurassic rocks. ‘The divisions and ter-
minology employed in this memoir must be regarded as provisional
only, as they may be to some extent modified and corrected by:
future investigations. Nevertheless, though different conclusions
may ultimately be arrived at as to the age of certain of these
beds of gravel and sand, yet their boundaries as indicated upon
the map will not be affected thereby; it should, however, be
remembered that these boundaries are themselves usually much
less clearly defined than those of the Jurassic rocks, and hence
they have been represented only by faint dotted lines. ; :

As the survey of the drifts in the sheets to the south of 64 is
not yet completed, and the map of the superficial deposits of the
latter as yet unpublished, only a very general sketch of the cha-
' racters presented by these overlying formations will be included
in the present memoir; and ‘in this sketch attention will be
principally directed to the illustration of their relation -to thé
older: formations, the description of which is the chief object:
of this memoir. Descriptive memoirs: on the drifts of the Mid-
land district and on the geology of the Fenland will be eventually
published by the Geological Survey. :

. The great mass of Boulder Clay, with its associated gravels
. and sands, which occupies so large an area in this sheet, marks
a grand and well defined epoch in the deposition of the Post-
Tertiary beds, which is known as the Glacial-Period: Hence we
have classed all the beds of: this age as the Glacial Series. There .
are certain Post-Tertiary deposits which everywhere underlie
these Glacial Beds, and are therefore of older date than them;
while others were, as clearly, deposited at periods subsequent to -
the Glacial epoch, for they are found lying upon‘the glacial. beds,
and contain materials derived from them. Hence the Post-
Tertiary beds fall naturally into three groups—the Pre-Glacial,-
the Glacial, and the Post-Glacial. (See the Table on page 56.) _-

In the present state of the inquiry I have not felt myself
justified in discussing the relation of the drifts in this area to
those of the East Anglian and north-western districts of England:
It may be, as suggested by Mr. Searles Wood, Junr., that the
Boulder Clay of the district under consideration only represents,
the younger of two distinct glacial series, and that the deposits -
which, in this district, are Pre-glacial will have to be grouped in
a more general classification as Mid-glacial.

A. Pre-Guaciat Deposits.

In this division are included a series of deposits of marine,
fluviatile, or estuarine origin, which are found lying directly upon.
the various Secondary rocks of the district, and are covered by
the Boulder Clay or other glacial deposits, ,
- THE POST TERTIARY DEPOSITS. 241

‘

a. Pre-glacial Valley gravels.—These consist of well stratified
gravels, composed almost wholly of the detritus of the Jurassic
rocks. In this respect they offer a very marked contrast with
all the gravels of Post-Glacial age, which usually contain abun-
dance of chalk-flints, and pebbles of rocks foreign to the district,
these having been -derived from the Boulder Clay. These
gravels, which are never of great horizontal extent, are seen
either skirting the edges of areas of Boulder Clay or capping
hills from which that deposit has evidently been denuded. In
certain sections they are seen to lie directly upon, and to fill
up hollows in, the Jurassic rocks, and to be covered with Boulder
Clay, often of very great thickness. One of the best sections
illustrating this fact is that in the gravel pit a little to the north
of Upper-Benefield. (See woodcut, Fig. 16.)

Fig. 16. Section in gravel-pit, near Upper Benefield.

 

 

 

a. Soil - - - - - lto2 ft
* 6, Bouldér Clay (*Boulder of Red Chalk)  - - 6f
c. Finely-laminated, greenish sand with seams of clay 12 to 20 inches.
; 4 d. Irregilarly stratified fine gravel - 3 ft.
_ 4 | e. Clay-band - - - - - 6 inches.
. DES. Irregularly stratified fine gravel - - - 2 ft, £
“2 @ Ig, Fine sand, with seams of irregularly stratified gravel,
ie bottom not seen - - _ - 8 feet.

- ’
‘

242 ~- GEOLOGY OF RUTLAND, &O .

 

‘Another interesting exposure of these-Pre-glacial gravels is seen near Newell

"+ Wood, between Pickwort and Holywell. (Fig. 17.)

 

Fig. 17. Gravel-pit on South side of Newell Wood.

Ne

me (YY 5 Ny iG
i ya i

CMY”,
EY yl
be,

—

oh ~~ 8 - = tk
b. Light-blue clay with a few fragments of chalk and flint

a. Soil

(Boulder Clay) - 1to2 ft. s

c. Reddish-brown sands with a few pebbles and waterworn ‘
fragments of ironstone - - ~ = 12 to 18 inches. -

d. Well stratified. gravels, almost wholly made up of pebbles (all well water-
worn) of the Lincolnshire Oolite Limestone with some of the harder beds

of the Northampton Sand. :
Note.—The upper surface of these gravels is very irregular, the sands and clays
above being let down into the hollows of its surface. ec.

Frequently we find at a similar level upon opposite sides of a
modern valley, or at two points on the “skirts of the same
outlier ‘of Boulder Clay, small patches of this gravel, and in
some cases evidence has been obtained in wells, of the existence.
of these gravels at intermediate points under the. Boulder Clay.

All the characters presented by these: point to the conclusion
that they occupy the beds of old rivers which drained the
THE POST TERTIARY DEPOSITS. 243

country before the deposition of the great marine glacial series.
It is even possible, by: comparing the positions and levels of
-these patches of gravel, to arrive at some approximate results
as to the courses in which these old pre-glacial rivers flowed.
The existence of similar old river channels under the Boulder
Clay of Scotland has been described by Messrs. Croll* and
R. Dick.t At Ring Haw Wood, one mile west of Yarwell, we
have a section of these beds displaying very interesting features. ,
Lying on the Great Oolite we find beds of white gravel 8 to 12
feet thick, made up of water-worn, fragments of the Lincolnshire
Oolite limestone. This white gravel gradually passes up into, and
is covered by, beds of dark brown gravel, made up almost ex-
clusively of the detritus of the Northampton Sand. Bearing in
mind the relative position of these parent rocks, we are at once
led to conclude that the river, which formed this gravel, must have
flowed from the west, and have cut its valley in the higher part
of its course, first through the Lincolnshire Oolite and then down
into the Northampton Sand. In some places, as near Holywell
Lodge, we find these gravels cemented by calcareous matter into
great masses of solid-rock.

b. Pre-glacial brick-earths:—There is only one point within the
limits of Sheet 64 at which I have found these beds exposed,
namely in the brickyards at Melton Mowbray. Similar: beds,
however, occur at Billesdon, at Moulton, near Northampton, and
at a number of points in the district of the Keuper. ‘In all cases
they appear to be formed of the ‘detritus of a local rock, re-
arranged and finely stratified. At Melton this local rock is the
‘clay of the Lower Lias, and. the beds might at the first glance
be easily mistaken for the undisturbed beds of the Lias, especially
as they include numerous derived fossils from that formation.
At this place these brick-earths are overlaid by beds of sand, and
these by the ordinary Boulder Clay, which near here attains a
thickness, as proved by well sections and borings, of not less than
200 feet. i , . ;

c. Pre-glacial Sands and Gravels.—These beds, which are much
more widely distributed than the two former classes, present very
variable characters. Sometimes they, consist of beds of well
stratified sand, with a few well rounded pebbles ; but they pass.
by insensible gradations into gravels, in no. respect different from
those intercalated in the Boulder Clay, and from which they are
only distinguished by their position below that formation. They
are probably of marine origin, but as yet, unfortunately, neither
bones nor shells have been detected im any of the Pre-glacial —
beds of this district; and we have no palzontological evidence to
assist us in determining their age.

* On two river channels buried under drift, belonging to a period when the land
stood several hundred feet*higher than at present, by James Croll. Trans. Edinb.
Geol. Soc., Vol. I. p. 330. . . ; ?

-f On the discovery of a “ Sand-dyke ” ‘or old River (Channel running north and
south from near Kirk of Shotts to Wishaw, Lanarkshire, by Robert Dick. Ibid,
' p. 845,
x

244 GEOLOGY OF RUTLAND, &C. .

d Pre-glacial? Lacustrine deposit—In the Casewick cutting.
of the Great Northern Railway a deposit, of small extent, con-
taining plants and shells of freshwater and terrestrial species, was ~

a observed and ‘described by Professor. °
Morris.* This déposit occupies a de-
pression in the Kellaways beds, and is
covered by gravels, which apparently
belong to the glacial series. It seems
sl & to have been accumulated in a shallow

pond or small lake; but its precise
geological age is very-doubtful. ©

Professor Morris’ description of the section
exposed in the Casewick cutting at the time
,of the construction of the Great Northern.
Railway is as follows :—
 Casewick Cutting. Freshwater beds. The
Casewick cutting traverses oolitic rock, which . |
represents the Kellaway, Rock and Oxford
Clay. These strata are overlaid by a deposit
of gravel 7 or 8 feet thick. Towards the
central part of the cutting a freshwater deposit
is intercalated between the oolite and gravel,’
occupying an excavation in the surface of |
the former. “This deposit is about 30 yards
in width; andit has an average thickness of
about 8 feet, and varies in thickness and cha-
racter on each side of the cutting. It consists -
in the upper part of grey sandy clay, 2 feet
brown sandy clay and veins of gravel, 13 foot;
a layer of peaty clay with fragments of plants
and shells, 14 foot; dark sandy clay, with
plants and shells, pebbles of chalk and flint,
and portions of the northern clay drift in
fragments. The base of the deposit is ex-
tremely irregular in outline (see Fig. 18 ¢.),
and the surface of thé oolitic stratum is
slightly disturbed and re-aggregated, as if is
throughout the cutting. ‘The following is the
list’ of shellst :— .
Bithinia tentaculata and opercula, plentiful.
Valvata piscinalis, plentiful. d
- cristata, rather rare.
Planorbis marginatus, rare.
—- carinatus.
—- imbricatus, only one.
Limneus pereger, rare and immature.
Succinéa: putris, rare and immature. ~
Anvylus fluviatilis, rather plentiful.
Veletia lacustris, rather plentiful.
Cyclas cornea, rare: fragments.
Pisidium amnicum, rather rare.
- Puslum |

   

along the base of the cutting.

e. Sandy rock (Kellaways).
Dark laminated Oxford Clay.

g. Cornbrash,

ater Bed, and the Oolites of the Casewick cutting.
SI

Vertical scale, 120 feet’to 1 inch.
Morais and the Council of the Geological Society.)

8.
lemnites, &c.

Length, 29 chains.

1

 

 

 

Fig. 18. Section of the Gravel, Freshw

(Inserted by permission of Professor

b. ‘Sand and fine gravel with Be

c. Freshwater deposit.
d. Sandy bed of the Oxford Clay.

a. Gravel and sand in wavy s

 

mostly immature.

 

pusillum
-- obtusale?
Helix hispida, rare. = :
——- pulchella, only two. Fe

 

 

* Quart. Journ» Geol. Soc., vol. ix, (1853), p. 321, Fig. 2., . :

+ © The above list has been corrected by Mr. Proxerina, who has kindly examined
some portions of the clay from this deposit. To Mr. T. R. Jones I am obliged for
determining the above mentioned Cyprides.”

« s
THE POST TERTIARY DEPOSITS. 245

Helix aculeata (young), only one.
Carychium minimum, only two.
Cypris (small species), one valve.

? Candona lucens (young), one valve.
Candona reptans, three valves.

Spine of Echinus - <I <
Belemnites - - » | 4 :
ne These are
Eats cs é S ~ >derived from
Cerithium “ = a - {the Oxford Cl
Other “casts and fragments of marine | 7° \*t0re Clay:
animals - - - a

Seeds and other vegetable remains, as
Ceratophyllum, Equisetum, &c. -

The freshwater deposit on one side of the eutting appeared to be intercalated
with the superincumbent gravel, but on the eastern side there appeared a well-
defined line between it and the overlying gravel, as if the freshwater deposit-
had been eroded ; the gravel forming a continudus and uniform covering over
this bed and the adjacent sandy and argillaceous strata, in a depression of
which the freshwater bed had been previously accumulated. The gravel deposit
consists, chiefly of rounded and angular flints, rolled quartz pebbles, and a few
other rocks, as oolite, &c:, and some small sandstone boulders, irregularly
stratified with occasional layers of small pebbles, seams of clay.and loam, and
others much mixed with a chalky paste, the. larger pebbles occurring at the
base. The gravel overlies 3 feet of greyish brown sandy clay, containing frag-
ments of Belemnites and Gryphea, with veins-of gravel at the upper part, which
is irregular and wavy.” ms

Three miles to the westward, in the valley of the Gwash, another freshwater
deposit, about 6 feet thick, intercalated with gravel, has been met with; ‘it
contains land shells, &c., and bones, and may be of slightly later date than the
one above described. .

'

B. GuacraL Deposits.

This division includes a'‘great mass of deposits, which, although
they have suffered very extensive denudation, yet are often of
great thickness in this district; in places. probably not less than.
300 feet. They were evidently deposited during a period of
intense cold, in which the land had undergone very extensive
submergence ; that portion of it which remained above the sea
appears to have been enveloped with great. glaciers, like those
which are now only found in the arctic and antarctic regions,
while all over the bed of the ocean transported fragments of rock-
were dropped by fleating icebergs..

a. Glacial or Boulder Clay—No formation occupies so large.an
area in this sheet as the great mass of clay usually crowded with
fragments of all sizes of rocks, for the most part foreign to the
district, and which. is known as the Glacial or Boulder, Clay.
This clay where unweathered is usually of a blue colour, and
though it occasionally appears to be rudely stratified, yet it is
generally characterised by the absence of any régular arrange-
ment in its materials, the confused heaping together of which is
a most striking feature. The rock fragments included in it,
which often exhibit the polishing, -striation, and grooving charac-
teristic of glacier- or icéberg-borne masses, consist of very various
materials ;-chalk and flint being the most abundant, especially in
the eastern part of the area. In places the chalk is so abundant
246 GEOLOGY. OF RUTLAND, &C.

that the bed is little more than a reconstructed mass of that rock,
and even produces the vegetation which characterises the: chalk
soils. Thus the Rev. M. J. Berkeley informs me that he, many
years ago, found growing on a patch of very chalky Boulder Clay
at Benefield specimens. of the Orchis ustulata, Linn. 3 @ species
which is usually confined to chalk downs and never appears on non- .
calcareous soils. It was probably a patch of this kind at Ridlington
in Rutland which led to a notice in the Philosophical Transaction
for 1821 on the discovery of chalk in that county, which has been
referred to both by Mr. Lonsdale and Dr, Fitton.* Next in
abundance to the fragments of chalk and flint, are those of the -
Jurassic rocks, which become more numerous in the western part
of the area; then follow blocks of coal-measure sandstone, mill-
stone-grit, and carboniferous limestone, while the older Paleozoic
and granitic rocks are comparatively rarely represented. The
Boulder Clay is found in many places capping the hills composed
of Jurassic rocks; but in other ‘cases it'may be seen extending to
the bottom of some of the deepest valleys, and it even underlies a
portion of the Fens, It appears to have been spread like a great
mantle over the surface of the denuded and submerged older |
rocks. When a junction is seen, these laiter often present the
appearance of having been eroded or reconstructed to the depth’
of several feet before the deposition of the Boulder Clay.

The far transported boulders in this district do‘ not generally
attain, to any great size, though blocks of coal-measure sandstone
and millstone-grit up to six feet in diameter are occasionally
met with, as at Upton and Hallaton, which have been left on the
surface by the denudation of the enclosing Boulder Clay. But
the transported masses of local rocks are sometimes of enormous
size, especially in the northern portion of this area, and in that to
the north (Sheet 70). The attention of geologists was first directed
to these great transported masses by Professor Morris, who found
that at the south end of the Stoke-tunnel on the Great Northern
Railway, an enormous mass of the Lincolnshire Oolite limestone
lay on undoubted Boulder Clay. During the mapping by Messrs,
Holloway, Skertchly, and myself, of the districts which I have in-
dicated, we have found a number of such transported masses, some
of them far exceeding in size that described hy Professor Morris, .
and composed both of the Inferior Oolite and the Marlstorie
Rock-bed. The position of these transported masses is indicated
upon the drift map. They always appear to occur in the lower —
part of the Boulder Clay; and by the denudation of the softer —
surrounding material often make a distinct boss, rising above the
general surface. Stone pits are often opened in them, and they:
sometimes give off springs at their base. The largest of these
transported masses, that capping Beacon Hill in Sheet 70, 1s
more than 200 yards across and is composed of the Marlstone»
Rock-bed, It is noteworthy that these masses always belong to

* Phil. Trans., vol. lxxxi. pt. 2, p. 281, referred to by Dr. Frrron in Trans, Geol, .
Soc., 2nd ser., vol. iv., p. 808, and notes, p. 888%. 2
THE POST TERTIARY DEPOSITS. . 247

the rocks which form the highest ground, and, which in the glacial
«submergence would constitute the last points remaining above
water, The only agency, it appears to me, by which these enor-
mous masses could have been transported, is that of floating ice.
Some of the masses of the Marlstone Rock-bed have been carried
across deep valleys, a distance of probably not less than 30 miles.

b. Glacial Gravels-—These consist of an accumulation of frag-
ments of rock, often of considerable size, and, not unfrequently, ~
retaining their glacial markings; they often exhibit the most

- remarkably contorted stratification. Their materials are almost
identical with those of the boulders in the Boulder Clay, consisting
of rounded fragments of hard chalk, often in prodigious abundance,
angular flints, masses of Oolitic, Liassic, and Carboniferous rocks
with some from older formations. Indeed these gravels might

‘aptly be described as Boulder Clay in which, from the action of
some local cause, the argillaceous matrix has not been deposited.
‘These gravels are in some places seen to be actually interstratified
with the ordinary chalky Boulder Clay, and at times to pass
insensibly into it ; while they are often found, through denudation,
capping hills of Boulder Clay; they are quite as often found under-
-lying a great thickness of that deposit. It is an interesting and
significant circumstanee, that in the western parts of the district,
where the glacial series occupies- the highest grounds, these
gravels acquire great importance, while in the eastern part of the
area they are generally confined to thin seams and patches in the
midst of the Boulder Clay. Probably we should be right in
regarding the glacial gravels as exhibiting the littoral condition
of the Boulder Clay.

Sometimes these beds of gravel are very violently contorted,.
‘ exhibiting -evidences of just such lateral pressure as would be
. produced by the grounding of icebergs. A good typical section
of these greatly contorted glacial gravels is exhibited in the large
pit between Whadborough and Ouston, (See Fig. 19, p. 248) -
As is well known, similarly highly contorted beds are not un-
frequently found in the midst of the Glacial Series, as in the cliffs
of Norfolk, Suffolk, &c. ‘These remarkable appearances have
been variously interpreted in different cases; by the grounding of..
icebergs, the thrusting up of ice-floes on a shelving coast during
storms, and the melting of great masses of ice, enclosed in the
deposits of mud and sand. _~
-Although some geologists have attempted to show that the
great glacial formations composed of clay, and sand or gravel,
respectively, belong to perfectly distinct periods and mark different
climatal and physical conditions in the Midland district of Eng-
land, and even entire changes in the disposition of the land and
sea of the period; yet nothing can be clearer that in the area we
are more particularly describing the beds of glacial clay, sand and
gravel, replace one another in the most capricious manner, and are
evidently dependent on the action of causes of extremely local
character.
GEOLOGY OF RUTLAND, &C.

248

 

ERS

4 : “yoaeas oul “w {7 ‘6 ‘a “g
. ool " qTeapad asreog *y ‘
spusg uy fo ! “£EIQ spine A

el

;
Y

“uojsng pup ybnoLogpny yy waamjag syaansy yoroD] gy) U2 jg “G1 “baz

liceous sands-usually of

tal Sands.--Thesé are cd

ce. Glac
a red colour

oarse, Si
Ise bedd

ear

sometimes, as n

ing, s

fa

much

and with

3

1
THE POST TERTIARY DEPOSITS, : 249

Pickwell, attaining a considerable thickness and being. inter-
stratified with the other glacial deposits. Their relations to the
Boulder Clay are identical with those of the last described beds,
into which, indeed, they sometimes pass by insensible gradations,

C. Posr Guaciat Deposits.

In this group we include all those masses of material, which,
from actual superposition, or from the fact of their containing
derived fragments of the glacial beds, are inferred to be of later
date than the last mentioned.

a. Cave Deposits.—The facility with which all limestone rocks
are hollowed into caverns. by the solvent action of subterranean
waters is frequently illustrated in this district; but the rapidity
_ with which the Oolitic rocks undergo denudation has probably,

in most cases, prevented such caverns from being the means of
preserving the exuvize of extinct animals like the great caves
of the Carboniferous and other older and harder limestone rocks.
The only point within the limits of Sheet 64 at which a cavern
has been found is at Tinkler’s Quarry near Stamford. Here,
. during the quarrying operations about 30 years ago, a small
cave was met with, the earth on the floor of which contained
the teeth and bones of Carnivora, Ruminants, and Elephants.
All traces of this cavern, which was of no great size, have dis-
appeared in consequence of the continued working of the quarry,
and: the remains found in it appear to: have become scattered.
Fortunately however some of them have been secured for scientific
examination by the zeal of §. Sharp, Esq., formerly a resident
at Stamford. These were submitted to Professor Rolleston of
Oxford, who pronounced them to be as follows :—-

Hyena. Teeth of two individuals.

Elephas. Portion of a tooth of a small individual.
Cervus megaceros. Tooth.

Cervide. Various remains.

The long bones appear'to have been in all cases broken for
the extraction of the marrow, and in some instances they exhibit
indications of having been gnawed.

I was unable to obtain exact information as to the size of
this cave: by some, who saw it, it is said to have. been from 15 to
20 ft. square, by others, to have resembled- only a large fissure.
There can be no doubt that this, like the caves of Settle and
Kirkdale in Yorkshire, the caves of the Vale of Clwyd in North
Wales, the Gower Caves in Glamorganshire, Wookey ‘Hole in
Somersetshire, and other similar caverns,was once the den of hyenas,
and that the other bones belonged to animals which had been
seized and carried, by the carnivores, to their lair to be devoured.

b. Valley Gravels.—These gravels are found occupying the
bottoms and sides of the existing river valleys, and in some places
extending to elevations of from 40 to 50, or even a great number
of feet, above the present levels of the rivers. ‘They are at once
distinguished from the pre-glacial valley gravels, before noticed,
250 - GEOLOGY OF RUTLAND, &C.

not only by their relations to the present system of drainage,
but by being composed of materials evidently derived from the
Boulder Clay of the district, such as chalk flints and fragments of
Paleozoic rocks, and mingled with the detritus, derived directly
from the beds of the Jurassic series. The pre-glacial valley gravels.
consist, as we have already seen, of the latter class of materials
only, It is along the valleys of the Nene and Weiland that we
find tke largest deposits of these gravels; but along the sides of
some of the minor valleys, such as those of the Chater, the Gwash
and the Glen, fringes of similar gravels are also found. At some
points, as about’ Elton, the passage of water through these masses
of gravel has, by the solution and re-deposition of calcareous
matter, resulted in the formation of indurated masses like those
described as occurring in the pre-glacial gravels, _

Along some of the larger valleys, these gravels may be classed
as belonging to two different series, according to their elevation
above the present level of ‘the river; and these are called the
high-level and low-level valley gravels. =

Occasionally the valley gravels yield shells which are found to
be all of a fresh-water character and belong to species still living
in the rivers which now occupy the valleys. Such_shells ave by™
no means common in the valley gravels of this area, and are
very local in their mode of occurrence. It is only where a-thin
seam of sandy loam occurs interstratified with the gravels that we
have usually any chance of detecting such molluscan remains
_ preserved.

Mammalian remains however are much more common in the
district, and local collectors might probably, by watching the
excavation of some of the large gravel pits of the district, obtain
interesting séries of such fossils.. As is well known the mammalia,
represented by the bones, teeth, &c. found in these gravels, include
species altogether extinct and others now only found in far distant
regions; and these are mingled with remains of forms still living
in the area. The tusks and teeth of elephants, with the teeth of
the rhinoceros, hippopotamus, hyzna, and horse, and the horns of
the red-deer and urus occur in the valley gravels of this district,

These valley gravels have of late years attracted much atten-
tion owing to the discovery in them of ‘flint implements, un-
doubtedly fashioned .by human agency and associated with the
remains of extinct mammalia, No such discovery of flint imple-
ments has as yet, however, been found. within the limits of
Sheet 64. os

At some points, as New England, near Peterborough, the
valley gravels are found to be covered by deposits of loam crowded |
with terrestrial shells of recent species. . These loams appear to be~
analogous in their character, and mode of occurrence, with the
continental “ Loess.”

c, Estuarine Gravels.—The valley gravels afford ample evidence —
that the existing rivers formerly flowed at much higher elevations
than at present. We have also clear proof that, at the periods when: -

s

eB
THE POST TERTIARY DEPOSITS. 251-

these higher level gravels were formed, the whole of the flat lands
_ of the fens were submerged beneath the sea, and the estuaries of
the Nene and Welland were at the points now occupied by the
towns of Peterborough and Deeping. At some distance above
these points the gravels, which form a continuation of the valley
‘gravels just noticed and serve to form a link between them and
the marine deposits of the Fenland, were of estuarine character
and contain an admixture of fluviatile and marine shells. Such
estuarine gravels have been found at Peterborough and at Over-
ton Waterville. At the latter locality they have yielded Ostrea
‘edulis, Cardium edule, Planorbis carinatus, Ancylus fluviatilis,
Bithinia tentaculata, Lymnea glutinosa, Pisidium amnicum, &c.
With these shells were associated the remains of Elephas primi-
geneus, Rhinoceros tichorinus, Equus caballus, Canis lupus, Hyena
spelea, Cervus elaphus, Bos primigentus, &c. *

d, Marine Gravels of the Fenland—As the ordinary valley
gravels graduate into the estuarine gravels, so these last pass in-
sensibly into the marine gravels of the Fenland. In the materials
of which they are composed, indeed, these several gravels are’
quite indistinguishable from one another, and the classification
adopted for them is based on their geological relation and the
nature of their-organic remains, The gravels of the Fenland
sometimes contain an abundance of marine shells and some
marine mammalia, these being mingled with the bones, teeth, and
horns of the same terrestrial species as occur in the estuarine and
fluviatile gravels. The marine shells are almost all of existing
species, and suchas inhabit neighbouring seas; they usually
present a marked littoral facies. Among those most commonly
found are Cardium edule, Littorina littorea, Turritella communis,
Buccinum undatum, Tellina solidula, Ostrea edulis, Mytilus edulis,
Cyprina Islandica, &c. 'The only indication of the prevalence of
climatal conditions differing from those of the neighbouring shores
which I have found in these gravels, is the abundance of Cyprina
Islandica, a shell which, ‘however, occurs in sufficient abundancé
on the coast of Yorkshire, only alittle distance to the northwards,

‘These marine gravels evidently formed beaches surrounding
the old sea which once covered the Fenland, and they are clearly
seen; not only at the boundary between the Fens and the higher
land surrounding “it, but forming belts round the numerous
islands, composed of Oxford Clay or Boulder Clay, which diversify
the surface of the former. In some cases the gravels are found
extending to considerable distances below the silt and peat of the
fens; and such deposits may mark the gradual extension of marine
conditions over the area in consequence of subsidence. The
marine gravels of the Fenland may therefore be considered as
representing the littoral condition of a considerable series of
deposits, among which are the silts to be hereafter noticed that
were formed while the greater part of the district was covered by
the sea: the small eminences which now make such marked
features in the Fens, such as those occupied by the towns of
252 GEOLOGY OF RUTLAND, &C.

Whittlesea and Crowland, and the villages of Eye, Thorney, &,-
then forming islands or shoals. 3

e. Peat interstratified with Marine silt—-Over the southern
part of that area of the Fenland included within the. limits’ of
Sheet 64, extensive beds of peat, intercalated with marine silt,
occur at the surface, but to the northwards these are covered under
a greater or less thickness of the marine warp deposited by tidal
waters, which we shall have to further notice hereafter. The
former district is distinguished by the prevailing black colour of
the soil, while that of the latter exhibits a marked reddish tint :
while the former, too, is comparatively infertile and can only be ren-
dered of service to the farmer by extensive operations of trenching
and “laying” (that is digging the substratum of Oxford Clay or
Boulder Clay and spreading it over the surface); the latter is, as
soon as it is drained, remarkable for its great productiveness,

There are usually two, and occasionally more, beds of peat,
varying in thickness in different places, and separated by masses
of marine silt. The peat, as ig well known, is made up of vege-
table remains, those of a species of Sphagnum constituting. a
great part of the mass. Trees of large size, including the oak,
birch, and other species still, growing in the eountry, are very
frequently dug out of the peat. The remains of animals which
once roamed through these old forests are also very commonly
found, Among the most abundant of these are the wild oxen
(Bos primigenius and B. frontosus), the Irish elk, the wild boar,
the red deer, bear, otter, beaver, wolf, fox, &c.

The marine silt which is interstratified with the peat, and
indicates the occasional submergence of the old terrestrial surface
‘beneath the surface of the sea, is generally of a light-blue or grey
colour and is locally known as the “ buttery clay.” Marine shells
such. as Ostrea edulis, Cardium edule, Scrobicularia piperata, are
-occasionally met with in it, but are by no means common; many
very beautiful species of Foraminifera have, however, been col-:
lected from it. The remains of marine mammalia, such as the
whale and seal, are by no means uncommon in it. —

The substratum of the peat, &c. of the fens is usually the
Oxford Clay which is locally known as “ galt.” _In some places,
however, the Boulder Clay is found lying immediately below the
peat and silt; and sometimes, where the peat is thin, beds of sand
and gravel occur. hs : , ;
~ The removal of the water from the peat, by drainage operations,
causes a great contraction in the mass and, in consequence, a
subsidence of the surface, which is often of very considerable
amount, An interesting example of this may be seen in the main
line of the Great Northern Railway where it crosses the Fenland
‘n this area. Although, originally laid quite level, yet, when the
eye is placed at the surface of the ground the ae are ae ae
to form a well marked curve, owing to this subsidence: At St.
Mary’s Station, in ‘consequence of the. shrinkage of the peat, one
wall has had to be built on the top of another, which has been
swallowed up. Neat Holme, an iron column erected upon the
THE POST. TERTIARY DEPOSITs. 253

foundation of the subjacent Oxford Clay shows that a contraction
of the superficial deposits of the fens, in that place, to the extent
of seven feet has occurred since 1848,

The peat is extensively dug and used locally for fuel. It is possible
that a more extended application of this material, so abundant in
the district, may result from some of the important methods of
treatment for it which have been invented during the last few
years. The marine silt is sometimes dug for brick-making.
Some years ago it was worked for this purpose at Crowland, which
is within the district described in this Memoir.

Ff. Alluvium of the Old Fen Lakes—Within recent years the old
lakes or “ meres” of the Fenland have all been drained, and the
sites of Wittlesea Mere, Ramsey Mere, Ugg Mere, and others
are now only marked by patches of alluvium or freshwater silt.
These lacustrine deposits are of a light-gray colour, and often
so crowded with shells of Unio, Anodon, Paludina, Planorbis,
Lymnea, &c., as to constitute a shell marl, which imparts fertility
to the land once occupied by the lakes. These lake alluvia are,
however, usually of insignificant thickness, and the operations of
the farmer are rapidly obliterating even these traces of the once
famous Whittlesea Mere and other similar lakes; of which there
will soon remain nothing but the name.

g. Alluvium of the present Rivers.—The flat bottoms of the
valleys of the existing rivers are covered with a fine black loam
or silt which is still in process of formation, a constant accession
to, and redistribution of, its material taking place as the result of
ordinary river action. This loam is often crowded with the shells
of those molluscs which live on terrestrial surfaces or in marshes;
and the deposit, which is in course of accumulation, in every
respect resembles that found at higher levels in connexion with
the old valley gravels, and which, as we have already stated,
presents so striking a resemblance to the continental ‘“ Loess.”
The flats formed by these alluvial deposits, which are very exten-
sive in the valleys of the Nene and Welland, are, during the
winter season, for the most part under water ; they are distin-
guished for their great fertility and constitute most admirable
grazing lands,

h. Marine Alluvium or Warp of the Fenland.—With the recent
deposits just noticed as still undergoing accumulation we must
notice the marine silts, which by the action of tidal waters are
formed in the “washes” of the Fens. Beds of this character are,
however, of very limited extent within the limits of Sheet 64,
being confined to. the Cowbit and Crowland Washes. Except
where beds of peat intervene, it is impossible to separate these
deposits, which are still being formed, from the old marine silt
before noticed as being probably of the same age with the gravels
which surround the Fenland.

32108. R
254

CHAPTER XI.

POSITION AND DISTURBANCES OF THE STRATA,
FAULTS &c.

General Dip.—As already intimated, the whole of the Jurassic
Rocks rise steadily towards the N.W. corner of Sheet 64, so that,
in that part of the area, beds as low in the series as the Marlstone
Rock-bed form very prominent hills, rising to heights of more
than 700 feet above the sea level; while the beds of Oxford Clay
form the substratum of the Fens in the S.E. corner of the map.
A line drawn from the Roman Camp, on Burrow on the Hill, to
Peterborough passes in succession over all the Jurassic rocks,
from the Marlstone to the Cornbrash inclusive, and is about 27
miles long; while the first-mentioned spot is, however, more than
700 feet above the sea the latter is only between 20 and 30 feet
above high-water mark. Knowing the thickness of the different
strata of the Upper Lias and Lower Oolites, we have thus the
necessary data required for calculating the general dip of the
strata between the two localities. This is found to amount to
about 1 in 120 or 44 feet per mile,

This area which, as we have shown, is so remarkably interesting
from exhibiting an almost totally new succession of beds, as com-
pared with the Oolites of the south of England, the Cotteswolds
and Oxfordshire, presents likewise some noteworthy phenomena
in the character of the disturbances which its beds have under-

one.
e Foremost among these we must call attention to the remarkable
change which takes place in the direction of the dip and strike of
the Jurassic strata. From the Cotteswold Hills to the northern
boundary of Northamptonshire, the strike of all the Secondary
strata is from N.E. to S.W., and their dip from N.W. to SE.
Throughout Lincolnshire and South Yorkshire, however, the
strike is changed to nearly due N. and S., and the dip to E. and
W. The line at which this change of direction takes place
nearly coincides with that at which the Welland and its tributary
streams has made a breach through the scarped table-lands
formed by the Middle Lias and the Inferior Oolite beds. It is
noteworthy that along this line occur the two greatest faults of
the district, namely, that passing by Billesdon and Loddington
and that from Tinwell to Walton. Between these occur a number
of smaller faults running in the same general W. by N., and E.
by S., direction, with others transverse to them. In pointing out
this fact, it is of course not sought to be intimated that the exist-
ing valley of the Welland has been directly produced by the faults
in question; although, by throwing down the softer beds against
those less susceptible to denuding forces, by determining the
initial course of streams when the land rose at successive periods
above the sea-level, and by the influence which they can scarcely
have failed to produce on the contours of the surface, they have
POSITION AND DISTURBANCES OF THE STRATA, FAULTS, &c. 255

doubtless directed, controlled, and modified the effects of subaérial
forces. The subterranean action to which these faults are due
must have acted side by side with the meteoric forces in producing
the existing forms of the surface ; and in this manner have con-
tributed to the definition of the position and form of the valley in
question.

Through the long line of the Cotteswold Hills and to the
southwards, it is noticeable that the strike of the Jurassic rocks
again becomes nearly due N. and S., or nearly parallel to that of
the strata of Lincolnshire. Where the change of strike takes
place we have here again a number of important faults; namely,
those producing, by the downthrow of the Inferior Oolite, the great
outlying masses of Bredon, Dumbleton, and Oxenton Hills; those
traversing the great Cotteswold plateau ;. and those which, in the
country §.W. of Banbury, throw the Northampton Sand and the
Marlstone Rock-bed into such frequent close proximity, and have
thus been the occasion of difficulty to many early observers who
sought to study the order of succession of beds in the area. The
direction of these great lines of faults is nearly identical with that
of those we have alluded to in Sheet 64. In North Yorkshire
the line of strike of the Jurassic beds again changes to N.E. and
S.W. At the line along which this change takes place the Jurassic
strata are almost wholly concealed by the overlapping of the
unconformable Upper Cretaceous rocks. There are indications
however, that transverse faults do occur at this line of change of
strike and dip, as well as the others already noticed.

Although the general dip is, as we have noticed, of small
amount in the area we are describing, the beds are affected by a
great number of local dips; these are like the perturbations which
affect a planetary orbit, but do not seriously interfere with the great
curves in which the body moves. Such minor curves can only be
detected where the geological lines are capable of being exactly
followed over considerable areas, though their effects are often
manifest in the preservation of small outliers and inliers. When,
however, the strata of a district are exposed in a sea-cliff, as on the
Yorkshire coast, these long sweeping curves, into which the strata
are thrown, are sufficiently obvious, especially when they are seen
foreshortened. Occasionally in railway-cuttings the same phe-
nomenon is visible, and this is the case within the district under
consideration in several of the very deep sections on the main
line of the Great Northern Railway. Thus in the Danes’ Hill
cutting the strata evidently lie in a long shallow synclinal (see fig. 15,
p. 196), and similar evidence of slight foldings of the beds are to
be seen in other cuttings on the same line. Sometimes the same phe-
nomenon is manifested when the small local dips are carefully
observed. Cases of this kind occur north of Elton and else-
where, and are recorded on the map. Precisely similar phenomena
have been described in the case of the Cotteswold Hills by Pro-
fessor Hull. (See Quart. Journ. Geol. Soc., vol. xi. (1855), p. 483).

At afew points the strata are evidently bent into folds of a
much more decided character. Thus at Helpstone pale the

R
256 GEOLOGY OF RUTLAND, &C.

Upper Lias Clay is brought up among the Lower Oolites,
through the agency of a very sharp fold and the dips here amount
to as much as 30°. This fold is situated close to, and is doubt-
less connected with, the great Tinwell and Walton Fault. The
inlier of Upper Lias Clay seen at Thornhaugh is probably
exposed in consequence of a similar but much less violent folding
of the strata. At Wild’s Ford, three miles west of Stamford,
there is evidence of another small anticlinal and this is near to,
and probably connected with, a small fault. Near Walton station
the Cornbrash beds show signs of disturbance, and a small anti-
clinal can be traced. In the two small inliers of Brigstock Parks
and Little Oakley the Inferior Oolites and Upper Lias have been
subjected to a number of small rolls and faults, which do not
affect the Great Oolite beds lying unconformably above them.
One of these anticlinals is admirably exhibited in an old pit in the
Northampton Sand opened in a field midway between Sud-
borough Lodge and the lodges in Brigstock Parks.

By far the largest amount of disturbance in the district is how-
ever due to the great faults which traverse it. The principal
of these cross the area in a W. by N. and E. by §, direction.
They have occasioned downthrows towards the N., some in places
amounting to not less than 150 feet.

The Billesdon and Loddington Fault has produced a very
marked effect on the geological configuration of the country,
The lateral displacement occasioned by it has thrown the outcrop
of the Marlstone Rock-bed far from its normal position, and
caused it to form the two great spurs culminating in Billesdon
Coplow and Burrow Hill respectively. It has also been the
cause of the preservation of a large tract occupied by the Upper
Lias Clay and of the interesting outliers of Northampton Sand
capping Whadborough Hill, Robin-a-Tiptoes, Barrow Hill and
another hill behind Loddington. Colborough Hill, too, though
now entirely formed of Upper Lias Clay, evidently owes its form
and preservation to a cap of the Northampton Sand, which .
certainly once existed at its summit, but has now been wholly
removed by denudation. The actual junctions along this line of
fault are often much concealed by great masses of Glacial gravel
and Boulder Clay. Where these are cut through by streams, as
near Tilton Wood, south of Wildbore’s Lodge, and at Loddington,
some very interesting cases of the juxtaposition of beds of dif-
ferent age may be made out. This fault appears to diminish in
amount towards the E.; but towards the W. it can no longer be
traced, as it traverses a district composed of various Lower Lias
beds almost wholly of an argillaceous character, which are deeply
covered by drift. The portion of this fault which is determinable
is about 7 miles long.

The great Tinwell and Walton Fault has a throw, probably of at
least equal amount with the last and, traversing, as it does, a num-
ber of comparatively thin and well marked strata, its effects are
very striking, even to a superficial observer of the structure of
the country. The curious manner in which the various beds of the
POSITION AND DISTURBANCES OF THE STRATA, FAULTS, &C. 257

Lower Oolite and the Upper Lias are thrown together at diffe-
rent points is very interesting ; as can be seen by an inspection of
the map; some of these junctions have been described in detail
by Mr. Sharp in his valuable memoir. Among the points of
special interest along this line, where its effects are strikingly
exhibited, we may instance Stamford, where, on one side of the
fault, the Inferior Oolite is seen, capping the hill south of the
town, while on the other side of the fault it occupies the valley.
At Helpstone brickyard, the effects of the fault are very conspicuous,
for here, in combination with the anticlinal roll already mentioned,
it brings into contact the Cornbrash and the Upper Lias Clay.
To the action of this great fault is due the circumstance that,
although on the south of the Welland valley at Stamford the plateau
is formed of the lower beds of Lincolnshire Oolite, diversified by
a number of inliers of Northampton Sand and Upper Lias Clay ;
yet northwards of Stamford the plateau is formed of the highest
beds of the Lincolnshire Oolite, over which a number of outliers of
the various strata of the Great Oolite are scattered. The length
of the Tinwell and Walton fault is about fourteen miles ; it appears
to diminish in amount and at last to die out both towards the east
and west. ‘ .

At the town of Stamford, as proved by the different levels at
which many of the springs arise, the district is complicated by
several faults parallel to the great one just described; but the
impossibility of obtaining reliable information concerning the
wells and other artificial openings, as well as the small scale on
which the map is constructed, has prevented their being indicated.

Between the two faults which we have just described, there are
a number of smaller ones which have a parallel direction, and,
lying in the country between them, may be presumed to belong to
the same system of disturbance. These are the small faults at
Whitwell, at Hambleton and Normanton, and at Lynton, the effects
of which, in the displacement of the strata, will be sufficiently
obvious to any one examining the map.

Running transversely to these E. and W. faults are a number of
others which appear to be connected with them, but are of less
amount and appear to represent cross fractures. ‘They have a

eneral N. and §. direction.

Such small faults are seen between Bainton and Barnack and
east of Helpstone, on the downthrow side of the great Tinwell
and Walton Fault. At Stamford is another similar fault which is
of very great interest in consequence of the manner in which it is
exhibited. Its effects, in throwing the Northampton Sand against
the Lincolnshire Oolite, are sufficiently obvious in mapping the
country; but, fortunately, the line of fault is actually crossed by
a cutting at the Midland and North-Western Railway Station at
Stamford. This interesting section is represented in Fig. 7, page
103. :
Running southwards from Wild’s Ford are several faults, one
of which can be traced for a distance of eight miles, by Ketton
and Duddington. Its effects are well exhibited in the broken
strata of the Geeston cutting on the Midland Railway, and still
260

CHAPTER XII.
MISCELLANEOUS.

Denudation—Nowhere are the results of denudation more
obvious and unmistakeable than among the thin and easily-
recognizable beds of the Lower Oolites. That limestones like
the Cornbrash and Great Oolite of the district, which everywhere
present such uniform characters, both lithological and paleon-
tological, together with the well marked argillaceous strata which
alternate with them, once extended completely over the whole
district must be plain to every one who has followed the de-
scriptions in this Memoir or traced the beds on the ground.
The exact correspondence of the strata on the opposite sides of
the valleys is everywhere so striking, that we soon learn in imagi-
nation to restore the continuity of the beds.

When, standing in a narrow valley, we note this exact corre-
spondence of the strata which form its opposite sides, the first
idea which suggests itself to the mind as the probable cause of
the phenomena presented, is that a mass of rock has been rent
asunder and that the valley is nothing but a gaping fracture. A
little consideration, however, will soon show that this ‘impression
is due to the want of correct appreciation by direct vision of the
true relations of horizontal and vertical dimensions, and is as
truly the result of an optical delusion as the apparent increase in
size of the sun or moon when near the horizon. It is only
necessary to measure the height of the opposite sides, together
with the breadth of the valley, and then to plot the whole on a
true scale to be convinced that the hypothesis of fracture is
altogether inadequate to explain the phenomena, and that an
actual removal of the large masses of rock which once filled the
valley has certainly taken place.

This view is confirmed when we come to examine the position
of those lines of fracture which, in the preceding pages, we have
proved to exist in the area. These seldom bear any direct relation
to the contours of the surface of the ground, and in fact the faults
as frequently run across to tops of hills as along the lines of valleys.
It is abundantly clear, however, as we have already seen, that the
faults have very greatly affected the existing contours of the surface
of the country by placing beds of different degrees of hardness in
new relations.

The truth of these views will be at once manifest to any one
who takes the trouble to examine with care the horizontal sections
across the area, which are published by the Geological Survey,
and are drawn on a uniform horizontal and vertical scale of six
inches to the mile.

When we inquire as to the causes which have operated in the -
removal of these great masses of strata we shall not have far to
look. In the stream which flows at the bottom of the valley we
MISCELLANEOUS. 261

find the instrument, in the peculiar sinuous orms of the valley
we find the characteristic tool marks, and in the patches of gravel
which lie upon its sides we see some of the heaps of chips which
mark different stages of its operation.

This Memoir is not the place to point out the various con-
siderations, such as the forms of the valley, the position and
composition of its gravels, the amount of rock-derived materials
in solution and suspension in the waters of the stream, which
have enabled geologists to demonstrate that the present valleys
have all been excavated by the streams that still flow in them;
and that in a great majority of cases these results have been
produced within periods which, though very great according to
our ordinary methods of computing time, are geologically speaking
of short duration. It is sufficient in this place to remark, that,
to the careful observer, the valleys of the Nene and Welland, and
of the numerous smaller streams which traverse the district,
afford innumerable and very instructive illustrations of the mode of
operation and the results, of the causes referred to.

Along the sides of the valleys and on the slopes of the steep
escarpments the effects of another of the great denuding forces
may be constantly observed. This is the production of landslips
by the slipping of the great masses of solid rock over the clays
on which they so frequently rest. This action is greatly aided
of course by the jointed condition of the limestones, and the
springs which so constantly burst out at their junction with the
clays. Interesting illustrations of these landslips on a considerable
scale are to be observed at the village of Gretton, which is built
on a mass of Inferior Oolite that has slipped for some distance
over the subjacent Upper Lias Clay. That the causes which
have brought about this displacement of the beds +have not ceased
to operate, is shown by the fact that cracks appear from time to
time in many of the houses of the village. Similar slipped masses
may be observed at various points along the faces of the two great
escarpments of the district, and indeed their frequency calls for
constant care in mapping the out-crops of the harder beds along
the escarpments ; in some places the true position of these out-crops
is so greatly obscured that they have had to be represented by
dotted lines. That evidence exists of similar landslips having
taken place from the great escarpments, which were probably
higher than at present, before the deposition of the Boulder Clay,
has already been shown. The slipping of great masses of lime-
stone rock over the clays along the sides of valleys is well
illustrated on the sides of the Willow Brook, at the village of
King’s Cliffe, and at numerous other points which might be
mentioned.

By the agency of the landslips the highest and hardest rocks of
the country are being gradually brought within the influence of
the streams, which in time wear away fragments of the shattered
masses and grind them into pebbles and sand.

The tendency of the effects produced by the erosion of streams
in the lower grounds and the contributory causes of landslips
262 GEOLOGY OF RUTLAND, &C.

and atmospheric weathering in the higher and more exposed
situations, is to gradually lower the surface of the country and to
destroy the prominence of its natural features. Thus it is plain
that, in the country under consideration, unless counterbalanced
by the action of subterranean causes producing elevation, the
valleys are being continually deepened, while the escarpments are
gradually receding and so being diminished in height.

In the Fenland we have an illustration of another kind of
denuding cause, the mode of operation of which is totally dif-
ferent to those we have been noticing. Between the outcrops of
the two great masses of hard rocks constituted by the Chalk and

_ Lower Qolites, there is in the Midland districts a wide extent of
country occupied by the soft strata of the Oxford and Kimmeridge
clays, which together attain to a thickness of probably not less
than from 1,000 to 1,500 feet. The confluence of a number of very
considerable rivers, namely, the Witham, Welland, Nene and
Great Ouse, which, with their tributaries, drain a very large
extent of country, has effected a breach in the great mass of chalk
strata and thus the sea has been able to find admission to, and to
operate on, the soft clays of the Middle and Upper Oolites,
While the hard chalk rocks have been cut back over a breadth
of only twenty miles, at the mouth of the Wash, the sea has
extended its boundaries through the soft clays over the enormous
area known as the Fens or Bedford level. As the erosive action
of the ocean is most powerfully displayed at its surface—where it is
the constant subject of tides and, at irregular intervals, converted
into a most powerful engine of denudation by, storms—marine
action always tends to produce an extended. flat plain. This is
the case in the Fenland, where only a few patches, which, on
account of theepresence of beds of exceptional hardness or from
some other accident, rise above the general level and once formed
islands or shoals in the Fen Gulf. These and the rest of the
old sea margins around the Fenland are frequently fringed with
gravels, often full of marine shells, and which are evidently old
beaches. The slight changes of level which have certainly taken
place in the district, as is evidenced by the raised beaches at many
points, on the one hand, and the submerged forests of the Norfolk
and Lincolnshire coasts, on the other, can have exercised only a
minor and altogether subordinate influence in the production of
the features of the Fenland.

In the area included within Sheet 64, it is evident that the
present valleys which intersect the great plateau have been mostly,
if not wholly, formed since the Glacial epoch. This is shown by
the manner in which the beds of Boulder Clay cap the opposite
sides of the valleys, across which they were certainly once con-
tinuous. I know of no grounds for believing that any of the
present valleys, which traverse the plateau, existed during pre-
glacial times, were filled with Boulder Clay in the glacial period,
and re-excavated since that era. On the contrary, the manner
in which the boulder clays are confined to the highest grounds

tends to quite the opposite conclusion.
MISCELLANEOUS. 263

To the west of the great escarpments, however, quite an opposite
series of relations'prevails. There the glacial clays and gravels are
found at every possible elevation, and it is clear that in some
cases the present valleys coincide with those of the pre-glacial

eriod.

. The present surface of denudation, though the one which can
be most easily studied, is not the only one made familiar to us by
the observations of the geologist. We have already shown that
the valleys in which pre-glacial rivers flowed can be traced by the
gravel deposits which occupied them, and by this means the physical
geography of the period can to a certain extent be re-constructed.
Of that old surface of denudation which marks the newer portion
of the Inferior Oolite period, and which lies between the Lincoln-
shire Oolite and the Upper Estuarine Series, we are able also to
obtain fragmentary, but very interesting, information as already
noticed.

Scenery.— Although no part of the area described in the present
Memoir is remarkable for presenting features of great wildness
or grandeur on the one hand, or scenes of striking béauty on the
other, yet the charms of a diversified, well cultivated, and richly
wooded country belong to it inan eminent degree. The variations
of elevation are sufficient to redeem the landscapes from tame-
ness; the constant alternations of field, pasture, and copse, afford
pleasing variety to them ; and the signs of comfort and productive-
ness, everywhere apparent, cannot fail to give pleasure to the
beholder. The abundance of trees, often evidently of great an-
tiquity, as in the case of the oaks of Morehay Lawn (which are
said to date from the reign of King John), gives many parts of the
district a remarkably park-like aspect; and perhaps no district of
equal area could be pointed out, which exhibits so large a number
of stately mansions standing in the midst of spacious demesnes;
such are Burleigh, Milton, Exton, Burley, Dene, Apethorpe, Sta-
pleford, Lilford, Farming Woods, Normanton, and others which
might be mentioned, Even the almost dead level of the Fenland
is not without peculiar charms of its own, as has been so admirably
pointed out by Charles Kingsley.

To the eye of the geologist the dependence of the characteristics
of the scenery on the nature of the rocks of which the country is
composed is everywhere apparent. These rocks, by their position,
inclinations, and varying powers of resisting denuding agencies,
have determined the situation and nature of the hills and valleys ;
by their peculiar modes of weathering they have given rise to the
varying contours of those features ; and, by the soils which they
yield, have decided the character of the vegetation by which they
are adorned. Further—by the manner in which the outcrops of
the various rocks have given rise to the water system of the
country, andthe sites of its springs and streams, and the way in
which they have influenced the nature of the soils and thus also
the tillage and other occupations of the inhabitants—the character
of the population has been determined, its distribution regulated,
and the position of its centres fixed.
264 GEOLOGY OF RUTLAND, &C.

As noticed by William Smith the Oolite and Lias districts of
Rutland and South Lincolnshire present much bolder features than
those of the South Midland area of Oxfordshire and Northampton ;
and in this respect sometimes even remind us of the Cottes-
wold Hills. This, as has been already noticed, is due to the great
increase of thickness which takes place as we go northwards in
the Upper Lias Clay, and the importance which is assumed by
the Marlstone Rock-bed. There is one great distinction which
must, however, be drawn between the Cotteswold Hills and the
North Midland area. In the former there is a single great
escarpment formed by all the strata between the Inferior Oolite
and the Lower Lias, and this is sometimes more than 1,000 feet
in height, the Marlstone forming only a ledge of greater or less
breadth along its face. In the latter, on the contrary, the same
strata form two distinct escarpments, those of the Inferior Oolite
and the Marlstone Rock-bed, usually some miles distant from each
other and attaining to nearly the same elevation, which rarely
exceeds 700 feet. Some of the most characteristic features of the
district are illustrated in the series of plates which accompany
this Memoir, prepared from sketches by Mr. Frank Rutley, F.G.S.,
of the Geological Survey of England and Wales.

The sinuous and branching valleys which diversify the faces
of these escarpments often present, in the cliff-like masses of hard
rock, rising above the green slopes formed of clay with its covering
of talus, features of considerable natural beauty. Among such, we
may mention, on the outer or Marlstone escarpment, the valleys
below Somerby (see woodcut, Fig. 5, p. 58), Pickwell, Burrow-
on-the-Hill, and Tilton-on-the-Hill; on the inner or Inferior
Oolite escarpment, those about Rockingham Park, Harringwarth,
Burley-on-the-Hill, and Market Overton; and between: the two
escarpments, Deepdale, Bushy Dale, and the numerous deep and
secluded valleys which intersect the outliers on which Uppingham
stands, those near it, and that between Dingley and Brampton.

The outliers of Upper Lias capped by beds of the Inferior
Oolite form bold hills, usually of a more or Jess tabular form, like
those of Whadborough, Robin-a-Tiptoes, Barrow Hill, the high
grounds about Uppingham, and the Neville-Holt, Slawston, and
the Dingley and Brampton outliers.

The great plateau, where it is covered with Boulder Clay,
usually shows little diversity in elevation; it slopes gradually
towards the S.W. and is in places broken up by long, narrow,
winding valleys. This great table land was the site of the great
forest of Rockingham, which, though long disafforested and broken
up, still presents in places areas only lately enclosed, and others
yet covered with extensive woods.

Where the surface of the plateau is not masked by drift, the
several hard limestone beds of the Great Oolite, with their inter-
mediate series of clays, give rise to numerous tabular outliers,
precisely similar to those formed upon the great Cotteswold plateau
by the patches of Great Oolite which rest on the Fuller’s earth.
The step-like contours presented by the denuded edges of the
 

 
MISCELLANEOUS. 265

hard strata alternating with series of clays, produce features
strikingly characteristic of the oolitic rocks in this country, and by
means of which they are almost always easily recognizable even at
a distance. Beautiful illustrations of these features are exhibited
in the numerous spurs and outliers formed of the various beds of
the Great Oolite series which occupy the country to the north of
the Welland.

Similar step-like contours, often of very striking characters, are
produced along the sides of the Nene and the Welland where
they traverse the Great Oolite strata. In these valleys, the
windings of the main stream and the falling into it of numerous
tributaries, give rise to numerous spurs and occasional outliers,
along the sides of which the out-crop of the several harder rocks is
often very clearly marked by the outlines which the masses present.

The bottoms of such valleys are covered by the flat plains
composed of gravel and ailuvium, among which the river winds its
devious way, through meadows, which, overwhelmed by constant
floods during the winter season, present in the summer plains of
unrivalled verdure constituting the richest of pasturages.

The Oxford Clay tract to the east of the Nene is almost every-
where thickly covered with drift, and forms a low undulating
country, sometimes well wooded, which slopes gradually towards
the Fens.

The Fenland itself does not present such monotonous features
as is sometimes supposed. Rising above its generally level surface
are a number of tracts composed of the older rocks covered by
gravels which were once islands ; and these, which constitute the
sites of the various towns, villages, and farmhouses, though of but
slight elevation, fofm conspicuous and often striking objects in a
peculiar landscape. The extraordinary and unrivalled fertility of
some portions of these tracts too, is sufficient to invest them with
considerable interest for the traveller during at least some seasons
of the year. To those familiar with the scenery of Holland, the
resemblances presented by the English Fenland are very striking ;
and before the introduction of steam engines had swept away the
numerous windmills, that were formerly situated at short intervals
along the banks of the numerous dykes by which the country
is everywhere -intersected, the similarity was even still more
marked.

Springs.—The frequent alternations, within the district under
description, of pervious beds of limestone and sand with impervious .
clays, gives rise to numerous springs—indeed these are among
the three things for which, according to an old adage, the county
of Northampton is remarkable. The constant outflow of these
along the base of the harder beds, by causing a broken condition
of the surface and imparting a freshness to the verdure, sometimes
makes the division of the formations very distinct, and enables
the eye to trace them even at a considerable distance.

It is interesting to notice the manner in which the presence of
springs has determined the sites of the towns, villages, and even
isolated habitations of the district. Thus, along the slopes of the
266 GEOLOGY OF RUTLAND, &O.

two great escarpments we find two series of villages, which obtain
their water supplies from the springs arising at the junction of
the Inferior Oolite and Upper Lias, and of the Marlstone Rock-bed
and Middle Lias Clays, respectively. The presence of such springs
would in the first place influence the choice of camping grounds for
a nomadic people; and the same localities would for similar reasons
be selected, when population first became fixed, as the sites of the
rising settlements. Along the sides of the great river valleys of
the district, numerous villages have been built, which depend for
be their water supply on the springs arising at the out-crops of
the various oolitic beds; while other villages have arisen on the
sides of the various outliers and inliers, which afford the same
advantageous conditions. But over the great intermediate tracts
not a single village occurs, and until modern times scarcely a
single habitation could be found upon them. In the Fenland, in
the eastern part of the area, and the drift-covered Lower Lias clay
lands of the western part, the position of the few villages and
houses, has been in almost every instance determined. by the
presence of beds of gravel yielding springs.

The question of the water supply of the area has, in modern
times, assumed great importance, and an entirely new aspect.
Although springs are so abundant in the district, yet as population
has increased it has been found necessary, either for the purpose
of supplementing the supply of water or for obtaining it in the
most convenient situations, to open numerous wells. These have
been for the most part of no great depth, passing merely through
the first pervious bed into an impervious one, and thence obtaining,
in almost every instance, an abundant supply. But the facility
with which the refuse matter of a considerable population can be
got rid of, where there is a substratum of porous material, has led to
openings in these same rocks of innumerable cesspools and drains.
Hence the water supply of the population is often poisoned
at its source; wells and cesspools existing in the same rock and
at no great distance from one another. Now it has been shown
that waters from such a tainted source, though bright and clear
to the eye and not unpleasant to the taste, may, nevertheless, be
the means of propagating the worst forms of epidemic disease.
Fortunately, in the district under notice, there generally exists a
remedy, and it is in most cases easy of application ; it is in fact
only necessary to carry down the wells to the next impervious

.stratum, and to protect them from infiltration in their upper parts.
Thus in the case of a village standing upon the Cornbrash, in
which the water-bearing bed has been hopelessly deteriorated by
the drainage, it will only be necessary to carry down the new wells
through the Great Oolite Clays into the Great Oolite Limestone.

The district being an almost purely agricultural one, the civil
engineer is not called upon to make provision for large and closely
packed populations, like those which demand such great works
for procuring and storage of water supplies in manufacturing
districts. In very few cases are the towns of sufficient size pro-
bably to need deep artesian wells, such as might be sunk into
MISCELLANEOUS. 267

the Lincolnshire Oolite Limestone or the Marlstone Rock-bed. At
Bourne, such wells have been sunk to the former stratum and
most abundant supplies of excellent water obtained. In making
similar attempts in other localities, it will be necessary always to
bear in mind that the two rocks thin away towards the south and
east, and that in the case of the former this attenuation takes place
very rapidly. It will be necessary therefore in every instance to
inquire as to the probabilities of the rock, which is to be bored
for, being actually present under the locality at which the trial is
made.

Swallow-holes— These may be regarded as the complements of
springs, and their abundance in the district is due to the prevalence
of the same set of conditions which produce the latter, namely—
the repeated alternation of rocks of pervious with those of im-
pervious character. When water passing through a pervious bed
reaches a bed of clay or other non-absorbent rock, it flows out at
the surface in the form of a spring. When on the other hand
water flowing over an impervious rock, reaches a pervious stratum,
it is rapidly absorbed, and by its passage downwards gives rise,
either by mechanical or chemical action, to the production of an
underground channel. The openings into such underground
channels are called “swallow-holes.” They are very abundant
-within the area embraced in Sheet 64; indeed the lines of
junction of rocks like the Upper Estuarine Clays and the Lin-
colnshire Oolite are often marked by a series of these natural
drains; in many cases a slight depression of the surface level
indicating their position. In some cases the volume of water
carried off by means of a swallow-hole is very great, and the
roar produced by it in descending, is heard at some distance.
In the case of the smaller swallow-holes, they may often be
detected by placing the ear near the surface of the ground.
These swallow-holes are well known to fox hunters, for the long
sinuous fissures worn by the constant passage of water through
the jointed limestone rocks constitute retreats for foxes, from
which it is almost impossible to effect their dislodgement. Doubt-
less also the caverns so frequently revealed in the midst of limestone
rocks during quarrying operations, owe their formation to the
same agency. ;

In effecting draining operations, these natural means of carrying
off the surface waters are often imitated, and artificial swallow-
holes constructed. Thus when a tract of Boulder Clay overlapping
limestone is drained, it is only necessary to carry the pipes to the
outcrop of a thick bed of limestone and to allow them to terminate
in an excavation in the latter. Similarly, in draining a bed of
clay overlying a stratum of limestone, an occasional pit sunk
through the former into the latter will serve for the ready removal
even of the largest volumes of surface water. Many examples of
these modes of procedure may be seen in the district described in
this Memoir. : ;

Subterranean Streams.—Frequently when a brook or river,
flowing over an impervious bed, meets suddenly in its course
the out-crop of a stratum of limestone, its volume is greatly
268 GEOLOGY OF RUTLAND, &C.

diminished by the escape of part of its waters underground ;
these waters are usually thrown out in fresh springs farther down
the valley where the limestone is underlaid by an impervious
rock. QOecasionally the whole volume of the stream thus dis-
appears, and for a portion of its course, sometimes several miles
in length, it becomes subterranean. Nota few interesting ex-
amples of the disappearance of rivers, which thus leave their beds
for a considerable distance quite dry, occur within Sheet 64. As
especially noteworthy may be mentioned the River Witham, near
Thistleton, the River Glen, between Little Bytham and Careby,
and the brook which flows by the village of Benefield.

Mineral Springs——The springs of this class found within the
area described in this Memoir are not now of great importance
and do not demand an extended notice at the hands of the geologist.
At an earlier period, and especialiy in medieval times, it was other-
wise, however, for the wonderful curative powers attributed to
many springs, which are now quite disregarded, led to their being
dedicated to certain saints, and even in some cases to the erection
of hospitals or monasteries in their neighbourhood. The only
mineral water within the district which has been, during recent
years, resorted to by invalids under medical advice, is that of
Braceborough. The traditions of the virtues of many of the once
famous springs are still maintained among the peasantry, who
even now make use of them for certain classes of disorders among
themselves and their cattle. ,

As might be expected in a district which is largely composed
of limestone beds, so called Petrifying springs are common. The
water of these contains such an excess of carbonic acid that they
are able to dissolve a large quantity of carbonate of lime; and
this, through the escape of the gas, when the water is exposed to
the atmosphere, is readily deposited in a crust on any object over
which the stream from the spring flows. Masses of travertin, or
carbonate of lime deposited under such circumstances, are very
common in many places; good examples may be seen on the side
of the Nene Valley, at Alwalton Lynch near Peterborough. In
some cases tufts of grass, fragments of wood, shells of snails, and
other objects are found encrusted and enclosed in these masses ;
while in others only the hollow casts of such bodies are found
traversing the mass in all directions, the objects themselves having
decayed and disappeared. At several localities within the district
are found masses of travertine which enclose numerous encrusted
specimens of plants, in a manner precisely similar to those de-
scribed by Mr. Sharp, as being found near Old,* which is situated
to the south of the district now being described. In some places,
as at Halstead, the “‘petrifying springs” have been made use of
like those of Derbyshire, &c., for the purpose of obtaining those
incrustations (erroneously called petrifactions) of objects like
birds’ nests, wigs, skeletons, branching twigs, &c. which were at
one time so conspicuous in almost every collection of “ curiosities.”

 

* Geological Magazine, vol. v., p. 563.
°

MISCELLANEOUS. 269

The passage of waters of this class through beds of gravel has
sometimes effected a cementing of the pebbles into indurated
masses, which can sometimes be raised as large blocks of solid
stone; these blocks, resisting denudation better than the sur-
‘rounding unconsolidated portions, sometimes stand in fantastic
shapes above the surface of the ground. Examples of this may be
seen in the case of the pre-glacial gravels near Clipsham quarries,
and in the valley gravels near Elton.

Next in abundance to these springs of hard water, or those
containing an excess of carbonate of lime, must be noticed the
Chalybeate waters. Some of these contain such a small proportion
of iron salt as not to interfere with their use for drinking and
ordinary domestic purposes; and such springs only betray their
character by the brown crust deposited on the vegetation around,
or by the irridescent scum that floats on the pools in which their
waters collect. Other springs of the class contain a much larger
per-centage of iron in solution, as is manifested by their nauseous,
inky taste; and some of these have obtained considerable fame for
their curative Virtues.

Many of the springs which arise in the ironstone beds of the
Northampton Sand, the ferruginous band ofthe Upper Estuarine

eries, or the nodular ironstone bands of the Great Oolite Clay
contain a small amount of carbonate of iron in solution. Some of
these had sufficiently pronounced chalybeate characters as to enjoy
some fame in former times. Such appear to have been the now
altogether neglected, if not quite forgotten, Burleigh Park Spa,
Wittering Spa, and Tolthorpe Spa, described by Dr. Short in
1734. Waters of this class traversing beds of gravel, sometimes
bind the pebbles together with a ferruginous cement into a rock
of great hardness ; the water which traverses peat bogs, as is well
known, readily takes: up iron in solution, and frequently the feu-
- gravels are found, in certain of their beds, cemented into a rock
of such extreme hardness that, in order to carry drains through
them, blasting has to be resorted to; a good example of this kind
of indurated gravel may be seen at Greatford. Occasionally the
chalybeate springs traversing certain of the oolite rocks indurate
and stain them; such is seen to be the case with the oyster-beds
of the Great Oolite between Benefield and Glapthorn, and to the
west of Oundle. Boe,
_ Other mineral springs in the district, like those of Kings-Cliffe,
Stamford, Neville-Holt, Burton Lazars, Little Dalby, Brentingby,
and others, are probably deep seated and owe their existence to
the presence of faults in the strata. The proximity of several of
these mineral springs to proved lines of dislocation has been already
pointed out. Some of these waters are still used by: the people
dwelling in the neighbourhood, especially for outward application,
"in cases of cutaneous disorder and diseases of the eyes; but in
"- former times the fame of several of them was very widely spread,
and they were resorted to by patients from all parts of the
country. The three most noteworthy of these were the mineral
waters of Burton Lazars, Neville-Holt, and Braceborough.
32108. 8
270 GEOLOGY OF RUTLAND, &C. *

Burton Lazars derives its distinctive appellation from the
Lazar house, or hospital for lepers, which once existed here. This
‘institution, which was very richly endowed, was devoted to the
relief of a class of disease which was ‘extremely common in this
country in medisval times, but which has now, thanks to the
existence of better sanitary arrangements, the greater abundance
and excellence of food, and the spread of habits of cleanliness
among the population, entirely disappeared. In the year 1135
Roger de Mowbray, aided by a general collection throughout
England, laid the foundation of an~-establishment for a master
and- eight sound brethren of the Order of Saint Augustin, as
well as several poor leprous brethren,-to whom he gave two
carucates of land, at Burton, a house, mill, &c. “The hospital
was dedicated to the Blessed Virgin and St. Lazarus, and- all
.the inferior houses in England, were in some measure subject
to ifs master, as was also the master of the Lazars at Jeri-
salem hospital, belonging to the Knights of St.John of Jeru-
salem.” At its dissolution in 1535 the Burton Lazar hospital
had a clear annual revenue of 2651. 10s. 2d', its possessions were
granted to the Earl of Warwick and the Duke of Northumberland.
The spring at Burton Lazars, beside which this important establish-
ment sprang up, is said to have contained chloride of sodium and
a large quantity of sulphuretted hydrogen among its ingredients,
and ‘it was resorted to, long after the dissolution of the monastic
establishment, by great numbers of persons afflicted with scorbutic
disorders; these are said to have obtained great benefit from the
use of the waters, As late as the year 1760 a bathing room was
. built at the spring, but in recent’years this has been pulled down;
subsequent excavations carried on near the spot.have caused this
once most famous well to disappear altogether, so that even its
very site will soon be known only by tradition, . ~

The Neville-Holt Spa was discovered in 1728, and its compo-
sition and medical properties were investigated by Dr. Short
(see the list of works at the end of this Memoir, Appendix II.). It
appears to have been chalybeate and for a long time its waters
were in great request, but they are now almost entirely neglected.

‘ The baths erected over this spring still remain, ev

At Blatherwycke a spring containing sulphuretted hydrogen was
discovered through the sinking of a well (see p. 102). Its waters
are said to have been analysed, but I have not been able to obtain
any record of its composition. =

The chalybeate water at Kings-Cliffe Spa at one time acquired
some fame; but, as in so-many other cases, it has either fallen
wholly into disuse or is resorted to only by the peasantry living
in the neighbourhood. , i

The Braceborough Spa does not appear to contain an excessive

amount of any particular mineral ingredient, but is remarkable ‘© :

for the quantity of gas (carbonic acid) which rises through it. A
bath has been erected over it, and: the spring was at one time
much resorted to by invalids. *
MISCELLANEOUS. 271

Mineral Resources of the District.—These we have noticed in
considerable detail in connexion with each of the formations, and
here it is only necessary to remark that, although, with the ex-
ception of the iron-ore of the Northampton Sand, the district
cannot be regarded as rich in minerals of great economic value,
nevertheless to a very large extent, not-only the comfort of the
population, but the nature of the architecture adopted by them
both in their homes and their religious edifices, is due to the ex-
cellence of the building materials with which they are so liberally

farnished. : !
+. Sotls.—The principal characteristics of these and their depen-
dence upon the rocks on which they lie have also been noticed in
the foregoing pages. Although almost every portion of the area
described is now under cultivation, yet such was not always the
case. ‘The tracts covered by the richest soils were evidently
those which were first cleared and occupied ; and the wants of a
- continually increasing population, combined with the adoption of
more settled habits, have occasioned the successive absorption
of more and more unpromising areas, till at last waste lands have
almost wholly disappeared within the limits of the district.
_ -Conclusion.—No one can have followed the descriptions of the
_ present memoir without reflecting to how large an extent the
present characteristics and the past history of the district are
dependent on its physical structure. A mere glance at the map,
as geologically coloured, will sliow how the selection of the original
sites for those settlements, which have since become villages and
towns, must have been, in the first instance, determined by the
outcrop of the various water-bearing beds. The features of its
surface, the nature of its soils, and the character and abundance
of the mineral productions of the district, have evidently been the
conditions on which the number and distribution of the population
-have mainly depended, and the causes to which their industries,
_ their sports, and even their peculiarities, have largely owed their
origin.

And the production of the physical features which distinguish
the district have been due, as we have seen, to the combined opera-
tion of two distinct sets of geological causes, Firstly, the succession
of events by which series of rocks of very various characters were
deposited within the area; and, secondly, the action upon these
.of subterranean forces producing upheaval, flexure, and fracture,
and acting side by side and in combination with those of subaerial
and marine waste; these deep-seated and surface operations work-
ing concurrently have gradually moulded and sculptured the
surface of the Iand into the forms which it at present wears.
APPENDIX I.

PALHONTOLOGICAL TABLES

PREPARED BY

R. ETHERIDGE, F.RS.,

PALZONTOLOGIST TO THE GEOLOGICAL SURVEY.
274 GEOLOGY OF RUTLAND, &c.

APPENDIX I.

TABLES OF THE STRATIGRAPHICAL AND GEOGRAPHICAL D1sTRIBUTION
or Fossizs, sy R. Erueriper, F.R.S.

The accompanying tables of fossils have been drawn up expressly to
elucidate the distribution of the Oolitic species through the Lower
Oolites of the counties of Rutland and Northampton, and also to show
their geographical distribution.

Table 1 is devoted te a comparison of the fossils of the Inferior
Oolite of the area above noticed with those of the same formation in the
-south-west of England and Yorkshire respectively.. This comparison
- and correlation is made with the view of ascertaining the relation that
exists between the two distantly separated Faunz of the same age, or
belonging to the same horizon in time, the physical aspects of which,
however, greatly differing, there being ‘nothing in common litho-
logically between the Oolitic series of Yorkshire, and those of the
Midland district and south-west of England. Yet the species ranging
through the series are identical, and hold the same stratigraphical posi-
tion, and are of equal value in determining the sequence of the beds _
constituting the Oolitic series through the whole of England.

In the column headed “ Great Oolite of West of England,” are enu-
merated those species that occur in or are common to both the Great
Oolite of the South, and the Inferior Oolite of one or other of the five
horizons named, viz., the Lincolnshire Limestone, the Collyweston Slates
and Northampton Sand of the Midland district ; also the Inferior Oolite
of the south of England and Yorkshire.

The letters R.C. 1. ce. denote the rarity or abundance of the species,
the capital R. expressing extreme rarity, and the capital C. extreme
abundance; the smaller letters their ordinary condition or occurrence.
This must be regarded as only approximative, being really a question of
exhaustive research.

As far as able, I have tabulated every species occurring within the
area described and mapped by Mr. Judd, and embraced in Sheet 64, &c,

Samuel Sharp, Esq., F.G.S., of Dallington Hall, Northampton, who ~
possesses the finest Collection of Northamptonshire fossils known, sub-
mitted the whole series to our examination, and from his materials, with
those collected 'by the Geological Survey, have ‘been constructed the
tables numbered 1 and 2, the latter being strictly geographical. Mr.
Sharp’s two able papers on the Oolites of Northamptonshire* contain
every species known to him, arranged both geographically through the
text of the paper, and zoologically tabulated also.

 

* On the Oolites of Northamptonshire, by S. Sharp, isq., F.G.S., Quart. Journ.
Geol. Soc., vol. xxvi. p. 354, and yol. xxix., p. 225.
APPENDIX. 27 §

Table No. 2 illustrates the distribution’ of the species known in the
Great, Qolite.and Cornbrash of Northamptonshire and Lincolnshire,
The Great Oolite of Rutland and the Cornbrash of Stilton (Hunts)
arranged in their geological horizons and according to localities. ,
~ These two tables thus illustrate the distribution of the fauna of the
Lower Oolites of Northamptonshire and Rutlandshire; Table No. 1
being devoted to range ‘and correlation, and in which are tabulated
‘394. species, whereas Table No. 2 contains 354 known occurrences,
through their distribution,

Mr. Judd, in this able memoir, has so completely written,the history
of the area that no notes of special stratigraphical value can be added
to this Appendix, and due attention to the table illustrating.the varia-
tions of the Lower Oolites of the Midland district at page 6 in the
memoir will enable the reader to understand, by comparison with the
typical column headed “ Geological Horizons,” the sequence, distribution,
and arrangement of the Rutlandshire and Northamptonshire deposits
and fossils. a ee

The recent investigations into the true correlation of the Northern
and Southern Oolitic groups, and especially those members of the lower
series with the Lincolnshire Oolites and Northampton Sands of the
Midland area, has resulted in clearly defining the true stratigraphical
place of both horizons. Based upon superposition and on fossil data,
both Mr. Sharp, of Northampton, and Mr.'Beesley, of Banbury, through
‘independent observations and well directed work over their respective-
districts, arrived at the same conclusions; and the careful and patient
labour of Mr. Judd,,as mapped in the field and now detailed in the,
pregent memoir, conclusivély show, both on stratigraphical and paleon-
tological grounds, the real relation of the Northampton Sands to the
underlying Upper Lias Clays and thé great. Limestone of Lincolnshire
above.* 5

*

 

* Professor Morris in 1869 reconsidered his previous views upon the Lincolnshire
Limestone, and assigned it to the age of the Inferior Oolite. :

%
“ 1

276 GEOLOGY OF RUTLAND, &c.

we

Taste 1.—Comparison of the gaan of the Inferior Oolite of the

: Midland District with those of the same formation ° in the South of
et England and Yorkshire respectively.

 

 

 

 

 

 

 

 

 

 

e ig
mp aatend " Compared
District. ;
ale H/k, esl
Class. Species. jos ‘@ie 13 2 || Sed
i ‘ . 85) £18 (82 a ae
° |28| 8 |eulsu lejos
; a4| 2 |£5|aa/ 88/35
an) 38 2714 a”
Plante , - | Aroides Stutterdi - - Carr. -| B }
Paleozamia pectinata - Brong. r +] +
Pecopteris polypodioides Lind. & Hutt.) r| ¢ :
Polypodites ae - Gopp. -| C +.) +
Zamites ~ am - = r -
Carpolithes ~~ - me . -| R
Coniferous wood =~ - + r al
Coelenterata | Anabacia orbulites - -Lamaroux| ¢c] - + 7
Eunomia radiata -E.&H.-| Ry} : +
Cladophyllia Babeana =~ D’Orb. r > +
Isastrea explanulata - M‘Coy -| ¢ + +
sy limitata - - Lamaroux| c + | +
5 Richardgoni . - Ed. & H. e ri] +
Latomeandra Davidsoni - Ed.& H.| c¢ .e[ +
Sy Flemingii .Hd.& H.| r = | =
Microsolena excelsa ?Ed.& H.| r s Pl +
Montlivaltia De la Bechei Ed. & H. r +, «
4 lens -Ed.&H.| r +
$s tenuilamellosa Ed. & H. | r | +
ie trochoides - Ed. & H. r »~| Ri +
Wrightii -Ed.&H./ 1 P| a
Stylina solida, ; - M‘Coy r, ao] +
Thecosmilia gregaria - M'Coy'- | -C e| +
Wrightii - Ed. & H. | rx |- o| +4
Thamnastrea Lyellii - Hd. & H. | c¢ . . . +
as eoncinna - Goldf. -] ¢ . of oF - s
- Defrancii - Mich, -| ec} . e| + 2
sy Terquimi - Ed.& H.| R R| +
Awnxutorpa | Acrosalenia hemicida- Ms
Echinoder- | , roides m5 = Wie - ral :
mata. 3 Ly cettii - - Wright ri} .[/ ret.
-| Astropecten Golleswoldiz *
Oe Colesnaiie | Wright-| R} RB =
Cidaris Bouchardii .- Wright. - r .| +
»  Fowleri.: - Wright -.| r ol +
»  Wrightii Desor. - |-1r P| +
Clypeus. Plottii a ce ri + +
95 Hughii r .| +
"4, Michelini Tight -|¢ on
Echinobrissus clunicularis Lihwyd - | C el +] fy
Pedina rotata “a : - Ag. ~-| +
Galeropygus (Hybocly-] 74. a
‘ pus) sonercitoraiin : I Hlorhas: = & ee oF
; Holectypus hemisphewricus Desor. - | ¢ | +
Hyboclypus ovali Wright - | r Pe +
Pygaster semisulcatus - Phi -| C] ».] ec] +] +] +
- Pseudodiadema depressa Ag. -| c 2] ep t
Stomechinus germinans - Phil. -j| ¢ ry +t] +
Pentacrinus Milleri- - Aust. -| RJ] .j rit] -] +
subsuleatus - Goldf. -| R , F | +
Stellaster Sharpei - -Wright,MS) .' ./ BR

 
APPENDIX. 277

Table 1—Comparison of the Roaetly &c.—cont.

 

 

 

 

Inferior Oolite 5
f Midian Compared
“Districts with
3 oe | eee Ee
3 og) o | F
_ Class. Species. EE e g as £ is rs]
- (a) 2 |e [SB /68| 28
83) $ |u| eC | seIO8
/E8| & | $5] 85/52) 8
a”) 8 jada |e [é°
Annelida - | Serpula convoluta - Goldf. -j > r rj] +
» intestinalis - Phil -| rj. 5 ol +
7 »  Plicatilis - Goldf. - ? a Poe SPE I) oa
»  Ssocialis . - - Goldf. -| C : ry +]4
»  sulcata - Sow. r ‘ +1 +
Vermicularia compressa - Y.& B.-| rj. +
.  nodus - - Phil. - r , | pF
: | Annelide tubes : -| ¢
Articulata: . ‘
Crustacea - | Remains of  - ee ted ee a
/ Pseudophylliasp. - - - -| RB
Mo.Liuscorpa Priors straminza - Phil, = ol ep
Motiousca Lingula Beanii? = - - Lye. -| R
Bracuio- Rhynchonella angulata - Sow. - r “ gle 1
PODA x Crossii - Dav. R ~|R
- cynocephala Rich. -| cj} . r] +
a plicatella  - Sow. Cc ‘ r
3 quadriplicata Ziet. e . e
a5 Lycettii - Dav. r - fir] +
9 spinosa - Schloth.-/| C/] .| R| +
9 sub-decorata Dav. -| r . r
” ey Davy. -| ¢ - rj +
Boe tetrahedra - ? Sow. .| Rj} .| r
9 varians - Schloth.-| C} -j rj] .| .] +
variabilis Schloth.-| C | .| ¢ ;
33 var. bidens Phil. -| ¢] .] wv] + :
55 var. triplicata Desh. | Fr ‘ rij + =
concinna - Sow. -| ¢] .« a] + | o+
Terebratula Buckmani , - Dav. - r ‘ ri +
35 fimbria - -Sow. -| rj. ri +
55 . globata ~ Sow. c 7 ry +
5 Ampressa, ~ V. Buch r . P| +
5 maxillata -. -- Sow. e| .| rl +] +] +
» * ovoides- ' -Sow. -| rj] . ri +
»  » Phillipsi. -Mor.&Dav rr]. ri +
35 simplex -~ Buckm.-| Fr] . rj +
5 spheroidalis Sow. -] ce] . rl] +
sub-maxillata Lt s e ri +
Avicula Braamburiensis - Phi R/] BR] +/+
es. A »  clathrata - Lycett .- . r
(Monomya- »  complicata - - Buckm.-| . | ri +
RIA) » ~ digitata - - Deslong o| rl a] rl +
; »  echinata? . - Sow.’ -| RB] . ~| + +
» inequivalvis - Sow. Cy .} ec] +
»  Munsteri - Golet. -| Cl ej] ec] +] +
subcostata - Rém. rl or ;
‘Lima bellula -L.&M.-| ¢]| ef ee] +] +
»  ecardiiformis - -L.&M.-| C}] ec} ec] . o| +
‘ » duplicata ~- - Sow. Cl} «j Cl] +] +) +
» ~- Dustdnensis, n. sp. - _e}] | C ;
»  deltoidea, n. sp. = es . r |:
» electra ~- - - D’Orb. -] . ; ri +
»  gibbosa - -Sow. -]|] Cj c¢ ol + | +

 

 

 

 

 

 

 

 
 

 

 

 

 

278 - GEOLOGY OF RO MGAND,. &o. ¥
Table 1.—Comparison of the Bosdllas ‘&e.—cont.
Inferior Oolite Compared ;
i ’
oOeiriot | > with
z ; 5
Class. Species. es a & 2a Bgiek
BE; Sle (sess (eal
as a |Ca|Sa| se
28! $ | eg| 50) 52/o
Ss ja | & pz 3 Te le
Lamellibran: | Lima Etheridgii Wright,MS.| r| ./ ri +
chiata (Mo- i impressa ~L&M.-| C} ./ e¢] +
nomyaria). »  inoterstincta - Phil, - r r Tr
—cont. >», ovalis - - -Sow. -|-.]-. » fo ak
. » Luciensis  - D’Orb. rps) 2 |
; »  pectiniformis - - Schloth.- | C] ej] ce] +] +] +
a » Pontonis .- -Lycett -| C}] .] ec} +
a » > punctata - Sow.- -|/ ¢ ec} .| +
! » Yigida - -~- Sow. -| C ri ri +
», Rodburgensis, n. sp. -| Cy]. a fae
» Yudis - -. = Sow -| e¢ _ r
»  semicircularis - Goldf, -4 = o | + a
A Sharpiana, n. sp, ay ye : R
Ostrea acuminata ~ ~ - Sow.. - ‘ .| BR 5 | +
»  costdta  - Sow. -| . ae ee | +
»  eristagalli - - Quenst.- | . Fi r :
»  abelloides Tam.- -| C : ef +] +
» gregaria - -Sow. -/ ec] ec] ec] + | +
»  suleifera ~- - Phil. r x ame |) ees ih oe
Pecten arenatus - - Sow. | 3 ¢ {tit
»  articulatus- Schloth.-} C}/ ee} e] +
»  aratus - ~ Waagen. | r
»  clathratus - _+ Rom. ri} or] ri + - | +
»  Gemissus.- . ~ Phike -} efoe} ri +] + i
and var. gingensis Quenst. i.
» lens - .° =Sow. =| C] ce] e| + oft
>»  parodoxus- - Miimst. -| rj} or] .] + ,
»  Personatus ~ Minst. -{| c}] c}] RB] + | +
se texturatus - - Mist. -} ec] r].r| +
»' Vagans var, pere- |
‘ “primis - } Sow. -j_-¢ of tp te] +
Perna quadrata “= Sow. -] tr] or] ri] + {+
',, qrTugosa - -Goldf- -/| rj r/o rc] +] +] +
Pinna ampla - -Sow. -}; «} .]| ec] + ]°>. ] +
»  cancellata - Bean -} ric] . «| +
» cuneata. - - Phil. -| ec] e}] ec} +) +4 +
»  Hartmani - - Ziet. --}| «| « |o e] +:
Placunopsis ornatus = .- Lv & M.- |r ‘ . , t+
3 -pocialis -.-L.&M.-| c¢}] vr] . . ~| +
33 Jurensis ~ Rom. - . é r {
Pteroperna ei alana - Desk -{ @}] ri] r] +} .] +
» |, gibbosa --Lycett -; @}] .] P| +
$8 plana - Lycett -| c}] rj-e] +] +
. pygmea - Dunker ~j| TI] ..].. : «|
Gervillia acuta |= Sow. -{ ¢].e] ee] +] +) +)
55 lata - - Phil -f c] . ee] ti + a
a ornata ? - - Lycett -|. 48
5 pernoides ° - Deslong- | . oh | +
a Pe - Lycett ot o«] vl +
” Gastiocheena Say ‘
: tortuosa , _} Phil - ey ery a
Hartmannii - Goldf. ec} .| ¢] +] +
Grypheea subloba - - Desh. ‘ r|{ +
Hinnites abjectus - - Phi. -[| C} c] Cl] ++

 

,

 

 

 

 

 

 

 

 
APPENDIX.

279

Table 1.—Comparison of the Fossils, &c.—cont.

 

 

 

 

bers nos Compared
District. wi
3 Bg [8 [E
‘ wm oO:
Class. Species. es| 4 g 25 2 ‘ sg
Ssle|a |Soplog las
42 “3 8 .| nel aa 5 %
oS E TS} Sa. | OM
g8| © |2/E5/ 55/32
ac 3 — 5” 3 pm & o
Lamellibran- | Hinnites tegulatus -L.&M.-] rj or] .l'+ at aS
chiata (Mo- 95) velatus - - Goldf. -/| ec] ¢ ec] + . |
nomyaria). | Inoceramus Fittoni ? -L&M.-| . : ? : a de Ze
—cont. as obliquus -L&M.-} Ri] rj] ri. +
Plicatula tuberculosa -L&M.-| ¢ : r 7 | +
Trichitis nodosus - -Lycett -| R| . @ | » | +
Dimyaria - | Arca emula var. transversa L. & M. - I ‘ r . > ahs
» -eancellata - - Sow. -] ¢ ‘ -{ +
» minuta - - Sow. -] . ail Pw | +
» Prattii var. rugosa - L.& M.-| c| . ri] + anal Ses
> pulchra - Sow. r . r| + = eae
Astarte depressa - Goldf. - | cr r rl| + 2
» elegans -Sow. -| C}] ec} Cl] # |] +
>»  excavata Sow. -| c] ec] ec] +] +] 4
a » var. com-
pressiuscula -L.&M.-| r] r] .| +
» minima - - Phi. -| ¢ ‘ ryt] + f+
»  Pontonis - . + Mor -|] ¢ i+
»  recondita - - Phil -] 4 3 ~f Flt
rhomboidalis -L.&M.-| ¢ : ri} +f] +]4+
Cardium Buckmani L&M.-} C} ¢} Cl] + ~| +
5 cognatum _- Phil, -] ¢ ec] +] 4]4
” incertum - Phil. r ; . of +
35 semicostatum - L.&M. - - . ? | +
9 Stricklandi L.& M. ‘ r < | ae
a subtrigonum - L.&M.-| ¢
Ceromya Bajociana -D Orb. -| C} ri ec] +] +
ay rience -Sow. -| c] ce e| +] +] +
imilis - - Lycett -| ¢
Corbis (Corbicilla) Batho-
nica? - -L.&M.- 3 : rj]. eh ae
Cucullea cancellata - Phil. -| ec} r}] r] +4] +
23 eucullata - Goldf. -{ ec] ce} ce] + of +
$5 elongata -Sow, -/] rj - rl + [+
5 Goldfussii - Rom. -| c] . p . ale
7 imperialis - Phil. r . | «fe
» oblonga Sow. -| ¢ “ e| +] +
ornata - - Buckm.-| . -| rit
Cypricardia acutangula - D’Orb. -j} «| . | rj) +] +
35 Bathonica - D’Orb. el «at @¢ | ¥ -| +
3 nuculiformis - Rém. - |? c¢ a ? . | +
Cyprina Jurensis - Goldf. rl « 2 . ~| +
»  Loweana -L&M.-} C; .] . r «| +
a5 dolabra - -Phi., -| rl] . rl] oe] +
as nuciformis - Lycett -| c ‘ . | + i
trapeziformis - Rom. -| rj .j ry] + ol +
Goniomya angulifera Sow, -/| «| 2] e] +] +] +
»4 _ literata -Sow. -j| ¢c] ec] . + | +
v-seripta Sow. -{ c] . oft] +
Gresslya abducta - - Phil -] . 5 cle] +
33 latirostris *- Ag. ~| ec]. r{| +
<5 peregrina - Phil, -|] . oe) Je! ed BOR
Ss rostrata - - - - ‘ r
Homomya crassiuscula -L.&M.-| Cj] c{ -} +] +

 

 

 

 

 

 

 

 

 
280 GEOLOGY OF RUTLAND, Sc. .

Table 1.—Comparison of the Fossils, &c.—cont.

 

 

 

 

 

 

 

 

—
Inferior Ootte | Compared
District.
aa oo
Class Species. S B 33 3 :
SS. ; 2 ¢ BSl36|o8
Be gis [sess |ee
23 8 a / se | 52 (oP
a. é je |e |e jo”
Dimyaria— | Homomya (Myacites) uni-
cont; ~ ya cari ft. & M.- Cy # :
is a Vezelayi - D’Arch.-| r
Isocardia cordata - - Buckm. - | C e| +] +
Lithodomus inclusus - Phil. -| r ‘ r
Myopsis rotundata - - Buckm.-| r
Lucina Bellona - - D’Orb. C! r] ec | +
»  despecta - - Phil. ry} ry} cl +]4f+F.
»  @ Orbigniana D’Arch-| rj] c}] rj +
»  votundata - Rom. r j r ‘ ap
»  Wrightii  - - Oppel. -)] rl] rj or 2
Macrodon Hirsonensis - D’Arch. - c % e| + | +] 4°
Modiola Binfieldi -L&M.-/ ¢r . r o | +
$5 cuneata - Sow. -| c¢ 3 e{ +] +
99 gibbosa = - -Sow. -/| C}] ec] C] +
»  explanata - Mor. r r
»  Leckenbyi - -L&M.-| r 3 c ~ | +
>»  Lonsdalei - -L&M.-| ¢ r - eo | se: IP
5 solenoides -L.&M.-| r 5 r oe a]
»  Sowerbyana’ -D’Orb -| c/ ce} r{| +] +] +
35 subreniformis -L.&M.-| rj] . Ti ss of +
sublevis ? - - Sow. -|] r 2 axl | +
Myacites eequatus  - Phil. . rior] .] +/+.
2 Beanii Leck. ri) « j of + fi
” compressiusculus a . s r
35 calceiformis - Phil. -] ¢ : ee] + |.+
os dilatatus  - Phil. - : 5 ri o+ »| +:
3 decurtatus - Phil. ry} ow | ao. be
! ay Scarburgensis - Phil, -/| ?] . r
securiformis - Phil. -/] ‘ r
Myoconcha crassa - Sow. -{| ec] .f] ef] +) +
9 striatula - Minst’ - r | +
Mytilns furcatus = - Goldf. Te} ove r| + +
8 imbricatus - Sow. , C} ef cf] +.) + 4 +
os Junularis- - Lycett r| ? r j
Opis gibbosus - Lycett -| rl]... ~| +
» Junulatus - - Sow., ry) .j rit of +
4.1 gy Similis - - Desh. -| r ~| + | +
m Pholadomya acuticosta Sow. -/ or ‘ : +
5 ambigua .- Sow. -| ¢ 3 r ;
5 Dewalquei - Lycett -| r 5 ot +
5 fidicula Sow. -| ¢ rj cf +
is Heraulti Ag. Cc : ry Fi +] t+
a lyrata - - Sow. -/ ¢
a ovalis Sow. -| CC] r]j‘r :
” ovulum- Ag. ~| ¢ ‘ rl] + pot
‘ Zieteni Ag. =] ae og | 2
Pholas oolitica - Le&M.-| rj} .] ry. } «] +
Quenstedtia levigata +L&M.-} ec] .] e} +] +] + I!
5 oblita - - Phil. ‘ cj} + wl
Tancredia angulata Lycett.- | r 7 r . -| +
a5 axiniformis' - Phi. -j| rj «| e¢} +] +] +
93 donaciformis - Lycett c : ri] +
55 planata - -L&M.-] . ° rj. | +

 

 

 

 
APPENDIX. 281

Table 1.—Comparison of the Fossils, &¢.—cont.

 

 

 

 

 

 

 

 

 

 

 

 

 

- tniyrioe Colite Compared
District. wy
. ~~
ass. Species. gs] a | aa Be ae
ms/ 8/2 (68 6s mS
q B S 3 Pe | Fe] 38 be
B8| & Seles /e5 | a0
S”| 8 |2"|8"|a"|6°
Dimyaria— | Trigonia Beasleyi - - Lycett -| .| .| BR
cont. 35 compta - Lycett -| ri] rj] vr
35 costata - - Park. -| C}] c] cy +] +) +
35 denticulata ie Lycett R ‘ r
f ss formosa - Lycett r é ri +
5 Moretonis -L&M.- 5 r ‘ : | +
33 producta - ~ Lycett ‘ ri +
3 hemispherica - Lycett ~| rv] r
= impressa- -Sow. -| . c r
35 pullus, var. of costata ae c : +
5 Phillipsii - L&M.-{ ri. r
a stulpta -. - Lycett r
»  Spinulosa®” - -Y.&B-| £|] &
5 signatas - | - Ag. - 3 ril+]+
* 55 subglobosa ~L.&M.-| R/ . ri + ~| +
a: 5 striata, - - Sow. e 5 e| +
> . ss tenuicosta -Lycett -| RR] . ?
39 v-costata < - Lycett -| © . e| +] +
Sharpiana - \ Lycett -| BR -| BR
Unicardium depressum  - Phil, -| ec] «| rl +] +
5 impressum -L.&M.-| ¢}] rj} rj] . 2 | #
95 parvulum -L&M.-| +r r ‘ ~ | +
gibbosum - L.&M.-| . e| +] +
GASTEROPODA Actzon Sedgvici - - Phil. , a |
pullus- = - - Koch. -| r
Actzonina glabra - Phil -/| r] . . | oF
“5 parvula - Rom. -| rr] .- * : «|
Alaria armata - -L&M.-| rj] .|] r] . 2] +
>»  hamus - - - Desh, -| r] - is ‘ . | +
»  hamulus - Desh, -| R/ . 3 : | +
»  CPhillipsii - - D’Orb. ri rj] .J| +] +
»  sub-punctaia - - Goldf. -| r
trifida - - - Phil -|] r]:- Fil. % «| +
Ceritella acuta - - -L.&M.-| rl] . 2 . t+
Cerithium Beanii L&M.-| rr] . be Ref) ae
3 gemmatm -L.&M.-| cy] .- ry] .] +
5 limeeforme - Rém. -j| ¢ ‘i Dae es | +
35 quadricinctum - Goldf. @| « a SB o| +
»  (Kilvirtia) stran-
gulatum - D’Arch.-| r] .| - . a
Chemnitzia Scarburgensis- L.& M.-| c] -/ ri «| +4].
a vetusta ? - Phil. =|, F - « | +
59 Wetherellii? L.&M. r ; | oe] +
‘ - | Cirrus nodosus -  - Sow. =e r| +
Cylindrites * acutus' - Sow. -| rele] of «f «| +
35 cylindricus- L.& M. -|] rj] -] - a t+
L: 33 brevis? -L.&M.-| r/ . ‘ % at
8 3 bullatus ? L&M.-|] ri. areal - | +
95 gradus Lycett - r j ~| +
‘3 tabulatus ? - Lycett = - r # il +
59 turriculatus? Lycett - r 5 é o le
cin 8
. * These are all very doubtful species, small and imperfect.

4 -

 
 

 

282 GEOLOGY OF RUTLAND, &C.
Table 1.—Comparison of the Fossils, &c.—cont.; i
Inferior Oolite -
Midlan Compared
istics a
| lejz E
Class. * Species. os| 2 g 23 2 3|o
He| 8 |e | SBIShi25
an g a oe
£8/ 3 aa] so] seior
e5| & |E2| 25/88 | 8:
A] 8 |2°| 8° |e" |e"
Gasteropoda | Euspira cincta - - Phil. c
—cont. Delphinula alta - , -L.&M. R
: 35 Prattii - LL. &M. r
Natica adducta  §-.  - Phil. e zc] +]+
‘ >» (Buspira) ‘ canali- \ :
culata -L&M.-} cf] r| ec] + +
» formosa - -L&M, Cc . : E | +
»  Leckhamptonensis Lycett -| C|] rj ?
»  Michelini - D’Arch r . 5 : 7 | +
»  neritoidea ? - -L.& M. r 3 e ‘ ~{| +
»  punetura - Bean ~~] c| . F «| +
»  Verneuelii -’  - Arch. ee} . ec . a] +
Monodonta levigata — Sow. Yr oe ;
3 Lyellii - -D’Arch -| rl] . [+ | +
Nerita costulata  - - Desh. . . ri + :
»  CNeritoma) hemi-
spherica - - Rém. 7 sed se yt
Nerinea cingenda - - Brown -| C ri + | +
i Cotteswoldize - Lycett ¢c 5 t+
35 Eudesii -L&M. - é * ‘ ~ ~{ t+
» gracilis - -Lycett- -| e] . ap dtl ee
% Jonesii - -Lycett -| c] . «| +
eS Oppeli - -Lycett -| rj. -| +
» pseudocylindrica D’Orb. -| 1 ol +
5 punctata ? - Voltz. -| ? ;
»  triplicata - Brown + sf oe| +
" Voltzii - - Desl. e ‘ | + 3) +
9 Sticklandi? -L.&M.-|] rj . of + | +
Onustus Burtonensis - Lycett Py of BR ‘
Patella inornata -L&M. -| ¢ . ri +
>» nana - - Sow. fi ae] 8 ’
» rugosa -  «- Sow. e| ¢ rj +
Pleurotomaria aglaia - D’Orb. -| . @| 2
55 armata - Minst. - | .c] . ri +
55 clathrata- L.& M. -j| . . Yr
5 ornata - Defr, -} c¢}] .] rl +
5 pyramidata Phil. -| 4 ia | aE
3 sulcata - Sow. -| rt. o{ +
Phasianella* acutiuscula L.& M.-|} rj . . ‘ « | #
gy cincta - Phil. -| ?
35 elegans L. & M. ry . ‘ Py +
si latiuscula - L.&M. -| ¢
55 -parvula .- L.&M.-| ¢
33 Pontonis - Lycett -| ¢
‘5 5 striata ~ - Sow. -| ri. ote | +
5 tumidula -L.&M.-| r
Pterocera Bentleyi -L&M -|} r|] C
2” Sp. = ¥
Pileolus plicatus - Sow. = ae ~t+
Rimula Blottii - - Desl. sey A ell SD
Rissoina obliquata - - Sow. -J rj]. ott

 

 

 

 

 

 

 

 

* Many of these are very doubtful forms,—small species.

 
 

 

 

 

 

 

 

 

APPENDIX. 283
Table 1.—Comparison of the Fossils, &e.—cont.
- \
* Inferior Oolite
of Mi Compared
Distrion . with
£ 34(3 [>
: 3. os C=)
Class. Species. gs = g aa as ee
asi 8./2 |681685/a8
- as dg|s2| 52/631.
sH| 6 |SE|E>| es | ae
TE] s JE" /e" (2 |é°|
Gasteropoda | Trochotoma calyx - Phil. -le¢ r/ +] +
—cont. - extensa -L&M. -| r
9 obtusa L. & M. c r
3 tabulata L. & M. r rl +:
Trochus bijugatus ? Quenst. ~ r :
»  Dunkeri - -L&M. Tr
»  Ibbetsoni- -L&M. -|] r j
‘5,  Leekenbyii L. & M. r : +
»  Monilitectus - Phil. . of tf +
33 ornatissimus, { D’Orb. - i ~| +
‘var’ Pontonis | Mor. ¢e - r
s3 spiratus - - D’Arch e
3) squamiger -L.&M.-| ¢
Turbo depauperatus - Lycett -| ¢
» gemmatus - - Lycett r,
»  Phillipsii -L.&M.-]| ¢ +
sp. - -_-
Cephalopoda Ammonites bifrons - Brug. F R
33 Blagdeni - Sow. R ~] th s+
sa garantianus - D’Orb, -| .,! R
8 Murchisonie- Sow. -,| ¢ Cl] +
x - var. corruga- *
tus’ - - Sow. 7 Cl +
5 niortensis D’Orb. A r
si opalinus - Rein. -| . Aloe
- subradiatus - Sow. -| Fr Sd
59 ~ Jurensis ? Ziet, Ie) r{
39 terebratus - Phil, - r ;
s insignis - Schub. -| .) «| ri +t,
Belemnites Aalensis - ,Ziet. * : c
8 ‘acutus - ~ Miller e/ .]|
= bessinus D’Orb. -} & ‘ r
5s Blainvillii - Voltz..-| rj] .| e¢
“ canaliculatus - Schloth.- | rj] ..j| r] + j +
3 ellipticus - Miller - e ri] +)
- elongatus - Miller - c
giganteus = - pele - ej}; + {+
Nautilus Baberi - L.&M.-| . |. R -
ss obesus - ” Sow. -{ 2 ri] +
»  polygonalis Sow. -| R P| or
‘ sf sinuatus? - -Sow. -|] . rv
Pisces Strophodus magnus - ~ Ag. -| C ‘ Cc
ss subreticulatus - As -| C
, Pycnodus - - R
Reptilia  - | Teleosaurus (scale. of) - -  -!| BR R
Megalosaurus? sp:, tooth- - -| | R

 

 

 

 

 
284 GEOLOGY OF RUTLAND, &o.

Taste 2.—Showing the GzogRAPHICAL DisTRIBuTION of the GREAT OOLITE °
and Cornsrasu Species, collected and occurring in the area of Sheet 64.
-

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GzEaT OoLITE.
Northamptonshire.
Species. 3 $\32 ;
. Z Bis | a gis) 4
8) a|eles| | 813] 214
2/2) e|ee)2/3/8| 2|
FlLo|/ ole | al| ae] F}] a| Ss
EcHINODERMATA.
Acrosalenia hemicidaroides - Wright - ‘ ‘3 a fe |
Clypeus Miilleri - - . E ot + z
Echinobrissus Clunicularis - Llhwyd - . | + ‘ 7 js ‘ ; so)
* Griesbachii - Wright -| < ‘ - : 3 - ‘ -| +
3 sinuatus - - Leake -/} . | + 3 . ‘ . {| +4
- Woodwardi Wright -| . - : é ei - és [+
Pygaster semisulcatus / Phi =) w |] «| «| + i
, : ANNELIDA.
Serpula obliquestriata - L. & M. Teall) “ae lh Sse Hee li, se), cane | fects
CRUSTACEA.
Glyphea rostrata - - Phil. oe ee ; ‘ oe hae elle ee
Motuusca. J '
(Brachiopoda).
Rhynchonella concinna - Sow. - o| + , - 5 4) Be |g:
5 obsoleta - Sow. x se | “ ‘ eel ae [eB
35 varians Schloth. - » | ae J 5 ‘ - .| +
Terebratula globata - - Sow. + . : é «|.
se maxillata - Sow. - | + + ‘i z ele Pee]
mn intermedia - Sow. . : ~| + . A ‘ ~ | +
‘5 ornithocephala Sow. . efomd oo. : . ol tl ek
3 submaxillata - Dav. . . ‘ . 7 i | +
LAMELLIBRANCHIATA.
Monomyaria. :
Avicula echinata = - Sow. . b F 3 ie . {| ttt
». Munsteri - - Goldf. -| .|°. . ‘ ‘ ‘ ‘ ~|l +
Gervillia aviculoides . - Sow. >| + ol ce) eh al a
Hinnites abjectus 3 Phi. -| + | + 7
Ostrea gregaria = - - ~ Sow. +
» Sowerbyi - ~- <-L&M.-}| «| +] + i ‘ +
»  subrugulosa - L. & M.- a |e : : ‘i | tL +
Perna quadrata = - -Sow -]| -| +] +] .] + i
Pinna ampla - .- Sow. o | Blea b+ ?
Plicatula tuberculosa L.&M.-} . | + i af
Pecten annulatus : - Sow. - Slt Pes é 3 z ‘ 3 +
»  demissus - - Phil. + Par oO
» lens - Sow. - H + [+
>  Clathratus - Rém. 4 : +
Pteroperna costatula - - Deslong-| . ‘ . ‘i fe |!
5 gibbosa - ~ Lycett - | +
3 plana - 1» Lycett +
Lima duplicata = + - Sow. -| + 7 ~| + * - || ok
» impressa - - +L&M-| . : . ; ‘ i & |) ae) Bef
» interstincta -. - ~ Phil. +
» pectiniformis- - - Sthloth.-| . j .| +
» semicircularis - - -Goldf. -) .[ + . ' ie ei) Sk ee |

 

 

 

 
- Table 2.—Geographical Distribution of the Great Oolite, &c.—cont.

APPENDIX.

285

 

GREAT OOLITE.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

32108.

Northamptonshire.
Species, $ g 2 5 <
a\alalesla| el 2l€| 4
2\/s}| 8/83] £] g 5
S|] /2e/2/3/2/2|€
Fi S|/si5°| 4/4} EF] a] 4
Dimyaria.
Anatina undulata - - -Sow, -] .] + . , | +
Arca Prattii - - L.&M.- | + ‘ ‘ . o| +
» weroula - - - Phil. 5 ot + °
Cardium Buckmanii - L.& M.- . ‘ z -| +
35 cognatum - - - Phil, - i ‘ | +
Ceromya concentrica - Sow. . . 3 +
eae o»  Plicata - - - Ag. : -| os +
_ '-@ypricardia Bathonica - - D’Orb. - a+ el +
‘ a5 rostrata - - Sow. | + ‘ +
ae nuculiformis - - Rim. - + 3 @ +
Cyprina Loweana - - - L.&M.- + + +
» trapeziformis - - Rim. - +
Cerbicella Bathonica - - L.&M. - + . +
~ -Cucullea Goldfussii - - Rim. - ie - +
Gresslya peregrina - “ - Phil. . - 5 of
Isocardia tenera st. . -Sow. - + he
Homomya crassiuscula - L.&M. - a . +
= Vezelayi - D’Arch. - +
Modiola furcata = - - Goldf. - +
» imbricata - - - Sow. +/+] 4+] r] t+ +
_ y»  _Sowerbyana - D’Orb. - af beet aii os +
Lucina despecta - Phil. a ~| +
» Bellona - - - D’Orb. - ~| + - +
Myacites calceiformis  - - Phil. -| «| +
4 decurtatus - = Phi, - P ‘ -
- securiformis - - Phil. ol +
-Newra Ibbetsoni - Morris - 3 5 +
Nerinea foniculus - Desl.
Sy Voltzii - - Desl. - “| oe
Myoconcha crassa - - - Sow. ri eee +
Pholadomya deltoidea - Sow. 2] +
55 Heraulti - Ag. +
35 Lyrata - - Ag. . . +
35 socialis - -L.&M.~ . . +
Tancredia extensa - - Lycett ‘i o| +
Trigonia costata - Sow. -| . ef +
5 Moretonis - - -L.&M.- ol ete] + . oe
GasTEROPODA.
Natica globosa - - -L&M.- +
Nerita minuta - - - Sow. - ‘ . +
Nerinza funiculus - - ‘-Desl - +
»  Voltzii - - - Desl. +
CEPHALOPODA. i
Ammonites bullatus - - D’Orb. - A . . +
- Nautilus Baberi L. & M. - “ ef +
»  hexagonus -  »~ Sow. : te
»  subtruncatus - L.&M. - +
Pisces. ~
Strophodus magnus - Ag. -| .| + + ‘i
Hybodus dorsalis - - Ag. med te ‘ ° +
Pycnodus Bucklandi - - Ag. -| | . +
T

 
286 GEOLOGY OF RUTLAND, &Cc.

Table 2.—Geographical Distribution of the Great Oolite, &¢.—coné.

 

 

 

 

 

 

 

 

 

 

 

CoRNBEASH.
‘ Northamptonshire,
Bul |
Species. 3 ,| 2/3 3| 2
' a) ic S| 8
$\a al 8 geal s
3 5 e 3 8 lad =
EIES/ §| 3 | 20) 8
6/8 | 8] &/s*| &
EcHINODERMATA.
Acrosalenia - +
Echinobrissus dluyiediaris - Lihwyd. + 5 ‘ af Bx,
. orbicularis - Phil. . ‘ a ot tpt
Holectypus depressus - Leske ee fe cep oe fh ae wf aE
_ ANNELIDA.
Serpula intestinalis Phil. ‘ ‘ 3 - af eB
»  tricarinata Sow. . : F | +
Vermicularia nodus - = Phil. : 7 ‘é o| +
MoLiusea.
Brachiopoda.
Rhynchonella obsoleta - Sow. eA ed al) cat a | ae
varians - Schloth. ¢ 3 ~[ +t] +
TerebratulaBentleyi - - Morris . . . é oi oF]
ss lagenalis - Schloth. . Fi a ‘ +
33) ornithocephala - - Sow. ‘ : ‘ » | +
a obovata - - Sow. + ; Lr +
5 maxillata ’ - Sow. . a : ~{ +
LAMELLIBRANCHIATA.
Avicula echinata - - -- Sow. + 3 ‘i ~| + | +
>  Munsteri Goldf. é : * ‘ ~| +
Gervillia aviculoides - - Sow. + é - ~ | +
Ostrea flabelloides - Lam. +
Lima duplicata Sow. . ef wf ed ee te
>» pectiniformis - - Schloth. oll Ns [| of] ett
» Tigida - - - - = Sow. 3 )) eect he we | oe Fa
Pecten anisopleurus - - Buv. . . - | +
>  articulatus -  Schloth. p s a o] +
>»  annuatus - - Sow. 5 fs ‘ 3 ~| +
»  demissus - - Phil. + ‘ 2 o | +
»  vagans - - Sow. + 3 . f+
Isocardia tenera - Sow. + - " r .{ +
Gresslya peregrina - - Phil. . ait aa of tl +
Lucina crassa Sow. | +
Lithodomus inclusus Phil. is r - | +
Modiola imbricata - - - Sow. + a . : ~| +
Myacites decurtatus - Phil. ) + . A of +
»  secnriformis - - Phil. + ‘ s | +
‘Pholadomya deltoidea Sow. Tae aw] +
5 ovulum - - - oe Tee NM) Gag ill cus gill vee ae
Trigonia elongata ? - _ Sow. +
»  Moretonis - - L&M. +
GasTEROPODA.
Acteonina Scarburgensis - -  Lycett. el ede ahh ae ce
Chemnitzia sp. - = - > . ‘ Fi o | +
CErPHALOPODA.
Ammonites maceocephalus - -  Schloth. eN at wh ae a ae

 
APPENDIX. 287

Table 2.—Geographical Distribution of the Great Oolite, &c.—cont.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CoRNBRASH.
Northamptonshire. ;
ote
Species. gz A c 8 %
18a} 3] 3/38] 2
o g sla] -¢ oO! 6
wl28| a/.8 |Ss| 3
BiB) 8 | 3 | ss! 8
O}> | Rl eso] ms
Pisces. ,
Pycnodus sp. -: - = 4
Strophodus magnus - 2 - Ag: . .
” subreticulatus . Ag. +
ei tenuis = a Ag. £ 4d
i
~. GrEaT OOLITE.
' Lincolnshire.
a Species. \e
Stamford
Open Danes
Soe Fields. | Hill.
EiCHINODERMATA.
Acrosalenia hemicidaroides - Wright -
Clypeus Miilleri - - - 2 = s :
Crvstacra.
. ec %
Eryma elegans -- = " ss - - - Oppel. - = a
Mo tusca.
. Brachiopoda.
Bhynchonella coricinna - -Sow. - +
Terebratula intermedia - - - - - Sow. - +
6 maxillata - - - - Sow. +
53 ornithocephala - - - Sow. +
55 obovata "= - - Sow. - +
“ sublagenalis - - - Dav. - +
jf LAMELLIBRANCHIATA. *
Avicula echinata - - - - -Sow. - +
Lima cardiiformis - - - -L.&M. +
-duplicata - - - - Sow. +
Ostrea Sowerbyi- - - - - -L.&M.- + +
» subrugulosa - - - - L.& M. + +
Pecten annulatus - - \- ~ Sow. - . +
Perna rugosa - - - - - Miinst. +
»  quadrata - - - - - Phil. +
Cyprina Loweana Oy. eye - L.&M. - +
»  nuciformis aq Se - - -Lyc - +
Ceromya concentrica - - - - - Sow. +-
3 Symondsii - - = -L. & M.- si +
Cardium cognatum - - - = - Phil. - : os
» Buckmani_ - - - - -L.&M.- +
igs lingulatum = - i - - - L.& M.? f +
33 Stricklandii - - - - L.&M. - +
subtrigonum ~ - - - L.&M.- . +
Modiola imbricata - - = - Sow. - + +
Lonsdalei - - - - -L&M + ot

”
T2
288 GEOLOGY OF RUTLAND, &c.

Table 2.—Geographicar Distribution of the Great Oolite, &c.—eont.

 

 

 

 

 

 

 

 

 

 

Geeat OoLrtE.
Lincolnshire.
Species,
Stamford
Open | Danes
Fields, :
Myacites securiformis - - - - Phil, - ‘ +
Cypricardia caudata = - - - - - Lycett é + es
/ ss nuculiformis - - -Roém - : +
Isocardia tenera = - - Sow. - : +
Pholadomya acuticosta -, - - Sow. - +
f - Phillipsii - - - - Morris - . +
»  _ lyrata = - - -Sow. - ‘ +
Taneredia angulata = - - - - - Lycett - +
Nera Ibbetsoni - - S - Morris - + _
Trigonia costata - - - - Sow. - : +:
x»  Moretonis - - -~ L.&M. - ‘ +
GaSTEROPODA.
_Amberleya nodosa - - - - - Buckm, - ‘ +
Natica canaliculata - a - - L.& M.- - +:
»  globosa, - 4 - - - L. & M. - * + 7
_» formosa - - - -L&M.- +
»  pyramidata - - - L.&M. - . +
CEPHALOPODA.
Ammonites gracilis = - - - - - Buckm, +
Nautilus Baberi - - - L. & M. - +
>  subtruncatus - - - - - L.&M.- ‘a +
CoRNBRASE.
oS, 2 Lincolnshire,
Species. a 21S |
8! Se Rg é
2/53 |23 §
B/S a |
EcHINODERMATA.
Cidaris Bradfordensis - - - - Wright -| +
Echinobrissus clunicularis ~ - - Lihwyd -[ +
a5 orbicularis  - - - Phil. ~| + of ef +
' sm quadratus - - Wright -| +
Holectypus depressus - - - Lam, -| + . | +
ANNELIDA..
Serpula intestinalis - - - Phil. - + . | +
+ 5  tetragona - - - - Sow. -| +) ‘
~ ~
Moxzusca. &
Brachiopoda. - e
-Discina =~ is - a -| 5 ols
Rhynchonella concinna - - - Sow. -| + [+ o| +
a Morieri - - - Dav. Sp ow tok
oe 3 varians - - + Schloth. -| +] ef oe] +
Terebratula Bentleyi - - Morris = + +
3s coarctata. - - Park. Sl gap eae decaf ae
i intermedia - - - Sow. -l+

 

 

 

 

Sy
APPENDIX. “ 289

‘Table 2.—Geographical Distribution of the Great Oolite, &c.—cont.

 

 

 

 

 

 

 

CoRNBRASH.
Lincolnshire.
Species, - a [eet re
a /4elae| 5
g BE| 2B! a
#5/86| 2
B|S°|A-| &
Terebratula lagenalis - - Schloth. + «|
ine grnithocephala - Sow. - | + +/+
” maxillata 2 - Sow. - é +
53 obovata - - Sow. -| + oe
- sublagenalis - - - Dav. -| + +
e LAMELLIBRANCHIATA.
Avicula echinata Sow. &, | 38
se Munsteri - - Goldf. +
Gervillea aviculoides SP ge Ss - Sow. - +
Hinnites abjectus - Phil. és 4
Ostrea flabelloides - - - Lam. - {+ +
>»  Sowerbyi - - - - L& M. - +
»  subrugulosa - - - L. & M. - 3 +
Lima duplicata - - - - Sow. + : +
»  pectiniformis - - - - Schloth. w]e | SB
” impressa = i = L. & M. ‘ 5 + +
» _Tigidula - - Phil. -| + eds
2» rigida i = = - Sow. +
»  puncturata - - - Sow. ‘ +
Pecten demissus - - - - Phil. - . f +
» lens - - - Sow. - . i +
»  peregrinus - - - - L&M. - : . +
»  ‘vagans - - Sow. a é +
Pinna cuneata - - - - Bean +
Cardium cognatum - - - - Phil. - +
ae subtrigonum - - - L&M. - +
Cyprina Loweana - - - - L&M. - ‘ 5 +
Goniomya v-scripta - - - Sow. | + +
Gresslya peregrina - - Phil. - +
Homomya crassiuscula -_ - L. & M Es
55 gibbosa - - - Sow. +
Isocardia tenera = - - - Sow. - &
Lucina Lycettii. - - - - Oppel. - +
Modiola gibbosa ss - - Sow. - le. | +
» imbricata - - Sow. - +
Myopsis Jurassi; = - - - - Brong. +
Myacites calceiformis - - Phil. - 43
a decurtatus - - - - Phil. - ae
55 modica_- - - Bean - +
»  Sinistra - - Ag. a
»  securiformis - - Phil. - as
»  Terquemi - Buv. - & 3 el ae
Pholadomya deltoidea - Sow. / -| ef ep oe} +
9 acuticosta - - Sow. - ih ae
Trigonia costata - - - - Sow. ‘( Z a
- elongata ? - - - Sow. - F , +
35 cassiope - - - - D’Orb. +
3 Moretonis - - - L&M. = +
35 Scarburgensis - - - Lycett i 3 +
Quenstedtia oblita - - - Phil. ~[o»s] io. +
GasTEROPODA.
Chemnitzia vittata - - - ~- Phihoo -] +
290 GEOLOGY OF RUTLAND, &e.

Table 2.—Geographical Distribution of the Great Oolite, &e.—cont,

*

 

 

 

 

 

 

 

 

 

 

 

 

 

CoRNBEASH.
Lincolnshire.
Species. g 4i fa op é
eles) 28) §
. .| 8] 20180] &
P.1o |A |
Crrnanoropa. ,
Ammonites Herveyi - - Sow. a4 #
ai macrocephalus - - Scehloth. + .| +
Nautilus Baberi - - - - L.& M. +
Pisces. : es
Strophodus magnus — - - - Ag. =
< | Great Ooxrre!
Rutland.
| é
re ae ie
Species. : g
E| ) 2
‘g| ala
-- CRUSTACEA. :
Eryma, allied to Elegans - ‘. S < al el
: Mo zvsea. e
Brachiopoda.
Terebratula intermedia - - - - Sow. - = + |
” perovalis . - - - = Sow. - ~) +
LAMELLIBRANCHIATA. | i
Gervillia monotis - - -  - Desh - ae eee cere
»  Islipensis - (+ - - L.&M -| +
Lima cardiiformis - - + L&M -] eft] +
» puneturata - - - e a et gel a
Pecten annulatus - - - Sow. - -{ .-[ +f
» demissus - - - - - Phil. - ef oe b+
» lens. * - - > Sow. - ol +
Pinna cuneata - - - - Bean - -| 2] +
Perna quadrata ss - - - - Sow -| [+
Pteropersa costatula =. - - Desl. - . | te]
OstreaSowertbyi  - - - - - L&M. «|| eh
»  subragulosa - - - - L.&M. of Fl +o
Ceromya Symondsii - - - L. & M. -f +] +
Cardium subtrigonum - - - - L&M. ob aR
»,  Buckmani ° - - - L.&M. »| +
Corbicella Bathonica - : - - L&M. +
Cyprina depressiuscula =~ - - - L&M. 7] +
»  Loweana - - - - L&M. - ° | +
Cypricardia nuculiformis - = - - L.&M. -| + [+ ) +
aj Bathonica - - L&M. -) - | +
5 rostrata ¥ - Sow. - el is ~| +
Gresslya peregrina - - > Phil. - -]oel +
Homomya crassitscula = - - - - L&M a a
»  Vezelayi - - - D’Arch eel) oe PSE Ps
Isocardia tenera' - - - Sow. - ~ft] wd t+
Myacites calceiformis - - Phil. - ele pt
»  securiformis - - Phil. - a of lap
y,  Terquemea - - - Buv. - ot +
Modiola imbricata - - - - - Sow. ~-Jadl of +

 

 

 
APPENDIX.

291

Table 2.—Geographical Description of the Great Oolite, &c.—ont. ©

 

 

 

 

 

 

 

 

5 QGrezat OoOLITE,
Rutland.
g
Species. ;
pecies, g 2
a1 oa
2 ql
p\e| 2
a] A]
Macrodon Hirsonensis - - - D’Arch, - ; | +
Nera Ibbetsoni  - fe < ~ Morris = || 4
Pholadomya deltoidea = - Sow. - Bel eee
» Heraulti fale - Ag. - -| .[ +] 4
3 oblita - - - - LL&M. | +
ud lyrata, - - Sow. - et +
a socialis - - ie - L.&M. = | eb ae
as solitaria er gusece - L&M. ~| +
Tancredia axiniformis ~ ~ Phil. aul aay
Trigonia costata - - - Sow. -bo ow] +t] +
» elongata ? - - Sow. - +
» Moretonis - * - - L&M +
Unicardium varicosum = - - - Sow. - +
GASTEROPODA:
Natica globosa - a - L&M.' + +
» grandis - - L&M | +
» formosa . - - - - L.&M -[ + | +
+ intermedia - 7 - + L. & M « +
CErHALOPODA. Z
Nautilus Baberi  - - - - - L&M. + | +
»  subtruncatus - Su L.-& M. Pa tee
PIscEs. :
Hybodus sp. - ‘ 3 - +
Rerritia.
Teleosaurus sp. - - - - - = +
’Pterodactylus sp. ~- - - +
CORNBRASH.

Srrzton, HUNTINGDONSHIRE.

ECcuINODERMATA.

Clypeus Miilleri. « Wright.
Echinobrissus clunicularis. Llhwyd.
ff orbieularis. Phil.
Holectypus depressus. Leske.
i ANNELIDA.
Serpula intestinalis.. Phil.
»  squamosa, Beai.
»  tetragona. Sow.
CRUSTACEA.

Glyphza rostrata. Phil.

BRACHIOPODA.

Rhynchonella concinna. Sow.-

‘8 Moorei. Daw.
». . obsoleta Sow. = —
varians. Schloth.

”
292

GEOLOGY OF RUTLAND, &C

Terebratula Bentleyi. Morris.
Ais coarctata. Park.
ey intermedia. Sow.

mi lagenalis. Schloth.
»  sub-lagenalis. _Dav.
3 maxillata. Sow.

ss obovata. Sow.

93 ornithocephala. Sow.

LAMELLIBRANCHIATA,

Anomia semistriata. Bean.
Avicula echinata. Sow. °
Lima duplicata. Sow.

x» impressa. L, & M.

», leviuscula. Sow.

» pectiniformis. Schloth.
35 rigida. Sow.

rigidula. Phil.
Pecten anisopleurus. Buv.
»  articulatus. Schloth.
»  annulatus. Sow.

»  demissus. Phil. /
y» . inequicostatus. Phil.
» lens. Sow.

»  Michelensis. Buy.

vagans. Sow.
Cardium cognatum. Phil.
Cypricardia caudata. Lycett.
Goniomya v-scripta. Sow.
Homomya crassiuscula. L. & M.

35 gibbosa. Sow.
Isocardia tenera. | Sow.
Lucina striatula. Buv.
Modiola gibbosa. Sow.

» imbricata. Sow.

»  Lonsdalei. L.& M.

»  Sowerbyana. D’Orb:
Myacites ealceiformis. Phil. ,
” decurtatus. Phil.

» -recurvus. Phil..

ss securiformis. Phil.
35 sinistra. Ag. wt
Pholadomya acuticosta. Sow.

a deltoidea. Sow.

3 Lyrata. Sow.

5 Phillipsia. Morris.
Trigonia Scarburgensis. Lycett.

GASTEROPODA.

Chemnitzia simplex. L.'& M.
Pleurotomaria granulata. Sow.

i

Crrmazoropa.
Ammonites Harveyi. Sow.
macrocephalus. Schloth.
modiolaris. Llhwyd.
Pisozs.
Strophodus magnus. Ag.

» - subreticulatus.” Ag.
Pycnodus Bucklandi. Ag.
Asteracanthus verrucosus. Ag.

Reprint.
Ichthyosaurus sp.
Plesiogaurus sp.
Teleosaurus sp.

 
APPENDIX IL

' BIBLIOGRAPHY OF THE DISTRICT.
294 GEOLOGY OF RUTLAND,’ &.

List or Booxs, Papers, &c., ON THE GEoLogy, PALZONTOLOGY,
AnD MineraLocy or THE County oF RUTLAND, TOGETHER WITH
THOSE RELATING TO THE PORTIONS or Lancoin, Leicester,
NorrHampton, HUNTINGDON, AND CAMBRIDGE, INCLUDED WITHIN
THE AREA OF SHEET 64,

From MatrerIALs suppLiep By W..Wairaxker, B.A.,, F.GS, &e,

Alphabetical List of Authors, whose writings are cited in this Appendix,
(The numbers refer to the titles as Chronologically arranged.)

Anonymous Papers, 7, 67. Lycett, Dr. J., 49, 58, 62, 64, 78, 108.
Anderson, Sir C., 46. ' Maw, G.,.91.
Ansted, Prof. D. T., 82. Mitchell, Dr. J., 37.
Baker, J. L., 58. Morris, Prof. J., 47, 49, 47, ae 62, 97.
Barker, T., 9. Morton, J., 2.
Bathurst, C., 32. Murray, a. 92.
Bayne, A. D., 106. ‘ Owen, Prof. R., 39, 98.
Bearn, W., 54. : Parkinson, R:, 16, 19.
ee Brayley, E. W., 13,14. , ~ "1 Perey, Dr. a 80.

Brewer, J. N., 18. i Phillips, Prof. J., 42, 85, 100.
Britton, J., 11, 12, 14. Phillips, W., 22,28. . -
Brodie, Rev. P. B., 43, 48, 50, 68, 72,89, | Pitt, W., 15, 19.

94, Porter, Dr. H., 75, 79.
Brown, —, 73. = Pusey, P., 40.
Buckland, Rev. Dr. W., 24. Riley, E., 16.
Clarke, J. A., 51. ” ~ =| Rome, Rev. J. L., 98.
Coleman, Rev. W. B., 45. Rose, C. B., 41. 2
Conybeare, Rev. W. B., 28. Saunders, J, Jan., 34.
Davidson, T., 52, 55. Sedgwick, Rev. Prof. A, 31.
De la Beche, A. T., 38. Seeley, H. [G.], 86, 87.
De la Condamine, Rev. H. M,, 56, Sharp, 8.799, 101, rie 110.
Duncan, [Prof.], P. M., 90. Short, Dr. T., 4, 8, 6,7
Edwards, L., 8. Smith, C. H., "44, 38°
Fairley, W., "102.- Smith, W., 21, 23, 25-27, 38, 42.
Fitton, Dr. W. H., 35. Sowerby, ae 20, 29, 30, 33.
Herman, W. D., 103. Sowerby. J. D., 33.
Holdsworth, J., 83. Topley, W., 105.
Hull, E., 70, 84, 107. Townshend, Rev. J., 12,
Hunt, a. 74. Trimmer, J, 59, 60.
Tbbetson, Capt., LL.B., 47. ‘| Trollope, Rev. B,, 68.-
Jecks, C., 95. W., 67.
Judd, J. W., 96, 104. Wood, S. V., Jun., 81, 88, 93.
Lewis, Rev. —,3. Wright, Dr. T., 61, 65, 66, 69, 71, 77.
Lister, M., 1. Young, A., 10.
Lonsdale, Ww. 36.

 
lL

APPENDIX. 295

"Chronological List of the Papers referring to the District.

1671.
Lister, M. A Letter , . . . . on that ‘of M. Steno concerning
Petrify’d Shells. _ Phil. Trans., vol. v. (No. 76), p. 2282.
1712.

‘2. Morton, J. Natural History of Northamptonshire, &c. Fol, Lond.

3.

10.

ll.
12.

13.

14,

15.

1728.

Lewis, Rev. —. An Account of the several Strata of Earths and Fossils
found in sinking the mineral Wells at Holt..  .-
a Phil. Trans., vol. xexv. (No. 403), p. 489.

1734.

. SHort, Dr. T. The Natural, Experimental, and Medicinal History of

the Mineral Waters of Derbyshire, Lincolnshire, and Yorkshire, Par-

ticularly those of Scarborough,...... Together with the Natural

History of the Earths, Minerals, and Fossils through which the chief of

them pass. vA . 4to. Lond.
1740.

. Sort, Dr. T. An essay Towards a Natural, Experimental, and

‘ Medicinal History of the’ Principle Mineral Waters of. .... . North-
amptonshire, Leicestershire, and Nottinghamshire, Particularly those
of Nevile Holt ...... &e.. Ato. Sheffield.

—— Natural, Experimental, and Mé@dicinal History of the ~
Mineral Waters of England. 4to. Sheffield.

1765.

 

. Anon. [Dr. T. SHorr]. A General Treatise on various Cold Mineral

Waters in England, but more particularly on those at . . . . . re
Neville Holt, &c. 1769 8v0. London.

. Epwarps, L. Survey of Witham (some geological notes).

1791. ,

. Barker, T. Abstract of a Register of the Barometer, Thermometer,

and Rain at Lyndon in Rutland. Note, “ Chalk found in a new place.”
Phil. Trans., vol, lexai., Part 2, Pp 281.

1799. ;
Youne, A. Agricultural Report of the County of Lincolnshire, with a
Map and Plates: . ; 8vo0. London.
‘ 1807. s ‘

Brirron, J. A Topographical and Historical Description of Leicester
shire. Beauties of England and Wales, vol. ix., p. 313. 8vo. London.

 

— A Topographical and Historical Description of Lincoln-
shire. 2 _Ibid., p. 523.
1808.
Bravyury, E. W. <A Topographical and Historical Description of Hunt-
ingdonshire. Ibid., vol. vii., p. 325.
Brayuey, E. W.,and J. Brirron. A Topographical and Historical
Description ‘of Cambridgeshire. Ibid., vol. i.
: 1809.
Pirr, W. Agricultural Report of the County of Northamptonshire,

drawn up for the Board of Agriculture and Internal Improvement. °
, '8vo. Lond.
296 GEOLOGY OF RUTLAND, &c.

1811,

16. Parxinson,-R. Agricultural Report of the County of Huntingdon,
drawn up for the consideration of the Board of Agriculture and Internal
Improvement. 8vo. Lond.

, 1812.

17. TowNSHEND, Rev. J. The Character of Moses established for veracity

as an Historian. Recording Events from the Creation to the Deluge;

with Plates of Fossils. 4to. Bath and Lond.
; . 1813. .
18, Brewer, J. N. A Topographical and Historical Description of the
County of Rutland. ‘

Beauties of England and Wales, vol. aii., Part II. 8vo. Lond.

19. Pirr, W., and R. Parkinson. A General View of the Agriculture of
- the Counties of Leicester and Rutland, drawn up for the consideration
of the Board of Agriculture and Internal Improvement, with a Map

and Plates. “ 8vo. Lond.
1816-1818.

'20. Sowzrsy, J. The Mineral Conchology of Great Britain. Vol. II. -

1817 8vo. Lond.

21. Smitu, W. Stratigraphical System of Organized Fossils with reference
to the specimens of the Original Geological Collection in the British
Museum. Explaining their state of preservation and their use in
identifying the British strata. 4to. Lond.

1818.

22. Puruiips, W. ‘A Selection of Facts from the best authorities, arranged
so as to form an Outline of the Geology of England and Wales. With

a Map and Sections. 12mo. Lond.
1820. .
, 23, Smitu, W. A New Geological Map of England and Wales. Lond.
1821.

24, Buckuanp, Rev. Dr. W. Notice of the Chalk at Ridlington. *
Trans. Geol. Soc., vol. v., p. 539.

25-27..SmirH, W. Geological Maps of Rutlandshire, Leicestershire, and ,

Huntingdonshire. Lond.
. 1822,
28, Conveearz, Rev. W, D., and W. Puiuirps. Outlines of the Geology
of England and Wales. 8v0. Lond.
1822-1823,
29. SowzrBy, J. The Mineral Conchology of Great Britain. Vol. IV.
‘ 8vo. Lond.
1824-1825.
30. SowERBy, J. The Mineral Conchology of Great Britain. Vol. V.
: 8vo, Lond.
1825.

31. Sepewicx, Rev. Pror. A. On the Origin of Alluvial and Diluvial
Formations. Ann. of Plil., Ser. 2, vol, iz., p. 241, and vol. z., p. 18.

1826.
32. Baruurst, C. Account of the Geology of the county between Stam-
ford and Bedford. MS.
1826-1829.

33. Sowzrsy, J., and J. D. The Mineral Conchology of Great Britain.
Vol. VI. : 8v0. Lond.
37.

39.

40

41,

42,

43.

‘45.

46.

47.

» 48,

. LonspaLz, W. Maps of the Oolitic Districts of England. Sheet

APPENDIX. 297

1834,

. SAunpers, J., Jun. History of the County of Lincoln, with a Map:

and Plates. [Geology, chapter 2, p.17.] 4¢o. London and Lincoln.
1836.

. Frrron, Dr. W. H. On the strata between the Chalk and the Oxford

Oolite in the South-east of England (Chalk at Ridlington).

Trans. Geol. Soc., Ser. 2, vol. iv., p. 308, and notes, p.383*,

64,

MS.
1838.

MitcHe.t, Dr. J. On the Drift from the Chalk and the Strata below
the Chalk in the Counties of Norfolk, Suffolk, Essex, Cambridge,
Huntingdon, Bedford, Hertford, and Middlesex.

Proc. Geol. Soc., vol. tit., p. 3.
1839.

. De ta Becue, H. T., W. Smrru, and C. H. Smiru. The Result of an

Inquiry undertaken under the Authority of the Lords Commissioners
of Her Majesty’s Treasury with reference to the Selection of Stone for
building the new Houses of Parliament. Parliamentary Report.

1841.

Owen, Pror. R. A description of a portion_of the Skeleton of the
Cetiosaurus, a gigantic extinct Saurian Hepes occurring in the Oolitic
formations of ‘different portions of England. ‘ /

_ Proc. Geol. Soc., vol. tii., p. 457.
1843, e

Pusey, P. On the Agricultural Improvements of Lincolnshire.

‘Journ, Roy Agric. Soe. vol. iv., p. 287.

Ross, C. B. On the Alluvium of the Bedford Level. Geologist, p. 73.

— 1844,
SmitH, W. Memoirs of William Smith by Pror. JoHn PHILLIPS.
’ 8v0. Lond.
1845.

Bropigz, Rev. P. B. A History of the Fossil Insects in the Secondary
Rocks of England, accompanied. by a particular account of the strata
in which they occur, &c. i 8v0. Lond.

. Smitu, C. H. Lithology, or Observations on Stone used for Building.

dio. Lond.

-

1846,
Coteman, Rev. W. H. Ariicle on the Geology of the County of
Leicester. W. White’s History, Gazetteer, and-Directory of Leicester-
shire and the small County of Rutland. Witha Map. ~

a "3 12mo. Sheffield.

: 1847.
Anperson, Str C. A Short Guide to the County of Lincoln, with
notes on the Geology, Botany, &c. 12mo. Gainsborough, *
1848,

IBpErson, Capt., LL.B., and [Pror.] J. Morris. Notice of the
Geology of the neighbourhood of Stamford and Peterborough.
Rep. Brit. Assoc. for 1847, Trans. of Sections, p. 127.

1850.

Bropiz, Rev. P. B. Sketch of the Geology of the neighbourhood of
Grantham, Lincolnshire; and a comparison of the Stonesfield Slate at
Collyweston in Northamptonshire with that in the Cotswold Hills. —

Ann. & Mag. Nat. Hist., Ser. 2. vol. vi., p. 256, and Proc. Cotteswold
Nat, Club, vol.t., p. 52.
298 GEOLOGY OF RUTLAND, &c. :

49, Morris [Pror.] J., and J. Lycrrr. A Monograph of the Mollusca
from the Great Oolite. Part I., Univalves [Collyweston, p. 15].
Paleontograpk. Soc. 4to. Lond.

1851.

50. Bropiz, Ruv. P. B. Remarks on the Stonesfield Slate’at Collyweston,
near Stamford, and the Great Oolite, Inferior Oolite, and Lias, in the
neighbourhood of Grantham [equivalent to No. -, but with slight-
alterations]. Rep. Brit. Assoc. for 1850, Trans. of Sections, p. 74.

51. -Cuarke, J, A. Farming of Lincolnshire.

. Journ, Roy. Agric. Soc., vol. xii., p. 259.

52. Davipson, T. A Monograph of British Oolitic and Liassic Brachio-
poda. Part II. [Northampton, pp. 10, 40-43, and 58].

: Palaontograph. Soc. 4to. Lond.

1852.

53, Baxer, J. L. An Essay on the Farming of Northamptonshire, with a
geological map, &c. é 8v0. Lond,
54, Brarn, W. On the Farming of Northamptonshire [with description
and map of the soils]. Journ, Roy. Agric. Soc., vol. witi..p. 44.
55. Davipson, T. A Monograph of British Oolitic and Liassic Brachio-
poda, Part III. [Plates 14-18, and p. 68].
: Paleontograph. Soc, 4to. Lond.

1853, i

56. De La Conpamine, Rev. H. M. On a Freshwater Deposit in the
“Drift” of Huntingdon. Quart. Journ. Geol. Soc., vol, ix., p. 271.

57. Morris [Pror.] J. On some Sections in the Oolitic district of Lincoln-
shire. Quart. Journ, Geol. Soc., vol. ix,, p. 317.

58. Morais, [Pror.] J. and J. Lycerr. A Monograph of ‘the Mollusca
‘from the Great Oolite; chiefly from Minchinhampton and the Coast. of
Yorkshire. Part II. Bivalves. Palwontograph. Soc. 4to. Lond.

59. Trimmer, J. Notes on the Geology of the Keythorpe Estate, and its
relations to the Keythorpe System of Drainage. ; -
Journ. Roy. Agric. Soc.; vol. xiv., p. 96,
60. Trimmer, J. On some Mammaliferous Deposits in the Valley of the
Nene, near Peterborough. Quart. Journ. Geol, Soc., vol. ., p. 343,

1854,

61, Wricut, Dr. T. Contributions to the Palzontology of Gloucestershire.
A description, with Figures, of some new Species of Echinodermata,
from the Lias and Oolites. . de
_ Ann. and Mag. Nat. Hist. Ser..2, vol. witi., pp. 312, 376, and Proe.

Cotteswold Nat. Club., vol. ii., p. 17 (18602). ,

1855. \
62. Morris, [Pror.] J., and J. Lycerr. A Monograph of the Mollusca,
from ee Got Oolite chiefly from Minchinhampton and the Coast of
Yorkshire. Part ITI. Bivalves. Paleontograph. Soc. to. Lond.

1857.
63. Bropiz, Rev. P.B. Remarks on the Inferior Oolite and Lias in parts
of Northamptonshire, compared with the same Formations in Glou-

stershire. A ;

Prob, Cotteswold Nat. Club., vol. ti., p. 182, and Ann. and Mag.
Nat, Hist., Ser. 2, vol. wiz. p. 56. * i

64, Lyczrt, J. The Cotteswold Hills. Hand-Book Introductory to their

Geology and Paleontology.  8v0. Lond. and Stroud, p. 131, §e.
APPENDIX. 299°

'

65. Wricut, Dr. T. A Monograph on the British Fossil Echinodermata
of the Oolitic Formations. Part First, containing the Cidaride, .
Hemicidaride, and Diademade. [Pp. 1-154.]

: Paleontograph. Soc, 4to. Lond.

1858.

66. Wricut, Dr.T. A Monograph on the British Fossil Echinodermata
from the Oolitic Formatians. Part II., containing the Diademade,
Echinide, Saleniadz, and Echinoconide. [Pp. 155-302.]

Paleontograph. Soc. 4to, Lond.

1859,
67. Axon. [W.] The Deposition of Warp.
68, Trotuore, Rev. E, On the Alluvial Lands and Submarine Forests
of Lincolnshire. 4 : ;
Proc. Geol. and Polytech. Soc., W. Riding, York, vol. iii., p. 687.
‘69. WricHt, Dr. T. A Monograph on the British Fossil Echinodermata
from the Oolitic Formations. Part III. containing the Collyritide,
Echinobrisside and Echinolampide. [Pp. 303-388.]
Paleontograph. Soc. 4to. Lond.

1860.

70, Huu, E. On the South-easterly Attenuation of the Lower Secondary
Formations of England; and the probable Depth of the Coal Measures
under Oxfordshire and Northamptonshire.

God. Journ. Geol, Soc., vol. zvi., p. 63.

71. Wricut, Dr. T. A Monograph on the British Fossil Echinodermata
from the Oolitic Formations. Part IV. containing the Echinolampide. '
- The stratigraphical distribution of the Echinodermata, &c. [Pp. 389-
* 468.) Paleontograph. Soc. 4io. Lond.
1861.

72, Bropiz, Rev. P. B. On the Geology of South Northamptonshire.
; Proc. Warwick Nat. and Archeol. Field Club, p. 4.

73. Brown, —. The Iron Ores of Northamptonshire.
Trans. S. Wales Inst. of Eng., vol. ti., p. 193.

\

(Discussion, p. 232.]

74, Hunt, R. On the Iron Ore Deposits of Lincolnshire [with analyses
and sections], ae. oy :
. Proc. Geol. and Polytech. Soc., W. Riding, York, vol. iv., p. 97.
75. Porter, Dz. H. The Geology of Peterborough and its neighbourhood.
es 8vo. Peterborough. °
1862.

6. Rinuy, E. On the Manufacture of Irpn. ¢ [Analyses of Ores and Coals.]
aa Trans, Soc. Eng. for 1861, p. 59.
77. Wricut, Dr. T. A Monograph on the British Fossil Echinodermata
: from the Oolitic Formations, Vol. 2, Part First. On the Asteroidea. °

Paleontograph. Soc. 4to. Lond.
1863.

78. Lycert, Dr. J. Supplementary’ Monograph on the Mollusca from the
Stonesfield Slate, Great Delite Worest Marble, and Cornbrash.
? Paleontograph. Soc. 4to. Lond.

79. Porter, Dr. H. On the Occurrence of large Quantities of Fossil
Wood in the Oxford Clay, near Peterborough. .
: Quart; Journ. Geol. Soc., vol. xix., p. 317.

1864,

80. Percy, Dr. J. Metallurgy [Vol. II.], Iron and Steel. [Analysis of Iron
Ores, pp. 208, 209, 225, 226.] 8vo,. .. Lond.
300 GEOLOGY OF RUTLAND, &C.

1865. =

81. Woon, S. V., Jun. A Map” of the Upper Tertiaries in the Counties of
Norfolk, Suffolk, Essex, Middlesex, Hertford, Cambridge, Huntingdon,
and Bedford. (With Remarks and. Sections.) Privately printed.

1866. .
82. AnsTED, Pror. D.T. Physical Geography and Geology of the County
of Leicester. (Natural Hist. of Leicestershire). 4¢0. Westminster.

83. HoLpswortu, J. On the Extension of the English Coal-fields beneath
the Secondary Formations of the Midland Counties. Also, Does Coal
exist near London ? 8vo. Lond.

84. Huu, E. ‘The new Iron-fields of England. ‘

Quart. Journ. of Sci., vol. itt., p. 323.

85. Putuuips, Pror. J. A Monograph of British Belemnitide. Part II.,

"containing Pp. 29-52, Plates I.-VII. [Liassic.]
; Paleontograph. Soc. 4to. Lond.

86. SexLey, H. [G.] A Sketch of the Gravels and Drift of the Fenlands.

Quart. Journ. Geol. Soc., vol. xwit., p. 470.

87. ——_—— Theoretical Remarks on the Gravel and Drift of the

Fenlands. Geol. Mag., vol. iti., p. 495.

1867.
88. Woop, S. V., Jun. On the Structure of the Post-glacial Deposits of
the South-east of England. i

Quart. Journ. Geol. Soc., vol. xetii., p. 394. Corrections in Geol.
Mag., vol. v., pp. 43, 534 (1868).

 

1868,

89. Broptz, Rev. P. B. A Sketch of the Lias generally in England, and of
the “ Insect and Saurian beds,” especially in the lower division in the
Counties of Warwick, Worcester, and Gloucester. With a particular
account of the fossils which characterise them.

Proc. Warwick Nat. Archeol. Field Club, p. 1, with a shorter °
title in Trans. Woolhope Nat. Field Club for 1866, p. 205 (1867),
and Trans. Dudley and Midland Geol. and Sci. Soc. (1868).

90. Duncan, [Pror.] P. M. A Monograph of the British Fossil Corals,
Second Series, Part IV., No. 2, pp. 45-73, Plates XI1—X VII. [Liassic].
- Paleontograph. Soe... 4to. Lond.
91. Maw, G. On the Disposition of Iron in variegated Strata.
Quart. Journ. Geol. Soc., vol. xeiv., p. 351.
92, Murray, G. Onthe Farming of Huntingdon. (Note on the Geology.)
; Journ. Roy. Agric. Soc., Ser. 2, vol. iv., p. 251.
93, Woop, S. V., Jun., and Rev. J. L. Rome. On the Glacial and Post-
glacial Structure of Lincolnshire and South-east Yorkshire.
Quart. Journ, Geol. Soc., vol. xaiv., p. 146.

1869.

94, Bropiz, Rev. P. B. Geological Notes on Northamptonshire, &c.
Geol. Mag., vol. vt., p. 236.
95. Jecxs, C...On the Ferruginous Sandstone of the neighbourhood of
Northampton. :
Geol. and Nat. Hist. Repertory, vol. ti., p. 261; and Rep. Brit, Assoc.
for 1868, Trans. of Sections, p. 69.

96, Jupp, J. W. On the Origin of the Northampton Sand. (Abstract.)
Geol. Mag., vol, vi., p. 221.

97. Morris, Pror. J. Geological Notes on Parts of Northampton- and -.
Lincolnshires. Ibid., p. 99.
98.

99.

00.

101.

102.

103,
104,

105.

106.

107.

108.

109.

110.

APPENDIX. 301

Owen, Pror. R. Monograph on the British Fossil Reptilia from the
Kimmeridge Clay. ‘No. III. containing Plesiosaurus grandis,’ P. tro-
chanterius, and P. Portlandicus. Pp.1-12. PlatesI-IV. -

Paleontograph. Soc: 4to. Lond.
Suarp, S. Notes on the Northampton Oolites. 5G
7 : Geol. Mag., vol. vi., p. 446,
1870. ;
Puiuuirs, Pror. J. A Monograph of British Beleminitide. Part V.:
containing pp. 109-128, Plates XXVIII-XXXVI. [Oxford Clay and
Kimmeridge Clay.] Paleontograph. Soc. 4to. Lond.
Suarp, S. The Oolites of Northamptonshire. 5 ?
Quart. Journ. Geol. Soc., vol. xavi., p. 354,

1871.

Farrtry, W. Rambles in Northamptonshire. (Iron Ores, &e.) .
Colliery Guardian, vol. axi., pp. 362, 472, 533, 577, 662, and vol. xaii.,
pp. 7, 60, 83. '

Herman, W. D. On Allophane and an allied Mineral found at North-
ampton. _ Quart, Journ. Geol. Soc., vol. xavii., p. 234.
Jupp, J. W. On the Anomalous Mode of Growth of certain Fossil
Oysters. Geol. Mag., vol. viii., p. 355,

Toritey, W. On the Comparative Agriculture of England and Wales. .
Journ. Roy. Agric. Soc., ser. 2, vol. vit., Part I. p. 268.
1872. x

Bayne, A. D. Royal Illustrated History of Eastern England including
a survey of the Eastern Counties, Physical Features, Geology, &c. of
Cambridgeshire, Essex, Norfolk, and Suffolk. Vol.I. 8v0. Yarmouth.

Huu, E. A -Treatise on the Building and Ornamental Stones of
: Great Britain and Foreign Countries. 8vo. Lond.

Lycett, J. A Monograph of the British Fossil Trigonie. No. I. Pp.
1-52. ‘Paleontograph. Soc. 4to. Lond.

: 1873.
Si 1
Suarp, S. The Oolites of Northamptonshire. Part II.
- " Quart. Journ. Geol. Soc., vol. xxiz., pp. 225-302.

1874. -

Saarp,S. Sketch of the Geology of Northamptonshire.
: : Proc. Geol. Assoc., vol. iti., No. 6, p. 243.

32108. U
.

303

INDEX. :

 

Achurch, Cornbrash at ; 222.
Age of “ ‘Great Oolite Clay. 8;” 32.
—— of Lincolnshire Oolite ; 86, 38, 39.
Ailsworth, Great Oolite Limestone at; 208.
—_, table of Fossils from; 284, ‘
—— Heath, Cornbrash at; "o24,
—_—_—. , Upper Estuarine Series at; 189.
Aldwinkle, oblique lamination at ; 114,
—. 2 ebay cating, Northampton Sand
in; 98.
—, eunsbcich of beds in valley at; 169.
Alwalton, Cornbrash near ; 224. .
~—, flaggy limestones at ; 201.
——, railway-cutting near ; 208.
, table of Fossils from Great Oolite
- at; 284,
_Alwalton Lynch, Escarpment of the; 208.
Lynch, Travertine near ; 268.
~— marble; 202, 208, 209.
-Allexton, thickness of Rock-bed at; 65.
—— pit, section and fossils in; 72, 83.
-Alluvium of the Old Fen Lakes ; 253,

 

 

‘—— of the present rivers ; 253.

Ammonites angulatus, zone of ; 59.
——- armatus, zone of ; 59.

— Bucklandi, zone ‘of; 59.
—— capricornus, zone of; 60.
—— communis, zone of ; 79.

ibex (?), zone of; 60.

— Jamesoni; 60.

—— margaritatus, zone of ; 64.
ozynotus, zone of ; 59. 8
— planorbis, zone of 3 58.
semicostatus, zone of; 48, 59.

 

 

 

Analysis of inner and outer portions of

Northampton Iron-ore; 125.

of Tron-ore from Hardingstone ; 3 124,

from Heyford, near Weedon ; 125.

~—— from Wellingborough; 122, 123, 124,

‘ Analyses of Northampton Tron-ores; 3 122,

Analysis of unweathered portion of North-
amptonshire ore, by Mr. D. Forbes ; 3
126: :

- Anderson, Sir C., on- county of Lincoln;
297.

Ansted, D. T, on county of Leicester ;
300.

Apethorpe, Upper Estuarine Series near ;
194,

 

 

—_ Lodge, sections in Great ‘Oolite Lime-
Stone near; 206. -

— Town-pit, ” Great, Mente Limestone.

in; 207.
_— Lower Estuarine Series i in; 100.
Area occupied by Lower Lias ; ‘60.
Artesian wells at Bourn; 267. _
Ascott, thickness of Jurassic beds at ; 32.

 

Ashley, sections in Rock-bed near; 75.
——, Upper Lias near; 81.

Ashton Brickyard, section of Oxford Clay
at; 224. 2

» Cornbrash outcrop’ near ; 223.

- Ashwell, sections in Rock-bed near; 70.

—— and Oakham,. railway-cuttings i in Up-
per Lias between ; 85.

Aunby cutting, section in; 197,

—, Lincolnshire Oolite at; 175.

‘Ayston, Northampton Sand : at; 109.

B.

Bainton, faults near; 257.

—— Heath, Great Oolite at; 207.

—_— , Upper Estuarine Series at; 195.

Baker, J. "Ly on the farming of North-
amptonshire ; 298.

 

' Banbury, age of Oolites of; 4.

—, faults’near ; 255.

——,, forest marble near ; 215.

—, marble; 45.

——., Northampton Sand of; 29.
Banthorpe, cuttings near; 218, 226.
Barford Brook, pie Lias along the; 81.

          

Barker, T., on meteorology at Lyndon and
chalk in "Rutland ; 295,

Barkston, escarpment at ; 42. °

Barleythorpe, section of Upper Lias at ; 87.

» faults near; 257.

——, quarries at; 179.

——, section at ; "178.

Barnack, shelly facies at; 140.

stone, instances of the use of ; 180.

 

 

“Barnack-rag,” extensive use of ; 141,
172.
' Barnsdale, Lincolnshire Oolite at; 167,

168.

Barnwell All . Saints, section of Cornbrash
near; 222.

Castle, sections of Great Oolite near;

216.

railway-cutting, Great Oolite in ; 204,
216.

—— railway station ; 234.

——— station, pit in Cornbrash near; 222,

Barrow Hill outlier of Northampton Sand;
109.

Barrow, sections of Ironstone rock at; 97.

——, Upper Lias; 85.

Barrowden, outlier of Great Oolite at;
213.

Barrow on Soar, Lias at; 41.

Barrow on-the-Hill, Upper Lias sections
near; 84.

 

 

’ U2
304

eee Lincolnshire Oolite near ;
—— Northampton Sand near ; 95.
. Hay, Cornbrash pallies at; 229,
Bath, Fuller’s Earth at ;
“ Bath Oolite,” sense in which used; 3.
’ Bathurst, C., on the country between ‘Stam-
ford and Bedford ; 296.
Beacon Hill, mass of Marlstone Rock-bed
on; 246.
Bedford Purlieus, formations at ;
, Great Oolite Limestones at; 207.
» Great Oolite Clays at; 215.
—, ; Cornbrash at; 229.
——, the Duke’s Brickyard on ;, 217.
Bee ‘Hill, outlier of Northainpton Sand;
107.
Beesley, me on age of Oolites near Ban-
bury; -4.
Bain, A. D., geological notes, &c.; 301.
Bearn, W., on farming of Northampton-
shire ; 298,
Balewth ape, Cornbrash near ; 226.
railway-cutting at; 209.
—— table of Fossils from Great Oolite
at; 290.
Belton brickyard, horizon of beds i in ; 64.
list of fossils from ; 71.
Bentley, Mr.; 158, 225, 230,
Berkeley, Rev. M. J.; 170, 246.
Benefield, Cornbrash near; 224,
Table of Fossils from; 286.
—— Kellaways beds at ; 232, 234.
-—— chalky Boulder Clay at ; 246.
—— subterranean stream near; 268.
—— chalybeate spring near ; 269.
—— section and list of fossils ; 205.
——— Upper and Lower, section in Great
Oolite near; 266.
—— Upper, section in grayel-pit near 5
241,
See also Upper and Lower,
Bibliography- of the district ; 294.
Billesdon, Brick-earth near ; 243.
—— Fault, line of ; 254, '
--— prickyard, section at; 69.
—— Coplow, boring'for coal ; 62.
—— and Loddington Fault, effects of the;
71, 256.

 

 

 

 

 

 

 

 

‘Billing Brook, beds-along course of the;,

195, 208, 224, 284. -

Bisbrook, Lincolnshire Oolite at; 177.

— Northampton Sand at; 109.

Blackingrove, beds and list of fossils at ;
27.

Blake, Rev. J., ou zone of Ammonites angu-
latus; 41.

Blashfield, Mr., on clays near Stamford ;
201.

Blast furnaces erected in the district ;
112,

Blaston, age of beds at; 64.

Blaston, St. Giles, pit in Upper Lias at;
82.

—— St, Michael’s section and fossils ; 3 74.

Blatherwycke, chalybeate spring at ; 270.

——, inlier of Northampton Sand at ; 101.

194, .

 

j INDEX,

Blatherwycke, Lincolnshire Oolite at; 149,

153.
——, outlier of Great Oolite; 213.
——., Upper Estuarine Clays at; 192.
—— mill,-succession of beds near ; 228,
—— Park, Lower Estuarine Series in wells
at; 102.
Blisworth, , analyses of Tron-ores from ; 126,
127.
Boulder Clay, filling sand pipes; 191.
—— and glacial deposits ; 240.
—— at Brigstock Parks; 239.
—— at Melton Mowbray, thickness of the ;
243,
—— at Werrington Mill; 236,
—— at Yaxley; 238.
——, mode of occurrence; 262.
——, old river channels under the; 243.
—— and pre-glacial gravel; 229."
——, remarkable boulders in the; 246.

|) ——, thitkness of the; 141, 221.

—— under the Fenland ; 237,

Boring for coal at Billesdon Coplow ; 62.
—— at Neville Holt; 107.

—— at Stamford; 85, 104.

Bottlebridge, Tronstone dug at; 215, 217.
—_— railway-cuttings at; 209.

| Boundary line between the Great and In-

ferior Oolites in Midland District ; 30.
Bourne, fossils frum Cornbrash near ; 227,
228, .
—, section of .Kellaways at; 237.
Braceborough, mineral spring at ; 268, 269,
270.
Bradford Clay, local character of; 9.

‘—— represented .by Great Oolite Clays ;

186.
Brailes Hill beds at; 13, 17.
, list of fossils from ; ae .
—, ; outlier at; 17. ~~
Brampton and Dingley, outlier of North-
ampton Sand ; 106.
Bramston ; Middle Lias at; 76. »
Btaybrook, Upper Lias at ;- 81.
Brayley, E. W., on Huntingdonshire, and”
Cambridgeshire ; 295.
Breaks in the Lias, probable cause of;
46. —
Bredon Hill, fault at; 14, 256.
—_ outlier, sections ‘at 5 12, 14.
Brentingby mineral spring ; 269.
Brewer, J. N., on the county of Rutland ;
“296.
Brickmaking, - Great Oolite Clays for;
189.
Brickyards at Melton, Mowbray, beds in;
60.
Brickyard between Whissendine and Pick-
well, horizon of; 64.

 

: Brigstock, Upper ‘Eotuarine Series near 5.

189.
——, Great Oolite near; 213.
——,, section in Lord Lyveden’s pits near ;
191,

‘—— Mill, brickyard and wells at; 101.

——— ——, Lincolnshire Oolite at 3 149,
— Parks, inlier at ; 38, 197.
, outlier at ; 298, 239.

‘
INDEX.

Fiigshook Parks, disturbances, faults, &c.
at ; 38, 256, 259.
— "Taferior Oolite and Northampton
Sand at; 101:
—— sections in inlier at; 197.
—-— Upper Lias Clay at; 86.
— well at; 289.
Brixworth, Northampton sand at; 30...
Britton, J., on Leicestershire, Lincolnshire,
and Cambridgeshire ; 3 295.
Brosilway Hill, Inferior Oolite at;
Brodie, Rev. P. B., on “Fish and Insect
~ beds ;” 41, 79.
—, ‘Geological papers by, relating to the
district ; 297, 298, 299, 300. -
—-P. B, on Oolites near Grantham ; 3.
Brook Hall, Rock-bed at ; 76.
Broom Hill Farm, ironstone at; 20.
Brown, Mr. on the Iron-ores of Northamp-
tonshire ;. 299.
Browns Oak, sections near; 226.
Buckland, Rev. W., on the Chalk at Rid-
lington; 296.
“ Bueklandi” beds in the: Froddingham
cutting ; 41, 42.
Buckman, on Cornbrash fossils ; 219.
ee district celebrated for ; ;
5
—— of the Lincolnshire Oolite, durability
‘of the; 180.
—— for the New Houses of Parliament,
report on; 179.
-Bulwick, Great Oolite near; 191. *
— -—— table of fossils from; 284.
Bulwick, inlier of Northampton Sand at;
101.
-— Lincolnshire Oolite at ; 149, 153.
— outlier at; 213.
Building materials, remarks on; 176.
Burford, thickness of Jurassic beds at; 32.
Burghley Park, Ironstone Quarry, section
at; 164.
Bavisig Park, fault at ; 172.
——, Iron-ore at; 104.
, Northampton Sand at ;’ 103.
—, sections of Upper Lias i in; 86.
——~ spa; 269.
—, ‘Northampton Sand escarpment at ;
97.
Burley-on-the-Hill, Upper Lias along es-
carpment to the north of; 85.
Burrow Hill, Middle Lias at ; 66.
Burrow-on-the-Hill, Middle Lias at; 66.
3 254.
Burrows, the, outlier of Northampton
Sand; 107.
Burton "Latimer, Northampton Sand at;
114.
Burton Lazars, mineral spring at; 61,
269, 270.
Bury, brickyard with Saurian remains
near; 237. .-
Bushy Dales, section in Marlstore Rock-
bed at; 72. °

 

 

12, 14,

 

| Carruthers,

305
C.

Cadges Wood, Cornbrash and fossils near ;
228,

| Calcareous beds in Northampton Sand’; 94.

Campden Hill, beds representing zone of
Am. Murchisonae at; 15.
Campden, pea grit; 12.
Carboniferous beds, local character of; 6.
Carbonate of iron, central nodules of in
ironstone ; 133,
Careby,, Lincolnshire Oolite at; 175.
——, railway-cutting, Great Oolite Clays
with fossils ; 195.
—— Lings, Cornbrash outlier near; 229.
—— Mill, pit in Great Oolite NE. of ;
211.
Carlby, Lincolnshire Oolite at; 175.
Carruthers, Mr., on plant remains in the
Northampton ‘Sand ; 120.
Mr., on plant remains in
Whittering “ Pendle’”; 165.
Casewick cating, Lacustrine deposit in
the; 244,
—, Oxfordian series in the; 282, 236.
——, table of Fossils from Cornbrash at;
288,

- Casterton, building stones at ; 141. .

—— Upper Estuarine Clays at ; 189.°

Castle Bytham, inlier of Northampton .
Sand at; 106.

Castle Bytham, Lincolnshire Oolite (coral-
line) ; 139.

Castor, disappearance of Lincolnshire
Oolite ;.178.

——, Great Oolite at; 201.

——, Lincolnshire Oolite at ; 143, 173.
——-, masses of valley-; gravel near; 174.
—, Oyster beds of Great Golite at;

208.
—— Hanglands ‘Wood, Upper Estuarine
Series at; 195.
— Heath, Cornbrash at’; 219.
—_—— ‘Alwalton Marble at; 208.
Catmos, sections in vale of; 70. ©
Causes of the decline of early i iron manu-
facture; 111.

green colour of some ores; 127.

—— —— position of towns and villages ;
55.

Cause ve Nani character of Oxford .
Clay ;

Cave debate 5 249.

Cells, prismatic form of,in the North-
ampton Iron-ore; 133.

Cellular structure in iron-ore ; 103, 118.

Chalybeate Waters in the district; 269.

 

. Changes attendant on the passage: ‘of water

through the Northamptonshire i iron-ore ;_
135. \
Change from estuarine to marine con-
ditions in the Northampton Sand ; 129."
Chater River, {nliers of Middle Lias in
the valley of; 76.
_—., Lincolnshire Oolite ibog the sides
of ‘the valley of ; 153.
— , Northampton Sand in the valley of;
96.
306

Chater River, pre-glacial gravels in the
valley of ; 250. es :

Chemical character of springs from North-
ampton Sand; 134.

Chemical characters of the Northampton
Sand; 122.

Chesterton, Cornbrash near; 224.

Chipping Campden, Midford Sands at; 12.

Chipping Norton, “ Clypeus Grit” near 311."

Churchfield Lodge, Cornbrash at, and list
of fossils ; 223.

——- Green, table of fossils from Cornbrash
at; 286.

Clarke, J. A., on the farming of Lincoln-
shire ; 298. ~

Clays with Ammonites (group Cordati),
where dug; 233.

-—— (group Ornati), where dug; 7b.

— with Belenmites, Hastatus, where
dug; 7. . :

 

making ; 2b. . :

—— with Nucula, when used for brick-
making ; 232. 7

Classification of Jurassic strata inthe Mid-
land district; 1. |.

——, test of; 2b. -

Cleeve Hill, Upper. Freestones at; 11.

“ Cliff” of-Lincolnshire, commencement of ;
54, 93. - i

Cliff, basement bed-of the Lincolnshire
Oolite near ; 170.

Cliffe Parks, Cornbrash at ; 228.

Clipsham, building stones at 141, 167, 179.

——, Cornbrash outlier at ; 229.

—— freestone; 167.

—— , Great Oolite at ; 213.

——, Lincolnshire Oolite; 141, 167, 179,
189. 2

—— Quarries, Lincolnshire Oolite; 167. ~

—_— _——, mass'of indurated gravel near ;
269. -

——, Upper Estuarine Clays at; 199.

Clipston, Middle Lias at; 75.

« Clypeus Grit;? 11,0

Coal, boring for, at Neville Holt ; 107.

, boring for, at Stamford ; 104.
Colborough Hill, non-occurrence of North-
ampton Sandat; 109. | oe
Cold Overton, doubtful existence of North-

ampton Sand at; 110.
Coleman, Rev. W. H., on
Leicester; 297.

 

Geology of

Cole’s Lodge, Marlstone rock-bed near ; 76.

Collyweston, fault at 5 258.
—— Parks, Upper Lias in; 85. is
—— Qiarries, wells in Upper Lias in;
as tenure of land at; 183. -
village, Lincolnshire Oolite and-Slate
‘ at; 156. - =
and Hornstock Woods, section’ in
claypit near; 192. . ‘
—— Slate; 139. ; -
___ ——, beds representing the; 96,
106, 154,177. j
___. +, fossils of the; 140, 157, 276.
_—— Slates, extent-and characters of; 182.

 

 

. Oweni, where used for brick- |

| =~, strike of beds in; 255.

 

INDEX.

Collyweston Slates, how quarried; 182.

—-, mode of covering roofs with ; 183.

—., prices of the ; 183. ;

—— Slate separated from the Stones-
field; 5.

Collyweston Slates, tools used in working
the; 183. 2 a

Colouring matter of the Northampton iron-
ore; 127. :

iis Hill, outlier and list of fossils at ;

ie = ey >

_ Comparison of analyses of Northampton

iron-ores; 127.

— of. fossils of Inferior Oolites with
§.W. of England and Yorshire; 276.
Compton: Wingate, Northampton Sands at;

. 20. -» xy ee :

Concentric structure in iron-ore at Easton;

. 118, a

Conditions of deposition of the Northamp-
ton Sand; 128,

‘ Condition of iron in chalybeate springs ;

130,
Conderton, sections of white freestones
near; 14, .
Conington Brickyard, Oxford Clay at;
233, 237, ai ha ee
Conybeare, Rev. W. B., Geology of Eng-
land and Wales; 296. ;
Coral reefs in Oolitic Series ; 139.
——, Dr. Wright on; 139.
* Coralline Facies ;” 189.
Corby, Lincolnshire Oolite at; 149, 151.
—— and “Weldon, inlier of Northampton
Sand at ; 100." ° my
Cornbrash, the; 218. 7
——, altered by passage of water ; 115.
——, characteristics of the; 187. ~

~

—,, description ‘and, thickness of the ;

218. -
——, economic value of the; 219, 231
—-, extent of the; 219. ‘

| ——, persistence of; 7,31. -

—, inliers of the, 229.

——, outliers of the ; 221, 228.

“ Cornbrash of Scarborough ;” 187. -
Cornbrash (so-called), of North Yorkshire ;

-_—, table of fossils from the; 288,

291. .
Correlation of Oolites in South-west of -
England and Yorkshire’; 2.
—— of strata between Peterborough and
Stamford by Morris and Ibbetson ; 3.
—— of the subdivisions of the Lias; 88.
Cotterstock, Great Oolite near ; 206.
——, Upper Lias at; 86._
Cottesmore, Northampton Sand at; 97..
——, Upper,Lias near; 85. a
Cotteswold ‘Hills, Fuller’s earth of the;
189. ‘ ge
Cottingham brickyard, Lower Estuarine
Series ; 95.
——., Lincolnshire Oolite near; 140, 149,
_ 150.
—— stone-pit, Inferior Oolite in ; 95.
.

 

INDEX,

Counthorpe, railway-cutting and section
-at; 175,

« Crash- bed, ” vertical burrows of Litho-
domi in upper surface of the; 155.

- Creeton, Lincolnshire Oolite near; 175,

.

176.

Croll, J., on Boulder-clay of Scotland ;
243.

Cross, Rev. E., onfatina of zone of Ammo-
nites-semicostatus ; 45, 52.

Cross Leas, Great Oolite at ; 207.

Crowland, marine silt of Fenland at;
253. : i

Craphoe brickyard, Middle Lias and list of
fossils at; 64, 72.

Cross Barrow Hill, Rock-bed at; 72.

Cross-Way-Hands Lodge, oe Oolite |

near; 206.
—; , Upper Estuarine Series ab 194,
——, pit in, Lincolnshire Oolite ‘at ; 169.
—, well near; id.

-. ——, thinning out of Lincolnshire Oolite

near ;-141.
fe Curley 37 94,

D.

Dalby, Lower Lias at; 60.
Danes Hill railway-cutting, Great Oolite
at; 210.
—, ” Prof. Morris on séction in; 196.
, synclinal in; 255.
” table of fossils from, Great Oolite at;

 

287.
——, cornbrash at; 288.
_ Darwin, on cause of variations in strata ; 50.
Davidson, Mr. T., on Brachiopoda of
Oolites and Lias ; 298.
Deddington, fault near; 25.
, outliers and list of fossils near ; 5 ib.
Deep sea conditions chongme to shallow
water; 51.
Deepdale, Middle Lias at; 64.
—— Upper Lias near ; 84.
; Deeping, Estuarine Gravels at; 251.
-Dene, Great Oolite outlier at; 213.
——, Lincolnshire Oolite ats 140,
149, 152, 153.
—, Northampton Sand at ; 101, 114.
, slate pits at; 152, 182,
Dene-Thorpe, Upper "Estuarine Series ;
191.
Denudation ; 119, 182, 260.
of iron-ore ; 119.
ee iron-ore at ; 94,117.
. section in railway-cutting at; 94.
——, Upper Lias at; °81.
De | la Beche, Sir H., on oolitie structure of
rocks ; 184.
_——, report on building stones ; 297.
De Dela Condamine on Drift of Huntingdon ; ;
298
Development and occurrence of subdivi-
. sions of the “ Margaritatus” zone; 64.

 

 

“

141,

 

 

 

‘Dick, Mr. A. B., analysis of iron-ores ;

124.
——, R., on boolder-clay of Scotland ;
243. ©

XN
.

 

307

_Difference between malice of S.W. of
England and Yorkshire; 1.

Dingley Lodge, pit in “ Serpentinus ” beds ;
75, 81.

Dingley, section in Northampton Sand
near ; 106.

District ‘formerly celebrated for iron; 55.

Division between Middle and Lower Lias,
reasons for, in England; 59.

* Dogger” of Yorkshire ; 33, 92.

Dogsight, Cornbrash outlier at; 229.

Dogsthorpe, section in brick-pits at ; 226,

2 232, 235, .

Dotted lines on the map, reasons for draw-
Ing; 142.

Drainage of the fen-land ; 55.

_ Draughton, Northampton ‘Sand at; 30.

Duddington, Colly weston Slate’ in, old
> pits at ; 102, 141, 154. _
cornbrash, outlier section in; 228.

 

| —— fault near’; 257.

——, Great Oolite outlier ; 213.
——, Upper Estuarine Series; 192.
Dumbleton, fault near; 255.

« Dumbleton Series ;” 79.

Dunean, Prof. P. M., on corals ; 300.
Duston Slate ; 30, 94.

E.

East Carlton, Lower Estuarine Series near
94,

——, Middle Lias near ; 75.

East Farndon, Middle Lias at; 7d.

East Norton, Marlstone at; 72.

——., Upper Lias at; 83

Easton, section of the Northampton Sand
at; 103. :

, sections of Collyweston Slate at;
156. .

——, structure iniron-ore at; 118.

Eastrea brickyard, Oxford clay with fossils
at; 238.

Ebelman, M., on the blue colour. of rocks ;
127, 176.

Ebrington, outlier of Inferior Oolite; 12,
14, 15, 16.

Echinodermata of oolites near Hotham,

- and Cave; 4. .

 

.Eéonomie uses of. the ‘Marlstone Rock-

bed ; 65.

_Edenham, Cornbrash near; 227, 229,

Edith Weston, ‘occurrence of Lingula i in
Inferior Oolite; 167.

— , Northampion Sands at; 96.

Edmondthorpe, sections of Marlstone and
list of fossils found near; 64, 71.

——., Upper Lias sections near ; 85.

Edwards, L., on river Witham ; 295.

Egleton, Middle Lias near; 71. —

Eleanor Cross at Geddington, spring at
the; 93.

Elton, Cornbrash near; 228.

—-, fault at 5 258.

——, folding of atrata at; 255.

——, indurated gravel at ; 250,269.

——, Oxford clay near ; 264,

—, , Great Oolite in well near ; 207, 217.

é
308

Empingham, Northampton Sand at; 96.
— Upper Lias sections near; 85.
Epwell Hill, height of; 21.

, outlier at; 17.

 

‘Escarpments, causes, of height of; 54.

 

, direction and extent of ; 58, 54, 264. .

Escarpment formed by beds'of the zone of
Am. semicostatus ; 42.

—— of the Marlstone Rock-bed, southern
spur of ; 67, :

—— of Northampton Sand; 93.

Essendine, Great Oolite in railway-cutting
at; 209, 210, 211.

——, Lincolnshire Oolite in railway-cyt-~ |.

, tings at; 175. :

——-,. table of fossils from Great Oolite at;
290. : y

Estuarine Clays, unconformity between
pepe beds: of.and Lincolnshire Oolite ;

Gravels; 250.

—— Series, unconformity in; 33.

— —, Lower; 92. s

—— —— equivalent to Lower Beds of
Northampton Sand; 32.

— — inliersof; 100

— —, Upper, characters of; 31, 32,
33, 186, 188.

3 conditions of-deppsition of the ;

 

189. ‘
— ——, economic characteristics of the;
201. ne od oe
“ Estuarine Series, Upper’ equivalent to
upper beds of the Northampton Sand ; 32;
and of the lower zone of the Great Oolite;
11. . a
—— —, fossils of the; 189.
— ——-, inliers of the; 197.
—_— , ironstone nodules in; 33.
—— ——, outcrop of the; 190.
— — , outliers of; 198.
—— —, outlying “ pipes.” of the; 189.
—— —-, thickness of the; 189, 191.
Etheridge, Mr., on Lincolnshire Oolite ; 36.
Exton, Northampton Sand at; 96, 97, 114.
—— section, peculiarities of; 131. :
——- Hall, Collyweston Slate at ; 96.
Park, Upper Lias in; 85, 96.
Eye, Oxford Clay-at ; 238. :
Eye Green, Oxford Clay with fossils at ;
233, 238.
Eyebury, Oxford Clay at, 232, 283, 238.
-—, vertebrate remains at ; 238,
Eyford, “slates” at; 16. ‘

F.

Facies of zones dependent on conditions of
deposition ; 49, 50. 2

Farcett, Oxford Clay in cutting near; 238.

Fairley, W., on Northampton iron-ores ;
301. ee gam

Faults ; 14, 25, 38, 66, 102, 110, 256-259.

—, effects of, on outcrop’ of Middle
Lias; 66.-

Fault of Ketton and Duddington, effect of,
on outcrop of the Northampton Sand ;
102. -

“

 

 

 

 

INDEX.

\

Faults, when produced ; -259.

-Faunas of Great and Inferior Oolites, points

of distinction between; 2.
Fauna of base of Inferior Oolite; 15. . |
‘Faunas of the, Great and Lincolnshire
‘Oolite, difference between ; 2, 40.

- Fauna of the Lincolnshire Oolite; 4.

Fauna, the resultant of three sets of causes ;

Fauna of zone of semicostatus in north;

Fenland, denudation illustrated in the ; 262.

—, gravels overlapping the Cornbrash in
the ; 227.

——, scenery of the ;- 265.

Fens, Oxford Clay in the; 224, 233, 237.
Fimbria bed, probable equivalent of zone
of Ammonites Sowerbyt;'39.
‘Finchley Bridge, sections in Upper Lias

at; 83.

| Hineshade, Cornbrash outlier near; 221.

—,, Oxford Clay outlier near; 228.

——, Upper Estuarine Series at; 192.

—— Abbey, Lower Estuarine Series in
valley at; 102. _ -_

Firewards Thorns, §.W.-of Essendine,

Cornbrash at ; 229, ‘
“Fish and insect beds ;,” 41, 58, 74, 79.
Fitton, Dr., on chalk in- Rutland; 246,
297. :
Fletton, Oxford Clay with fossils at; 233,
235.
Flitteris Park, Marlstone Rock-bed at; 76.
Forbes, Mr. David, Analyses of unweathered .
iron-ore; 126. 7
Forest-land in the district; 55. '
Forest Marble, limits of; 215.

——, littoral character and variability of ;
9, 31, 32. :
—— represented by

186, 195.
Formations, absent; 40. . :
_—— oceurring in the district, table of; 56.-
Forty-foot bridge, Oxford clay with fossils
» aby 237. ’ ‘ :
Fossils. See Localities. c a
—— in iron-ore ; 116.
—-, tables of; 276.
——, list of, from Zone of Ammonites
semicostatus ;. 42, 44.
Fotheringhay, Great Oolite near; 207.
——, Lincolnshire Oolite, near; 170.
——, Upper Lias, near; 86. .
Freeby cutting, Lower Lias in; 59.
Froddingham, ironstone at; 45. j
—, maximum development of zone of
Ammonites semicostatys at; 45.

—— cutting, section at, thickness of beds
: of Ammonites Bucklandi zone; 41, 42.
Fuller’s earth, absence of, in Midland dis-

trict; 40.
—~, fauna of; 11.

Great Oolite Clays ;

 

G.

Galley Hill, railway-cutting, horizon of
- beds in; 60. - /
Geddington, Northampton sand at’; 98,

\
INDEX.

Geddington, thickness of the Lincolnshire

- sOolite at; 141.

—, Upper Lias at; 81.

-~— , Lincolnshire Oolite at;
145, 146

Geddington Chase, Great Oolite at ; 213,
214,

——, section in Duke’s pit at; 213.
Geeston Cutting, effect of fault j in; 257.
—— ——,, section in ; 156.

‘General Dip of the Strata in the district ;
254.
Geographical section of Great Oolite
Fossils; 284.
Geological causes of present scenery ; 54.
Geology of Yorkshire, Prof. Phillips on ; 2.
Glacial Deposits, conditions of deposition,
thickness, &c. ; 245. -
—- Gravel and: Boulder Clay ; 256.
Gravels ; 247, 248,
— Period ; 240.
—— Sands ; "248,
Glapthorne, ‘Chalybeate springs, effects of,
at; 269.
——, Cornbrash ; 216, 224,
, Great Oolite with fossils; 206. -
at, table of fossils from ; 284.
——, Upper Estuarine clays at; 194.
Glaston, Northampton sand at; 108, 109.
Glen River as a subterranean stream ; 268.
, Great Oolite along the; 190, 196.
——, Lincolnshire Oolite, along the; 142,
175.
» Valley Gravels along the; 250.
Glendon, Limestone used in blast furnaces
vy at; 178.
Godeby, thickness of Rock-bed at; 65, 72.
Grafton-under-W ood, Great Oolite near ;
212.
—, Lincolnshire Oolite near; 145.
Grantham, development of zone of Am-
monites semicostatus near; 42.
, Oolites of; 3.
Great Bowden, Upper Lias at; 87.
Dalby, Lower Lias at ; 61.
—-—- Easton, Upper Lias at ; 82,
—- Gidding Brickyard, Oxford Clay at ;
233, 234.
— Hilcote, Inferior Oolite at; 16.
Northern Railway, cuttings of the;
175, 189.
—— Oakley, Upper Wstuarine Clays at;
189, 190.
—- Oolite.

140, 141,

 

 

~y

 

 

 

 

 

 

See Oolite.’

Clays. See Oolite.

——— ——- Limestone. See Oolite.

~—— Ouse River, denudation of Fenland ;
262. : ‘

Rollwright, Northampton sand at;

 

 

23.
—— Tew, Northampton sand at ; 23.
— = Halton, Lincolnshire Oolite at; 151,

Gece, Cornbrash at; 227.

-, indurated gravel at; 269.

Greetham, Lincolnshire Oolite, near; 167.
——., Northampton sand at; 96, 97.

 

 

309

Gretton, Ironstone and: Lower Estuarine
beds, near; 95.

—,,. landslips at; 261.

——-, Lincolnshire Oolite at; 152.

Griesbach, Rev. A. W., list of Cornbrash:
fossils collected by ; 220. ,

Grimsthorpe Park, Cornbrash outlier in;
229,

Grouping of rocks ; 55.

Gwash River, Freswater deposit in the.
valley of the; 245.

—, Lincolnshire Oolite along the; 142,
175.

——, Middle Lias in the valley of the;
76,

sections of Upper Lias along the

valley ; 85.

valley gravels in the valley of the ;

250.

H.
Haddon, Oxford clay at; 232, 234, 235.

Hallaton brickyard, Lias in ; ‘62, 64, 74, *
, list of fossils from Middle Lias in;

 

 

 

Hallaton Brook, old pits in Capes Lias,
near; 83.

——,, section in pits, near; 73.'

Hallaton eon sections of Lias near; 74,
83.

—, section in Northampton sand, near

107.

Hallaton, large boulder at; 246.

Halstead, ‘ petrifying spring” at ; 268.

Hambleton, fault at; 257.

——., Lincolnshire Oolite outlier at; 179.

——-, outlier of Northampton Sand ; 110.

Handthorpe, Cornbrash with fossils at;
227. “

Harcourt, Rev. W. Vernon, on Oolites
north of the Humber; 2.

Hardingstone, analysis of iron-ore from ; ;
124.

. Harper’s Brook as a subterranean stream ;

190.

——, Great Oolite in.course of 190.

—, Lincolnshire Oolite along course of ;
148.

——, Upper Lias clay along the course
of; 86: :

Harrington, Lincolnshire-Oolite at ; 141.

Harringworth, ironstone beds, near; 95.

, Lincolnshire Oolite, near; 152.

Heaths and waste lands ; 55.

Heights; 21, 53. .

eee Cornbrash at; 217, 224, 225.

; fault at ; 224, 257, 259.
—, ’ Great Oolite, near; 207, 217.
——, Upper Estuarine Series, near; 189,
195.

—— brickyard, Northampton band at;
105.

——., Upper Lias at; 86, 255.

—— Heath, Lincolnshire Oolite at; 173,

Farm, Northampton sand at;

 

105, 115.
—— —, oblique lamination at; 114,

 
Missing Page
Missing Page
312

Little Bytham, Inlier of Northampton Sand
vat 5 106. is
—, Lincolnshire Oolite at; 140, tei,
168, 175, 176, 184, 199, 200. ©
—, ‘outliers of Great Oolite near ; 213."

——, section at the ‘‘ Clinker Works ;” ge

199.
—,, section in the Railway-cutting ; 200.
co Upper Estuarine Series at; 189, 199.
‘Little Casterton Quarries, Lincolnshire
Qolite at; 179, 198.
Little Dalby, Lower Lias at; 60, 61.
———, Mineral Spring at ; 61, 269.
Little Hilcote, pits at ; 16.
Little Oakley, Dip of Beds at; 191.
——, disturbance of Beds at ;-259.
——, inlier at; 256.
~- ——, Lincolnshire Oolite at; 147, 190.
——, section in Lincolnshire Oolite near ;
147.
——,, sections of Northampton Sand at;
101.
——, Upper Lias at; 86.
Little Weldon, fault at ; 258.
Littoral deposits; 30.
Liveden, Cornbrash at; 223.
Loddington, faults near; 254, 256.
——, Middle Lias at; 64.
——, Upper Lias at; 84.
—, outlier of Northampton Sand at;
109.
Lonsdale, W., on Chalk in Rutland; 246.
——, Maps of England; 297. :
——, on sequence of the Great Qolite
strata of the South Cotswolds; 5.
Long Compton, outlier at; 21.
Tone Hill, outlier.at; 17.
Long Mantle Wood, Well section at; 95.
Lord Lyveden’s Pits near Brigstock ;. 191.
Loseby Brickyard, list of fossils from ;
62.
— ; Lower Lias at; 59, 61.
Lound, Cornbrash at ; 227,
Lower Benefield, Upper Estuarine Series
at; 194.
‘Lower Estuarine Series. See Estuarine.
Lower Freestones ; 14, 15, 16, 17.
——, passage of into Pea Grit ; 12,
Lower Oolites, see Oolites.
Lower Zone of Great Oolite; Attenuation
of; 31.
— , littoral character of; 10, 11.
Laddington, Oxford Clay at; 233, 234.
eee Heath, outlier of Great Oolite
; 189, 198, 229.

— ’ North, Lincolnshire Oolitein Church- |

yard at; 167.
: representative of Collyweston Slate

.in Churchyard at; 96.
_—, railway-station, Northampton Sand
at; 96.
——, railway-cuttings in Upper Lias ; 84.
-—, South, railway-cutting near ; 167.
Gumby Terra Cotta Works, Upper Lias
at; 85.
Lycett, Dr. J., on the Cornbrash of North
Yorkshire; 9, 298, 301.

 

 

INDEX.

Lycett, Dr. J., on ‘Fossils of the Cotteswold
Hills ; 219, 298, 301.

——, on Oolites near Grantham ; 3.

—, on “ Ragstones;” 11.

Lyddington, Lincolnshire Oolite near;
177..

—, Northampton Sand at;
118.

Lyndon, faults near ; 257, 258.

——, outlier of Ni orthampton Sand at ; 110.

-——, Park, outlier of Lincolnshire

Oolite in; 178. »

107, 108,

M.

Maldive, Lincolnshire Oolite thinning out
3 141.

Msecctin Oxide of Iron in the Ore; 124,
128.

Mandeville, Northampton Sand at; 30.

Manthorpe, Cornbrash at; 227. -

——, Great Oolite Section, and list of
Fossils at; 212.

. Manton, Lincolnshire Oolite at; 179.

—, Upper: Lias Sections and list : of
" esailes 84,

- Manufacture of Iron formerly carried on

in the district ; 55.

Marholme, Kelloways at; 286.

Marine Alluvium or Warp of the Fenland ;

. 253,

Gravels of the Fenland; 251.

Market Harborough, Middle Lias near;
64, 75, 76.

— Brickyard, section of Middle Lias
and list of fossils in; 76.

— Upper Lias at; 63.

——, Upper Lias ‘section’ and list of
fossils at; 87.

Market Overton, Lincolnshire Oolite at ;
168, 179.° +

 

— Northampton Sand at; 97.

—, Upper Lias near; 85.

, Marlstone or Middle Las; 3 64,

» limits of; 45, 46, 47. ;

——, name used in two senses ; 47.
—-, succession of beds in the; 64.

—— Rock-bed; 47.

—— —— as an iron-ore; 65, 112,

 

——— asa puilding-stone; 65.

—+— ——, general characters and develop-
ment; id.

—— —, soil formed by; 66.

——-——, thickness of at various points ; 65.

—— —— unferruginous ; 84.

Martinsthorpe, Lincolnshire Oolite at; 179.

~_-, Northampton Sand, near; 96, ‘Lio.

Maw, Mr., on the Disposition of Iron in

. variegated strata ; 133, 300.

Microscopical characters of the Northamp-

’ ton Sand; 119-121. ~-

Medbourn, Collyweston Slate at; 141.

, Serpentinus (Upper Lias), beds at;
74, 77.

— Mill, Marlstone Rock-bed at; 77.

Melton Mowbray brickyards, aoe 7 60.

——, Pre-glacial brick earth at ;

 
INDEX.

Middle Lias. See Lias,
-—— Oolites. . See Oolites.
Midfofd Sand, at Campden Hill ;
—, Dr. Holl, on; 16.
——, doubtful equivalent of, in Midland
-district ; 39.
—, not Tepresented i in the district ; 92.
, thinning out of; 32.
—-, zones of, on the continent ; 12,
Midland district, boundary between the
Great and Inferior Qolites in; 30.
5 changes from deep to ‘shallow water
conditions, and vice versa in; 51.
——, classification of Oolites in; 1.
——, grounds of classification of beds in; 7
13.
——,key to Audis tis of Jurassic strata
found i in; 2.
» 10 certain equivalent of Midford
Sand in; 39.
——, Northampton Sand in; 30.
——,, significance of, unconformity n; 40.
, table showing difference in the suc-
‘cession of beds in; 35.
Milcomb, Northampton Sand at ; 23, 25..

 

 

 

Milton Park, thickness of Great Oolite |

Clays at; 217.

, Upper Estuarine Series at; 195.

——, Wells in Lower Estuarine Series at ;
100.

Mine Hill, list of fossils from ; 19.

——, Outlier at; 17, 18.

Mineral characters of Lower Oolites in
Midland district ; 31.

——- Resources of the District ; 271.

—— Springs, 268.

still used medicinally ; 269.

Mitchell, Dr. J., on Drift ; 297.

Mode of formation of. the Northampton
Iron-ore ; 130.

Molluscan remains in Northampton Sand
proving metamorphism ; 131.

Monk’s Wood, outlier of Cornbrash near ;
229.

Moor Hill brickyard, Upper Lias at ; 83.

 

 

 

 

Moore, Mr: C., on “ Fish and Insect Lime-.

stones ;” 79.

Morborne brickyard ; 235.

Morcot, Lincolnshire Qolite near; 140
154, 178.

-—; Northampton Sand at; 96, 109.

_—— Tunnel, Upper Lias at; 84.

Moreton, Vale of ; 14 et seq.

Morehay Lawn, Oaks of; 263.

- Morris, Prof. J., on faunas of the Lin-
colnshire and Great Oolites ; 4, 298.

——, on a large Boulder at Stoke 3 246.

——,on the Oolites of Lincolnshire; 11,
156, 162, 163, 125, 189, 195, 200, 210,
218, 226, 229, 282, 236, 244, 246, 298,
300.

Morris, Prof. J., on “Upper ‘Tehaadie

. Series ;” 11, 189.

Morris, Prof. J.,and Capt. Ibbetson, on
the oceurrence of Lingula at Edith
Weston; 167.

——, on strata around. Peterborough and
Stamford ; 3, 167, 238, 297.

 

313
* Mortar-pits ; ” 179, :
Morton, J., notes on Northamptonshire ;
295.
Moulton, Northampton Sand at; 30.
——, Pre-glacial brick-earths at; 243.
Murray, G., Farming of Huntingdon }
300. ; ‘

N.

Nene, Cornbrash along tributary valleys of
the; 222, t

—, Cornbrash along the valley of the;
224,

——, Denudation ; 261, 262, 265.

-, Estuarine Gravels’ in the valley of
the; 251.

—-—, Great Oolite along the valley of the;
_ 202, 208, 216.

—, ’ Lincolnshire Oolite along the tri--
butaries of the ¢ 166.

— , Lincolnshire Oolite in the valley. of
the; 142, 169, 172.

, Northampton Sand in the valley of.

the; 98.

, Pre-glacial gravels in the valley of
the; 207, 250.

— , Upper © Estuarine Series along the.
_ralley of the ; 190, 193.

, Upper Lias in the valley of the; 86.
Neville-Holt brickyard, Lower Liag ‘at;
60, 62.

—, effects of fault at; 258.
——, Lincolnshire Oolite at; 177.
——.,, outlier of Northampton Sand; 106,
117.
——, Serpentinus beds at ; 74, 82..

 

 

 

.—— Spa; 259, 269, 270.
'——, Upper Lias, and list of fossils at;

82. 2

New Close Cover, Lower:Estuarine Series
at; 100. .

New England, Great Oolite Clays at ; 215,
217, 218.-

—, Valley Gravel at; 250.

News ewell Wood, Pre-glacial Gravels at ;
242.

Newton, occurrence of slag near; 145.

              

Nomenclatare and classilleationtof Oolites
~ of the Midland district ; 1.

Normanton, fault at ; 179, 257, 258..

—,, Lincolnshire Oolite at; 167, 179.

—— Park, Northampton Sand iu ; 110.

North Midland district, beds of lay: in;
31, 32.

North Yorkshire, Cornbrash of; 9.

Northampton, ages of Oolites of; 4.

——, Northampton Sand at ; 30.

7 section at Racecourse at; 33.

——, section at, showing maconformity j

34.

—— Sand, as a ‘puilding-stone ; 92.

—— ——, asa delta deposit; 129.

— —, cellular structurein; 33.

—— ——, character of, when ‘dug under
elay;95.  —

\
314

Northampton Sand, equivalent of, in York-
shire; 92,

—— ——, equivalents of Upper and Lower
members of the; 32.

— ——, eroded surface of; 33, 36.

—— ——, escarpment of the; 93.

—— ——, exceptional charactersin the; 97.

—— ——,, formations represented by the ;

10.
—— ——,, fossils of the ; 276.
—_ — , general features of; 90, 114-119.

— history of the’ formation of |

the, 136.
—— —— in Oxfordshire; 13,
—— ——,, inliers of; 100.
— ——,, ironstone in the lower Borat
of; 115. .
—— ——., lignite in; 116.
— —, line of demarcation i in; 32.
—— ——, lithological characters of; 117.
——— ——, marine beds at base of; 32.
—— ——, microscopical and chemical
characters of; 119-121, 122.
— — , non-ferruginows ; 98.
—— —, origin of the; 113.
_ —— +, outliers of ; 17, 106.
—_—, paleontological characters of; 91.
—— —, plant remains in ; 116, 120:
——— ——, proofs of continuity with In-
ferior Oolite Freestone; 17.
,Tepresentative of base of Inferior
Oolite ; 17.
——,, springs in the; 156.
——, summary of features of; 1M
—— ——, thickness of ; 32, 91.
— ——, variations in; 20, 284 25, 33,
97,101. |
—— ——, wells in; 116.
Northamptonshire iron-ore, analyses of;
122 to 128. —
— —-, at Holt; 116.
—_ — , changes in, through passages
of water ; 115.
——.'+—, direct deposition of, untenable ;
131.
+ ——-, mode of formation of; 130. ,
—— ——, quantity of iron in; 92.
ore, re-distribution of i iron in; 133.
-Norwood’s Fauna of Lincolnshire Oolites ; 4.
O.
Oak Inn Farm, sections in Northampton
Sand near; 97. ‘
Oakham, prickyards at; 64, 70.
—, Fish and Insect Limestones and
sé Serpentinus beds” near; 85.
— Rock-bed at; 65.
— and Ashwell
between ; 85.
— and Barleythorpe, sections near; 70.
—— and Melton Canal, Upper Lias along ;
85.
Oakley, Great Oolite at; 213.
, Upper Estuarine near; 190.
Occurrence of old slag; 94, ‘99, 111.
Old, Travertin at; 268.
Ola Head Wood, unconformity at; 38.

 

 

railway, cuttings

 

 

INDEX.

Old Irom workings; 99.
Old slag-heaps, near -Wilbarston and
East Carlton; 94. -
=— Whissendine brickyard section, and -
list of fossils ; 69, 70.
Oolite beds, slight persistence: of; 6.
Oolite, Great, the ; 186, 218.. -
——, absence of, South Yorkshire 3.187.’
—, characteristics of the ; 187.
——, conditions of deposition of the; 186,
——, fossils of the; 188, 276.
amy of Northamptonshire ; 284.
—, overlapping of; 31. -
——, variations in ; % 11.
‘Oolite, Great, Clays, description of the ;214,
—— ——-, economic aspects of the ; 218,
—— ——,, extent of the; 215.
—- —, representative of Forést Marble;
9, 32, 186.
—— ——-, Ironstones of the; 215.
—— ——, thickness of the; 214.
‘Oolite, Great, Limestones, character of the ;
186, 201.

—, eondifiong of deposition of the ;

208.
——- — , economic uses of the ; 202, 214.
— — — , extent of the; 202.
—— ——-, outliers of the 5 213.
—— ——, soils of the ; 202, 214.

| ——- ——,, thickness of the ; 204, 209.
_—— ——.,, Upper Zone; 201, 214,

—— ——,, Lower Zone of, characters of
the; 10.

—— —,, 2 littoral deposit ; 80.

——,, Upper Zone of, character of ; 9, 10, 31.

——, Series, White ‘fireclays of. the: 3 198.

Oolite, Inferior, a lower Zone of, a ittoral
deposit ; 30. .

——-, alternation of ; 31.

——, base of; 12, 14, 15,

—, fault in, at Weekley ; 38.

——, of 8. of England, Fossils of ; 276.

——, of Yorkshire; 276,

——,, Freestone, formerly continuous with
Northampton Sand; 17. \

——,, of S.W. district, thickness of ; 32,

——. upper beds absent; 52.

——, variations in; 11, 12. ~

Oolites, Lower, changes in; 13 et seq.

+——, classification and nomenclature of ; 1.

—, general characters and condition of
the ; 90.
—, mineral character of, in South Mid-
land district; 31.
——,, of the district, grouping of the; 90.
Oolite Marl, an equivalent of the zone of
Ammonites Sowerby? ; 39.
——,, at Campden Hill;15. x
——, alternation of; 12. ~
Oolites, Middle ; 282.
—, conditions of deposition of the; 232.
——, main line of outcrop of the ; 233,
——,, of South Yorkshire ; 7.
Oolite of Lincolnshire ; 3, 33, 35, 36, 38, 89,
—, formerly identified with that of
Bath; 8...
Oolites, correlation of; 2.
——, unconformity in; 33, 36.
INDEX.

" Oolitic concretions in Northampton Iron-

‘ gtone; 131. ,

— structure, in the Northampton Sand ;
109.

—— —— of Rocks, origin of ; 183.

— —- of various formations, 184,

tina on. the Fauna of ‘the Lincolnshire
Oolite; 39,40.

on zone of Ammonites geometricus ;

 

42,

— ‘on zone of Ammonites Sowerbyi;
39, 40.

Origin of Northampton Sand; 113.

Great Oolite Clays at; 218.

, well at; 209.

Oundle, Chalybeate springs near; 269.

—., Great Oolite as a freestone at; 214.

Clays near ; 216.

——, Kellaways beds at ; 232, 234.

——, Lincolnshire Oolite at; 143.

— ’ fossils from Cornbrash near; 222,
286. ‘

——, lists of fossils from Great Oolite at ;
204, 205, 284,

, Oolitic structure of Great Oolite at ;

 

 

 

187.
-——, Upper Estuarine clays near; 194.

           

Wood, sections of Ironstone and old
-workings at; 99.
Ouston brickyard, Middle Lias in; 64.
——, section and list of fossils; 67.
——, contorted glacial gravels ; 247.
Outliers ; 12, 14, 17, 18, 19, 20, 21, 25,
‘76, 81, 86, 106.
Overbury, section near; 14.

 

 

Overton Longville, Cornbrash at ;~224,
, Great Oolite Clays in cutting near;
» 217.

Overton Waterville, Cornbrash at; 224.
. Shells and Mammalian remains at ;
251, ©
Owen Prof., on Saurian remains from
Essendine; 211, 297.
Oxenden Magna tunnel, Upper Lias, in;
81.
Oxenton Hill, fault at ; 255.
Oxford Clay, at Dogsthorpe ; 226.
, at Polebrook ; 223.
: ° at the Walk of Morehay ; 228.
———, general character and occurrence of ;
232, 239.
. ‘outliers of the; 224, 239.
~——, the substratum of the Fens; 254.
, uniform character of; 51.
——, variations in; 7.
Oxfordshire, Cornbrash in; 220.

 

 

 

 

 

P.

Paleontological “ Zones” value of; 48.

——, Tables; 274. e

Paper Shales, and Fish, and Insect Lime-
stones of Upper Lias; 79.

Parker, Mr. T., experimental sinking by ;
226, 235.

 

315

Parkinson, R&., on Huntingdonshire
Leicester and Rutland ; 296.
Pasture lands of the ‘Lower Lias; 63.
Pea Grit, occurrence and extent of; 12,
15, 16,
Peat, contraction of, when drained 252.
—, interstratified with Marine Silt,
remains of animals &e., in the; 252.
——, of the Fenland ; 55. ‘
Penarth beds; 40, 41, 57:
_Percy, Dr. on the Northampton Iron-ore ;
112, 121,299.

| Perio Mull, Lincolnshire Oolite absent at;
Orton, near Peterborough, thickness of |

169.
“ Petryfying Springs ;” 268.

Peterborough and-Stamford, Morris and

Ibbetson, on strata near ; 3.
-——, Cornbrash near ; 219, 224, Sas! -
— —,, table of Fossils from ; 3 286.
—, Estuarine gravels at; 25 L. :
——, fossils from Oxford Clay at; 235.
——, wells in Lower Estuarine series at ;
100.
= Prof. J. 00 Geology of Yorkshire :

——., on fauna of the Marlstone; 47.
——, on Belemnites ; 3 300, 301.
——, on Cornbrash in Oxfoniahire: 220.
——, on Forest Marble; 31, 32, 215.
—,on Fossil fruit from Whittering’;.
165.
—,, on “ Lima” or “ Buchlandi” beds ;
41.
——., on Oolitic grains ;~184:
—, on W.’Smith ; 297.
——, W. on Geology of England; 296.
Physical features of the district ; 53.

’ Pickworth, Great Oolite outlier at; 213.

 

‘ Lincolnshire Oolite at ; 167.
Pickwell, Marlstone Rock-bed at; 66.
Pickworth, Pre-glacial gravels near ; 242.
Pickwell, Upper Lias sections at; 84.
Pilton, fault at; 258 -

—, Lincolnshire Oolite near ; 178.

| ——, Northampton Sand near; 99.

——, Upper Lias near ; 84.

’ Pilton Lodge, estimated thickness of Great

Oolite Series near; 216.

-_—., Great Oolite near; 189, 203.

,Pipwell, fault at; 258.

—, Great Oolite Limestone near; 218.

—, "inlier of Northampton Sand at

100.

—— Lincolnshire Oolite; 147.

—— Abbey, pits near ; 86, 147, 148, 190.

_—— ——-, old pit at (Lincolnshire Oolite) ; ;

147, 148.
—— Lodge, pits
Series near; 190.
Pitsford, Northampton Sand near; 30.
Pitt, W.,.on Agriculture of Northampton-
shire, Leicester, and Rutland; 295, 296.
Plant remains in the Northampton Sand ;
116, 120.
Plungar, escarpment at; 42.
Polebrook Cornbrash, section and list of
fossils at; 223, 286.

 

            

in Upper Estuarine.
316

Porter, Dr., on clays of the Great Oolite at
Peterborough ; 217.

——, fossils collected “by ; 173, 209, 225,
235. ‘

——, on geology of Peterborough; 299.

Position and disturbances of the strata,
faults, &c.; 254.

‘Post Glacial deposits ; "249.

—— Tertiary deposits ; 240.

“ Potlids,”? near Iimington Downs ; 16.

Pre-glacial Brickearths, composition of
the; 243.

—— deposits’; 240. :

—— sands and gravels, composition of
the ; 243. cs

—— valley gravels, composition of the
241, af

Preston,;*Northampton Sand outlier ; 109.

Priestley Hill, outlier of Northampton
Sand; 107. a

Principal lines of escarpment ; 54.

Probable succession of changes in charac-
ter of the Northampton Iron-ore; 135.

Proofs of passage of water through the
Northamptonshire ore; 135.

Proportion of metal in the ores; 128.

Pusey, P., on the agriculture of Lincoln-
shire; 297.

Q.

. Quarries, number of, in the Lincolnshire
Oolite; 179.

Quartz, size of grains of, in the North-
ampton Sand; 119, 121.

Quenstedt’s stages of the Lias; 45, 46, 47.

R.

Ragstones, absence of ; 40.

-  Ragstones,” variations in; 11.
Railway-cuttings. See Localities.
Rainfall ; 54. -—

Rain-water, action of, along joint and bed-
‘ding planes; 135.
—— —,,on unweathered Iron-ore ; 134.

* Ranksborough. Hill, outlier of Northampton
“sand; 110. heh

Ramsey, Oxford Clay at; 233, 237. :

Re-commencement of iron working in the

district ; 111.

Re-distribution of Iron in the Northampton-
Shire ore; 133. :

Redmile, escarpment at; 42.

Remains of ore.and slag at Oundle Wood ; .

« O9y

Resemblance of the Northampton to the
. Bagshot Sands ; 97.

Rheetic beds; 40, 41, 57.

_Ridlington, discovery of chalk at ; 246.
~—— Lodge, Northampton Sand at; 109.
—— Northampton Sand outlier; 109.
Riley, Mr. E., analysis of Iron-ores by;

128, 299. : :
Ring Haw, Lincolnshire Oolite at; 171.
Rivers, see names of.
Robin-a-Tiptoes, outlier
‘Sand; 109.
——, section of Rock-bed near; 67, 68.

of Northampton

INDEX, ‘

Rocart, section in Middle Lias, and list. of
fossils at; 69, 70.
Rock-bed of the Marlstone, see Marlstone
Rock-bed.
Rockingham brickyard, section and fossils
at; 82.
——,, fault at; 258.
“—— Forest; 55, 264.
——, Lincolnshire Oolite at ; 149, 150, 152.
——-, Northampton Sand near; 95. :
—— Park, sections in; 95, 150.
—., “ Slate-pit” near; 182. :
Rocks, altered by passage of water through ©
them; 115. 5 :
——, two groups of, in the district; 55..
* Roe-stone ;” 12.
Rome; Rey. J. L., on the Drift of Lin-
\ colnshire; 300. ‘
Rose, C. B., on the Alluvium of Fens ; 297.
Rubble, produced by passage of water ;
115. _,
Rushden, fossils from Cornbrash at; 220.
Rushton, Upper Lias at; 81. , é
———, Lincolnshire Oolite at; 145, 146.
——,Lower Estuarine Series at; 93, 94.
“Rutley, Mr. F., sketches by ; 264,
Ryhall, outlier of Great Oolite at; 213.
——, table of fossils from Great Oolite
at; 290. ee

, S. ;
St. Martin’s, Stamford, Ironstone at; 164.
—, ——, sections at; 165. :

 

,——; 164.

Sands at White House, Warren ; 20, 22.

Sapperton Tunnel, Fuller’s earth at; 1]. |.

Saunders, J., jun., history of Lincoln ; 297.

Saxby cutting, horizon of beds in; 60.

Scenery, characters of ; 263.

—— dependent. on geological causes ; 54,

“Scunthorpe, development of Zone of Am-
monites semicostatus at; 44.

Seaton, Lincolnshire Oolite at ; 177.

_—-—, pit in Northampton Sand at; 109.

——, Upper Lias fossils from; 84.

Sedgwick, Rev. Prof. A., on alluvial de-
posits ; 296.

Seeley, H. G.,on gravels and drift of fens ;
300. .

Segregation, Mr. Maw on; 183.

& oe Beds,” general characters of ;

79...

——,, oceurrence of; 74, 81, 82,87.

Sevenhampton Common, “slates” at; 10.

Sharman, Mr. G., list of Cornbrash fossils
by; 220. :

Sharp, Mr., on Oolites’ of Northampton-
shire; 4, 32, 86, 120, 158, 164, 175, 221,
229, 249, 257, 268, 301. -

Shelly facies, use of term; 139.

Shenlow Hill, outlier at; 17, 19, 20.

Short .Dr., on Mineral Waters; 269, 270,.

© 295. ;

Sibbertoft, Middle Lias at; 75. -

Sibford-Ferris, Northampton Sand at ; 23.

Sibford Gower, Northampton Sand at ; 23.

Sibford, list of fossils found near; 238, -

’

 

——, outlier at; 17.
v

INDEX,

Sibson tunnel, Great Oolite at; 207.
——, Lincolnshire Oolite at; 174,
——, Upper Estuarine Series ; 194.
Slates ” at Eyeford, Sevenhampton Com-
mon, and Stonesfield ; 10.
‘Slate-beds”” of the Oolites, cause of
structure of the; 5.
Slawston Hill, Fish and Insect Limestones
at; 87.
——,, Northampton Sand outlier at ;' 107.
, Succession of beds at; 77.
\——., Upper Lias at ; 86.
Smith, C. H., on Buiilding-stones ; 297.
illiam, on name “ Marlstone ;”

aa ft

 

>
47, 7 .
—— ——,, on Building-stones ; 297.

—— ——-,, on scenery of the district ; 264.

——, =—, geological maps of; 296.

~—— and Greenough (general maps of);
2, 296. 3

Soil formed by the Marlstone Rock-hed; 66.

—— formed by Northampton Sand ; 93.

Soils, various, in the district ; 271.

Somerby, the Rock-bed at; 65, 66.

Sorby, Mr., on microscopic and chemical |

characters of rocks ; 128, 131.
South Luffenham railway-cutting, North-
ampton Sand in; 96.

South Cotswolds, sequence of Oolites in; 5.

South Yorkshire, Middle Oolite of; 7.
Sonthorpe; Great Oolite near; 207.

_ +, Lincolnshire Oolite at ; 173.

——, Northampton Sand at; 100. :
South-west of England and Yorkshire,
* difference between Oolites of; 1.
Southwick, Cornbrash near ; 216, 224.
——, Great Oolite near; 206.
——, Kellaways at; 232,
—— Lincolnshire Oolite at village of ;
169.
= , Northampton Sand at; 99.
———, Upper Estuarine Series near; 194.
’ Sowerby, J., on fossils ; 296.
* Spiller, Mr. J., analysis of Iron-ore by;
122. .
- Spires Wood, Lincolnshire Oolite near;
171.
Springs from the Northampton Sand,
‘chemical characters of ; 134.
——, occurrence Sa : an Rigs deas
tamford, boring for coal at; 85, :
ists effects of ‘Tinwell and Walton fault

at; 164. 4 :
eee excavations in, showing Slate beds;

163.

—— and Helpstone Fault; 86,257.- __
——, Lincolrishire Oolite at ; 140, 141, 158,
172, 175, 179. ate
or "list ‘of fossils in the Lincolnshire

Oolite at Squire’s Quarry; 158. -
« Stamford Marble ;” 158. E
Stamford, Northampton Sand at ; 103,117,
168.
—— Open Field, Cornbrash at; 229.
—, outliers of Great Oolite at; 213. |
——, Great Qolite at, Table of Fossils

from ; 287. a
__, railway-cuttings north of ; 195.

32108.

 

_

 

317

wt
Stamford, railway station, section at; 103.
——, section at Eldret’s Quarry, near ; 163.
——, Section and list of fossils at Tinkler’s
Quarry, near; 160. mS
ae section at Terra Cotta Works’ at;

; —— Spa; 259, 269,

“Stamford Stone ;” 158.
Stamford, Torkington’s Pit; 199.

ae Upper Estuarine Series at; 195, 199,

——, Upper Lias at; 85, 163. r

Standground, Oxford Clay at ; 233, 235.

Stanion, brickyard near (Lord Lyveden’s

_ pits); 191.

—., fault at; 258, 259.

——, Great Oolite at ; 202, 213.

—: Lincolnshire Oolite at ;, 149.

—— Mill, Upper Lias sections at; 86.

mee) Oolitic structure in Great Oolite at;

— Quhrries, Lord Cardigan’s pits; 149.

ae sections of Northampton Sand at;

——, Upper Estuarine Series at ; .189, 190,

——, Upper Lias at; 86.

Stapleford Park, horizon of beds in railway-
cutting at; 60. : :

——, beds reached in a well in 59, 60,

—, list of fossils from; 61. .

Staunton Wyvile, Lower Lias at; 60. ,

—— Hill, Middle Lias at; 77, 78.

—— pit, section and fossils,at; 62.

Stibbington, Lincolnshire Oolite at; 148,
173. '

— , Northampton Sand near; 100.

——., Upper Estuarine Series at ; 194.

——, “wood-pit” at; 178, 194.

—— ——, list of the fossils from ; 173.

, Stilton, Cornbrash at ; 219, 229,

 

—,,- , table of fossils from; 291.

—, fault at; 258,

Stockerston Road, Uppingham, pit in iron-
stone; 108.

+ Stoke-Albany, faults at; 258.

—, Lincolnshire Oolite at; 148, 177.

——, Lower Estuarine Series near ; 94.

—, Rock-bed near ; 75.

, Upper Lias near; 81.

Stoke Tunnel, boulder of Limestone at;
246. 1

 

' Stoke Doyle, Great Oolite Limestone at ;

204.

——, Northampton Sand near; 99.

Stoke Dry, Northampton Sand at; 109.

—— Wood, beds near; 16.

Stonesfield Slate; 11.

——, “Slates” at; 10.

——- and Collyweston slates; 3.

—— Slate, horizon of Upper Estuarine
Series; 186.

—— ——, separated from the Collywes-

ton; 5.

Stonepit Field Lodge, Lincolnshire Oolite
at; 141, 169.

Stowe, Northampton Sand at; 30.

Strata, cause of variations in; 50.

x
318 '

“Strensham Series,” Fish and Insect |
Limestones 58.
Strike and general dip of the strata; 254.
Structure in Northampton Sand ; 33, 118.
——, vesicular, in Oolites; 14.
‘Sub-divisions of the Ji urassic Rocks, local
character of ; 6.
Subsidence, effects of, on nature of deposits ;
30.
——, unequal, consequences of ; 52.
Subterranean streams ;' 267.
Sudborough, Cornbrash’ at; 221.
——,, disturbances of strata. near ; 256, 258.
——, Great Oolite near; 212.
—— brickyard, Oxford clay’ with fossils
in; 233.
Lodge, section of Northampton Sand
near; 101.
Sutton Basset brickyards ; 75.
—— Mill, Upper Lias at; 81.
— prickyard, section in; 75.
, representative of Rock-bed at 3 75.
Sutton Wood, Great Oolite -clays near ;
217.
Swallow holes ; 267.
Swinthley-Lodge, pits.in Rock-bed at; 76.
Swedish lake ores compared with North-
~ampton ore; 130.
Sywell, Northampton Sand at; 30.

~ “.

Table illustrating the correlation of the
beds of the Lids; 89.

—_—— changes in the Lower Onlites
8.

 

 

—— of formations oecurring in the ii
trict ; 56.

— of horizons of “slate beds” in the
Lower Oolites; 6.

— ofproduce of iron-ore in Northamp-
tonshire; 111.

- showing differences in the succession
of beds in the Midland area; 35.

Tansor, Great Oolite cutting near; 206.

 

Tate, Mr. R., on: Zone of Ammonites -

angulatus; 41.
—— on breaks in the Lias; 46.
Teigh, escarpment near ; 71.
——, Upper Lias, sections near; 85.
. Terra cotta, white clays used in manu-
facture of; 92.
, Works, Stamford, section at ; ‘1038.’
Tetbury, rudimentary condition of Kella-~
way’s rock at ; 7.
‘Thickness and general character of the
~Middle Lias; 64.
> of the Lias ; 57.
_—— of Middle Lias at Slawston Hill ; 77.
Thistleton, quarries near ; 167. .
» subterranean streams near; 168.
Thorney, Oxford Clay at; 233, 239,
Thornhatgh ; 256.
—=>, Northampton Sand at; 100.
— —, Upper Lias at; 86.
Thorpe, Cornbrash at 5 222.
——, Northampton Sand at; 80.
— ” Aychureh, ‘Oxford Clay nears 233.

‘

 

\

 

 

 

INDEX, ~

Thorpe Park, Great Uolite in; 209.
—_— Langton, fossils at; 63.
—- ——.. horizon of beds at; 60.
Thrapstone, ironstone at; 98.
Thurlby Wood, Cornbrash near ; 231.
Tichmarsh, ’ railway-cutting, Northampton
Sand in; 98.
———-, Upper Estuarine Series in ;. 193.
Tickepeote and Blatherwycke, ‘faults | be-
tween; 167,
Tickeneote Launde, swallow holes in; 199.
—— Lodge, Northampton Sand at; 103.
— ——, Upper Lias at; 85.
Tilton-on-the- Hill; height of ; 53.
—., thickness of’ Rock-bed at; 65.
——, Upper Lias sections near; 84.
Tilton Wood, fault near; 206.
Time, long interval of, between the deposi-
. tion ofthe two groups of rocks; 56.
Tinkler’s Quarry, cave in Limestone at ;
‘249, ve
Tinwell fault; 195, 224, 225, 254.
Tixover, Lincolnshire Golite at; 154, 167.
Toft, Great Oolite near; 209.
Tolthorpe Spa; 269. ~
Topley, W., on Agriculture and Geology ;
301. - ‘

| ‘Fowcester, sandy beds at; 30, =

Towns and villages, position of, dependent
on geological causes ; 55.

Tommihent Rey. J., on fossils; 296.

Trimmer, J., on Drift Deposits ; 298.

Trollope, Rev. E., on Alluvium ; 299. -

Tryon’s Lodge, ‘Northampton Sand at;
102,

TnEDy Hall, bakieyent in Upper Lias near;

Tysce Mill Hill, "aullien at, and. list of oe
sils from ; 17, 20.

U. ‘ .
E ee
.Uffington, Kellaways at ; 232.’ .
——, sections in Cornbrash near, and lists -
of fossils ; 226, 288.
Ufford, Lincolnshire Oolite near; 173.”
—, oblique lamination in Northampton
Sand at; 114.
—, section of Lower Estuarine Series at s
104.
—, well at; 195,207. -
Unconformity between Great and Inferior
Oolites ; 36, 88.
— between "‘Marlstone and Upper Lias ;
65.
— between Upper and Lower Estuarine
Series ; 83.
——~— between Upper Estuarine Clays and
_ Lincolnshire Oolite ; 36, 37.
——, significance of, in : Midland district ; 40.
Unweathered portion of iron-ores, analysis
of; 126.
‘Upper Benefield, pit near ; 205."
, table of. fossils from Great Oolite at >
"984. :
Upper Cretaceous rocks; 255.
—— Estuarine Series. See Estuarine.
—— Freestones, absence of; 40.
INDEX,

Upper Freestones, variability of; 11.

ee Lias. -

—— Zone of Great Oolite ; 31, 186, 215.
‘Uppingham, » brickyard in Upper Lias at ;

—— Lias.

——, outlier of Northampton Sand ; 107,
Upton, Boulders at; 246.

BA

Vale of Catmos, sections in; 70.

—— Moreton, rocks in ; 14-17,

Valley Gravels, composition of the; 249.

. Shells and mammalian remains in
the; 250.

 

Valley of the Nene and ‘its tributaries,

Northampton Sand in; 98. #
Variability in character of the Marlstone
Rock-bed ; 65.
Variable character of the Northampton
Sand ; 33, 101.
Variation, cause of, in strata ; 50.
Variations in the Oxford Clay } Tes
‘Voeleker, Dr., analyses of i iron-ores from
' Blisworth bys, 127.

Ww.

Waagen on Oolite Marl ; 12.
—— on zone of Ammonites Sowarhgss 3
; 39, 40. ¢
Wadenhoe, Cornbrash at; 222.
3 , Great Oolite at; 203, 216.
, table of fossils from ; 284.
——-, ironstone at; 98, 193.--
—., sections of Lower Oolites at; 99.
——, Upper Lias at;.86. ~
Wakerley, Great Oolite outliers at; 213.
, Northampton Sand at ; 95.
——, outlier of Upper Estuarine Series dt ;
f 198.

 

 

 

 

near; 153.
Walcot Park, “Barnack rag” in; 172.
Walk of Morehay, Cornbrash at; 228.
: . Great analy at; 206, 217.
Walk of Sulehay, Great Oolite at; 207.
, Lincolnshire Oolite at ; .171.
Walton, Cornbrash near ; 225..
, anticlinal and fault near ; 254, 256
Wansford, Lincolnshire Oolite near ; 100,
140, 141, 173.
— , Northampton Sand near; 100. ~
and Peterborough, ‘Area of the
' Cornbrash between ; (224,
— Tunnel, section at's 100, 217. .
—=, Table ‘of Fossils from ‘Great Oolite
_at; 284,
——., Upper Estuarine Series at; 194.
, Upper Lias near ; 86.
Wardley, ‘Northampton Sand at; 109..
Warmington, Cornbrash at ; 224.
——, Kellaway’s Sands at; 282, 234. ‘
Waste lands and heaths; 55. :
Water, action of, in rocks under different
conditions ; 115, 132.
Water-Newton Brickyard ; 100, 141, 174,
189, 195.
—, Great Oolite at; 208,

ane

 

 

 

 

 

.

, Quarries in the Tinoainakice Oolite |

319

Water-Newton, Lincolnshire Oolite at;
141, 145, 178, 174,

— Lodge, Cornbrash at.; 224.

, Lower Estuarine Series at, ; 100, 189.

Water Supply ; 266.

Weathering effect of water ;-115.

of rocks; 14.

Lipset Age ‘of contortions and faults at ;

Weedon, -Analysis of ore from Heyford

* ’ Tron Works ; 125.

Weekly Hall Wood, Sections and list of
fossils at; 145.

Weekly, unconformity between Great and
Inferior Oolite at; 37.

Weldon, Building stones at; 141.

——,, Great Oolite outliers at ; 218.

oo eer of Northampton Sand. ats
100..

—, Lincolnshire Oolite at; 140, 149.

——, Quarries at; 179.

——, Upper Estuarine beds near;
198,

 

 

191,

Welland, Upper Estuarine Series in valley
of; 190.
——, Denudation of the valley, &c. ; 261,
262, 265. 4
—, Estuarine gravels in the valley of
the ; 251.
—, Gravels in the valley of the; 250.
——, effect of great fault in the valley of
the; 172: ©
— "Great Oolite in the wally of the ;
202.
—, Lincolnshire Oolite in the valley of
the ; 142, 153, 154,
a Northampton Sand inthe salley of
the ;
—, batten of Great Oolite north of the;
209, 218. °
—_—, valley of, succession of beds i in; 38.
Wellingborough analysis of iron-ore - from 3
, 122,128, 124,
Wells’ in Northampton Sand, nature of
rock in; 116,.
Werrington, list -of fossils and section in’
Oxford Clay at ; 233, 236.
Westhay, Great Oolite at ; 207.
,. Whadborough, glacial gravels at; -247,
* __. Hill, outlier of Northampton Sand; 109,
Whichford, outlier at; 17, 21.

~

61.
—, Middle Lias at; 64, 71.
‘White clay in the Ironstone ; 181.

cotta ;_ 92.
White Home Warren, sands at ; 20.
Whittlesea, Oxford Clay at ; 283, 238.
Whitwell, Lincolnshire Limestone ‘and
Northampton. Sand at; 97, 167.
—, Lincolnshire Oolite at; 167.
—, faults at; 110, 257.
Wigsthorpe, Cornbrash at; 222.
— cutting, Oxford Clay i in; 233.
Wilbarston fault; 258.
_ ——; Lincolnshire Oolite at ; 149, 150.

 

\——, Lower Estuarine Series near; 94,

§ =

Whissendine brickyard, ‘Lower Lias ra

—— clays used in manufacture of terra~

?
320

Wildbore’s Lodge, pits in Lias near; 67,

Wild’s Ford, anticlinal and faults at; 166
256, 257. ‘

» Northampton Sand at; 103.
——, Upper Lias at; 85.

?

 

Willow’ Brook, Great Oolite in the valley

of the; 206.

——, Lincolnshire Oolite in the valley of
the; 149, 261,. .

-——, Upper Estuarine’ Series along the
valley of the; 190. :

i aa Upper Lias along the course of the ;

Wilsthorpe, Cornbrash near ; 227,
Wing ; 178.
Te outlier of Northampton Sand at;
0.
Witham-on-the-Hill, pits in Great Oolite
and lists of fossils from ; 212. .
Witham River; 262, 268.
-Witem, South, underground stream at;
168, # :
Wittering Heath, Lincolnshire Oolite at;
174.
——, “Pendle” beds at ; 165, 178.
Wittering, Northampton.Sand at; 100.
—— Spa; 269. , *
- Wood, 8. V,, jun., on Upper Tertiaries ; 300.
Wood-Newton, brickyard ‘and parish pit,
‘sections at; 99.
——, Great Oolite beds near; 207. -
—, Lincolnshire Oolite; 141, 170, 171.
——-, Upper Estuarine Series at; 171, 189,
- 194.
Woodcroft, Cornbrash at; 225.
—, Kellaways near; 236.
Woodstone, Cornbrash near; 224.
——, Oxford Clay near; 233, 235.
-Wold, Northampton Sand at; 30.
Wothorp, Collyweston Slate at; 182.
Wothorpe, section of Northampton Sand
near; 108.
Wright, Dr., on Cornbrash fossils ; 219.
—, on the fauna of the Lincolnshire
Oolite ; 39, 40. :
—, on Fossils; 298, 299.
——,, on Oolite Marl; 12,

INDEX. ‘

Wright, Dr. on “Ragstones” of the Inferior
Oolite ;' 11. Wd ,

——.,on Upper Freestones; 11. ,

Wymondham, Northampton Sand obscured
at; 97.

——, sections in Middle Lias at ; 71.

“Y.

Yarwell, fault near ; 258. 2
——,, Lincolnshire Oolite near ; 172.
——, Northampton Sand at ; 100.
——, Glacial Gravel near; 243.

——., Upper Estuarine Series at; 194.

238, “
Yorkshire’ and South-west of England,
difference between Oolites of; 1. ©
Young, A., on the Agricultare of Lincoln-
shire ; 295.

Zone of Ammonites angulatus; 41, 59.

Ammonites armatus ; 59.-

Ammonites Buchlandi ; 59.

—— Ammonites capricornus ; 60.

Ammonites communis; 79.

—— Ammonites geometricus ; 42.

— Ammonites. Humphresianus- absent
in Midland area; 40, 52.

—— Ammonites ibex ; (?) 60.

Ammonites Jamesoni ; 60.

—— Ammonites margaritatus ; 64.

—— Ammonites Murchisone; 17, 29, 33,
39,40. > ;

— Ammonites orynotus ; 59.

—— Ammonites Parkinsoni, absent in
Midland area; 40, 52.

Ammonites planorbis ; 41, 58.

— Ammonites semicostatus ; 42, 48, 45,
59. ;

— Ammonites Sowerbyi; 89, 40, 143.

Zones, abnormal development of; 51. ~

Zones, facies of, dependent on conditions
of deposition ; 49, 50.

—, in Midford Sand ; 12.

 

 

 

 

 

 

~ Zones, value of; 48, 1

-

 

LONDON:
Printed by Gzorcx E, Eyre and Wit114m Sporriswoopz,
Printers to the Queen’s most Excellent Majesty.
For Her Majesty’s Stationery Office. ‘

[1125.—525,—4/75.]

Yaxley, cutting in Boulder Clay near; -
A

Z. ii

a 8
GEOLOGICAL SURVEY OF ENGLAND AND WALES.

DIAGRAMMATIC SECTIONS ILLUSTRATING THE POSITION AND RELATIONS
By J.W. JuDD, F.G.S.

SECTION FROM THORPE SSATCHVILLE (LEICESTERSHIRE ) TO THE FENLAND NEAR

Distance about 22 Milos.

hor Burrow Hull
Thorpe Somerby y Cold. Overton Oakham Burley House Baton

Satchyille Camp

 

SECTION FROM STAUNTON WYVILE (LEICESTERSHIRE) 10 LUDDINGTON (Nor

Distance about 22 Miles.

River

Staunton Hill Slawston Hull Neville Holt Welland Corby Farming W
Rockingham

   

WH Holloway dol!

a Lower Lias Clay ce (Marlstone Rock -bed e Northampton Sand go Upper kstuaine Serves k Great Oolite. Clays m Oxford Clay o Gravel

6 Martstone Sands and Clays ad Upper tras Clay’ L lancolushive (Interior) Oolite ho Great Ooltte Lintestone f Cornbrash n Boulder Clav
Plate Hl atend of Volume

THE POSITION AND RELATIONS OF THE STRATA IN SHEET 64;
7 J.W. JUDD, F.G.S.

¢STERSHIRE ) TO THE FENLAND NEAR GREATFORD (LINCOLNSHIRE )

Distance about 22 Miles.

Fireward
Exton Horne Lane East Wood Thories Fenland

GN Radway River

  

SE

(LEICESTERSHIRE)TO LUDDINGTYON (NORTHAMPTONSHIRE )

Distance about 22 Miles.

Farming Wood Hall Stoke Doyle Barnwell Luddington

 

 

o Gravel
ase SeeN
Seen
meee
Ss

ay

r
a

Cay
an

Oe
Po SOE

 

 

SSeo ees AS
ENR SON S
Se Ses
Z era sates eens
SEEN

SS

SRE
SS

 

 

 

j ; 3 ; 3 RSE : a Se SS

ieee aera ees yi eee eee ae : 5 See RE

a « 5 5s y x
CE nes
aes LPP IID

Toy Se Seta
ee ITD

Kee
if

ek = Ses ; SE ETN
Ne ERS ‘ oS RS SOS RRS

ORNS SRS
REN Sheet
So SRS

Se

SESE

re
HE
Kate fe
Kis

ee
4S
te

ee
fg Py pes

ef
Py
ie

set
743

SS
ES

a.
sysstystes
RHE

ELE ? : y ees x 2 Sore eaten SETS 4 x SE
EE ORE: ERIE ee See
Si iar Pe, ie 2

ease at tees
attests
EL

x SS

Leia arate nes

 

eae ahs de