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1 2 3

Division of Palaeontolo(ry
SHHfliPates

Tte hnz and Potlioles at Rockwood, Ont

> »•» <

By Prof. J. Hoyes Panton, M. A., F. G S.

The followinj; is the fall test of the
Dftper read by Prof. Panton on the above
■nbjeot at the meef'ng of the Gaelph
Boientiflo Sooiety on t. 13th iiiat : -

Some time ago while on a trip to Rook-
wood, with ataden'B of GeoloRy from the
Agrionltnral Oollepe. for the purpose of
■howioK them some exarai)le8 of how
water aota upon limestone I was forcibly
impressbd by a moat interesting aeries
of Potholes found in that distriot, not far
from where the somewhat well known
oavea are aeen.

S3 impreaaive were these phenomena,
that tor three oonaeoutive holidays, the
Students made their way to Rookwooa.and
on two of the ooc^aiona.were accompanied

by myself.

A thorough examination of the locality
was made, and dat* ooUpoted, which I
purpose plaoini! before vou this evening,
and which should be interestina to a
Society that has bi-en established for the
parpoae of developing the history of our
neighborhood whether it be written upon
the rocka or pmes of a more perishable
character.

In treatint! the subject, the following
divisions are naturally presented : — 1.
The location of the Caves and Potholea ; 2.
AdeBoriptiDHof them; 3. An explana-ion
of thuir formation ; 4. Theories concerning
the otiein of the phenomena, that caused
their formation.

1 — LOCATION.

Rookwnod is a sm'ill village on the line
of the Grand Trunk Railway, eituntc-d
about 8 miles eafl-: of Guolph, and 4 J west
of Toronto. Leaving the station and pro-
ceeding in the direotior; nt the village, yon
verv iOO" obiervn that you iiro in a place
Wdil uamdd— Riokwood, from tha amiunt
of rock lu the vif.iiiit>. Ai^'ng ilv river,
whioh pisses ihrongh the villayo are
Btriking expnaur^a of rock, at some places
esoarpmoiits 50 to 70 feet liig>i made up
largely of masaivo Is.yers of Maguesian
limestone, bnlon^iing to the Niagara forma-
tion of the Silurian syBlem. Foesila are
not numerous, (kinoii stems are by far
the moat common ; a few sheila ocour.and
some fragmenta of coral, eapeoia'.'.y the
genns Faoosites. The fragmentary re-
maina of the Orihocaraa are seen at some
places, bat the fossils are neither common
enough, or so well defined aa to work up
the zeal of young geologiata. However,
»fter you have passed over the bridge that
laaila to aorae milla and the large q uarriea
Mid lime kilns near by, you reach looahtiea
well suited to arouse enthneiaam in the
mind of young students in science. The

presence of three large lime kilns "^pmon.
etrate, that this atone produces e^xjellent
lime, exceeding a' >ng and well adapted
for building purposes.

As yon pass westward, along by the
quarries, yon obtain a fine view of the
escarpment on both aidea of the so called
river land grand monuments of denuda-
tion are before you. In the distance
about half a mile is the "Pinnacle"; a
large isolated piece of high rock, standing
midway in the upper patt of the mill
pond. But at your side on the south side
of the road along whioh you are travel-
ling, your attention is arrested by a great
hole at the baae of the rocka. Thia is the
entrance to a cave, whioh on examination
proves to be of more than passing interest.
In a line almoat southeast of this *nd only
a short distance awav, but on the top of
the bluff, you reach a pothole which rivals
some that for yeara have b»ea a groat
source of attraction to tourists stopping
at Lucerne, Switzerland. Woodcuts of
these are snatterei in every direction, and
no one can say that he has made a proper
visit to Lucerne unleos he has visited the
"Glacier Garden" and obaerved the aeven
potholeti, that are ailent mouumenta of
glacial phenomena long since ended— Yet
here at Rockwood we can get a series of
potholea larger in some reepeota and more
unique than thoae at which so many
thousands g»zs in wonder each paesing
year. ihe formation and origin of these
we will consider Ruhaeqnently.

2— DESCRIPTION OF THE CAVES.

The entrance to the main cave is
1.5fe6t high and obatructftd by great maaaea
of rock, which have fallen from the roof.
From thf top of thfj oave to the anmmit of
th-t overhanging rook ia 40 feet o( solid
dolomitin lime atone. Prnofieding into the
cavern yon observe that the roof ia very
irregular, linking at timea to 5 feet, theu
riaiug to 7 and sinking again. At the
mouth it la 29 feet wide and narrowa to a
width of 16J at a diatance of 36 feet from
the entrance. Here it ia only 5 feet high
hut on paaaing thia point yoa reach anoth-
er chamber, whioh widena and haa at the
left aide a small chamber eight by aix feet,
but soon narrowing and dipping down till
the cave seema to terminate at a point 30
feet farther than the narrow part and 86
feet from the entrance. This is as muoh
of the cave as most visitors see, but beinjj
accompanied by studenta of more than or-
dinary pluck, endurance and zeal I was
eucoessful in securing data whioh -ill en-
able yon to form •ome interesting oon-

olosioDS about tbia oomparatively unknown
■pot. LigUt enda bere. A lantern was ob-
tained and entering one by one « pLtaaage
■oaroely lar^e enontth for a houiaii being
to f;otbrookh, for 8 feet, MeeBre. Craig,
Rayoor, Patterson, Sharman, Ztvitz,
Bisbop and Fee, wormed tbemeelvea
through into another aave, ahroaded in
Egyptian darkoeas and Kloora. Tbia ex-
tenda 10 feet to the lefl and 15 to the ri^bt
i.e., had a diameter one way of 25 feot and
13^ the other.

To the left and right tbev found a pillar
not far from where they entered , these
supports seem to have been formed by the
rest of ihe rook wbiob once made up the
solid rook bemg carried away. At th? ex-
tremity on the right hand side the floor
was very muddy, and two cm-ill caves ex-
tending still farther, one near the passage
by which thsy entered, the other at the
opposite Bide ; the farmer three feet by
four, the latter three feuc at the opening
and tapering to a point and dipping down-
ward. Prowling about in this .;loomv
chamber, not high eooagh to proceed com-
fortably, for It was only about live feet in
the centre, they shiw etalautit'-B nnd stalag-
mites, some of tbem a foot in length and
four to five inches indiamaterat tbe thick
CBt place. The flour of this chamber albo
dips slightly down. Directly aorotis they
came upon another pillar-like structure,
with a paseage on each side, opening into
another apartment, where the roof waa
not over three to four feet hibh.und gradu-
ally narrowed so as tn render farther pro-
gress difiionlt.

This extended ten fpet across and about
tbe same in width. Ou the oppoaiiti side
from tbe entrat'-p, there is ar opeuiog
leading, still fan her, bat the paseage
graduiilly narrows until ftrther advanoe-
ment is strpped. Through this opening
Mr. Riynor panged, an' thr>-Hded his way
13 feet, and reached a point llOJ feet from
the entfnoe to the main cavt 1 he fl jor
of the laet chamber inuiiues B'i;<hily, but
in this prolongation the elevHtion is oon-
eiderable. S )unding thin lant floor seemed
to icdioate lhat> it waH h illuw hi neath.and
from the faijt that the prolougttion of the
former chamber, near where thiM waa en-
tered liipa downward, it id HUppot>ed a p^S'
sage frim it oontiLUes i^tid likely paesea
onder this lawt fl rar. All thnu^h these
darkened caverns a good deal of rnul was
enooutitereJ. Water tri'klint! down the
side:! and dropping from tiH roof added to
the gloom of these darkened rec saea,
where daylight hai nevrr vet penetrated,
and whose walla dimly liiihttd by the
flickering light (^f the lantern, presented a
BOmewh'iti weird, unattractive appearance.
When the explorers emerMed from these
inner reoeasee of darkne>-8, their clothes
preeeiitei quite a ch-ing d appearance and
indicated that mnnh of their travelling
muBt have been done in a somewhat
menial position, and that they hud been
much associated with mud and wa'er
within. A little to the'left ot the • ntranoe
to the main cave there is an opening,
which leads to another series of obambera,
extending to a distanoe of 69 feet.

At a point in tbe vicinity of the flrst
narrow place in the main cave there is a
narrow passage leading into this series, in
which the apartments are not so oompli.
oated, and being dry are much more easily
examined. Tbe first ia some 25 feet long
and 12 wide, narrowing to a passage into
the second, 10 feet aoroaa, and opening
into the main cave.

The general direction of the main cave
ia E. by 8. E. to the narrow portion, then
S. E. by 8.; thia course ia maintained till
the end ia reached.

The roof through the whole seriea ia ex-
ceedingly irregular, and tbe floor in many
parts covered with fragments ot the lock,
which have fallen from tbe roof. 8talao-
titoa and atalagmites are found only in
the inner chambers, and the latter seeni
more common than the former. Some
mayiiave formed in the outer, but have
likely been carried away by visitors.

The diagrams before you will give a
clear idea of tbe arrangement of tbeaeBub.
terranean passagea and chambera, and
their relative position to each other. The
whole aeriea may be termed one cave, con-
sisting of six well defined caverns, and as
a sort of expansion on tbe sides of these
four small onea.

POTHOLSS.

Leaving the oaves :.,nd olamberinp up
the sides of one of the quarries near by,
you reach the summit of an apparent
peninsula of solid rock, along each side of
which a stream flows at tbe present time,
bordered by precipitous clifis 50 to 75 feet
high. The general direction ot this rooky
ridge ia north a-cd south.

The streams are united about a mile
farther to the north, and after passing
along the sides of this marked rork eleva-
tion, they join in the vicinity ot Farribh'a
mill, and thus forming in reality an
island, which terminates at its southern
extremity in a limestone oliff.

About 5C0 yards from the caves, and
near the end of tbe bluff, you suddenly
come upon an immense boie in tbe solid
rook ; it has an oval form, its longer
diameter being 20 feet and the shorter 15 ;
one side is 10 feet higher than tbe other ;
it' lies in a slight depressiin in the rock,
which terminates at the side of tbe hole,
with an abrupt fall of 22 feet. At the bot-
tom of the hole you perceive an opening 4
feet hith and 2 feet wide, but of an irregu-
lar outliue, thia opens into a aort of valley,
buli it must be remembered thia is 40 — 50
feet above tbe level where the streama are
fl )wing, Thia valley has rock on bjth
sideo and forma a baantifal glen, at
the present time a popular haunt for
boys delighting to revel in the pastimea ot
youth.

Following in a southwest direction for
BomeGOyarda the rock risea, and a little
farther on ends abruptly with a fill of
about 50 feet into the valley, through
which a very insignificant stream at pre*
sent passes.

On the opposite sidi? of the valley about
100 yards wide at this place, the
esoarpment is fully 75 yards high. About
the middle of this valley a slight elevation

of Bolid rook some 15 feet h'lKb oooars. It
ooonpies a peoatiar poaiiioa and form, ap-
pearing ae if BtroDg onrrenta bad worn
away rook material.and left this irregular
oatlier, as a raonaicent of oonditiona no
longer Been iu tbia pUoe, where a mere
oreek meandera throngb a well defined
ravine.

In tbis isolated area of rook on examin-
ation you find a a.oat intereatiog and in-
Btrojtive aeriea of Potholeci, 6 in namber,
to some extent in a line with the lurge
one already referred to, aa located about
' 150 yards to the N. E.

A more unique aeries oonld aoaraely be
imagined. Galling that already d^-aoribed
aa No. 1, then here we have : — No. 2, 6
feet by 6 and 7 fnet deep ; No 3, 1 foot by
by 1 and 3 f«et deep ; No 4, 6 feet by 6
and 12 feet deep ; No. 5 8 feut by 4} and
8 feet deep ; No. 6, 6 feet by 6 an < 10
feet deeo j No. 7, 12 feet by 6 and 3 feet
deep ; No 1, 20 feet by 15 and 30^ feet
deep, from the hitibest aide to the bottom
and 21 from the loweat.

Tbeee Lolea in the rock have nanally
a greater ditimeter about half way down.
The following raeaanrementB of No. 1 will
show thia :— Four feet from the bottom,
21} by 18 feet ; midway, 23 5-6 tba by 19^
feet ; six feet from the top, 25 by lOj^ feet.
Generally speaking the outline of a
vercioil n<«otton is oval.

Holes 2 and 6 are on the edge of the
rook, an.i oonstqaently are somewhat im-
perfect ; from 5, which oomt-s near the
edge, there is a small hole, which opens
into the valley ; tbia enabled us to empty
it and learn the nature of its oontenta. At
first we were deairoua to investigate the
oontenta of No. 1, and with that vie'v dug
for the flrdt day, and returned to continue
the work. Mnub soil, fragmeota of rock,
etc., were dug up and wheeled away,
but we found no trace of rounded etonea.
After several hjura of hard work, it was
resolved to proceed to the series in the
valley and explorn some there.

The facilitio!< far working »t the large
hole are good, iniiHtnaoh aa the material
OouM be lo'ided into the wheelbarrow at
the bottom and wheeled aw»y a short dis-
tance and emptied into the ravine a few
feet below. It is hoped on some future
oooiiaion mombrrs of the Society will
follow up the work undertiken here, and
finally olea.n out the bottom of thia atrange
place.

We proseeded to No 5 and entered npon
the work of cleaniui> it out ; only a few
spadefuls of earth were t^ken out when
some stones were found, whose rounHed
shape had a wonderful inspiring effeoli
npon the workers.

They wern very round, and were ct an
entirely d'ffdrenii compoaiiion from the
solid rook iu which the hole had been ex-
cavated.

After some two hours digging the
bottom waa reached and a fine collection,
about two p-iilfula, of rounded atones was
obtained, varying from 6 inchea io
diameter to half an inch. Many of the
email stones were at round as marbles.

These sixteen before yoa represent some

typioal forma, and will enable yon to form
an idea of the interesting nature of these
stones, whose very appearance suggest
qaestiona aa to how they came to be so
ronod, and bow they g^t where they were
found ?

We bad hoped to have found similar in
the large Pothole, whether euoh will be,
remaina to be seen. It might poB^ibly be,
that tbey have rolled ont throniih the
passage at the bottom of the hole and
mnat besought elsewhere.

No. 3 being small waa emptied and some
of the flaeat speoimena of small rounded
stones were got from it. Noa. 2, 4, 6, 7
have not been eximined,and it ia probable
that an examination of them will meet
with even more gratifying reaults than
those emptied. Having had thu pleaanre
of seeit^g the Potholes at Lucerne in
Bwitz^rland, "j does aeem to me that at
Bookwood there ia as interesting a series.
Along the river near the quarries 18 mure
or less defined holea appear, and in this
locality under conaideration 12 in all are
found, and of these the seven more par-
ticularly described are exjeediogly
unique in form, position aud structure,
and were they near a large city would be a
source of great attraction to visitors in-
terested in the worka of nature.
3 — fjrmation of thk oavks and potholbb.

In all distriota, where limestone
exists, it is not oncommon to find caves,
especially if water U near. Water con-
taining carbonic acid (a gns generated in
the deoompoaition of vegetable material
and largely present in the atmosphere,
from them the respiration of animals ; for
the air expelled from their luogs ia
charged with it,) has a powerful di»integ-
raticg effect upon the carbonates of lime
and maiinesia, forming from them bi-oar-
bonates, which are soluble in water and as
such are carried away ; consequently it is
only a matter of time before limestone (a
carbonate of iiorje) when acted npon by
water containing this gas ia completely
dissolved. A m-^re dripping in a crevice
will in time effect qai'.e a change and
form considerable of a cavity. If the
quantity of water ia considerable, the
change is accomplished in a shorter
ppriod Very f'iroible examples of this
disinte(/ratint> effect of water on limostoae
were observed by mo in DTbyshire thia
anmmer. There are ravines there which
are supposed to hive been formed out of
the SLlid rock in ages long receded into
the past.

These ravinea were once overoapped by
liranstone, the cave or ptssaue itself dis-
solved and ctrried away by water, finally
the top fell in and the debris carr ed bp-v-
ward, until now all that marks the great
oaves are the walls, which form esiarp-
ments along the ravine, through which a
rivuUt passes at the rreS'^nt time. Near
by a great cavern (Poole's) explains the
prooesi; the entrance ia narrow and low
ye^, 12 feet in, and you reach a much
wider passage, and as yen proceed
immense apartments are entered, ao that
you pa'js along a tortnona pathway for
several hundred yards. Borne of the apart*

manta are 30 by 30 feat high mad 40 wida.
Mo raanioK dtteain ie aevn to indicate the
oaaae. bat the w*ter trioklinK down the
■idea uzplaica thia ^reat diaintagration of
(ifae limestone ; so here, oominK nearer
home, at Rookwood, yon find oavei not
■O extensive, bat aa ohkraoteriatic of the
Mtion of wacera aa those I have been re-
ferring to.

The preaenoe of mad in the back part
of the iaoer cavttruti at BookwooJ seuma
to indicate a ooaneotion between them
And the sarfaoe throagb fiaaareb in the'
rook. Thia mud beara a cloae rcaemblanoe
to the aoil whioh oovera the rook above,
and baa likely been broa^ht down by rain
throneb theae orevioea. Thia rain charged
with oarbonio aoid in time ooald easily
diasolve oat the rook and leave the oaverna
M we find them no«. Frost would assiit
in breaking off fr«gmenti3. aa we find them
now Boattered along the floor o( the oave,
^hile the aidea preeent a very irregular
•ppearanoe.

The prewnoe of atalaotitea on the roof
and atalagmitea on the floor, also ahow
mooh disEoIving of rook by water, for
these atraotnrea are merely the pieoipi-
toted lime from the water, whioh haa car-
ried it down. The w«ter on reaching the
roof evaporatea, and the lime ia left, tbia
ffoea on adding partiolea of lime, until a
etraotnre is formed not unlike an ioiole in
form, but oompoaed of oarbonale uf lime.
Sometimes the drops fail upon the floor
and form something of the same in form.
The atalacti'^^ea areaometimea boUcw but
the stala^^mites are folid ; this is owing
to the one being formed on the roof and
the other on the floor. In some oasea,
those from the roof fall and beoome ic-
bedded in the material on the floor. At
Bockwood the stalagmites are more oom
mon than the sOaUctites, seeming to iudi
oate that the water ooucainiog lime in
aolution falls before evttporttticn takes
plaoe, and oonseqnently a tentlenoy for an
aooumnlation of lime on the floor.

POTHOLES.

The Potholes, too, aie no doubt tho re-
anlt of the antion of tbn water, but in this
case the aotion ia more meohanical than
ohemioal. Water moat have pa^ieed over
aa a atrccg current, tho place, where the
potholes aro now but in their flfat atai^es
only a slii^ht depret>aion w-xa in the rock.
In theae some Hard atonea collected and
according to the atrentith of th? current,
the raovfiment o( the etoneiJ would depend ;
the motion produced would aeon lea(T to a
wearing away of the rook. Holes would
form a,nd deepen, tia time roiled on, nntil
a cavity would b^ produced not unlike a
pot in outline. In uU the holes examined,

the diameter midway down was greater
than at any other point. The atonea
grinding thia ont bein>< harder than the
rook, for you uaaallv find they are pretty
maoh the aame aa our bonldera in the
field withatand the wear and tear well,
but in the ooarae of time they beoome
ronnded and finally auooeeded in making
a pothole, whioh will vary in size accord-
ing to the length of time the grinding haa
oontiuaed, the foroe of the oarrent and tiie
hardnesa of the rock acted upon. To-day
we aee no water near soma of theae holes,
but we find that when the loone aoil in the
bottom of the holes ia dug up ■ii oontaina
innumerable rounded stones of all sizea
from a marble to that of a common ball,
have already aaid the maohanical
aotion of stonea and water upon the lime-
atone, in whioh wh find theae holes, have
affected the condition of thint^a we at pre-
aent observe. Thpre are two waya in which
theau currents of water may have acted.

4 -THEORIES or FHENOMENA.

1. That of a great river, which filled the
whole space betwe^Ji) the highest banks at
Kockwood, a atreaabearing a'ong a great
body of water, with a strong out rent A.a
time rolled on it gradually leaaened in
volume and formed two atreams, running
along the valleya in which, we find the
streama of to day, but muoh larger than
they. At some period in this great river'a
exiatenoe it flowed across the depression,
where yon see the largest Pothole, and
flowing over the precipice pursued its
coarse along the line in which we find the
other Potholes.

2. The water may have been a oarrent
under a glacier as we m^e in some cased at
the present tim^ in Alpine diatricta. A
orevaaae (crack) may occur milea from the
end of a glacier, into thia water formed on
the surface, aa it pushes its way into
warmer loaaliti>'a, falls and finally makes
its way ont nnder tho threat stream of ice.
Such an under current setting! into a de-
preaaion in the rook, aided by atonea from
the glacier would bi aaroto produid Pot-
holes. This U the ori»^in of thospi at Lao-
erne. In Buoh casea yon are likely to fiad,
that th(4 stones derived from the glacier
that did the work are lar^^e, and that the
surface of the rnnk ia much abraded illas-

trating glacinl atrial vt ry impressively.

At Rookivood Potholes we so far have
not been beon ablo to discover glacial
markings, and among the ronnded stones
none exceeding six inches in diameter.and
thus are inclinei to think these holes have
been worked ont by the water of a river
rather than that found beneath a glacier.
However aa further information iaaecared
we may be led to modify the conolusiona
presented to-night,