a Lot CG 7TRWG6 ¢ \ ay of t- , ohne ee | ee Cornell Alniversity Library BOUGHT WITH THE INCOME FROM THE SAGE ENDOWNENYTY FUND THE GIFT OF Henrg W. Sage 1891 A: [3 5B FD y 4 19e0 6421 eum Ry ENGINEERING LIBRARY a) Wh Cornell University os QE 264.G78W6 2 heer s ation oft s ae ‘iil iii 3 1924 003 855 V— Ustaton stirs Mare of S atlerurmy, A Urieroumphins —Runrow Krad, 3.— Weatern Wiohoremohon. Be ec ccreerasnicgeail D.— Kuvfeudirightaho, A 135652 2 ute see ale aie Lege Pemoirs of the Geological Surbey, SCOTLAND. EXPLANATION OF SHEET 1. WIGTONSHIRE—MULL OF GALLOWAY. EDINBURGH: PRINTED BY MURRAY AND GIBB, FOR HER MAJESTY’S STATIONERY OFFICE. 1872. ~ hasoy Calis Sake eet a ey Price Threepence. IWD EX to the GEOLOGICAL SURVEY MAP = Sof SCOTLAND Publishedionthe Scale of One inch to amile L") Mareh 1872 ua mwaty Lo5 LOG Wo Seve : Tae ee 97 Yraserbitggh Banfr~ MURR Afy Nai NAIRN Harty Peterhead pst. BA 285 ° 86 87 WERT” BANFF {estaeianes AV BUERRUDRE SERN | MU Le Aly Io 13 | 7a 76 shoriteeni 7 | a ——aL~ Eom pBalnhoral 2 4 Fon Mati ee Ok 65- es 67 SHIRES Lerth LKIRK i {;ROXBURCH tfepwitte 14 18 ae Published ISN ny aVING$ | Irupreparation © Memoirs publish ed. sMemoirs of the Geological Surbev, SCOTLAND. EXPLANATION OF SHEET 1, WIGTONSHIRE—MULL OF GALLOWAY. EDINBURGH: PRINTED BY MURRAY AND GIBB, FOR HER MAJESTY’S STATIONERY OFFICE. 1872, “fle QE a4 CI1gWS aise Avl35652 PREFACE. THE Sheet of the Geological Survey Map which the present Explanation illustrates, was surveyed during the directorship of the late Sir Roderick I. Murchison and under my supervision, by Mr. D. R. Irvine, by whom also this Explanation has been written. The Appendix of Fossils has been prepared by Mr. Robert Ethe- ridge, jun As the Sheet contains so small an area, and forms geologically and geographically a part of the district to the north, it has not been deemed desirable to do more than merely enumerate as briefly as possible the local features, leaving fuller details regarding the Silurian rocks, with their fossils and intrusive igneous rocks, to be given in the Explanation accompanying Sheet 3. ARCH. GEIKIE, Director. GEOLOGICAL SURVEY OFFICE, EvinpurGu, February 1872. EXPLANATION OF SHEET 1. I. AREA EMBRACED IN THE MAP. 1. The present Map contains an area of 21-6 square miles, embracing the southern half of the peninsula which terminates southwards in the Mull of Galloway. This area belongs entirely to the county of Wigtown, and forms the extreme southern promontory of Scotland. Il. FORM OF THE GROUND. 2. As the area represented on the present Map is only a prolongation of the wide Silurian uplands of the south of Scotland, it presents the same general characters by which these uplands are marked, although, from its low elevation and its insular position, it possesses, on the whole, a more cultivated aspect than is to be seen in the higher ground to the north. Most of the surface has been brought under the plough; the more important tracts which still remain in a state of nature heing Barn- corkrie Moor and Grennan Moor, where, owing to the absence of super- ficial accumulations, the underlying rocks form rough bills and moorlands. The whole peninsula may be regarded as presenting a long range of pre- cipices to the west, and sloping gradually down to low shores along the eastern seaboard. The western cliffs reach a height of fully 400 feet at Dunman; the highest elevations in the district being one of 525 feet on Cairn Fell, and one of 529 feet on Muntloch Fell. In consequence of the general slope of the ground from west to east, most of the streams flow eastward, but none of them are more than mere brooks. Three promi- nent depressions interrupt the continuity of the western cliffs, one of these extends across the peninsula from Port Nessock or Port Logan Bay to erally Bay, the second forms a hollow between Clanyard Bay on the west, and Kilstay Bay on the east, while the third serves as a narrow, slightly elevated neck, to connect the headland of the Mull of Galloway with the rest of the peninsula. 3. The coast line of the present district extends in all to about 23 miles, of these fully 154 miles are ranges of cliff confined to the west side of the peninsula, except at the Mull of Galloway, where, for a space of two miles, the eastern shores are also precipitous. The low shore, shown on the present Map along the east side of the peninsula, extends for about 74 miles. Except at the three bays already indicated, there are no sandy beaches on the west side; the full force of the breakers beats there along the base of the cliffs. On the opposite side, however, which lies in the lee of the prevalent south-west storms, flat sandy beaches are continuous almost the whole way. III]. FORMATIONS AND GROUPS OF ROCK ENTERING INTO THE GEOLOGICAL STRUCTURE OF THE DISTRICT. Aqueous or Sedimentary. Alluvium, Peat. Recent. Blown Sand. Raised Beach. Drift Series. eon and Gravels, and Stratified clays. Boulder-clay. Lower Silurian (Llandeilo). Greywacke, Shale, etc. Igneous. Of Miocene age. Basalt-rocks in dykes. Lower Silurian rocks. Felstone. ‘Intrusively associated with Granite, Diorite. IV. GEOLOGICAL STRUCTURE OF THE DISTRICT CONTAINED IN THE MAP. 4, The whole of the district embraced in this Map consists of Lower Silurian rocks, pierced here and there by intrusive igneous masses, and overlain with Drift and other surface deposits. As usual these formations are described in ascending order beginning with the oldest. Lower Silurian. 5. This formation comprises, with the exception of the igneous bosses and dykes, the whole area embraced in this Sheet. The strata consist of greywacke and shale, and, on the whole, are very destitute of fossils. In some thin bands of black shale, however, graptolites are abundant; and they also occur in a thick band of flaggy grey shale, which has been worked for slates at Grennan. ; The greywacke is commonly of a grey or greyish-blue colour, occurring in beds of varying thickness, from six inches to six and sometimes eight feet. It is usually much jointed and split up ; "in many cases the sides of the joints being coated with carbonate of lime or hematite. It is thus rendered useless as a building-stone. It varies in texture from a fine- grained mudstone to a coarse gritty sandstone. It is interbedded with partings and beds of grey, greenish, or red shale, usually hard and splin- tery. At each end of Clanyard Bay there is a band of shattery black shales, which contains some graptolites. These beds are not traceable for any distance, the ground in the line of their strike being entirely covered by drift. A few graptolites have also been obtained from some beds of dark shale at Laggantalluch Head; and a thick band of flaggy- grey shale, running across the country from Kilstay Moor to Grennan slate quarries, has also produced some similar fossils. The above men- tioned localities are the only places where Silurian fossils have as yet been found in the tract represented upon this Map. The list given in the Appendix comprises all the species which have been collected. 6. The general strike of the rocks of the district is N.E. and 8.W., and the strata are almost always inclined at high angles. From the Mull of Galloway northwards to Port Nessock Bay the beds have a prevailing dip to the north-west ; but from the north end of the Bay to the edge of 7 the Sheet the dip is reversed, the beds being inclined to the south-east; Port Nessock Bay thus forms the centre of a large synclinal trough. There are also various minor folds seen in the section from the Mull of Galloway to Port Logan. Even when the dip is persistent for two or three miles, this need not imply that there is a continuously ascending series of strata for that distance, as the beds may be thrown back upon one another in a number of rapid reversed folds, the tops of which have been removed by denudation, thus bringing the same beds again and again to the surface - without a change of dip. From the general sameness of the rocks in lithological character, and the consequent absence of distinctive beds, it is impossible to discover how often such folds may occur; for, even with the help of the shore sections, which are more or less continuous for miles, it is difficult to ascertain with any certainty whether the highly inclined or vertical beds seen in a short distance are all distinct, or may not some- times be repeated by concealed and quite undiscoverable plications. 7. The Silurian rocks are all of Llandeilo age. This is indicated by their fossils; a list of which, with the localities yielding them, will be found in the Appendix already referred to. Intrusive Rocks. 8. The Silurian rocks of this district are pierced by numerous intrusive rocks, which occur in two forms. One of these is shown in the large boss of granite, forming a marked feature on the western coast; the other is that of the numerous little dykes and veins sometimes so con- spicuous on the coast cliffs. 9. The mass of granite just referred to covers an area of two square miles, extending along the west coast from Laggantalluch Head to the south of Crammag Head. It forms a line of sea-cliffs one mile and a half in length, and sometimes reaching 175 feet in height. This rock varies from dark grey to flesh colour, and from an exceedingly close grain when dark in tint, to a coarse crystalline character when it becomes pink. It consists of orthoclase, quartz, and black mica, with sometimes the addition of hornblende in considerable quantity, and of pyrites more sparingly. These marked changes in its character occur within com- paratively short distances. Thus, from Laggantalluch Head south to Portencorkrie it is generally light grey and coarse grained, though sometimes becoming very fine in texture and of a dark grey colour. From Portencorkrie southwards along the coast, it is pink and rather coarse in texture, while on the east margin it is again dark grey and fine grained. Along the north boundary the granite is traversed by numerous quartz-veins running as a rule north and south, at right angles to the line of junction with the surrounding greywacke. ‘The latter is consider- ably hardened and altered for some distance from the junction. Along the east margin of the granite the greywacke beds are seen abutting directly against it. At Laggantalluch Head, also, the junction of the rocks is well seen. 10. Besides this boss of granite there occur numerous intrusive rocks in the form of dykes and veins. The direction of these usually corresponds with the strike of the beds. The majority are mere veins, consisting of purple, pink, or pale fawn-coloured felstone, having the same character as those in Sheet 3, which lies immediately to the north of the present Map, and in the Explanation accompanying which they will be more fully described. A mass of pale compact fine-grained felstone, sometimes merging into hornstone, fully 200 yards broad, runs across the narrow strip of land which connects the Mull of Galloway with the rest of the peninsula between East Tarbet and West Tarbet Bays. The surface is 8 much broken up by lines of joints, which, running parallel to the sides of the mass, give it the appearance of bedding—a deceptive character, which is further heightened by the intercalation towards the edge of the mass of thin beds of greywacke and shale. It is owing to the gradual increase of these intercalations that the main felstone mass dies out. It is com- posed of felspar, with hornblende diffused through it, and some quartz. In some places it contains a considerable quantity of tale. The other dykes shown on the Map are of dark purple or grey felstone and diorite, with the exception of one small basalt-dyke only seen on the shore im- mediately to the south of Port Logan harbour. ‘These can also be better described in the Explanation to Sheet 3. Drift. 11. The area embraced in this Map affords abundant evidence of the Glacial Period or Ice Age in this country. This evidence consists of Scratched rock-surfaces, Boulder-clays, Sands and Gravels, and Erratic Blocks. ‘ 12. Where the Boulder-clay has been recently removed, exposing the rock surface beneath, the latter is generally seen to be polished, smoothed, and covered with striations, generally very well preserved. Although these strie have disappeared from the bare mounds and hummocks of rock which have been long exposed to the action of the weather, the characteristic rounded outlines of roches moutonnées, or ice-worn rocks, still remain. These rock-hummocks, seen from a little distance, appear per- fectly smooth. They are not frequent in this district, owing to the low- ness of the land, and the general spread of the Drift deposits over by far the greater part of the area. The general direction of the strie, which, with one exception, are only seen along the top of the cliffs, is about 8.S.W., as will be seen in the Map, where they are all put down in the positions in which they occur. This direction agrees with that of the strie to the north, shown on Sheet 3, and seems to point to the move- ment of a large ice-sheet from the high hills to the north-east. The ice must have crossed the head of the Bay of Luce, and mounting over the eastern shore of the peniusula, must have descended into what is now the Irish Channel. 12. The Drift deposits which lie upon this generally ice-worn surface of rock consist here of Boulder-clay, and overlying Sands, Gravels, and Clays. ‘he Boulder-clay,.which covers the greater part of this dis- trict, has the usual features of the lower part of the Drift in the Silurian tracts of the south of Scotland. It is generally pretty stiff, of a brownish- grey colour, and full of stones, partially rounded and generally covered with striations in the direction of the longer axis of each stone. Some of these stones are of considerable size, but the great majority average from one or two inches to a foot in diameter. They consist almost wholly of the rocks of the district, with a few granite fragments scattered amongst them. This part of the Drift is quite devoid of stratification, though in some places small patches of sand and fine gravel are imbedded init. At Clanyard Bay, there is a section of Boulder-clay exposed for a depth of fully 100 feet; but the average thickness of the deposit here is perhaps not more than six or eight feet. Shells have been obtained from the cliff of Boulder-clay at Clanyard Bay, a few of them entire, but the majority in a fragmentary condition. There is a sandy patch in the Boulder-clay at the south end of Port Logan Bay, from which shells have also been obtained. The names of the species, with the localities from which they have been obtained, are given in the Appendix. 13. Overlying the Boulder-clay there is a considerable accumulation v of stratified Sund and Gravel, which is spread out over the ground in large patches, seldom rising into ridges or hames. It is chiefly confined to the low eastern shore bordering the Bay of Luce, where the ground is much lower than on the other side. Much of these deposits may consist of fragments of ancient beaches which have een left here and there along the shores, but so broken up and irregular from the effects of denudation as to make it impossible now to trace their original form. These sands and gravels have yielded no fossils of any kind. The only example of stratified clays which occurs in this Sheet is at Terally Brickworks, where a small patch of greyish-brown stiff fine clay, containing very few stones and imperfectly laminated, is worked into bricks and tiles. It rests upon the lower Boulder-clay, and contains shells, as shown in the Appendix. 14. The ground embraced in this Sheet has been so long under culti- vation, that the larger Erratic Blocks, which may once have existed, have all disappeared. A few small ones may still be seen scattered over the district, along the sides of fields or roads to which they have been carted by farmers when reclaiming the land. These are almost all of grey granite, of the same character as that which forms the higher or Cairns- more hills to the north-east, from whence they have probably come. Raised Beach. 15. Although, as just mentioned, some portions of the sand and gravel deposits of the district may represent former sea-margins, only one well- preserved Raised Beach is here to be seen. It can be traced pretty con- tinuously along the eastern seaboard of the peninsula, bordering the Bay of Luce at the height of 25 feet, but never extending inland for more than 150 yards. There are a few fragments of an older terrace at the height of 64 to 70 feet, but they have been very much cut up and worn away by denudation. Blown Sand. 16. The only Blown Sand on the Sheet is a small patch beside Port Logan. It is being gradually levelled and brought under cultivation. Peat and Alluvium. 17. Peat is not now abundant in this district ; it occurs only in a few small hollows towards the north edge of the Sheet. The largest of these, near Balgown Farm, has been drained and brought under the plough, and in a few years will be hardly distinguishable from the surrounding soil. The other patches are also being reclaimed, none of them having a sufficient thickness of peat to be worked for fuel. 18. The Alluvium, as will be seen on the Map, consists of small patches along some of the larger streams; and the beach of sand, mud, and shingle, exposed at low tide, along the east shore of the Map. V. ECONOMIC MINERALS. 19. Building-sione—A. few of the least jointed greywacke beds in this district are quarried for Building-stone; but the great majority of the rocks are too much jointed and broken to be of use for any building purpose except making ‘drystone’ dykes. The granite shown on the Map has been quarried near the farm of Low Slock, and at other places, but only to a very limited extent. It would form a good building material if properly opened up. At Grennan and Kilstay Moor a band of grey flaggy shales has been quarried for roofing slate. here are, however, no true slates in the district, none of the beds being traversed lo by cleavage. but splitting along the lines of bedding. The shales are too soft and coarse to he employed, except merely for local use. 20, Rowd-metal—The common greywacke rock of the district is largely used for Road-metal, for which it is very suitable on account of its hardness and toughness. The granite also is available for causeway- stones; but it has not yet been used for this purpose. APPENDIX. A.—LIST OF LOCALITIES FROM WHICH FOSSILS HAVE BEEN OBTAINED BY THE GEOLOGICAL SURVEY IN SHEET I. North end of Clanyard Bay, 24 miles N.W. of Drummore. South end of Se a5 ‘a Grennan Slate Quarry, 2 miles N. of Drummore. Kilstay Farm, Quarry near, 2 miles N. by W. of Drummore. Laggantalluch Head, Cliffs 250 yds. N. of, 3 miles W. of Druammore. . Terally Brickworks, 3 miles N. of Drummore. 7. Port Logan Bay, Cliffs 8S. end of, 4 miles N. W. of Drummore. SRN Coro B.—LIST OF FOSSILS OBTAINED BY THE GEOLOGICAL SURVEY FROM THE DISTRICT EMBRACED IN SHEET I. Lower Silurian. Localities. Hydrozoa, Diplograptus pristis.— His. 15-2), 5% ‘8 » varn*— . I, i tamariscus.—.Vich. Ds Graptolithus convolutus.— His. 2 i (discretus ?—Nich.) 2. sty latus.—M‘Coy. . 3. > lobiferus. —M ‘Coy. 2: a (Nilssoni ?—Barv.) 2s 5 Sedgwickii.—Portl. 2: Pa tenuis.—Portl. 1. 55 Sp. . , 8, 4. Rastrites maximus. —Carr. i: 5 peregrinus. —Barr. 1. « Four specimens of this variety were noticed, having all the characters of D. pristis, but with the axis at the distal end much inflated, one especially so. Dr. Nicholson considered this to be a dis- tinct species, under the name of Diplograptus vesiculosus (vide Quart Jour. Geo. Soc., vol. 24, p. 527; also Monograph on British Graptohitide, pp. 40, 41). On the other hand Mr. Carruthers retains it in the normal species D. pristis (Geol. Mag. vol. y., p. 130). Lamellibranchiatu, Gasteropoda, Foraminifera, . Entomostraca, . Lamellibranchiata, : 12 Drift. (a) BouLpEr-cuay. Astarte suleata,—Da Costa . », var. elliptica.—F. and Hl. Cy srina, Islandica.—Linn. Tellina solidula.— Pult. Leda (like pernula. —Miiller.) i Saxicava rugosa.—Linn. Turritella terebra,—Linn. (6) Laminatep Cray. Polystomella striato-punctata.—F. and M. A few single valves much worn, Leda pygmxa.—Miinster, truncata.—Brown. ” rn HNNH PRAHA 3 Ve Geologioal Memoirs, to accompany the Sheets of the One-inch ap. Sheet 1. » 38 a » 18 » 14 ww ab 9 22 » «24. » 232. » 33. 5 34. Wigtonshire, Southern Districts. 3d. . Wigtonshire, South-Western Districts. 3d. [Nearly ready]. . Ayrshire, South-Western District. 3d. . Ayrshire, Turnberry Point. 3d. . Ayrshire, Southern District. 3d. . Dumfriesshire, N.W.; Ayrshire, S.E.; and Lanarkshire, 8. corner. 34d. . Ayrshire, Northern District, and Southern parts of Renfrew- shire. 3d. ‘ Peeblesshire. 3d. Edinburghshire and Linlithgowshire. 4s. Jn cloth boards, 5s. Haddingtonshire. 2s. Eastern Berwickshire. 2s. A Detailed Catalogue may be had gratis, on application to Messrs. W. ¢ A. K. Johnston, 4 St. Andrew Square, Edinburgh, or to Messrs. Smith g& Son, St. Vincent Street, Glasgow. Agents appointed for the Sale of the Publications of the Geological-Survey. London—Mr. Stanrorp, 6 Charing Cross, W.C.; Messrs. Lerrs & Son, Royal Exchange, E.C.; Messrs. Loneman, Paternoster Row; Mr. Wyxp, 11 and 12 Charing Cross. Edinburgh—Messrs. Jounston, 4 St Andrew Square. Dublin—Messrs. Hovces & Surra, 104 Grafton Street. LIST OF PUBLICATIONS OF THE GEOLOGICAL SURVEY OF SCOTLAND. I.—Maps on One-inch Scale. 1. Wigtonshire, Southern Districts. 4s. 3. Wigtonshire, South-Western Districts. 63. 7. Ayrshire, South-Western Districts. 6s. 13. Ayrshire, Turnberry Point. 4s. 14. Ayrshire, Southern Districts. 6s. 15. Dumfriesshire, N.W.; Ayrsbire,S.E.; and Lanarkshire,S. Corner. 6s. 22. Ayrshire, Northern District, and Southern parts of Renfrewshire. 6s. 24. Peeblesshire. 63. 32. Edinburghshire and Linlithgowshire. 6s. 33. Haddingtonshire. 6s. 34. Eastern Berwickshire. 4s. 40. Fife and Kinross. 6s. 41. Fife, Hast part. 6s. II—Maps on Six-inch Scale, illustrating the Coal-fields. Edinburghshire. Sheets 3, 8, 14,17. 4s. Sheets 2, 6, 7, 12, 13,18. 6s. Ed Haddingtonshire. Sheets 8,13. 4s. i ss Sheets 9,14. 6s. Fife. Sheets 33, 37. 4s. [ Sheets 24, 25, 30, 31, 32, 35, 36. 6s. Ayrshire. Sheets 26, 31. 4s. mi Sheets 11, 12, 13, 16, 17, 18, 19, 22, 23, 24, 27, 28, 29, 30, 33, 34, 35, 36, 40, 41, 42, 46, 47, 50, 52. 6s. Renfrewshire. Sheets 18,17. 4s. a5 Sheet 16. 6s. Lanarkshire. Sheets 1, 5,10. 4s. ' ss Sheets 6, 31, 32, 37, 38, 41, 42, 49. 6x. Dumfriesshire. Sheet 1. 4s. As Sheets 5, 6, 7. 6s. Dumbartonshire. Sheet 28 including 29. 4s. III.—Horizontal Sections. 5s. per Sheet. Sheet 1. Edinburghshire and Haddingtonshire. 2. Edinburghshire and Haddingtonshire. 3. Peeblesshire, Edinburghshire, Linlithgowshire. 4, Ayrshire Coal-fields (west side). : » 5. Ayrshire Coal-fields (east side). IV.—Vertical Sections. 3s. 6d. per Sheet. Sheet 1. Edinburgh Coal-field. 3. Kilmarnock Coal-field. [List of Publications continued on page 3 of cover. ” SMemoirs of the Geological Survey, SCOTLAND. EXPLANATION OF SHEET 2. WIGTOWNSHIRE—BURROW HEAD. EDINBURGH: PRINTED BY MURRAY AND GIBB, VOR HER MAJESTY’S STATIONERY OFFICE. 1873. Price Threepence. muOtod.e iN D HX to hee GEOLOGICAL SURVEY MAP = - of a SCOTLAND Lublished on the Scate af One inch te aimile a & April 1! 1873 ee cn Me tae oY ¢ ] we f 7 ne 119 le ra | SA Thiirso a és 116 me Ke 113 id LS :CAITHNESS ae | , | s | SUTHERLAND LOG a LOS 109 410 100 CR Teg ee - Sree ot + figs atl fe MIU PP Bom NAIRN + a at a eel Banit | ‘eter head 87 —\F 3 Neves / ai 0 PP Res * gS a =a | i d Yi oe ranks za} eS GO eee ae =f fi Lo ees) Published Ee) KNGrUViNg as Tn prpuration Gy Memoirs published Memoirs of the Geological Suriey, SCOTLAND. EXPLANATION OF SHHET 2. WIGTOWNSHIRE—BURROW HEAD. EDINBURGH: PRINTED BY MURRAY AND GIBB, FOR HER MAJESTY’S STATIONERY OFFICE. 1873. PREFACE. Tre Map illustrated by the present Explanatory Memoir was surveyed geologically, under my supervision, by Mr. James Craik, partly during the directorship of the late Sir Roderick Murchison, and partly under that of the present Director-General, Professor Ramsay. During the progress of the work, I frequently assisted in the mapping; and after it was completed, I requested Mr. John Horne, who had been engaged in the Kirkeudbright area, to visit the coast sections, with the view of correlating the Wigtownshire rocks as far as possible with those the order of which has been made out by the Geological Survey in the counties lying further to the north-east. The suggestion that the anticlinal axis, noticed in par. 5, is the main axis of the Silurian tract of the south of Scotland, and consequently that the strata along its line are somewhere about the base of the Scottish Lower Silurian Series, is due to Mr, Horne. Probably more precise information may be obtained during next year, when the area lying to the east of Wigtown Bay is surveyed. The Explanation has been written by Mr. Craik, with the exception of paragraphs 5, 6, 10, 11, and 15, which have been supplied by myself. The list of Fossils given in the Appendix has been prepared by Mr. R. Etheridge, by whom the specimens were determined. ARCH. GEIKIE, Director. GroLocicaLt Survey OFFice, EpinsurGH, December 1872. EXPLANATION OF SHEET 2. I. AREA EMBRACED IN THE MAP. 1. The present Sheet of the Geological Survey Map of Scotland represents that part of the county of Wigtown which forms the promontory ending in Burrow Head. It contains portions of the parishes of Whithorn, Glasserton, Sorbie, and Mochrum, and embraces un area of 32 square miles. Il. FORM OF THE GROUND. 2. Like the rest of the lower parts of the county of Wigtown, the district now under description consists generally of gently sloping ridges, separated by lower rocky tracts, the direction of both ridges and hollows having a pretty uniform trend from north-east to south-west. As a whole, the ridges rise towards the south-west, and attain, us they approach the coast- line on that side, their highest elevations. Thus, the ridge of Slate Heugh and Fell of Carleton reaches a height of 479 feet over the sea, terminating jn a bold rocky hill close to the south-western coast. Again, further inland, and to the north-west, the Fell of Barhullion attains a height of 149 feet. Most of these higher ridges have a rocky surface, and are devoted to pasture. The arable land lies mostly on the lower grounds and on the ridges of clay, although some tracts where the rock protrudes almost every where above the surface have nevertheless been brought under the plough. 3. The streams are numerous, but none of them flow for more than two or three miles. They are consequently of small size, and, indeed, throughout many parts of the district they flow in artificial channels as mere ditches. It is noteworthy that the larger streams run transversely to the general trend of the ridges and hollows, as, for example, the Ket and the Drum- mullin Burn, while the smaller runnels flow longitudinally between the ridges. As the land rises towards the south-west, the coast-line on that side of the promontory is higher than on the other side. -It consists alternately of steep rock-cliffs and of green slopes of boulder-clay. The loftiest cliffs of rock are those which range round Burrow Head to Cairn- head, since they here and there reach a height of 150 feet. The best. marked boulder-clay slopes extend from the Point of Lag south-eastwards to Portcastle Bay. Ill. FORMATIONS AND GROUPS OF ROCK ENTERING INTO THE GEOLOGICAL STRUCTURE OF THE DISTRICT. Aqueous. . : Sign on Map. Alluvium, Peat, . : ‘ ‘ : ‘ —- Recent. <~ Blown Sand, j 4 s 4 . (brown dots). Raised Beach, . : : j 3 ‘ i Sign on Map. Erratic blocks. Drift Series. «Sands, Gravels. Boulder-clays. Lower Silurian. | Greywacke and Shale, : s h? (probably of Llandeilo age). Igneous. Intrusive. Dykes of Felstone, etc... : ‘ : F ; ; F IV. GEOLOGICAL STRUCTURE OF THE DISTRICT EMBRACED IN THE MAP. Lower Silurian. 4. The area contained in this Map forms a part of the great Lower Silurian tract of the south of Scotland. From the want of fossils, and of any recognisable lithological features, it is as yet impossible to decide precisely to what portion of the Silurian system the strata belong. They are provisionally referred to the Llandeilo series. 5. From the work which has now been accomplished by the Geological Survey in the wide region between Wigtownshire and the uplands of Ber- wickshire, it is probable that the rocks which are now to be described belong to the lhottom beds of the Lower Silurian series of the south of Scotland. Certain well-marked zones have heen traced for great distances, almost com- pletely across the country, and these retain a notable parallelism with each other and with the prevalent south-west and north-east strike of the rocks. Tt has long been understood that an anticlinal axis traverses the Silurian rocks of the southern counties, and its position in the central and eastern tracts was indicated ly Professor Harkness as far back as the year From Eskdalemuir it strikes sonth-westward, keeping to the north of Lockerbie, and stretching thence hy Dumfries through Galloway. There is reason to believe that it is this major axis which runs through the eastern headland of Wigtownshire, as described in paragraph 6. In that case, the rocks which rise along its line should be the oldest in the district, and should agree in general characters with those which occur along the same line towards the north-east. And this appears to be the case. 6. Throughout the whole district there is creat uniformity of character among the Silurian strata. They consist of hard, well-bedded greywacke, of various shades of grey and blue, occasionally of red, and usually separated by partines or thicker layers or beds of hard fissile shale. Alternations of these two varieties of rock extend throughout the whole of the district. No very satisfactory structure has yet been made out among these strata. They strike from north-east to south-west, dipping usually at high angles. An anticlinal axis, referred to in the preceding paragraph, corresponding with the general strike, extends across the peninsula from near the old castle of Carghidown to the opposite coast-line about Cairnhead. So far as at present made out, the lowest rocks of the district rise to the surface along this axis, and appear to le a prolonga- tion of the axial beds from Kirkendbright. The rocks at Burrow Head, on the one side of the fold, are probably the same as those about Cruggle- ton Point on the other. In spite of numerous minor folds, there is probably, on the whole, an ascending section towards N.W.; for when 7 we pass into Sheet 4, the line of the black anthracitic graptolitic shales is met which rans from Drummore, near the Mull of Galloway, north- eastward across the Bay of Luce, re-appears to the south-west of Wigtown, and sweeps in a remarkably straight line through Kirkcudbright and Dumfriesshire, by Moffat and Ettrick, to Melrose. 7. The greywackes and shales of the present district exhibit much con- tortion, faulting. and occasional cleavage. These features may be seen to great advantage along the coast sections, as at Burrow Head and along the cliffs to the north of the Isle of Whithorn, and still more markedly between Portyerrock and Port Allan. From the number of anticlinal and synclinal folds seen on the coast-line, it is evident that, in spite of the high angles everywhere visible in the interior, the real thick- ness of rock is not so great as might at first sight appear, since the same beds are repeated again and again by folds. Although the rocks have undergone so much contortion and pressure, cleavage is neither abundant nor, on the whole, well marked among them. It occurs most markedly about the line of the great anticline. The best examples of this structure noticed in the course of the survey occur on the Fell of Carleton. In one or two places, where the beds have been thrown into minor curves, a set of cleavage planes, dipping at angles of from 70° to 80° towards the north-west, traverse the shales, where they are tolerably well defined, but cease as they pass into the interstratified hands of greywacke. Their direction remains persistent, and unaffected by the contortions through which they pass. 8. In those places where the rocks have been much contorted and broken, veins of carbonate of lime, barytes, and other minerals occur. One of the best developed of these veins has been formed along a line of fault which runs W. 15 N., on the shore at Tonderghie. In addition to barytes, cale-spar, and quartz, this vein contains iron and copper pyrites. As already remarked, no fossils have been met with in any part of the Silurian rocks of the district. But as the greywackes and sbales agree in lithological characters with those on the same line of strike further to the north-east, they are, together with these, provisionally referred to the Llandeilo series. Further light, however, may be expected to be thrown upon the present small district by the extension of the work of the Survey in Kirkeudbright. Intrusive Rocks. 9. Throughout the district the Silurian rocks are traversed by various intrusive masses. These always occur in the form of dykes or of veins, usually parallel with the general strike of the rocks, though in many cases transverse to it. They appear most abundantly on the coast-line, since the rocks are much more continuously seen in section there. There can be little doubt, however, that though less frequently seen, owing to drift, peat, and other surface materials, they must also be abundant in the interior. A fact which has been already frequently remarked in the course of the work of the Geological Survey is also noticeable here— namely, that the dykes are apt to occur in clusters, with wide spaces between in which none can be traced. As a rule, they are exceedingly short ; only in one instance has it been possible to trace one of them for a length of about three-quarters of a mile. In most instances, especially in the interior, a dyke cannot be followed with any certainty beyond the boss of rock on which it is first seen. 10, Petrographically, the dykes offer many points of interest, though, at the same time, they present many difficulties in the way of a precise nomenclature, owing to the great extent to which they have undergone 8 internal alteration and the more or less complete disappearance of part or the whole of their vriginal minerals. They may be ranged under three groups. Ist, Felstones—rocks having a compact orthoclase lase, and with few crystals of other minerals. 2d, Rovks having a similar base, but containing sometimes abundance of plates of foliated talc, occasionally mica; these might be called talcose felstones. 8d, Rocks in which the base is that of felstone, through which are scattered abundant crystals of hornblende, usually with tale and, less frequently, black mica. Occa- sionally crystals of striated felspar and of diallage make their appearance. For such rocks it is difficult to find a name in the present nomenclature of petrography. At one moment they might be termed syeniles; but as the hornblende is replaced by tale or mica, that name ceases to be appropriate. Throughout all these three eroups, black opaque specks and cubical crystals of pyrite are visible under the microscope, sometimes so abundantly as to form a considerable proportion of the rock. It may be added that this sulphide appears to have heen the most indestructible of the minerals in the dykes, seeing that while the felspar crystals have been greatly defaced, and the original hornblende has passed into tale, the pyrite cubes remain sharp and unchapged. 11. Examples of the first group occur at different parts of the coast section, as at Burrow Head. Of the second, at St. Nivian’s Cave, near Whithorn; Stirnie Burn, half a mile north from Whithorn; at Port- yerrock, and many other places. Of the third, at Morrach Shore, Cairnhead (this is microscopically a singularly beautiful rock, from the perfection of the hornblende crystals), Cairndoou Plantation, ete. Drift. 12. Traces of the movement of the ice of the Glacial Period are found over the whole of the district represented on the present Map. The usual evidence is observable in ice-worn rocks, boulder-clays, and erratic blocks. There occur also deposits of sand and eravel. 13. Ive-worn Surfaces of Ruck.— Wherever the rocks are exposed in the interior, they bear the characteristic impress of ice-action in the flowing outlines of crag and hollow. Owing to the nature of the greywacke and shale, and the facility with which they are acted on hy the weather, the finer markings sculptured by the ice are usually effaced from the weathered surfaces. Yet the knobs of rock throughout the district still show the unmistakeable contour of roches moutunnées, of which the longer axes usually point in a general soutl-westerly direction, nearly parallel to the strike of the beds. Wherever a surface of rock has been recently bared of boulder-clay, it is seen to retain the finer strize and groovings. Some good examples may be seen, in the centre of the Map, on the farm of Broompark, where the striz point W. 42 8. The direction of the grooves and of the voches moutunnees indicates the movement of the ice from the range of high grounds to the north-east. 14. Boulder-clay.—One of the most striking features in the distribution of the drift in this district is the manner in which the boulder-clay is scattered over the ground, in large, oblong, smooth ridges, to which the name of ‘drums’ is locally given. As these ridges are always cultivated, while the surrounding lower ground consists often of bare rock, peat, and heather, the contrast between these mounds of drift and the barren ground around them strikes the eye at once. Throughout the present district the general direction of the longer axes of these drift-mounds is about north-east. In many cases the bottom of the drum is the limit of the drift, the bare ice-worn rock coming out sharply from underneath. But the boulder-clay is also abundantly scattered through many of the hollows. 9 It appears, indeed, to have been at one time somewhat more thickly dis- tributed over these low grounds than it is now, since scratched stones, evidently once a part of the boulder-clay, are found on rocky slopes, mingled with the angular debris of the weathered rock. 15. The drums, however, are not due merely to denudation, though their outlines may have been thereby greatly modified. We find them, for example, rising sharply from the margin of a lake, the bottom of which, when drained, shows a wide expanse of bare, ice-smoothed rock (as at Dowalton Loch, in Sheet 4). Had the drwms been merely remnants of a once continuous sheet of boulder-clay, these hollows would necessarily have been filled up with the detritus. Moreover, they lie in irregular strips or bands, corresponding generally with the direction of the strig on the rocks. This is not so well shown in the present Map as in that to the north. These Wigtownshire duns appear to be identical in character and origin with the Irish d-wmiins. 16. Some of the thickest masses of boulder-clay in the district occur on the shore, on either side of the Fell of Carleton, where they rise to a height of more than 200 feet above the sea. This deposit is usually reddish, with the ordinary stiff uustratified character. Sometimes it con- tains interstratified beds of gravel and sand, as on the side of a cliff to the south of Glasserton Hill, in a section on the roadside west of Monreith village, and at the Monreith tile-works. At the latter place there is an upper reddish-brown, rather friable, clay, containing many scratched pieces of greywacke, and a lower stiff blue clay, with few stones. The latter deposit contains shells, usually in a fragmentary state. (See Appendix.) 17. Sands and Gravels—Besides the intercalated strata already referred to as occurring in the boulder-clay, sand and gravel are found in several places covering the clay. Caps of gravel lie on some of the hills in Monreith Park, and sand is found on the top of the slopes to the east of Monreith Village. A similar deposit has been ridged into the kame shape, on which stands the old camp of Laggan, between Carleton Fell and the Hill of Glasserton ; and another to the east of Whithorn, on the farm of Portyerrock. The most prominent sand and gravel deposit in the district, however, lies on the farm of Arbrack, and is crossed by the road from Whithorn to Isle of Whithorn. Its summit is upwards of 125 feet above the sea level. It consists of inclined beds of fine sand, with alter- nate layers of gravel of various degrees of coarseness. The stones generally consist of blue and grey greywacke, grit, and shale, grey granite, and decomposing micaceous schist. No shells appear to have been found in this deposit, the only organic relic it has yielded being a large piece of amber, which was found, several years ago, deeply imbedded in the gravel. Some portions of the gravel have been cemented together into a conglomerate by carbonate of lime, probably from the decomposi- tion of shells. 18. Erratic Blocks.—These occur over the greater part of the district, resting sometimes on drift, sometimes on bare rock. They consist cbiefly of granite, but blocks of grit, greywacke, and felstone occur among them. The largest observed is one of granite, containing nearly 200 cubic feet. It is called the ‘ Wren’s Eee,’ and lies on a gravel deposit about 125 feet above the sea, near Monreith. Many boulders are yearly cleared off the surface by the farmers, and may be seen filling up old quarries, or lying in heaps in the corners of the fields. ‘Those of granite are often used for building purposes. Although more abundant in some localities than in others,—as, for example, on tlie farms of Claymoddie, Dinnans, and Drum- maston, and in the neighbourhood of Monreith,—they have been pretty generally distributed, even to the extreme southern edge of the promon- 10 tory, where one of granite, containing 35 cubic feet, lies at a height of 150 feet above the sea, at Burrow Head. There can be no doubt that these boulders have travelled from the granite hills to the north-east. Raised-Beaches. 19. Although the coast-line of this promontory is exposed to a heavy sea, portions of a former sea margin have been preserved on the south- west side. On some parts of the coast-line which consist of boulder clay, a terrace has been cut out of that deposit at a time when the land was from 40 to 50 feet lower than it is at present. The largest fragment of this terrace now to be seen in the district extends for about three miles from Port Counan to Cairndoon. Its surface is very shingly, though at its north-western end it has been to some extent cultivated. Another frag~- ment runs northwards from the village of Monreith. Blown Sand. 20. Only at one part of the coast-line does blown sand form any marked feature. At the Point of Lag, it rises into a hill 75 feet above the sea. North-west from Monreith it is sparingly spread over the slopes of boulder-clay. Peat and Alluvium. 21. Before cultivation had changed so many of the features of the district, most of the hollows, and to some extent even the slopes of the hills, appear to have been covered with peat. Even now, along those rocky tracts which have not been brought under the plough, peat is usually found covering the bottoms. But as farming operations extend, more and more of the peat is ploughed up, and in a few years it becomes difficult to ascertain what were its former boundaries. The largest peat-moss in the district is the Whithorn Moss. Another of smaller size lies a little further west, on the farm of Barmeal. 22. The streamlets of the district have hardly any alluvium along their courses. At one time; however, there must have been many lakes in this part of the country, lying among hollows of rock and drift. These lakes bave almost wholly disappeared, their sites being marked now by flat tracts of alluvium. Large trunks of oak and other trees are taken out from the peat-wosses and these alluvia. A stone celt was ploughed up on the farm of Chapelheron, to the north of Whithorn. It was formed of one of the hard altered shales of the district, and had acquired the white crust so often assumed by stones which have lain long under peat. V.—ECONOMIC MATERIALS. 23. Building Materials—The chief stone employed in building is the ordinary greywacke of the district. Owing to the number and irregu- larity of the joints, however, it is not well adapted for its purpose. The corner-stones are frequently of granite, obtained from boulders, though considerable quantities of this stone now come from Talbeattic. Red sandstone is also used for the facings of door-ways and windows, and occasionally for flags; but it is obtained from Whitehaven, whence also comes a white freestone which is used to some extent in this area. The field-dykes and walls are alsu built of greywacke, though occasionally granite and other boulders are built into them, and in the vicinity of felstone dykes detached blocks of these igneous rocks are used. 24. Road-metal—The common greywacke of the country is employed 11 or road-making, but owing to its rapid weathering it forms a bad material for this purpose, and the substitution for it of some of the harder igneous rocks would be of great advantage to the traffic on the roads. 25. Metals—Traces of iron and copper occur in the more southerly parts of the district, the iron usually as chalybite, the copper as copper pyrites. The vein already mentioned as occurring at Tonderghie has been worked to some extent, but never to any profit. With this excep- tion there have been no workings, owing to the small quantity in which the metals occur. 26. Fuel.—tThe only fuel supplied by the district is the peat which is brought from Whithorn Moss, before alluded to. It is rarely of good quality, yielding a large quantity of dusty ash, and being in many places of a pale colour and earthy, when it is here called ‘ flow.’ 27. Soils—The decomposing greywackes and shales of the district generally form a soil which is warm and quick. That which is underlaid by till has usually what is called a ‘cold bottom.’ The soils formed of weathering rock chiefly occupy the south, west, and south-west portions of the area, with a considerable part of the centre. The boulder-clay soils occupy a great part of the north, north-east, and north-west, and east and south-east portions. The distribution of the gravels has been already alluded to. They form a good soil when rain is plentiful, but in a dry season cause trouble and loss. 28. The Scare Rocks, which are included in this Sheet, are about 8 miles, in a west-south-westerly direction, from Monreith. They consist of several small rocks in cluster, and a larger rock at a distance of three- quarters of a mile from the small group. These rocks consist of thick- bedded hard grey greywacke, with rel and grey shaly partings. The strike is E. 30 N., and the dip varies from 65° to 85° to N.W. The ‘Big Scare’ is crossed by two dykes of dark-coloured felstone, with horn- blende, and two of the smaller recks are crossed by a dyke of like character. The extreme length of the large rock is 180 yards. 12 APPENDIX. As mentioned in the Memoir, no Fossils have been obtained from the Lower Silurian rocks of the district. The only organic remains yet noticed occur in the superficial deposits referred to in par. 16. In the clay beds of the Monreith Tile-works remains of broken shells are not infrequent, the only form recognised in the collections made by the Survey being a Leda. By washing the clay from that locality, three genera and four species of Foraminifera and a few valves of Entomostraca were obtained. Many of the Foraminifera have a very starved appearance. The Entomostraca have been kindly determined by Mr. G. 8. Brady. LIST OF FOSSILS FROM THE GLACIAL DEPOSITS. Leda, sp. Fragments of shells. Nodosaria humilis. Roemer. Nonionina depressula. JValker and Jacob. Lamellibranchiata ( Polystomella striatopunctata. Fchtel and Moll. Foraminifera Quinqueloculina sp. Cythere emarginata (?). Sars. LORD: Cythere pulchella (?). 3 IV.—Vertical Sections. 33. 6d. per Sheet. Sheet 1. Edinburgh Coal-field. 5, 8 Kilmarnock Coal-field. Vier Galena Memoirs, to accompany the Sheets of the One-inch ap. Sheet 1. ” 2. oe » 4. AS =, aa sake » 22. 9 Be » 24 ” 32 Wigtownshire, Southern Districts. 3d. Wigtownshire, South-Eastern Districts. 3d. Wigtownshire, South-Western Districts. 3d. [Nearly ready]. Ayrshire, South-Western District. 3d. Ayrshire, Turnberry Point. 3d. Ayrshire, Southern District. 3d. Dumfriesshire, N.W.; Ayrshire, 8.E.; and Lanarkshire, 8. corner. 34d. Ayrshire, Northern District, and Southern parts of Renfrew- shire. 3d. . Lanarkshire, Central Districts. 3d. [Nearly ready. ] . Peeblesshire. 3d. 2. Edinburghshire and Linlithgowshire. 4s. In cloth boards, ds. . Haddingtonshire. 2s. . Eastern Berwickshire. 2s. A Detailed Catalogue may be had gratis, on application to Messrs. W. & A. KH. Johnston, 4 St. Andrew Square, Edinburgh, or to Messrs. Smith § Sun, Nt. Vincent Street, Glasgow. Agents appointed for the Sale of the Publications of the Geological Survey. London—Mr. Sranrorp, 6 Charing Cross, W.C.; Messrs. Lerrs & Son, Royal Exchange, H.C.; Messrs. Loneman, Paternoster Row; Mr. Wy p, 11 and 12 Charing Cross. Edinburgh—Messrs. Jounston, 4 St Andrew Square. Dublin—Messrs. Hopees & Surry, 104 Grafton Street. LIST OF PUBLICATIONS OF THE GEOLOGICAL SURVEY OF SCOTLAND. I.—Maps on One-inch Scale. 1. Wigtownshire, Southern Districts. 4s. . Wigtownshire, South-Eastern Districts. 4s. . Wigtownshire, South-Western Districts. 6s. . Ayrshire, South-Western Districts. 6s. . Ayrshire, Turnberry Point. 4s. Ayrshire, Southern Districts. 6s. . Dumfriesshire, N.W.; Lyrshire,S.E.; and Lanarkshire,S. Corner. 6s. . Ayrshire, Northern District, and Southern parts of Renfrewshire. 6s. . Lanarkshire, Central Districts. 6s. . Peeblesshire. 6s. . Edinburghshire and Linlithgowshire. 6s. . Haddingtonshire. 6s. . Eastern Berwickshire. 4s. . Fife and Kinross. 6s. . Fife, East part. 6s. Oe teoW Slt Lee WAT let We Poo oo Le Ne te ee et — II—Maps on Six-inch Scale, illustrating the Coal-fields. Edinburghshire. Sheets 3, 8, 14,17. 4s. o% Sheets 2, 6, 7,12, 18,18. 6s. Haddingtonshire. Sheets 8,15. 4s. 55 Sheets 9, 14. Gs. ’ Fife. Sheets 83, 37. 4s. Sheets 24, 2.5, 30, 31, 32, 35, 36. 6s. Ayrshire. Sheets 9,26, 31. 4s. - Sheets 11, 12, 13, 16, 17, 18, 19, 22, 23, 24, 27, 28, 29, "30, 38, 34, 35, 36, 40, 41, 42. 46, 47, 50 52. bs. Renfrewshire. Sheets 18, 17. 4s. ‘3 Sheet 16. Gs. Lanarkshire. Sheets 1,5, 10. 4s. be Sheets 6, 31, 32, 37, 38, 41, 42, 49. Gs. Dumfriesshire. Sheet 1. ds. 33 Sheets 5, 6, 7. 6s. Dumbartonshire. Sheet 28 including 20. 4s. III.—Horizontal Sections. 58. per Sheet. Sheet 1. Edinburghshire and Haddingtonshire. . Edinburghshire and Haddingtonshire. . Peeblesshire, Edinburghshire, Linlithgowshire. . Ayrshire C toal-fields (vest side). Ayrshire Coal-fields (east side). [List of Publicatians continued on page 3 of cover. 47 ae) oy orm CoN + ” Plemoirs of the Geological Surbev, SCOTLAND. EXPLANATION OF SHEET 3. WESTERN WIGTOWNSHIRE. - EDINBURGH: PRINTED BY MURRAY AND GIBB, FOR HER MAJESTY’S STATIONERY OVFICE. 1873. Price Threepence. INDEX to the CEGLOGICAL SURVEY MAP ; of SCOTLAND Published on the Scate of Gnee trch to a mile oh . ORKNEYS April 1 1873 an ap > | a7 ns | us 12024 V, | = I+ Lv iLG. ya WS CAITHNESS 5 | a | | SUTHERLAND | LLO 4 —— Peterhead BT | KINCARDIKLEP tenho ven) \J o7 | Gt t Fy Xe Blad thon eS Published RB Engr LNGPUNING ESeal In preparation | O Memos published | Memoirs of the Geological Surbhey, SCOTLAND. EXPLANATION OF SHEET 3. WESTERN WIGTOWNSHIRE. EDINBURGH: PRINTED BY MURRAY AND GIBB, FOR HER MAJESTY’S STATIONERY OFFICE. 1873, PREFACE, Sueet No. 3 of the Geological Survey Map of Scotland, to which the present pamphlet is intended to form an accompanying Explanation, was surveyed during the General Directorate of the late Sir R. I. Murchison, and with my supervision and assistance, by Mr. D. I. Irvine, except a strip about half a mile broad at the extreme north-western edge of the Map bordering on Sheet 7, which was examined by Professor Ramsay. Of the following Explanation, pars. 6-30 have been written by myself, the remainder by Mr. Irvine. The list of fossils in the Appendix II. has been prepared by Mr. R. Etheridge, jun., by whom the specimens were determined. Regarding the geology of this part of Scotland, a number of papers have been published chiefly by Mr. Carrick Moore, who, as far back as 1839, brought to the notice of geologists the occurrence of fossils in the rocks of Galloway. The following list comprises, I believe, all the special papers which treat of the area embraced in the present Map :— 1839. On the occurrence of Graptolites in the Slate of Galloway. By C. Lyell (Proceedings Geol. Soc. vol. iii. p. 28). [A brief notice of the discoveries by Mr. Carrick Moore of graptolites in the slaty rocks of Loch Ryan. No species are given. | 1840. On the Rocks which form the West Shore of the Bay of Loch Ryan in Wigtownshire, N.B. By John Carrick Moore (Proc. Geol, Soe. iii. 277). [In this paper the author recognises the rocks as forming part of ‘the great greywacke chain.’ He notices the prevailing strike, the conglomerates, and the graptolites of these older rocks, also two of the ‘trap-rocks’ by which they are traversed. He brinvs to light the fact that rocks newer than the greywacke occur on the west side of Loch Ryan, identifying the red and white sand- stones, etc. with the ‘coal measures of Ayrshire,’ and noting the occurrence in them of Stigmaria and Calamites. He shows that the breccia overlies these sandstones, but he assigns no geological horizon to it.] 4 1848. On some Fossiliferous Beds in the Silurian Rocks of Wigtown- shire and Ayrshire. By J. Carrick Moore (Quart. Journ. Geol. Soc. v. 7). [Gives a map, sections, and description of the western part of Wigtownshire from Corsewall Point to the Mull of Galloway. Notices the occurrence of graptolites at several points, of granite to the north of the Mull of Galloway, and of the coarse con- glomerates near Corsewall Point. Reports the existence of fossil- iferous Silurian limestones from the south of Ayrshire. In an appended note the late Mr. Salter descriles the fossils from ‘Wigtownshire and Ayrshire. ] 1851. On the Silurian Rocks of the South of Scotland. By Sir R. 1. Murchison (Quart. Journ. Geol. Soc. vii. 187). [In one section of this paper, devoted to the ‘schistose rocks ranging through Wigtownshire and Galloway to Kirkcudbright,’ the author suggests that possibly these rocks may overlie the Ayrshire limestones—an idea which subsequent researches have not confirmed. | 1856. On the Silurian Rocks of Wigtownshire. By J. ©. Moore (Quart. Journ. Geol. Soc. xii, 359). [Gives the results of a careful examination of the geological structure of the western part of the county, and states that in the plication of the rocks the axes of the folds have been inclined to the north. Places the graptolitic shales under the coarse con- glomerates of Corsewall, and suggests a possibility that the rocks of the Mull of Galloway are repetitions of those of Corsewall.] I have here and there inserted a reference to the recent work of the Geological Survey in the Silurian uplands of the south of Scotland. » That work has now extended over nearly the whole of these wide uplands, with the result cf establishing the order of succession upon careful and minute mapping of the districts. For the first time the great mineral groups have now been recognised in their stratigraphical order, and traced across the country, parish by parish, from the headlands of Galloway to those of Berwickshire. The black shale group, for example, known as the Moffat shales, with the overlying and parallel zones, has in this patient way been tracked from district to district. It has thus been possible to make out the structure of this Silurian region—a task which has hitherto proved impossible from the want of correct details. The general result of the work shows that the Silurian rocks of the south of Scotland belong for the most part to the Llandeilo formation. Their base is nowhere seen, for along the great axis which passes from Dumfries north-eastward across Eskdale, it is still rocks belonging to the same great series which rise to the surface. From that axial line, a general ascending series, as is well known, may be traced towards the north-western margin of the Silurian high grounds. Innumerable minor pheations of the strata occur, together with several which cover a con- 5 siderable breadth of country. It is in some of those broader folds that certain detached outliers of Caradoc age occur. One of these has been described in the Explanation to Sheet 15, as occurring among the Lead Hills. Others have since been traced both to the south-west and north- east. From the fact that these Caradoc patches do not always lie on the same zone of the Llandeilo series, but even cross from one zone to another, it is evident that in the south of Scotland there occurs an un- conformability between the Caradoc and Llandeilo rocks—a new feature in the geology of Britain. Another and still more violent unconformability must exist between the Upper and Lower Silurian rocks. This may be suspected from the comparatively untilted condition of the former at only a short distance from the crumpled beds of the latter, as at Lesmahagow and Muirkirk. On the southern headlands of Kirkcudbright also, Upper Silurian rocks appear but a short distance from the great Lower Silurian axis—a position only intelligible on the supposition of a great unconformable overlap of the later upon a very low part of the older series. The details of this work will be given in subsequent Explanations. I will only add that it is mainly by the zeal and ability of my colleagues, Messrs. Peach, Jack, Horne, Skae, and Irvine, that the detailed struc- ture of the Silurian uplands of the south of Scotland has at last been unravelled. In Appendix ITI. there is added a List of Silurian fossils, the greater part of which were collected and named by the officers of the Geological Survey as far back as the years 1863-4. Owing to the necessity of proceeding with the mapping of the great coal-field tracts after the Silurian edges of that area had been traced, the further examination of that part of the Silurian region had to be delayed, and hence this list has hitherto remained unpublished. As it may be of service to geologists who take an interest in these rocks, it is now printed in anticipation of the fuller and more detailed lists which will be given in the Explanation to Sheet 8, where the geological structure of the districts will be described. From the list it will be observed that in the south-west of Ayrshire there occur representatives of Upper Silurian, Llandovery, Caradoc, and Llandeilo rocks. ARCH. GEIKIE, Director. GEOLOGICAL Survey OFFICE, Epinsurey, August 1873. EXPLANATION OF SHEET 3. I. AREA EMBRACED IN THE MAP. 1. The area included in this Sheet amounts to 178 square miles, the whole of which lies in the county of Wigtown with the exception of a small portion at the north edge of the Map, towards the mouth of Loch Ryan, which comes into Ayrshire. Rather more than half of it belongs to that portion of Wigtownshire locally known as ‘the Riuns,’ stretch- ing between the Irish Channel and the line of Loch Ryan and Bay of Luce. The remaining portion of the Map, consisting of the high ground to the north of Lucé Bay and the east of Loch Ryan, forms part of the district called ‘the Moors, the greater portion of which comes into the neighbouring Sheet 4. Il. FORM OF THE GROUND. 2. The area represented in this Map is divided into three distinct forms of ground :—lIst, The rough hilly ground of the Rinns; 2d, the heathy uplands of the Moors; and 34d, the flat plain or valley separat- ing these two areas, and stretching between the hollow of Loch Ryan and that of Luce Bay. The eastern division is an undulatiny table- land, which towards its southern edge has an average height of about 400 feet above the level of the sea, but gradually slopes upwards to the northern edge of the Sheet, where it averages 700 feet in height. This area is nearly all moor and pasture land, the cultivated tracts being almost entirely confined to narrow strips along the courses of some of the streams. There is not much rock exposed in the upper half of this division, the greater part of the ground being covered with a coating of peat from one to ten feet in thickness, thus giving the surface a smooth, undulating aspect, which is wanting in the south half, the ground there being much more broken and rocky, with low but precipitous hills rising up here and there. The highest elevation in this district, and also in the whole Sheet, is the hill of Mid Moile, at the north edge of the Map, half way between Loch Ryan and the Main Water of Luce. It reaches a height of 844 feet above the sea level. The middle division is a low, flat plain, about four miles broad, lying between Loch Ryan and the Bay of Luce. It has an average height of from 70 to 100 feet above the level of the sea, with a gradual slope down to the beach at either end. This platform is cut through the centre by Piltanton Burn, which forms a broad alluvial flat at Genoch House. There are numerous hollows here and there over this area, most of which still contain deep lochs of different sizes, the largest being the White and Black Lochs of Castle Kennedy, each of which is fully a mile in length; and where lakes arc now wanting, there are evident signs, such as the fragments of old beaches, 8 of their having once filled the depressions. Indeed, some of these dry hollows have been emptied by drainage within the memory of some of the older inhabitants of the district. The whole of this tract has long been under cultivation, with the exception of a strip of sand-hills along the shore of the Bay of Luce, only used as a rabbit warren. The remaining district is a continuation of the ground in Sheet 1 to the south, which forms the peninsula ending in the Mull of Galloway, though from Port- patrick northwards it is generally higher in level. The greater part of the surface has been brought under cultivation, the most important tracts still remaining in a state of nature being the Moors of Galdenoch and Larbrax, and the rocky hills of Cairn Pyot, Craigenlee, and Killan- tringan. The highest elevation in this district is Cairn Pyot Hill, 593 feet above the sea. 3. The coast-line along the whole extent of the western boundary of the Rinns presents a line of precipitous cliffs facing the Irish Channel. From the northern edge of the Map south to Portpatrick, these cliffs, though broken and steep, are not so high as they become farther to the -outh, where, between the bays of Portayew and Cairngarroch, they reach the height of 400 feet above the sea. Broken cliffs also, seldom 100 feet high, and usually much less, rise from either side of Loch Ryan for two miles south from its mouth. Along the rest of the coast-line of the Map, the ground slopes gradually down into the sea, forming for miles together flat sandy and muddy beaches, which are laid bare along the greater part of their extent for about half a mile at low water. On the west shore of Loch Ryan, at Kirkcolm, a spur of gravel runs into the loch for fully a mile, most of which is covered by high tides. One feature of the coast- line cannot fail to arrest the attention of the observer, viz. the constant relation of the indentations to the varying nature oi the rocks. The head- lands are found to consist usually of hard rocks, such as massive beds of greywacke, while the bays and creeks have been cut out of softer rocks, which in most cases are fissile shales. 4. There is only one main river-valley in this Map, that of the Water of Luce, which runs through the high ground forming the eastern division of the Sheet. Its general direction is from north-west to south-east, or at right angles to the line of strike of the greywacke rocks through which it cuts. The only other stream of any size is Piltanton Burn, which rises about three miles north-west of Stranraer, running south-east for the first half of its course, when it forms a boundary between a band of Permian and Carboniferous rocks and the Lower Silurian area. It then turns eastwards, and flowing in that direction with many windings, enters the Bay of Luce near the eastern edge of the Map. II. FORMATIONS AND GROUPS OF ROCKS ENTERING INTO THE GEOLOGICAL STRUCTURE OF THE DISTRICT. Aqueous or Sedimentary. Alluvium, Peat. Recent. Blown Sand. Raised Beaches. 4 ' §Sands and Gravels, and Stratified Clays. Drift Series. { Boulder-Clay. : Permian. Red Breccia. Carboniferous. Reddish Sandstones and Clays. Lower Silurian (Llandeilo). Greywacke, Shale, Conglomerate, etc. 9 Igneous and Metamorphic. Of Miocene Age. Basalt-rocks in dykes. Altered Strata, with distinct bedding, passing Associated with Lower into crystalline amorphous masses. Silurian Series. Felstone. Diorite. 1V. GEOLOGICAL STRUCTURE OF THE DISTRICT EMBRACED IN THE MAP. 5. The portion of Scotland shown on the present Map forms part of the extreme south-western end of that great range of Lower Silurian rocks which stretches from the Mull of Galloway to St. Abb’s Head. The basement rocks belong, therefore, to the Lower Silurian series, and cover the whole of the surface, with the following exceptions :—1st, For about seven or eight miles on the west side of Loch Ryan a narrow strip of Carboniferous and Permian rocks occurs; 2d, Much of the surface is obscured with drift, more especially in the low grounds; and 3d, Along the margins of the larger streams, «lso along the sea coast at the head of Loch Ryan and of Luce Bay, considerable masses of alluvium or of blown sand obscure the solid rocks underneath; while throughout the whole of the district peat spreads sometimes over considerable areas, not merely on the sites of former lakes, hut on the less steeply-sloping surface of the moors. Lower Silurian. 6. With the exception of the small strip of Carboniferous and Permian rocks on the west coast of Loch Ryan, all the other solid aqueous strata belong to the Lower Silurian series. Magnificent sections of these strata are laid bare along the whole extent of coast-line washed by the Atlantic, and good exposures are also met with on the eastern shores of Loch Ryan and the western coast of Luce Bay. Others may be seen along the course of the Water of Luce and its numerous tributaries, and in the many streams that flow down the western slopes of the moory tracts stretching between Mid Moile and Cairnscarrow into Loch Ryan and Piltanton Burn. A glance at the Map will show that, north-west of a line drawn froin Morroch Bay by Garthland Mains and Dunragit Moor to Camrie Fell, the general dip of the strata is towards the south-east, the strike being, of course, north-east and south-west. There are frequent dips, however, in the opposite direction, showing that the strata are in some places rapidly folded. The persistent south-east dip is best seen along the sea coast, where the strata are most exposed. In the hilly districts east of Loch Ryan, the sections are less continuous, and a general south- east dip is by no means so apparent. It may be added that the angle of dip is seldom less than 50° or 60°. South of the line just referred to, it will be observed that while the strike of the strata continues the same, the beds yet dip towards the north-west—that is, in precisely the opposite direction. This line then forms a synclinal axis. On the southern as well as on the northern side of the syncline, the strata are thrown into innumerable minor folds. The dips are frequently deceptive. There is reason to believe that the strata are, in many places, folded back upon each other in a series of rapid plications, the tops of which have been removed by denudation. Thus we have the appearance of a vast thickness of strata dipping, often for 10 long distances, in one determinate direction. The same beds, in fact, vein and again appear in the section; and what seem to be overlying, are, in truth, frequently underlying strata. Examples of this structure ay be seen abundantly along the coast sections, as between Grennan Vuint and Saltpans, and between Broadsea Bay and the Lighthouse. 7. From the fossil evidence obtained from these rocks, it may be inferred that they are all referable to the Llandeilo series. Their base is not seen, nor have they been observed to be covered here by rocks containing Caradoc fossils. Evidently they form a continuation of the Llandeilo rocks, which have been already described as they occur to the north-east in Sheet 15. l‘rom the labours of the Geological Survey over the Silurian region hetween the present district aud Clydesdale, it has been found possible to divide the older rocks of these uplands into several groups, which, though on the whole not well discriminated by fossils, have, nevertheless, tolerably persistent lithological characters, by which they have been traced across the kingdom. Several of these groups are clearly recognisalle in the pre- sent area, though with some differences from the aspect under which they wire first studied and named in the central district of Nithsdale and Clydesdale. In the order of superposition they are as follow :— (6.) Upper or Lead Hill Black Shale Group, (Group G of Sheet 15). (5.) Lowther Group, x a. ole (4.) Dalveen Group, si. | a tee (3.) Queensberry Grit Group, a3 ee (2.) Lower or Moffat Black Shale Group. (1.) Ardwell Group. %. Had the rocks been folded into a simple synclinal trough, those on the one side should have been approximately a mere repetition of those on the other. Owing, however, to the complicated foldings just referred to, some of the vroups are made to cover a much larger space, or to occur a ereater number of times. For example, on the north side of the syncline, the group No. {is so crumpled back upon itself that it covers by far the largest part of the arca up to the edge of the Map. On the south side, on the other hand, that group, being less crumpled, is made to occupy a much narrower breadth, while the lower groups are repeated over a considerable space. 9. (1.) Ardwell Group.—Under this name is included a series of hard, well-bedded greywackes and grits, with bands of hard shale or slate. These rocks have a prevailing reddish or brownish hue, especially on weathered surfaces. The shales are sometimes grey, often red or purple, and frequently show cleavage. No fossils were noted in them in this district, though obscure markings occur here and there like the Protovirgularia, The same rocks rise from under the Moffat shale group all the way across the country through Kirkcudbright, Dumfriesshire, and jselkirksbire, into Roxburghshire. In the present district, they vecupy a band nearly three miles broad, extending from near Grennan Point, at the southern edge of the Map, northwards by Ardwell Point, where they are well developed, to near Slunkrainy. The general inclination of the beds throuvhout that band is south-eastwards. In spite of this apparent dip, however, there can be little doubt that on the whole the rocks are arranved in an anticlinal fold, and that many of the dips are really reversed. This may actually be seen to be the ease at several parts of the coast section. On the band at Saltpans, for example, a well-marked anticlinal axis is shown, aud yet the prevalent south-casterly dip is not changed by it. In the Map to the south of the present (Sheet 1), the same rocks rise up again from under the lower 11 black shale group, and form the headland of the Mull of Galloway. The band of them in the present Map lies thus to the north of the normal line of strike by which these rocks are carried from the Mull of Galloway across to Tweeddale. It is brought up along one of the lines of axis already referred to. Much farther to the north-east, in the high grounds of Hartfell, Loch Skene, and the head of Yarrow, other axes occur, sometimes bringing up parts of the Ardwell beds, as is done so con- spicuously on the Wigtownshire coast-line. The mapping out of these folds is of the utmost importance in enabling us satisfactorily to reduce the apparently enormous thickness of the Lower Silurian rocks of the south of Scotland. 10. (2.) Lower or Moffat Shale Group.—This name is applied to a series of flaggy greywackes and grey shales, of which the distinguishing characteristic is the occurrence among them of several bands of black carbonaceous shale. These dark shales have long been known as occur- ring in many places among the southern counties of Scotland. In the neighbourhood of Moffat they are particularly well developed, and hence they have been termed the Moffat Shales. They have now been traced by the Geological Survey from near Melrose across the whole breadth of the kingdom to the far shores of Wigtownshire—a distance of more than 100 miles. Throughout that long distance, they present a remark- able similarity of character. Sometimes three bands can be made out; in other places the bands come together so as to form a thick shale zone. Intercalated with them are green and red shales, while there frequently occurs also a hard argillaceous bed, paler in colour than the grey shales, and not laminated.? The black shales are usually much broken and twisted. They likewise abound in iron pyrites with veins of quartz. They have yielded graptolites. (See Appendix.) 11. As the coast sections display the succession of beds in this im- portant group better than any of the streams of the interior, it may be of service to describe one of these, viz. that which is exposed at Drum- breddan Bay. The strata have a general south-easterly dip, resting on the Ardwell Group at the one end of the section, and passing under the Queensberry Grit Group at the other. The following section shows the succession from the latter group down to the former :— Grey fissile shales. Some beds are very sandy, and abounding in grey, hard, sandy, calcareous nodules and lenticular beds. Part of the bend is obscured by gravel and boulders; but these shales probably cover a space of about 140 yards. As they are nearly vertical, their thickness may be not far short of 400 feet. Black shale bands, 12 to 18 feet thick, embedded in the lower part of the grey shales, which contain numerous thin lenticular partings of similar black shale both above and below the main bands. Grey shale, finely laminated, 3 or 4 feet. Grey flagstones, flagey greywacke, and grit, in beds of various thickness up to 3 or 4 feet, with abundant partings of grey shale. This flagey series covers a space of about 100 yards, and probably exceeds 250 feet in thickness. The beach is now obscured by red boulder-clay, gravel, and sand for a space of 86 yards. This blank probably represents the place of another zone of shales, for beyond the interruption the next strata visible are Black shales, so much jumbled and jointed that their true thickness cannot 1 ene out of the north-eastern area is at present in the hands of Mr. B. N. Peach. 2 This clay-bed has been used by Mr. B. N. Peach in the survey of the Selkirk- shire and Roxburghshire area ag an index, since it always ovewrs there immediately below the lowest band of black shale, where it reminds one of the fire-clay below a coal-seam, 12 be satisfactorily determined. In the upper part of the visible section they contain several thin bands of the soft grey and yellow clay above noticed, together with hard, thin, black, flinty bands. The crumpling and fracture of these strata are such, that probably the same layers are re- alee again and again. At one place the black shales appear to rest irectly upon hard, grey, flaggy shales, at another, upon one of the clay- beds. This shale zone is succeeded immediately by Well-bedded greywacke and grit, in beds varying up to 3 or 4 feet thick, with occasional shaly partings and one or two thicker bands of grey flaggy shale, This zone has a total breadth upon the coast-line of about 140 yards, and is probably not much less than 400 feet thick. The grey- wacke beds, though still parted with thin shale, are more massive at the base, where they rest directly upon Black shales. This zone shows admirably all the characteristic features of the black shale of the Silurian rocks in the south of Scotland. The strata are so intensely plicated as to defy any attempt to ascertain satis- factorily their true thickness. They contain some striking examples of the intercalation of those pale grey, greenish, or yellow clays like the fire-clays of the coal-measures. The contrast of colour between these beds and the black shales lends additional aid in following out the beautiful curvatures and faults exposed upon the beach. It is possible that, in spite of the frequent alternation of the two kinds of rock, there may be in reality only one band of the pale clay, its repetition being due to the innumerable foldings which the strata here have undergone. Another conspicuous feature of the black shales is the occurrence in them of cal- careous nodules and lenticular bands like the cement stones of the Lower Carboniferous rocks, while their resemblance to these younger paleozoic strata is further borne out by the appearance in them of ribs and nodules of a coarse pyritous clay-ironstone. Although this strip of black shalo covers the greater part of the little inlet north of Drumbreddan Bay, it perhaps does not amount to as much as 40 or 50 feet in actual thickness. At the base lies a series of Grey and reddish shales, and clays with calcareous bands and nodules, and enclosed bands of black shale, perhaps about 50 feet thick. At the base they are hard and flaggy, and rest immediately upon a vast series of grey and reddish greywacke flags forming the Ardell Group (par. 9). irom this section it would appear that the Moffat Shale Group in this part of the country has a thickness of somewhere about 1000 feet, con- siderably more than half of which consists of flaggy greywacke beds. 12. To the south of Drumbreddan Bay lies a great synclinal trough of the Queensberry Grits (Group 3), on the farther side of which, at Clanyard Bay, in Sheet 1, the Moffat shales rise in full force again, to be succeeded by the Ardwell beds of the Mull of Galloway. On the north side of Drumbreddan, the underlying Ardwell series, after occu- pying the coast sections from Grennan Point to near Slunkrainy, allows the black shale group once more to appear. At that part of the coast- line, a thick series of shales and hard greywacke bands occurs containing several bands of black shale. The rocks are here much twisted and broken, besides being invaded by intrusive masses of felstone, but grapto- lites have been obtained from the dark shales. The two lines of outcrop now described, stretching north-east- ward, the one from Drumbreddan Bay, the other from Slunkrainy, are the only places in the present Map where this lower series of black shales can be seen. Their existence is due to the rise of the Ardwell axis, from which they dip away on either side. To the north they are suc- ceeded by higher members of the Llandeilo series, which, though thrown into innumerable folds, never allow this lower series of shales to rise again to the surface. 13. (8.) Queensberry Grit Group.—The general characters of this well-marked and persistent band are given in the Explanation of Sheet 15, where the rocks are described as occurring in great force in Queensberry 13 Hill, and stretching thence north-east and south-west in the general line of strike of these rocks. They retain the same features even to the extreme south-western coast-line of the country, consisting of thick- bedded greywacke and grit in massive courses, with occasional bands of grey and greenish shale. The massiveness of the beds in this arenaceous series, the regularity of their bedding and jointing, whence they can be readily used for lintels and flags, and the frequent coarseness of their texture, passing at times into coarse conglomerate, distinguish the Queens- berry group from all the others. In the present district they have not yet yielded any fossils. 14. This group crosses Wigtownshire in three parallel bands, which are raerely repetitions of each other caused by the plication already referred to. The first of these lies to the south of Drumbreddan Bay, and comes only partially into this Map on the east coast, south from Chapel Rossan Bay. But in the Map to the south (Sheet 1) it covers a con- siderable space, since it occupies the synclinal trough between the outcrop of the Lower Black Shales in Drumbreddan and that in Clanyard Bay. To the north-west of the Black Shales of Slunkrainy, an admirable exposure of the Queensberry grits may be seen on the cliffs of Money Head. The general dip is north-westerly at high angles. There appear to be comparatively few curvatures in this part of the coast section, consequently the Queensberry group is made to cover a smaller breadth upon the Map than it usually does. Some of the strata are quite pebbly in texture, but no actual conglomerate was observed in the course of the Survey,—a fact which is deserving of remark, since bands of course con- glomerate occur in the other two bands above referred to. A gradual increase of the flaggy character may be traced as we round Money Head towards Scarty Head. The strata of greywacke become thinner and more divided by partings of shale until the group passes insensibly into the next in order, that which has been named the Dalveen Group (No. 4). 15. When this change takes place, the coast-line northwards continues to be occupied by higher members of the series. The synclinal trough, as already mentioned, runs north-eastward from Morroch Bay. But, while on the south side of that trough the whole breadth of the different groups above the Queensberry beds is less than three miles, on the north side these beds are separated from the centre of the trough by a space of fully twelve miles—a difference due to the much greater plication and repetition of the rocks on the latter than on the former side. After passing over these twelve miles, which are covered almost entirely by endless folds of the group next in order, we again come upon the charac- teristic thick-bedded greywackes and grits of the Queensberry series. These begin on the coast between the Genoch Rocks and the Ox Rocks, where the overlying flaggy and shaly group passes down into them. Several faults occur on the shore hereabouts, one of the most conspicuous being marked upon the Map. The actual throw of these dislocations is probably insignificant. They are fractures rather than faults, occurring among highly-inclined or even vertical beds; and strata having the same characters, and belonging to the same group, are found on both sides of them. ‘There is, therefore, no sensible interruption here of the usual order of succession among the strata. The Queensberry group gradually passes out from under the overlying beds, and soon assumes its charac- teristic features. But it acquires also a very remarkable conglomeratic aspect. Beds of conglomerate occur in abundance, and so coarse as to deserve the name of boulder-beds. Many of the stones are two or three feet in diameter. As a rule, they are well rounded. In a hundred stones, 14 broken at random from the thick bed of conglomerate at the Corsewall Lighthouse, the following proportions were noted in their composition :— Granite, chiefly pink ‘ 30 per cent. Diorite y é - 24, Quartziferous porphyry ‘ 5:2 55 Felstone : : 1G 55 Lydian Stone é i é i gg Greywacke, usually altered és 8 5, Quartzite . : ‘ ; 4 4, Quartz é : ‘ ‘ r . hs These massive conglomerates with bands of greywacke form all the northern end of this promontory of Wigtownshire. 16, (4.) Dalveen Group.—Under this name are here included all the strata which intervene between the Queensberry group and the Lowther Shales (No. 5). The lower part of the series is sometimes remarkably shaly, and this cannot he better seen than where it begins to overlie the Queensberry group to the south of Corsewall Lighthouse. But thick masses of jointed greywacke likewise occur. The whole group, as developed in this part of the country, may he described as consisting of well-bedded, jointed greywacke, with partings and frequent thick zones of grey and blue shale. In some of the shale bands fossils occur. To this group belong the so-called *‘slates” of Cairn Ryan, from which, as well as from other similar bands, numerous graptolites have been obtained (see Appendix). But the group appears to be further charac- terized by the occurrence in it of a thin band of black shale containing graptolites. This seam occurs twice along the western coast section. On the south side of the syncline, it crops out in the cliff at Portayew among the bands of greywacke and shale; on the north side, it has been noticed on the shore of Knock Bay, embedded among similar rocks. It has the usual characters of the lack shales already described, the erumpling and fracture of the layer being particularly well shown at Portayew. The evidence seems to he, on the whole, in favour of classing this black shale with the Dalvcen group, although it may possibly in the end be shown to be really the upper black shale of Group 6, as explained in par, 22. 17. The Dalveen group is found on both sides of the synclinal trough. On the south side it may be revarded as stretching from Scarty Head to beyond Knockienausk Head—a distance of rather over two miles. As the strata throughout this distance are for the most part thrown inty high angles of dip, or quite on end, the thickness might be supposed to be enormous. On examination, however, it is found that here as elsewhere the rocks have been folded again and again back upon themselves, so that the actual thickness of rock is probably not a third of what it seems at first to be. Some magnificent curvatures of the strata are to be seen on the face of the huge cliffs hy which Cairnmon Fell shoots out of the sea. On the north side of the syncline, the Dalveen beds, as already remarked, cover a much greater space. They begin where the Queensberry group ends off, near the Ox Rocks, and their southern limit seems to stretch beyond Portpatrick, though, owing to the metamorphism of that area, described in par. 23-27, its southern boundary there cannot be very accu- rately defined. Thus, over a breadth of fully eleven miles, the Dalvecn series passes across this peninsula of the county. Such a breadth indicates the extreme plication of the rocks, for there is no reason to suppose that they are thicker on the one side of the basin than on the other. In fact. they are repeated upon themselves times without number, 15 and this even though a general southerly dip is preserved, for the axes of the folds are not vertical, but rise towards the north-west. This can be seen along many parts of the fine coast sections, as, for example, to the south of Portobello. Amid such intense contortion, one might naturally expect to find that sometimes along the anticlinal folds some parts of the underlying group would be brought up, while, in the synclinal folds, portions of the overlying series would be caught and retained. It is possible that some of the greywacke zones may be parts of the Queens- berry series, but this is not certain. More satisfactory are the proofs that here and there, in the deeper troughs, portions of the overlying shale series have been folded. Two or three conspicuous examples occur of this pro- bable structure, one a little north of Broadsea Bay, where, for a space of about half a mile, the coast is oceupied by a thick series of grey and olive shales, precisely similar to those of the Lowther series. Some beautiful examples of foldings with reversed dips may be seen among these shales. Another instance occurs farther north, between Slouchnawen Bay and Strool Bay, where similar shales and flagstone, sometimes wonderfully twisted and curved, cover the shore for a space of about three-quarters of a mile. These zones are thicker than any shale bands in the Dalveen group, and have so exactly the character of the next group that they may, without much hesitation, be referred to it. 18. It is this Dalveen group of greywacke and shale which, stretching towards the north-east, covers most of the rest of the Silurian area of the Map. The same characters, which are so well seen on the western coast-line, may be traced inland across the moors, though the continuous sections there are comparatively few. The harder or greywacke beds form the knobs of rock at the surface, while the softer or shales are usually more or less buried under turf or drift. About Auchmantle and to the north of Gleniron Fell there is a decided preponderance of thick- bedded gritty greywackes, with only occasional bands of grey shale. About Crailloch, and crossing the tract of low drift-covered ground about Stranraer, in the hilly ground between Inch and New Luce, the dips are both to the south-east and north-west, showing considerable foldings in the beds. The shales and shaly greywacke beds are often a good deal hardened in this group. They likewise show very twisted and con- torted bedding. Near the metamorphic area, at the south edve of the group, they have suffered a slight metamorphism, the shales being very hard and splintery, and often baked into a solid mass. Here the cleavage lines, which are more or less discernible in the shaly beds all along the coast-line, become much more distinct. .A good example is seen at the headland of Catebraid, a little north from Portpatrick, where some bands of shale are traversed by cleavage planes, cutting through tlie bedding, and dipping with it, but at a lower angle. At the north end, near Corsewall, the alteration of the shales has been considerable; they have there been converted into a shattery compact rock, resembling a coarse kind of porcellanite. The greywacke and gritty beds have likewise been hardened and otherwise slightly altered towards the south. Much broken by joints, they all contain numerous veins of quartz and some- times of calcite—the latter being frequently found, with hematite, and now and then chlorite, forming coatings along the sides of the largrr joints. Diffused oxide of iron occasionally stains the rocks of a red and purplish colour. The bands of black shale are very much crumpled and broken. In a series of grey shales, with interbedded greywackes, to the north of New Luce, some thin veins of lead ore occur, which have been worked at Knockibae. 19. (5.) Lowther Group.—Next in order comes a series of shales and 16 flags, with greywacke bands, answering in general character to the corresponding series in the Lead Hills region, to which the name of the Lowther Group has been given by the Geological Survey. In that region the group, as its name implies, consists in great part of shale. Traced south-westward, however, the shale gives place more and more to greywacke flagstones and grits with shale bands and partings. This character is more especially marked along the north side of the syncline of Black Shale described in par. 22, where it would appear that sandy deposits were laid down as a long bank during the time that the more muddy material of the shales was accumulating to the north-east and south. Hence on the south side of the syncline the group is more decidedly shaly than on the north side, as may be seen by comparing the coast sections to the south and north of Morroch Bay, or the ground to the south-east of Camrie Fell, with the rough craggy area to the north- west of that hill. From the boundary of the Dalveen beds northwards, close up to the synclinal axis, this group stretches from the west coast across the Map, by the head of the Bay of Luce, to Glenluce, whence it passes into the adjoining Sheet. Most of this area, however, is covered with drift and sand, the only good section of the rocks being along the shore of the Irish Channel. The strata form there a line of cliffs from 100 to 300 feet in height, between Morroch Bay and Knockie- nausk Head, and consist of masses of grey and greenish shale, often twisted and broken, sometimes very fissile and micaceous, and of grey flags, with interbedded hard, blue, fine-grained greywackes, much broken with joints. Veins of quartz and calcite run more or less through all the beds, and dykes of igneous rock are likewise abundant along the face of the cliffs. The flags are most fully developed at the top of the series, and have been quarried for roofing and flooring purposes. East- wards, also, at the edge of the Sheet, in the Water of Luce, the grey flagey shales are still the most prominent beds. Along the coast, north to Port of Spittal Bay, the strata of this group dip to the north-west, generally at a high angle, and, with the exception of a south-east dip which comes on for a short distance in Eldrig Burn, two miles inland, this is the constant direction across the Sheet. Though the synclinal axis appears to begin in Port of Spittal Bay, on each side of which the beds have a general dip towards each other, yet, if we may be guided by the structure of the wide region to the north-east, it is more probable that the black shale group, which comes on in Morroch Bay, some hundred yards to the north, marks the true line of the fold. Towards the eastern margin of the Map, the dips of the rocks show that the latter group really does lie in the line of the synclinal axis, and therefore over- lies the shale and flagstone group just described, as, in the typical region of the Lead Hills, the black shale group overlies the Lowther group. The beds between the black shales and the apparent axis in Port of Spittal Bay are inclined at a very high angle, so that a small amount of reversed folding would suffice to give them a south-east dip. 20. From Portpatrick to Piltanton Burn, the area occupied by the flags and shales, which are here classed with the Lowther group, has been metamorphosed very considerably, and will be separately described further on. The position and extent of this area of metamorphism are shown upon the Map. As already mentioned, the alteration of the beds obscures the boundary between this group and that below. No good section of these rocks can be obtained inland along the northern side of the trough; but where they are exposed on Glenwhan Moor, and still more admirably on the Fells of Craig and Gleniron, they dip at high angles towards the south-east. Both the greywackes and shales have 17 been considerably hardened, and show the usual reticulated veins of quartz, with sporadic patches of still greater alteration. [aint cleavage appears here and there among them. Some of the greywackes pass here into coarse grits, 21. (6.) Upper Black Shale Group.—Though this series of strata has not yet been traced by the Geological Survey completely across the wild and rugged tracts of Galloway, between the valley of the Ken and the Wigtownshire Moors, there is every probability that the bands of black shale, which in the present Map lie along the synclinal trough, are the same as those of the Lead Hills. From the latter region they have been followed in two parallel bands south-westward up to the base of the great mountainous range of the Kells, and it is in continuation of the same line of strike that the black shales of the present Map reappear, and run from the Water of Luce south-westward to the Irish Channel. Judging, therefore, from the general parallelism of the zones, we are probably justified in at least provisionally placing these Wigtownshire beds on the same horizon with those to the north-east. Two bands of this upper shale group, each lying in a synclinal trough, cross the area of the Map. One of these crosses from Morroch Bay to Camrie Fell, and thence is prolonged into Sheet 4. The other appears to the south- west of Stranraer, and crosses the moors to the north-east, where it is well seen in the bed of the Water of Luce below Cairnarzean. If the bands of black shale alluded to in par. 16 as occurring in the Dalveen group should in the end be found to form part of the present group, the number of lines of outcrop will be increased. The difficulty of settling this point arises chiefly from the change (already mentioned, par. 20) of the Lowther shales into a more flagey series that insensibly passes down into, and cannot in many places be satisfactorily discri- minated from, the underlying Dalveen beds. 22. By far the best section of these black shales in this region, and, indeed, one of the best anywhere to be seen in the country, is that of Morroch Bay, about a mile and a half to the south-east of Portpatrick. As already explained (par. 6), they lie here in a synclinal trough, so that those in the northern half of the Bay are brought up again along the southern half. As nothing is found overlying them here in the centre, it is neither possible to ascertain their true thickness nor the character of the strata which come above them next in order. Arranged in descending sequence, they appear to be made up of the following zones : e. Thick mass of black shales, with lenticular nodules and seams of coarse clay-ironstone, nodular layers of greywacke, and pyritous kernels (some- times five or six pounds in weight) and partings which decompose. These shales have the usual fissile character, with hard flinty ‘ribs’ in- terstratified with the more shaly parts. They show much crumpling and fracture, besides being invaded, especially. on the cliffs, by intrusive masses and veins of felstone. (See pars. 28-30.) Owing to these features, their thickness cannot be satisfactorily ascertained ; for in spite of the space which the strata are made to cover, they may in reality be no more than fifty feet thick. For the graptolites of these shales, see Appendix. b. Shales and flagstones. On the north side of the Bay these strata are of a general greenish grey colour, sometimes yellow, and occasionally purple. On the south side they become in parts bright red. The shales have « general fissile character, but become in some places hard and flinty, and intercalated with thin flagstones, bands of greywacke, and occasional lenticular seams of black shale. This zone may perhaps be about the same thickness as the black shales above it. a. Hard lenticular and sometimes thick-heddel jointed greywacke, with numerous remarkable included masses of black shale of 5 18 the usual characters. In some parts the greywacke looks like an intrusive rock which has been injected in veins through the shales, as may he well seen at the north end of the Bay. This curious zone may be taken to be about thirty or forty fvet thick. It passes down into the hard greywacke flagstones and shales which represent the Lowther group, and in the upper part of which, at the north end of Morroch Bay, thin seams of black shale are intercalated. In continuation of the Morroch Bay band the same shales may be seen occupying the centre of the syncline on the Water of Luce, between the old abbey of Glenluce and Gabsnout. As expressed upon the Map, they cover a larger space here than at Morroch Bay, seeing that the synclinal trough widens. The hill called Camrie Fell may be regarded as lying exactly in the trough. On its north side the shales may he seen resting upon the hardened flagstones, greywackes, and shales of the Lowther group of Gleniron Moor and plunging south-eastward. On its south side, again, the same shales can be traced dipping to the north- west. Camrie Fell itself appears to consist partly of crumpled black shale and partly of a small portion of the hard greywacke beds which, farther to the north-east, are found to overlie the upper black shale group. As already mentioned, another band of black shale, which appears from the evidence obtained up to the present time to be in all probability a repetition of the Morroch Bay band, occurs at Crailloch Burn, a little to the south-east of Stranraer, and again where the rocks of the turf- covered moors have been deeply trenched by the Water of Luce below Cairnarzean. At the former locality the black shales have been thrown into several folds. and show the associated red and greenish shales as at Morroch Bay. In several of the synclinal troughs they are overlaid by a coarse gritty greywacke which recalls some portions of the Caradoc series of Kirkcudbrightshire and Nithsdale (Sheets 9 and 15). In the line of strike of the Crailloch Burn black shale band, a thick set of grey shaly beds and flagstones occurs upon the shore at Killantringan Bay. It is suggested that these may be a syncline of Lowther beds in which, were it a little wider, the Crailloch band should be found. That band, however, appears to ‘nose out’ before it reaches the shore, unless indeed we try to connect it with the black shale seen among the greywacke and flagstone of Knock Bay, which has already been provisionally classed with the Dalveen group (par. 16). Metamorphism of Silurian Rocks. 23. Throughout the Lower Silurian tracts of the south of Scotland there occur, often at wide intervals, scattered areas over which the original greywacke and shale beds have undergone alteration, even to the total obliteration of the granular sedimentary character and the stratified arrangement, and to the conversion of the rocks into more or less crystalline amorphous masses, like those which are ordinarily regarded as igneous rocks. In some cases this metamorphism is associated with the appearance of a central nucleus of granite round which the Silurian rocks assume a schistose texture, as in the high grounds of Kirkeudbright and the north-west of Dumfriesshire. In other cases no granite appears, but the Silurian strata are found to pass into rocks which possess most of the ordinary characters of por- phyrites, felstones, diorites, or other crystalline intrusive masses. ‘This may be seen near Sanquhar (Sheet 15), and also between Girvan and Ballantrae (Sheet 7). 24. In the present Sheet, besides numerous smaller patches where the 19 rocks have been considerably hardened, a detached and limited area of metamorphism occurs, presenting features somewhat different from those of the two kinds of alteration just referred to. This area, as shown upon the Map, lies round the village of Portpatrick, extending along the coast-line from Morroch Bay to near Catebraid, and inland for two or three miles. It will be seen that there is no granite nucleus, and that no great mass of any intrusive rock occurs either in the centre or at any part of the meta- morphosed area. Throughout this area the rocks, which farther to the north-east are still the ordinary greywackes and shales of the district, have been considerably altered. Their granular character has not been wholly effaced, but in many places an incipient crystallization may be traced, as if it were the remains of an arrested metamorphism of the Sanquhar or South Ayrshire type. Single specimens, or even detached cliffs of these rocks, are sometimes exceedingly puzzling, and not until a considerable part of their extent has been gone over does their true character become evident. They have been largely quarried on the coast at Portpatrick, especially to the south of the village, where the quarries lay open many excellent sections. The strata as there exposed are nearly vertical, and strike towards the north-east, sometimes hanying slightly to north-west, at other points to south-east. Though the stratification remains distinct, it has been much disturbed in some parts into minor folds. 25. The whole of these rocks have been greatly hardened. Where the metamorphism has been most developed, it shows itself in the grey- wacke by a partial obliteration of the granular texture and the appearance of an indistinctly crystalline texture, through which may be traced here and there striated plagioclase crystals and cubes of pyrite. Examined with the microscope, these more altered portions clearly show, what is sometimes tolerably distinct even to the naked eye, that the character and extent of the metamorphism have been largely determined by the original composition of the rock. The quartz grains form a minority of the sand-particles out of which the greywacke was made,—sometimes, indeed, almost disappear. These grains have suffered little or no change. They remain sharp and distinct as they originally were. It is the dark argillaceous base or matrix in which they lie which has undergone meta- morphism. Hence, where a coarse quartzose grit occurs, it is observed to have suffered little change. Where, on the other hand, the quartz- sand has been small in quantity, and the rock has probably been a fine sandy silt or muddy sand, the metamorphism reaches its muximum. Yet the shale bands seem on the whole to have undergone less alteration than the greywacke. They are dark in colour and much hardened, but not porcelainized. Where most changed they cease to be fissile, and break with a splintery sub-conchoidal fracture. Here and there among them a rude cleavage is developed. Where they are interbedded in partings or other bands with the greywacke, the two rocks, instead of being as usual easily separable, are, as it were, welded into each other. It may be noticed also that small patches of the same material as the shale, either rolled fragments of some previously consolidated shales, or what were originally mere pellets of clay, like the ‘clay-galls’ in sandstone, occur both in the metamorphosed and ordinary greywacke. 26. Besides being hardened and partially crystalline, the strata are so shattered by innumerable joints as to present on a weathered face an angular rugged surface. Along these joints run veinings usually of calcite or quartz, sometimes of chlorite or barytes. They likewise show occasional veins or dykes of intrusive rock, some of which have been laid cpen in the cutting of the railway. One of these, coinciding nearly, if zZ0 not quite, with the line of bedding, shows much decayed hornblende, with a little mica and granules of quartz, in a basis of apparently plagioclase felspar. To such a rock the name of diorite is perhaps most appropriate. But the same rock is found not many yards distant to be exceedingly compact, and weariug much of the general aspect of the most highly altered parts of the greywacke. 27. Towards the north the metamorphism may be traced gradually passing away into the ordinary character of the rocks. On the southern margin the metamorphic area is more sharply defined by the band of black shale stretching inland from Morroch Bay. This thick band, which occupies the hollow of that bay, and indeed is the cause of its excavation between the two masses of hard greywacke which form its headlands, shows how rapidly the metamorphism disappears when the more alterable greywacke is replaced by shale. At the north end of the bay, next to the altered greywacke, the shales are black, and though much hardened, twisted, and broken, yet continue to show abundant graptolites. Farther south they appear as red and greenish bands, much less hardened and dislocated, while at the southern headland ordi- nary unaltered greywacke succeeds them. Tyneous Rocks in Silurtvan Series. 2x. As shown upon the Map, the Silurian strata are traversed by numerous veins or dykes of intrusive rocks. As a rule, these intrusive masses run with the general strike of the district, that is, from south- west to north-east. Their date cannot be fixed from any evidence to be obtained in the district; but, like the other abundant dykes of similar character among the Silurian rocks of the south of Scotland, they are probably to be placed between the deposition of the Upper Silurian and Upper Old Red Sandstone rocks. The only exceptions to this probable date are presented by the dykes of basalt-rock, some of which are here found penetrating the Permian strata, and which from other evidence are assigned to as late a time as the Miocene Period. 29. Of the older or palaozoic series of dykes several petrographical varieties may be distinguished. The majority belong to the rock named Felstone, consisting of a white, grey, pink, or reddish orthoclase base with sometimes a little hornblende, or tale, or quartz intermingled. The base is usually compact crypto-crystalline, but sometimes assumes a finely crystalline character. A second variety of rock contains, in addition to the same kind of base, a much greater quantity of hornblende, as near Craigoch, two miles south-east from Portpatrick. These rocks are syenites, according to the German nomenclature. It often happens that part of the hornblende has been replaced by talc, as in the dyke near Little Float, four miles south-west from Stoneykirk, though this replace- ment does not seem to have been carried so far in this district as in that represented upon Sheet 2. (See the Explanation of that Sheet, par. 10.) A third variety is made up of a felspar base, very like that of the two previous varieties, in which, under the microscope, no trace of strie can be seen, but through which are scattered, more or less abundantly, well- marked crystals of a striated felspar. They appear to consist of a finely crystalline orthoclase base, and to be porphyritic with crystals of plagio- clase. A good illustration of this character is seen at Cairngarroch Bay, where also hornblende and black mica make their appearance. A fourth variety has the felspar of the base distinctly striated, and sometimes be- comes porphyritic from the separation of large crystals of the same felspar—hornblende, talc, or mica being frequently superadded. Such 21 rocks are probably best classed with the dorztes. Examples may be seen at Morroch Bay and Cairngarroch Bay. It should be added that pyrite occurs in all these rocks,—sometimes, indeed, forming a considerable pro- portion of the mass. 30. The mode of occurrence of these various intrusive rocks can best be understood by a reference to the Map, where the abundant dykes and veins along some parts of the coast sections are well exhibited. It has often been remarked, in the course of the work of the Geological Survey among the Silurian rocks, that these intrusive masses are apt to occur in segregated clusters of dykes and veins, with intermediate spaces, some- times of wide extent, wholly or nearly free from them. The present Map furnishes additional examples of this fact. It may be observed also that the dykes and veins are frequently crowded together among the shaly or thin-bedded rocks, while in the thicker greywacke masses they are com- paratively scarce. A curious feature was noticed at Portayew, where the band of black shale is traversed by a mass of pink and yellow felstone. The latter rock sends into the shale veins and threads, which, as well as the outer parts of the main mass in contact with the carbona- ceous shale, are dull, pale, and earthy, strongly recalling the appearances presented by the ‘ white rock’ in the coal-fields, where an ordinary dark pyroxenic mass has been injected among coals or bituminous shales. Carboniferous. 31. This formation is represented in the present Sheet by a band, a few hundred yards wide, of grey, reddish, and mottled sandstones, and purplish clays, which extends for five or six miles on the west side of Loch Ryan, between the Silurian and Permian rocks. Few exposures of the rock can be seen, the surface being mostly covered with drift. A small outlier of sandstone is shown in a stream a quarter of a mile north of the main boundary line. These rocks have yielded a few fossils and plants of common carboniferous species. (See Appendix.) They may be provisionally referred to the lower group of the calciferous sandstone series—the base of the carboniferous system of Scotland. Permian. 32. The Permian area in this Sheet extends from a mile and a half north of Kirkcolm, southwards to within a short distance of the hamlet of Lochans, two miles south of Stranraer. It forms a narrow band about eight miles in length, with an average breadth of about a mile, stretching along the western shore of Loch Ryan. It consists entirely of a coarse dark red breccia, lying unconformably on the carbouiferous sandstones which divide it from the surrounding Silurian rocks. It is best exposed along the shore from its northern boundary to Corsewall House, where it forms a line of cliffs 150 feet high at the highest point. These are very much split up and broken by joints and weathering; and along the base of the higher cliffs numerous caves have been tunnelled out by the action of the sea. The lines of stratification are marked in this breccia by thin seams of sandstone from half an inch to two inches thick, and also by the position of the stones, with their longer axis parallel to the line of bed- ding. The general dip of the beds is to the east or south-east, but at a low angle, those forming the line of cliff already mentioned being quite horizontal. This breccia is made up of angular or sub-angular stones, which vary in size up to about one foot in length. They have much the same appearance as the stones in boulder-clay ; but though they have 22 been searched for striated surfaces, they have not yet furnished any. They are generally covered with a thin coating of hematite. This rock has been entirely derived from the waste of the surrounding Lower Silurian grits, greywackes, and shales—no fragments of the underlying carboniferous sandstones having been noticed in it. The matrix in which the stones are embedded is but scanty, and consists of red gritty sand. That this rock is of Permian age, may be inferred both from its position —lyiug unconformably on the carboniferous sandstones already men- tioued—and from its similarity to the recognised Permian breccias of South Ayrshire and Dumfriesshire. Igneous Rocks later than the Permian Period. 33. Of the basalt dykes, which play so important a part in the geology of some parts of the Silurian region of the south of Scotland, as between Crawfordjohn and Moffat, there is but a poor representation in this district. One is exposed on the beach alyout one mile south of Kirkcolm, cutting through the Permian breccia, and running nearly north and south. There is another small exposure seen two miles to the north, near Corsewall Mill, of what may be the same dyke, but it is seen nowhere between these two localities. Along the west shore a fine-crained basalt dyke crops up on the beach near the Ox Rocks, and another, some miles to the south, in a small burn near Brightpark. There are two more basalt dykes exposed at the south-west corner of the Sheet, one at the north end of Ardwell Bay, and the other a mile to the south, near Grennan Point. These dykes have all a general north and south direction, and none of them cau be traced for any distance. Drift. 34. The same evidence of ice-work, so abundant over the south of Scotland, is furnished by the surface of the present district—abrasion and striation of the rocks, boulder-clay, with sands, gravels, and erratic blocks. In spite of the thick coating of turf and peat which obscures so much of the ground, the hills present on every side that smoothed and worn axpeet which marks the passage of land-ice. Frequent more or less perfectly preserved roches moutonnévs occur throughout the district. This form of surface has in many cases not been wholly effaced, even where the rocks have been subjected to much subsequent atmospheric waste. In many places the hills appear upon a near view to be rugged and broken, but at a little distance this roughness seems to vanish, and the slopes and tops then assume the normal ice-worn aspect. These appearances are well displayed in the hilly ground overlooking the Water of Luce, and they are also very conspicuous in the neighbourhood of Portpatrick, as at Craiyenlee and Cairn Pyot. Glacial strie are seldom or never observed upon the exposed faces and tops of the hills; but in places from which the overlying drift has not long been removed, the rock weierally exhibits fine parallel strie and grooves. The general direction followed by these strix is from north-east to south-west, but here and there strix are observed running at right angles to these. The localities of a number of these strie are indicated upon the Map. 35. All the lower grounds are found to be more or less concealed below a coveriny of drift deposits. These deposits, arranged in descend- ine order, are as follow :— 23 Erratic Blocks. Brick-Clays, containing marine shells. Sands and Gravels. No fossils yet obtained from this group. Till or Boulder-Clay. Iu the lower part of the deposit, shells, chiefly fragmentary, occur. 36. Till or Boulder-Clay.—This deposit varies in character according to the locality in which it occurs. Thus over the Riuns of Galloway it consists of a fawn-coloured or light brown sandy clay, quite unstratified and abundantly charged with angular and sub-angular stones, which, as a rule, are well striated. None of the stones are true erratics: as far as observed, they are all of local origin, consisting of greywacke, grit, shale, metamorphic rocks, and frequently of felstone or other intrusive rocks. The clay is not so compact and tenacious a deposit as that which is met with in carboniferous districts in central Scotland ; its looser and sandier texture being probably due in part to the nature of the rocks, from the abrasion of which it has been derived. In the hilly districts, near the Water of Luce, the boulder-clay is a still more loose and earthy deposit, and the included stones are not generally so well glaciated. Many are quite angular and unpolished, and not a few are of large dimensions. Towards the high grounds the deposit assumes the character of moraine débris, as on the slopes which overlook Loch Ryan from the east. In some of the stiff parts of the till on the low grounds, fragmentary shells are to be met with, as at Lady Bay, Innermessan, and Sandhead. The arrangement of the till in long ridges or drums, corresponding generally with the trend of the strie on the rocks, can be traced, more or less definitely marked, over the peninsula to the west of Loch Ryan and Luce Bay. These features, however, have not the same decided character by which they are distinguished farther to the east in Sheets 2 and 4. 37. Sand and Gravel—These deposits are scattered here and there over the low grounds forming the Rinns of Galloway. Examples occur in the extreme north of the Sheet, and extend from Dally to Portmullin ; others may be seen about Lochnawe and on Larbrax and Galdenoch Moors, near Portpatrick, around Stoneykirk, Sandhead, and Float; and in the extreme south, at Ardwell, Auchness, etc. The deposits, instead of rising into well-marked ridges or kames, as in other parts of Scot- land, rather group themselves into low mounds and undulating banks. They are usually well stratified, occasionally show cross bedding, and consist of layers and beds of sand, alternating with similar deposits of gravel. They rest upon the boulder-clay. The greatest height they attain is only some 300 feet above the sea. 38. Brick-Clays—In the neighbourhood of the sea, certain clays are worked for brick-making. They are usually reddish-brown in colour, tough and tenacious, and not well laminated. Here and there they have yielded a few small scattered stones, and several large boulders have been obtained during the working of the clay. Those observed consisted of greywacke, and may have come from the high grounds above the Water of Luce. At the tile-works at Clashmahew near Stranraer, the clays have yielded organic remains, a list of which will be found in the Appendix. These clays, as a rule, are not found at a greater elevation than 60 feet above the sea. At Cairnbrock, however, an unfossiliferous brick-clay is wrought at a height of 160 feet. It contains more stones than usual, is not perhaps so tough as the others, and may possibly be really only a part of the true till. At Stranraer, the clay is said to rest. upon sand and gravel; at Cairnbrock, the underlying deposit consists of boulder-clay. The relation between these brick-clays and the sand and 24 gravel series cannot be very clearly made out; but it is most probable that the former are the younger deposits. 39. Erratic Blocks——Here and there boulders of grey granite are found scattered over the surface. None of them are more than a few tons in weight; but, as much of the district has been a long time under cultivation, it is probable that many loose boulders have been removed. Those observed in the course of the Geological Survey consisted of grey granite, derived, in all probability, from the granitic high grounds of Kirkcudbright. Numbers of greywacke boulders are also scattered over the surface, many of which are no doubt true ice-floated erratics; but since the underlying rocks consist of the same materials, this point is not capable of demonstration. Raised Beach. 40. A broad belt of low-lying and gently undulating ground extends from the shores of Loch Ryan to Luce Bay. Nearly the whole of this tract is covered with sand and gravel. Although the ground is for the most part undulating, still, an examination shows that the surface deposits are arranged in a succession of broad terraces, which are best marked at the lower levels. The lowest of these terraces is indicated upon the Map as the 25 foot beach. It is composed of shinyle, gravel, and sand, with numerous remains of recent littoral shells. The higher terraces are com- posed of rounded gravel and sand, and, as far as known, have yielded no organic remains. Though much denuded and cut into by small brooks, they are nevertheless still sufficiently well-marked. After passing inland from the level of the 25 foot beach, we fiud the ground rising slowly from the level of 50 feet up to that of 75 feet, forming a long and very gentle slope. Another higher terrace occurs at a height of 90 to 95 feet. Above this height lie the slopes of boulder-clay. It is not improbable that much of the sand and gravel already described may belong to the period of these old beaches, and, if not brought together, may at least have been rearranged at the same time. Along the western shores the only patch of raised beach deposits appears immediately to the south of the Ox Rocks, where there is a thin covering of mud on the level worn surface of the rocks. Blown Sand. 41. A strip of blown sand occurs at the head of the Bay of Luce, stretching between Sandhead and the mouth of Piltanton Burn, and extending inland to the main road between Sandhead and Glenluce. It forms hillocks and ridges covered with coarse bent. Peat and Alluvium. 42. The high ground occupying the eastern portion of this Sheet is generally covered with considerable accumulations of turf and peat, which completely hide the underlying drift and rock, except in the beds of the streams. This growth attains its greatest thickness on the hill-tops and in intervening depressions, the peaty turf on the hill-sides seldom exceed- ing one or two feet in thickness. The more cultivated ground, forming the western portion of the district, also contains numerous hollows filled with peat, a considerable amount of which is ent for fuel. 43. The alluvial areas of the present Sheet are confined to the larger 20 stream courses, with the exception of the beaches of sand and mud which are laid bare at low tide along the shores of the Bay of Luce and Loch Ryan. The chief patches of fluviatile alluvium occur in the lower course of Piltanton Burn between Barsolus and Whitecrook, and up the valley of the Water of Luce. ECONOMIC MINERALS. 44, Building Stones—Yellowish and red sandstone has been quarried for building purposes in the carboniferous band at Challoch Hill near Leswalt, and near Meikle Mark, about a mile south-west from Stranraer, but it is too soft and friable to be of any value. Some of the beds of greywacke are available for building, and quarries have been opened in them at different points along the coast. The largest is in the metamorphic area at Portpatrick. Most of the houses in the village and the greater part of the pier and dock have been built of stone from this quarry. A band of grey shales and flags at Cairn Ryan has long been worked for roofing and paving purposes. They are not true slates, however, as they have no traces of cleavage, but split along the lines of bedding. 45. Road-metal—The greywacke and gritty rocks are suitable for road- metal, for which they are used on account of their toughness and dura- bility. Some of the felstone dykes and bosses are also used for this purpose. 46. Lead.—Some thin veins of galena have been found on Knockibae Hill, to the north of New Luce. These have been workel for lead at Knockibae mines; but, owing to the scarcity of the mineral and the expense of working, the mines have been abandoned. APPENDIX. I—LIST OF LOCALITIES FROM WHICH FOSSILS HAVE BEEN COLLECTED BY THE GEOLOGICAL SURVEY IN THE WESTERN PART OF WIGTOWNSHIRE.—(Sheet 3.) The numbers are those by which the localities are denoted in the succeeding List of Fossils, Glacial. Brick-Clays, 1. Clashmahew Tile Works, 1 mile S. of Stranraer. 2. Culmore Tile Works, 1} mile S. of Stoneykirk. Till or Boulder-Clay, 3. Lady Bay, 2 miles N. of Kirkcolm. 4. Innermessan (Escarpment of Till), 24 miles N. by E. of Stranraer. 5. Sandhead (Escarpment of Till), 2 miles 8. of Stoneykirk. Carboniferous. Red Sandstones, probably 6. Craigoch Burn, Loch Connel, 1 mile S.W. of belonging to Calciferous Kirkcolm. Sandstone series. 7. Small Burn near Low Knockglass, 14 mile 8. W. of Stranraer. Lower Silurian. Upper Black Shale Group, . 8. Morroch Bay, 14 mile S. of Portpatrick. 9. Burn E. of Colfin, 3 miles S. of Stranraer. 10. Gabsnout Burn, 24 miles 8. of New Luce. 11. Shore near Clachan Heughs, at junction of Permian breccia, 14 mile N. of Kirkcolm. Dalveen Group, . Z + 12. Cairn Ryan Quarries. 18. Portayew Cliffs, 35 miles W. by 8. from Stoney- kirk. Lower Black Shale Group, . 14. Grennan Point, Drumbreddan Bay, 6 miles 8. of Stoneykirk. II.—LIST OF FOSSILS FROM WESTERN PART OF WIGTOWNSHIRE.—(Sheet 3.) Glacial. Brick-Clays. Class, ete. Name. Locality Number. Lamellibranchiata, . Astarte.—Sp. , ‘ é : 5 Cardium edule.—Lin. . 53 Norvegicum. 7 Spengler, Cyprina Islandica.—Zin. Leda truncata.—Brown, L, 25 Class, etc. Name. Locality Number. Gasteropoda, . . Littorina—Sp. 5 : 1 Natica Montacuti. _Forbea, ' . At Loc. 2, shell fragments were obtained—too fragwentary to be determined. Sands and Gravels. {No Fossils yet noticed from this subdivision. } Boulder-Clay or Till. Foraminifera, Polystomella striato- ne —F. é M. 4, 5. Lamellibranchiata,. Astarte.—Sp. si ‘ 3. » sulcata.—Da Costa, } », compressa. —Montagu, » var striata. —AWidll. Cardium N orvegicum.—Spengler, Cyprina Islandica.—Lin. Leda (like pernula.—Afiiller), ; ‘ Mytilus ( probably modiolus.—Lin.), ; 4, Tapes. —Sp. s Tellina crassa, —Gmelin, Venus.—Sp. Gasteropoda, . . Littorina littorea. —Lin. é Pleurotoma turricula.—Jfontagu, . Turritella.—Sp. Carboniferous. Red Sandstones, probably belonging to the Calciferous Sandstone series. The organic remains from the carboniferous beds of Loch Ryan consist, with one exception of plant remains, in anything but a good state of preservation. ‘The exception referred to appears to be the remains of an encrinital stem. The specimen from locality 7 is, however, far too indefinite for a decided opinion to be passed upon it. Asterophyllites (like dubia.—Brong.), Poacites (linear plant-like), Calamites dubius. —Brong. : Stigmaria (like ficoides. — Sei ), with rootlets attached, z Plante, . j . Alethopteris (Pecopteris) lonchitidis.—Sternd. | 6 Lower Silurian. Upper Black Shale Group. Hydroxoa, . Dicellograptus eee —WNicholson, ; - Ap. is Dicranograptus Clingani. —Carr uthers, é 8. ramosus.—Hall, . 10. Diplograptus mucronatus. —H all, cf 8, 9. pristis.—Hisinger, . A é 8, 9, 10. Graptolithus tenuis eae! . : 10. 4 Sp. ; . : 10. Lowther Group. [No Fossils yet obtained from this subdivision within the area embraced by the Map. ] Dalveen Group. Hydroza, . . Climacograptus scalaris —Lin. 11. Dicellograptus Moffatensis.—Carruthers, 12: ” Sp. 12, 29 Hydroza, Dicranograptus Clingani.—Carruthers, . VL. j Sp. é ‘ . 13. Diplograptus pristis ’— Hisinger, . 11, 12. Graptolithus (like latus.—J[‘Coy.), ‘ 12, 59 Sp. ‘ ‘ . ‘ ‘ Ee Queensberry Group. [No Fossils yet obtained from this subdivision within the area embraced by the Map. ] Lower Black Shale Group. Hydrozoa, Diecranograptus ramosus.— Hall, 3 Diplograptus tamariscus.—Vicholson, . Pe pristis. —Hisinger, ‘ P 14. Graptolithus. —Sp. ‘ 3 ‘i i ; Rastrites peregrinus.—Barrande, : ‘ Ardwell Group. [No Fossils yet obtained from this subdivision within the area embraced by the Map. ] In the collections made by the Geological Survey from the present Silurian area, no remains of mollusca or other organisms besides graptolites have been detected, although in the paper by Mr. Carrick Moore, cited in the Preface, two species are mentioned—one which ‘appears to be the cast of a J/ytilus, in slaty shales and flags at Portobello Bay, near Cairnbrock, north of Portpatrick, and a shell from red slate on the shores of Loch Ryan, recognised by the late Mr. Salter as Huomphalus furcatus, M‘Coy., common to the Llandeilo flags of Wexford and Cardiganshire. In the list accom- panying that paper, two species of graptolites are mentioned which have not been observed in the Survey collection, viz. Diplograptus folium, His., and Didymograptus sextans, Hall. JII—LIST OF FOSSILS COLLECTED BY THE GEOLOGICAL SURVEY FROM THE SILURIAN ROCKS OF THE SOUTH-WEST OF AYRSHIRE.—(Sheets 7, 8, and 14.) ? 1, High Mains, about 6 miles N.E. of Girvan.—(Sheet 14.) Nidulites favus.—Salter. Favosites aspera.—D’Orb. Heliolites interstinctus.— Wahlenberg. ie tubulatus.—Lonsdale. Petraia elongata.— Phillips. Ptilodictya costellata.—M‘Coy. Atrypa hemispherica,—Sow. Leptena tenuicincta.—lM ‘Coy. Orthis calligramma.—Dalman. », reversa.—Salter. Orthonota simplex.—Portlock. Macrocheilus elongatus, —Portlock. Murchisonia cancellata.—Sow. o elongata !—Portlock. Maclurea Logani.—Salter. 1 The fossils comprised in this preliminary list were collected by R. Gibbs in 1863-4, and were examined conjointly by Mr. R. Etheridge, Palontologist to the Geological Survey, and Professor Young. Those from the localities marked with an * were subsequently collected by A. Macconochie, and identified by Mr. R. Etheridge, jun. 30 2. Kirk Hill, about half a mile N. of last locality.—(Sheet 14.) Nidulites favus.—Salter. Heliolites interstinctus.— Wahlenberg. 8 tubulatus.—Lonsdale, Petraia equisulcata. — M/ ‘Coy. » elongata.—Phillips. Illenus Thomsoni.—Salter. Atrypa hemispherica.—Sow. Leptiena tenuicincta.— Jf ‘Coy. Holopella obsoleta.—Sow. * 3. Little Burn, S.W. of High Mains.—(Sheet 14.) Calymene.—Sp. Trinucleus seticornis.— Hisinger. Orthis elegantula.—Dalman. Pterinea Sowerbyana.—M ‘Coy. Cardiola striata. —Sow. Orthoceras.—Sp. * 4. Quarry at Pond, SW. of Rough Neuk, about 64 miles N.E. of Gir- van.—(Sheet 14.) . Favosites.— Sp. Petraia subduplicata, var crenulata.—M ‘Coy. Glyptocrinus? basalis.—J/‘Coy. Calymene Blumenbachii.—Brong. Meristella angustifrons.—M ‘Coy. Orthis.—Sp. Strophomena.—Sp. * 5. Quarry at Rough Neuk—(Sheet 14.) Nidulites favus.—Salter. Petraia bina.—Lonsdale. Calymene Blumenbachii.—Brong. Ttilodictya.—p. Meristella angustifrons.—I‘Coy. Orthis calligramma,—Dalman. * 6. Roadside near Old Fort, at Kirkhill—(Sheet 14.) Meristella angustifrons.—21 ‘Coy. Strophomena.—Sp. * 7. Quarry on roadside east of Old Fort, at Kirkhill—(Sheet 14.) Ulenus Bowmanni.—Salter. Orthis calligramma,—Dalman. * 8. Little Burn, Quarrel Hill, near Auldthorn, about 6 miles NE. of Girvan.—(Sheet 14.) Meristella angustifrons.—Jf‘Coy. Orthis calligramma.— Dalman. Strophomena (expansa or grandis). Loxonema.—Sp. 9. Drummuck Burn, about 4 miles N.E. of Girvan —(Sheet 14.) Diplograptus pristis.—Hisinger. Serpulites longissimus. —Afurchison. Ampyx rostratus.—Sars. Calymene Blumenbachii.—Brony. Illenus Bowmanni.—Salter, Phacops.—Sp. Proetus.—S}). Trinucleus seticornis.—/Hisinger. Lingula attenuata, —Sow. Orthis elegantula.—Dalman. Ctenodonta.— sp, Orthonota.—Sp. 3h Ten etos ee Holopella obsoleta.— Sow. Raphistoma lenticularis.—Sow. Bellerophon acutus.—Sow. ‘5 carinatus,—Sow. 55 perturbatus.—Sow. a5 trilobatus.—Sow. Conularia elongata.—Portlock. Theca corrugata.—Salter. »» triangularis.—Portlock. » vaginula.—Salter. » 2Sp, unde. * 10. Lady Burn, a little above Drummuck.—(Sheet 14.) Calymene Blumenbachii.—Brong. Pn tuberculosa. — Salter. Proetus latifrons.—M ‘Coy. Trinucleus seticornis. —Hisinger. Orthis elegantula. —Dalman. Holopella.—Sp. ? Murchisonia pulchra.—M ‘Coy. Bellerophon bilobatus. —Sow. 5 perturbatus.—Sow. 49) trilobatus.—Sow. * 11. Lady Burn, opposite Threave. Calymene Blumenbachii.—Brong. Bellerophon bilobatus.—Sow. - trilobatus.—Sow. 12. Craighead Quarry, about 3 miles N.E. of Girvan.—(Sheet 14.) Nidulites favus.—Salter. Favosites fibrosus.— Gold fuss. Heliolites favosus.— Jf ‘Coy. Petraia equisulcata.—A/ ‘Coy. » elongata.—Phillips. Encrinurus punctatus. —Briin. Discina rugata.—Sow. Leptena sericea. —Sow. », transversalis.—Dalman. Lingula ovata.—M ‘Coy. Orthis biforata.—Schlotheim. » calligramma.—Dalman. », filosa.—Sow. Raphistoma lenticularis. —Sow. Orthoceras politum. —M ‘Coy. 13. Craigens, W. of Kirkhill, about 54 miles N.E. of Girvan.—(Sheet 14.) Nidulites favus.—Salter. Dictyonema sociale.—Salter. Favosites asper.—D’Orb. Heliolites interstinctus.— Wahlenberg. #3 tubulatus.—Lonsdale. Petraia equisulcata.—M ‘Coy. » elongata.—Phillips. Tentaculites Anglicus.—Salter. Ptilodictya costellata.—MM ‘Coy. Atrypa reticularis. —Lin. Leptna tenuicincta,—M ‘Coy. Meristella angustifrons.—J1 ‘Coy. Orthis calligramma.—Dalman. », confinis.—Salter. » elegantula.—Dalman. » Teversa.—Sailter. Strophomena compressa.—Sow. 55 pecten.—Lin, Holopella obsoleta.—Sow. 32 14. Ardmillan Braes, about 24 miles 8.W. of Girvan.—(Sheet 7.) Favgsites fibrosus.— Goldfuss. Petraia elongata. —Phillips. Asaphus gigas. —De Kay. » rectifrons.—Portlock. Bronteus Hibernicus.—Portlock. Tenus Bowmanni.—Salier. Staurocephalus globiceps.—Portlock. Stygina latifrons.—Portlock. Discina oblongata.—Portlock. ” ” ” var. Leptiena scissa.—Salter. » Sericca.— Sow. » tenuicincta.—Af‘Coy. Orthis calligramma.—Dalinen, » €elegantula.—Dulinan. Rhynchonella cuneata.—Dalman. Strophomena aranacea. —Saller. 9 expansa.—Sow. grandis, —Sow. Ambon} ychia. —Sp. Arca EF dimondidetorinia 1—M ‘Coy. Ctenodonta.—4 Spp. unde. Cucullella,—Sp. Mouiolopsis cnodictant: —Conrad. ss 2 Spp. unde. Cyclonema crebristria.—Jf‘Coy. 5i5 Sp. Ophileta compacta.—/Salter. Raphistoma lenticularis. —Sow. p. Bellerophon acutus.—Suw. a carinatus.—Sow. qa minor.—Portlock, Scoticus.—lU ‘Coy. Theca reversa. —Salter, », triangularis.—Salter. + vaginula.—Salter. Orthoveras ibex.— Sow. se imbricatum. — Wuhlenberg. 15. Piedmont Glen, S. of Girvan.—(Sheet 7.) Diplograptus pristis, Hisinger, var bullatus, Salter. 16. Laggan Burn, about 14 mile SE. of Girvan.—(Sheet 7.) Diplograptus pristis. —Hisinyer. 17. Ardwell Shore, about 3 miles S.W. of Girvan.—(Sheet 7.) Cytheropsis Aldensis. —Jf ‘Coy. Conocardium dipterum.—Salter. Orthoveras.—Sp. 19. Penwhapple Glen, E. by 8. of Girvan.—(Sheet 7.) Favosites asper.—D’Orb, Ampyx mammillatus.—Sars. 3ronteus Hibernicus.—Portlock. Cybele verrucosa. —Dalinan. Encrinurus punctatus.—Briinn. Menus Bowmanni.—Salter. Glyptocrinus? basalis.—J‘Coy. Atrypa hemispherica.—Sow. », marginalis.—Dalman. », reticularis.—Lin. Leptena sericea, —Sow. » quinquecostata. —If‘Coy. 5 tenuicineta. —Af‘Coy. Orthis alternata. —Sow., 20. 23. 26. 27. 33 Orthis biforata.—Schlotheim. » calligramma.—Dalman. » confinis.—Salier. a3 elegantula. —Dalnan. », tricenaria.—Conrad. vespertilio, —Sure. Pentamer us oblongus.—Sow, var levis. —Sor. Stricklandinia lens. — Sor. Strophomena depressa.—Dalman. Murchisonia gyrogonia. — AL ‘Coy. Ophileta compacta.—Salter. Raphistoma. —Ap. Bellerophon acutus.—Sow. ai bilobatus.—Sow. 36 perturbatus.— Sow. Maclurea Logani.—Salter. Lituites.—S/. Orthoceras canaliculatum.—Sow. Saugh Hill, about 14 mile E. by S. of Girvan. Sheet 8.) Diplograptus pristis. —Hisinger. . Camregan Plantation, about 2 miles E. of Girvan.—Sheet ¥ ) Atrypa hemispherica. —Sow. Pentamerus oblongus.— Sow. . Balelatchie, about 4 miles E. by S. of Girvan.—(Sheet 8.) Favosites asper.—D’Orb. Heliolites interstinctus.— Muhlenberg. 8 tubulatus.— Lonsdale. Petraia elongata. —Phillips. Tramitchell, about 3 miles S.E. of Girvan.—(Sheet 8.) Tentaculites ornatus.—Svve. Atrypa hemispherica,—Sow. . Barbae, nearly 3 miles SE. of Girvan.—(Sheet 3.) Nidulites favus.—Salter. Favosites fibrosus.—Gold/uss. Petraia bina.—Lonsdale. Glyptocrinus? basalis.— Mf ‘Coy. Maclurea Logani.—Sulter. . Pinmacher, about 24 miles S. of Girvan.—(Sheet 7.) Heliolites favosus.—Jf‘Coy. Graptolithus priodon.—Dronn. Maclurea Logani.— Salter. Letterpin, nearly 4 miles S. of Girvan. Sheet 7.) Nidulites favus.—Salter. Favosites fibrosus. —Goldfuss. Diplograptus pristis.—Hisinger. ramosus.—Hall. Graptolithus priodon.— Bronn. Leptena sericea.—Sow. 5 tenuicincta. —A/ ‘Coy. Orthis reversa.-—Salter. Auchensoul, about 5 miles S.E. of Girvan.—(Sheet 8.) Heliolites favosus. Lingulella Davisii ?—Salter. Cleidophorus. — Sp. Cc 34 28. Aldons, about 5 miles S. of Girvan. Cytheropsis Aldensis.—IM ‘Coy. Murchisonia.—Sp. Maclurea Logani.—Salter. * 29, Head of burn, passing Bargany Pond, about 6 miles E. by N. of Girvan.— Sheet 8.) Graptolithus.—Sp. Chondrites (like verisimilis. —Salter). Lingula Symondsii.—Salter. * 30, Hillside opposite Blair Farm, about 84 miles N.E. of Girvan.— (Sheet 14.) Graptolithus.—Sp. Retiolites Geinitzianus.—Barrande. Beyrichia Kledeni.—J/ ‘Coy. a impendens.—Jones. Lingula Symondsii.—Salter. Orthis.—Sp. Cardiola fibrosa.—Sow. Orthoceras subundulatum.—Porélock. ‘31. Quarry on roadside near Knockgardner, about 10 miles N.E. of Girvan.—(Sheet 14.) Beyrichia Kloedeni.—J/‘Coy, var. Dictyocaris.—Sp. Primitia.—Sp. Pterinea pleuroptera.—Conrad. Orthonota truncata.—I‘Coy. Grammysia.—Sp. Note.—The Entomostraca recorded from localities 30 and 31 were kindly deter- mined by Professor Rupert Jones, F.R.S. They are Upper Silurian forms, one—B. Kledeni, M‘Coy—being very characteristic of the Lesmahagow beds, the other—B. impendens, Jones—eyually so of the Pentland Hill deposits. Accompanying the above, from locality 30, Professor Jones has recognised an apparently new Entomos- tracan, the only analogue of which is an undescribed form from the Pentland Hills ; but there appear to be important differences between the two. Unfortunately, the remains yet obtained from locality 30 are only in the form of casts. 3 IV.—Vertical Sections. 33. 6d. per Sheet. Sheet 1. Edinburgh Coal-field, 8. Kilmarnock Coal-field. bP) Ve Geological Memoirs, to accompany the Sheets of the One-inch ap. Sheet 1. . Wigtownshire, South-Eastern Districts. 3d. . Wigtownshire, South-Western Districts. 3d. . Ayrshire, South-Western District. 3d. . Ayrshire, Turnberry Point. 34. . Ayrshire, Southern District. 3d. . Dumfriesshire, N.W.; Ayrshire, 8.E.; and Lanarkshire, 8. ” Wigtownshire, Southern Districts. 3d. corner. 3d. . Ayrshire, Northern District, and Southern parts of Renfrew- shire. 3d. . Lanarkshire, Central Districts. . Peeblesshire. 3d. . Edinburghshire and Linlithgowshire. 4s. In cloth boards, 5s. . Haddingtonshire. 2s. . Eastern Berwickshire. 2s. A Detailed Catalogue may be had gratis, on application to Messrs. W. & A. K. Johnston, 4 St. Andrew Square, Edinburgh, or to Messrs. Smith g Son, St. Vincent Street, Glasgow. Agents appointed for the Sale of the Publications of the Geological Survey. London—Mr. Stanrorp, 6 Charing Cross, W.C.; Messrs. Lerrs & Son, Royal Exchange, E.C.; Messrs. Loneman, Paternoster Row; Mr. Wytp, 11 and 12 Charing Cross. Edinburgh—Messrs. Jounsron, 4 St Andrew Square. Dublin—Messrs. Hopces & Saute, 104 Grafton Street. LIST OF PUBLICATIONS OF THE GEOLOGICAL SURVEY OF SCOTLAND. I.—Maps on One-inch Scale. ; 1. Wigtownshire, Southern Districts. 4s. 2. Wigtownshire, South-Eastern Districts. 4s. 3. Wigtownshire, South-Western Districts. 6s. 7. Ayrshire, South-Western Districts. 6s. 13. Ayrshire, Turnberry Point. 4s. 14. Ayrshire, Southern Districts. 6s. 15. Dumfriesshire, N.W.; Ayrshire,S.E.; and Lanarkshire,S. Corner. 6s. 22. Ayrshire, Northern District, and Southern parts of Renfrewshire. 6s. 23. Lanarkshire, Central Districts. 6s. 24. Peeblesshire. 6s. 32. Edinburghshire and Linlithgowshire. 6s. 33. Haddingtonshire. 6s. 34. Eastern Berwickshire. 4s. 40, Fife and Kinross. 6s. 41. Fife, East part. 6s. II.—_Maps on Six-inch Scale, illustrating the Coal-fields. Edinburghshire. Sheets 3, 8, 14,17. 4s. 35 Sheets 2, 6, 7, 12, 18,18. 6s. Haddingtonshire. Sheets 8,13. 4s. Sheets 9,14. 6s. ” Fife. Sheets 33, 37. 4s. 5 Sheets 24, 25, 80, 81, 32, 35, 86. 6s. Ayrshire. Sheets 9, 26,31. 4s. Sheets 11, 12, 13, 16, 17, 18, 19, 22, 23, 24, 27, 28, 29, 30, 33, 34, 35, 36, 40, 41, 42, 46, 47, 50, ” 52. 6s. Renfrewshire. Sheets 18,17. 4s. 5 Sheet 16. 6s. Lanarkshire. Sheets 1, 5,10. 4s. " Sheets 6, 31, 32, 87, 88, 41, 42, 49. 6s. Dumfriesshire. Sheet 1. 4s. 34 Sheets 5, 6,7. 6s. Dumbartonshire. Sheet 28, including 29. 4s. Ill. —Horizontal Sections. 5s. per Sheet. Sheet 1. Edinburghshire and Haddingtonshire. 2, Edinburghshire and Haddingtonshire. 3. Peeblesshire, Edinburghshire, Linlithgowshire. 4. Ayrshire Coal-fields (west side). 5. Ayrshire Coal-fields (east side), [List of Publications continued on page 3 of cover. Alownoirs of the Geological Survey, SCOTLAND. EXPLANATION OF SHEET 4. WIGTOWNSHIRE (EAST PART). KIRKCUDBRIGHT (PORTION OF WESTERN DIVISION). EDINBURGH: PRINTED FOR HER MAJESTY’S STATIONERY OFFICE, as AND SOLD BY W. & A. K. JOHNSTON, 4 ST ANDREW SQUARE; auso In LONDON sy SranForD, 6 Cuarine Cross, W.C.; Lerts & Son, Roran Excuanes, E.C. ; Loveman & Co., Paternoster Row; anp Wrtp, 11 anp 12 Cuarine Cross ; AND In DUBLIN sy Hopass, Foster & Co., 104 Grarron Srrezr. 1878. INDEX GEOLOGICAL SURVEY MAP of ey: ngraving ae preparation O Memoirs published Actions of the Geological Survey, SCOTLAND. HXPLANATION OF SHEET 4. WIGTOWNSHIRE (EAST PART). KIRKCUDBRIGHT (PORTION OF WESTERN DIVISION). EDINBURGH: PRINTED FOR HER MAJESTY’S STATIONERY OFFICE, AND SOLD BY W. & A. K. JOHNSTON, 4 ST ANDREW SQUARE; atso IN LONDON sy StanForD, 6 Cuarina Cross, W.C.; Lurts & Son, Royrat Excuanes, E.C.; Loneman & Co., Parzrnostzrn Row; anp Wrytp, 11 anp 12 Cuarine Cross ; anp In DUBLIN sy Honegs, Foster & Co., 104 Grarton STREET. 1878. PREFACE. THE Map illustrated by the present Explanation has been surveyed by Mr D. R. Irvine, with the exception of some square miles of granite to the east of Cairnsmore, traced by Mr John Horne. The ground south of Wigtown was partly worked out by the late Mr James Craik, but has been re-examined and completed ly Mr Irvine, who has also written the Explanation. The Appendix of Fossils has been prepared by Mr Robert Etheridge, jun. I have, as usual, supervised the mapping of the ground, and edited the following descriptive account of the results obtained. The area has not been the subject of any previous important special memoirs. The papers referred to in the Preface to the Explanation of Sheet 3, and in the Appendix to the Explanation of Sheet 9, embrace those to which reference may be made. ARCH. GEIKIE. GEOLOGICAL SURVEY OFFICE, Epinpureg, April 1878. EXPLANATION OF SHEET 4. I, AREA EMBRACED IN THIS MAP. 1. This Sheet contains an area of 358°6 square miles, about two-thirds of which lie in the county of Wigtown, the remainder being in Kirk- cudbrightshire. It is approximately bounded on the west by the valley of the Main Water of Luce and the shore of Luce Bay; on the east by the Little Water of Fleet and Wigtown Bay; along the north edge it extends from the source of the Fleet, by Loch Grennoch and Auchinleck, to the Loch of Cree at Glenhapple ; westwards by the village of Knowe on the Snap to the source of the Tarf Water in the Blood Moss. The south edge of the Sheet cuts across the lower portion of Wigtownshire from Port William on Luce Bay to Palmallet Point on Wigtown Bay. IL FORM OF THE GROUND. - 2, The area embraced in this Sheet forms the south-west extremity of the great stretch of hilly ground extending from the German Ocean to the Trish Channel, and known as the southern uplands of Scotland. Nearly two-thirds of the whole district consist of hilly ground and moorlands, covered with heather and peaty turf. The line of railway from Newton- Stewart to Glenluce may be taken as a rough boundary between the high and low grounds, most of the cultivated area lying to the south of this line. No well-marked range of hills traverses this Map ; the high ground consists rather of irregular and independent ridges. ‘' 3, On looking at the Map'it will be seen by the darker shading that the highest ground in the district lies in the north-east corner, to the east of the river Cree. This river forms the boundary between Wigtown- shire and Kirkcudbrightshire, and from its source to where it enters the sea in this Sheet it flows between the base of the mountainous elevations of Cairnsmore and the Kells on the one side, and the lower and flatter moors of Wigtownshire on the other. In the centre of the Kirkeudbrightshire portion of the Sheet rises the great granite mass of Cairnsmore of Fleet, which reaches the height of 2331 feet. This is the greatest elevation attained in the present Sheet, save on the south-west side. It is surrounded by hills, most of which are higher than those of Wigtownshire, The most prominent amongst them are Fell of Fleet (1544) and Craig Whinnie (1250 feet) to the east, and Pibble Hill, Cambret Hill (1150), Cairnharrow (1497), and Larg Hill (969 feet) to the south. To the west of the Cree none of the hills reach a height of 1000 feet above the sea. The most important of them occur as solitary eminences far apart from one another, the highest being Airyglasson (708), Bal- 6 murrie Fell (807), and Artfield Fell (888) in the north-west ; Culvennan Fell (702), Barskeoch (579), Barraer Fell (401), Knock of Luce (513), and Craigeach Fell (426), in the centre; and Mochrum Fell (646) and Bennan (500 feet) in the south-west, Though the high grounds are arranged in no regular order, yet the contour of the whole district bears a strong relation to the character of the underlying rocks. Thus, the greater portion of the low cultivated area lies among the rocks of the Ardwell series, which, from their shattered and jointed nature, easily yield to the influence of the weather, and do not form very prominent features ; while all the hills mentioned as occurring in the centre of the Sheet have a rough craggy ontline, and are composed of the thick tough grits of the Queensberry group. The high grounds in the north-west corner owe their elevation to the occurrence of some thick grits in the Dalveen series, and also to the presence of the bands of fine conglomerate, called the Tlazvis rock, which pass through their centre. Those beds offer much more resistance to the action of the weather than the surround- ing softer flags and shales, and are left rising from among them as pro- minent hills. The highest ground in the Sheet (Cairnsmore of Fleet) is composed of hard tough granite, which breaks up and wears away much more slowly than the stratified rocks. The beds comprising the high hills to the south of Cairnsmore are part of the Ardwell group, but they have been so hardened as to become very tough and durable. 4. There is no tract of flat ground of any extent in this Sheet, with the exception of some square miles of raised beach and alluvium at the mouth of the Cree. The cultivated area of Wigtownshire south of the railway consists of undulating hillocky ground, arranged in ridges and hollows, running in a general north-cast and south-west direction—the contour presented by the districts where the Ardwell group of rocks in the Lower Silurian series occur all over the southern uplands. This district is locally known as ‘f The Machars” of Wigtownshire, a similar tract of low ground on the west side of Luce Bay (Sheet 3) being called “The Rhins.” 5. A considerable extent of ground has been brought under cultivation north of the railway near Glenluce, Newton-Stewart, and Creetown, and alone the north shores of Wigtown Bay, while tracts of rich alluvial land occur up the valleys of the main streams. A peculiar feature of the Wigtownshire portion of this Sheet is the occurrence of sharply-defined ridges of boulder clay, called “ Drums,” often rising up as single mounds from bare rocky moors. These will be noticed in the description of the drifts. Some large flat peat mosses lying among clusters of those drums near Glenluce are also very marked features. 6. The coast-line along the shores of Wigtown Bay forms precipitous cliffs here and there, which show good sections of the rocks. From the east edge of the Sheet round Fleet Bay and westwards to Ravenshall the shore rises into a continuous line of rocky cliffs, which for most of the distance seldom exceed 30 feet in height. Between Kirkclaugh and Ravenshall, however, they rise to fully 100 feet. Another line of steep cliffs, from 50 to 100 feet high, running along the west side of the bay, from Innerwell to the south edge of the Sheet, is interrupted by the two bays of Garlieston and Cruggleton, which mark the position of some hands of soft shales and flags, and owe their formation to the ease with which these beds wear away. On the shores of Luce Bay, in the south- west corner of the Nheet, a continuous line of cliff extends for over 3 miles, from Kilfillan at the edge of the Map to Auchenmalg Bay. At Sinniness it forms a precipitous face 150 feet above the sea, though as a rule the height varies from 50 to 80 feet. The rest of the coast-line consists 7 of banks of boulder clay, rising from a flat shingly beach, Large flats of mud and sand are exposed at low tide at the head of Wigtown Bay and in Fleet Bay. 7. The main lines of drainage in this Sheet are those of the Cree, Bladenoch, and Tarf. Besides these, several large streams drain con- siderable independent areas—Palnure Burn and Moneypool Burn, which run into the tidal waters of the Cree, and the Water of Fleet and Skyre Burn, which empty themselves into Fleet Bay, being the most consider- able. The Bladenoch with its tributaries drains the largest area. It has a very winding, sluggish course of about 25 miles from the north edge of the Map to where it enters the sea at Wigtown. All the larger streams, with the single exception of Moneypool Burn near Creetown, occupy transverse valleys, running from N.N.W. to §.8.E., more or less at right angles across the strike of the Silurian rocks. 8. The best example of a narrow rocky valley, due to stream erosion, is that of the Palnure Burn. From the north edge of the Sheet to Bar- galy, this stream flows through a deep, narrow glen, which it has worn through the rocks across their line of strike. Between Dallash and Bar- galy Farm it forms some striking gorges, where the channel contracts to a width of 35 feet between precipitous walls of rock. Several of the smaller streams also have worn deep channels through the drifts and the softer varieties of rock. A very good instance, seen from the road near Ravenshall, occurs at the Kirkdale Burn, which has there cut a ravine about 50 feet deep through the Ardwell rocks. IIL (9.) FORMATIONS AND GROUPS OF ROCK ENTERING INTO THE GEOLOGICAL STRUCTURE OF THE DIS- TRICTS SHOWN UPON THIS MAP. Aqueous. ; Sign on Map. Recent and Post- { Aluvium, ae Tertiary. Peat, : : Raised Beaches. ~ ( Moraines, Erratic Blocks, Drift Series. Sand and Gravel, Till or Boulder Clay, with Ice- worn Rock surfaces, ( Carsphairn Group, Upper or Lead Hills Black Shale Group, Lower Silurian Lowther Group, | Llandeilo. | Dalveen Group, Lower or Moffat Black Shale Group, Ardwell Group, b2 Ni Metamorphic. Altered Silurian Rocks passing from Schistose Greywackes into fine-grained Gneiss, Be Igneous. Sign on Map Of (1)Miocene ase, Basalt in Dykes, ‘ . B Associated with j Dioritic Rocks, ; . Di Lower Silurian / Felstones, F Racks, Granite, , j : G IV. GEOLOGICAL STRUCTURE OF THE DISTRICTS EMERACED IN THIS MAP. 10. The whole of this Map, with the exception of the areas of granite and other igneous rocks, is occupied by strata of Lower Silurian age, which cross the Sheet in parallel bands from south-west to north-east The only granite mass of any extent lies round Cairnsmore of Fleet, andl occupies the north-east corner of the Sheet. Two other narrow strips are exposed some miles to the south of the main mass, stretch- ing inland in a north-east direction from the mouth of the Cree. One of these lics about a mile and a half south of Creetown ; the other extends from Burnfoot up the Carsluith Burn. Itound the main mass runs a belt of metamorphosed strata of varying breadth. Numerous veins and a few larser intrusive bosses of various igneous rocks rise through the Silurian croups. Lower Silurian. 11. In the area embraced by the present Map, forming part of the Silurian uplands of the south of Scotland, the rocks, so far as can be letermined from their position and fossil contents, may all be assigned to the Llandeilo formation, Good sections are obtained here and there along the shores of Luce Bay and Wigtown Lay; but the arrangement and character of the rocks are best secn ly traverses across the bare hum- mocky woors which occupy most of the district. Some of the transverse valleys, such as those of the Bladenoch and Toarf, also show pretty con- tinuous exposures. The strike of the leds is in the same general direc- tion as prevails over the whole Silurian area, namely, from south-west to north-east. The successive rock groups in the Llandeilo series which have now been made out by the Geological Survey over the south of Scot- land have also been established in this area. On examining the Kirk- cul)rightshire side of the Map, from Fleet Bay along the north-east side of the Cree to the northern margin, it will be seen that the general direction of the dip of the strata is to the north-west, showing an ascending series in that direction, The same beds continue to the south-west right across Wixtownshire, but there the dips become much more confused, owing to fie increased crumpling and folding of the strata. This is easily noticed where well-marked lands, like the black shales, are seen folded pack on cach other, In the north-west corner of the Map, along a line from Camrie by Loch Reuald to Glenhapple, the upper black shales lie in a synelinal trough, which cxtends into Sheet 8, where it runs out against the Loch Dee granite. ; "12, The following table shows the names and the order of succession, with the nature, relations, and roughly-estimated thicknesses of the vari- ous groups. It will be seen to correspond generally with that given in the Explanations of 3 and 9 :— 9 (7.) CARSPHAIRN Grovup.—Fine conglomerates and coarse grits, with thick grey- wackes and shale partings. (6.) Upprr Buack SHaxes.—Black shales, containing graptolites, with bands of chert and grey and purplish shales. Estimated thickness, 450 feet. (5.) LowrHer Grour.—a set of soft grey shales, with grey and blue flags and grey- wacke bands. (4.) Datveen Grour.—A set of jointed greywackes, with grey and blue flags and shales, including a band of fine pebbly conglomerate, called the ‘‘ Haggis Rock.” Estimated thickness of Lowther and Dalveen groups together, 2500 feet to 3000 feét. (3.) QUEENSBERRY Grovup.—Thick massive grits and greywackes, with regular jointings. Some bands of grey and blue shales and flags. At the bottom of the series there is a considerable thickness of grey sandy shales, corresponding to the ‘‘Grieston beds,” in Sheets 9, 15, and 24. Estimated thickness, 3500 to 4000 feet. (2.) Lower orn Morrat Brack SHALE Grovp.—Black shales, with graptolites. Some bands of grey and blue shales and flags. Estimated thickness, 200 feet. (1.) ARDWELL Grovup.—Brown-crusted red, blue, and grey jointed sandy greywackes, grey and purplish argillaceous shales, and bluish and yellow sandy shales. Thickness not ascertainable in this Sheet. ARDWELL GROUP. 13. The strata comprised under this name extend over about one-third of the area in this Sheet. Their northern limit, formed by the most southerly outcrop of lower black shales, runs from Eldrig Loch, in a north- east direction, by Wigtown and Creetown, to the east edge of the Sheet, one mile south of the granite boundary. The whole district south of this line is occupied by Ardwell beds. Good sections are obtained along the shores of Fleet Bay and on all the hills east of Creetown. The relation of this group to the overlying black shales is best seen up the English- man’s Burn, north-east of Creetown. A narrow strip of shaly, and some- what altered or even schistose beds, belonging to this group, occurs between the outcrops of black shale in Englishman’s Burn and at Cul- cronchie viaduct. They are here brought up within an inverted fold of the black shales. Another narrow band of the Ardwell group, brought up in the same way by an inverted arch of the black shales, runs from Minnigaff to the edge of the Sheet at Talnotry, and consists of a set of brown-crusted, yellowish, sandy schistose shales and flagey greywackes, well seen in the Cree below Minnigaff manse. The fold must ‘“ nose out” rapidly south of the Cree, as neither the black shales nor the underly- ing beds are seen to the south-west. This same arch extends across the corner of Sheet 8 into Sheet 9, in the Explanation of which it has been noticed (par. 10). The best section south of the Cree is obtained along the coast-line from Baldoon Sands to the edge of the Sheet. The cliffs, about 50 feet high, run almost at right angles to the line of strike, so that the numerous sharp folds and curves characteristic of this portion of the Silurian series are very well seen. 14. In lithological characters the Ardwell group may be described as consisting of greywacke in beds from 1 to 4 feet thick, flags and shales. So greatly have they been contorted and crumpled into sharp and often inverted folds, that it is impossible to form even a rough estimate of their thickness. From the numerous folds and reversed dips seen along the coast sections, it may be presumed that the actual depth of the group is considerably less than, from the breadth of country occupied by the strata, might be supposed. As a rule the beds of this group have a soft, brown, crumbly, weathered crust, about half an inch thick. In Kirkcudbrightshire the surface is often pale yellow, almost white, but when broken up the rock is grey or bluish in colour. In Wigtownshire again, the prevailing tint of the freshly fractured rock is red or pink. The Ardwell beds are likewise very shattery and full of joints, often filled with quartz, some- 10 times with calcite, or coated with hematite. They generally break up into small angular fragments under the hammer, but some of the more Haggy greywacke Innds split regularly along the lines of bedding and mike excelent building stone. The shales often show a rude cleavage in the opposite direction to the dip, and ata high angle. This is best seen along the Kirkeudbright coast-line from Carsluith to the Isles of Fleet, but it is nowhere so well developed that the shales split along the cleavage planes. In Kikcudbrightshire the top beds of this series immediately under the black shales assume a much more shaly character than they have further to the west in Wigtownshire. This feature becomes more develuped in Sheets 8 and 9 to the north and north-east. 15. This group, everywhere sinvularly barren in fossils, has yielded a fury forms in the present district. Specimens of Profor/rgularia have been found in sume bands of grey fissile shales in Garliestown Bay; while some grey and reddish shales in the railway cutting at Whauphill have yielded numvrous fragments of graptolites. Worm-tracks are also numerous in the ruil and yrey shales exposed along the line of railway from Bladenoch Guede south to Whauphill Lower or Morrat Buack SHALES. 16. This set of beds, owing to their well-marked lithological character, form a most important subdivision of the Lower Silurian rocks. In the area included within the present Map their thickness is inconsiderable, leing not more than 200 feet where they are best developed. They con- sist of a set of grey and blue slabs and flags, sometimes with whitish arcillaceous seams like fire-clays and one or two bands of black shales. It is these black strata which form the characteristic feature of this group, both from their striking colour and from the number of graptolites which they generally contain.* So contorted and folded over are they that they often appear to have a much greater thickness than is really theirs. They frequently abound in veins of quartz. 17. In the present area this group is generally brought up along sharp anticlinal folds in the overlying Queensberry beds. The most northerly outcrop occurs at Talnotry, along the north edge of the Sheet. It runs to the south-west by Loch of the Lowes and Cumloden to the Cree below Knockstocks, where a good section is exposed, showing the crump- ling of the black shales. The beds lie here along the anticline, which, as has been already noticed, brings up a portion of the Ardwell group for a short distance, but ‘noses out” so rapidly that the black shales do not again appear along this line south-west of the Cree. A short distance to the soth, on the crest of another anticline in the Queensberry group, the black shales rise up in the Gillespie Bun near Culroy. This arch nowhere else allows such a deep part of the Silurian series to appear at the surface. Still further to the south two other exposures of black shales occur near each other at Black Loch and Crailloch, and again at Glenluig and White Dyke, along an arch at the bottom of the Queensberry beds, the folding here leiny great enough to expose some of the beds below the black shales themselves. The strata here are inverted, so as to dip in the same direc- tion on both sides of the anticline, which, in the space of a mile or two, dies out to the north-east. The final outcrop in a southerly direction is seen at Eldrig Loch near the village of Eldrig. Here the black shales appear in the proper order of succession, coming on above the Ardwell beds, and passing under the Queensberry grits of Mochrum Fell. They do not again appear in Wigtownshire along this line of outcrop, pro- * See Explanation to Sheet 3, p. 10 11 bably owing to the ground being so inuch covered with peat and drift. Along the same line in Kirkeudbrightshive, however, they crop out in Englishman’s Burn north-east of Creetown and on Pibble Hill, Imme- diately to the north of that outcrop they are once more thrown up ina sharp fold at Culeronchie viaduct, whence they may he traced almost continuously to the cast edge of the Sheet, a distance of about 4 miles. From Pibble Hill eastwards it will be scen that the dips all point to the south-east, or contrary to the normal direction, as exhibited between Fleet Bay and Newton-Stewart. It is believed that the discrepancy must be due to an inversion of the dip. From Creetown, northwards, along the edge of the granite, numerous outcrops of the black shales appear along sharp anticlinal folds, some- times bringing up the upper beds of the Ardwell series. In this district the black shales, often passing from black to blue and dull grey, have been so much compressed and baked as to have become schistose, and to have completely lost all trace of the original lines of bedding. When in this altered schistose condition they become remarkable tough, and generally split up into large square blocks. No traces of graptolites have been observed in any of those altered dark shales. They are abundantly veined with quartz, and often contain quantities of iron pyrites in veins and diffused through the mass. The best exposures of the black shales in this metamorphic area occur half a mile north-east of Cranmer Hill, at the head of Cairnsmore Burn. Here, in an area not more than a quarter of a mile wide, they appear in four outcrops, separated by schists and altered greywackes, the whole of these strata invariably dip- ping to the north-west. In this case, also, it is evident that the apparent steady succession of beds is deceptive, and that the same portions of the group are repeated several times in inverted folds. These curvatures are well seen on the faces of several small cliffs on Bardrochwood Moor ; also up the Mill Burn, east of Bardrochwood, and in the Knock Burn a little further to the north. A ridge of highly altered and schistose dark blue and black shale is seen running along the western margin of the granite boundary from Blairbuies Burn to near Dallash Cairns in an N.N.W. direction, at right angles to the normal line of strike. As shown upon the Map, the strike of these and the other adjacent strata is considerably deflected near the granite junction. This feature, which is much more marked round the Loch Dee granite (Sheet 8), is again referred to in par. 36. QUEENSBERRY GRIT GROUP. 18. This well-marked and important group of strata is well represented in the present Sheet, where it occupies fully one-third of the total area. It occurs in a broad band, which, extending diagonally across the Sheet with an average breadth of about 9 miles, is bounded along the north by a line running north-east from Glenluce by Carscreuch, Culvennan, Barfad, and the north edge of Glenrazie Wood to Penninghame House, where it crosses the Cree, and passes into Sheet 8 near Terregan. Its southern boundary coincides with the lowest outcrop of the Moffat black shales, already traced in par. 17. The whole area included between those boundaries, with the exception of the narrow denuded anticlinal “ inliers” of black shales already mentioned, is occupied by this group, which has been thrown into a series of large folds, sometimes sharp enough, as we have seen, to bring up the lower black shales along the line of axis. None of the synclinal troughs, however, are deep enough to have pre- served any part of the next overlying group. 12 19. The Queensberry grits have here much the same characters as in Shect 9, lying to the north-east. (See Explanation to that Sheet, par. 14.) They consist for the most part of thick massive grits and greywackes, with occasional zones of grey and blue shales. The beds are traversed by a very regular system of joints, owing to which they easily split up into square blocks and slabs, and on this account are largely quarried for building purposes, paving, &e. Fossil remains, which occur so rarely in this group, have as yet been met with only at two localities in the present district. Some bands of grey and bluish shales on the coast-line near Sinniness, south of Glenluce, have yielded fragments of graptolites; and some rather better specimens have been obtained from a bed of dark blue shale, exposed in the Tarf at Wauk Mill beside Kirkcowan. 20. This group consists of two well-marked subdivisions, which may be trace almost continuously to the north-east through Sheets 8 and 9 into Sheet 16. The lower of these lies at the bottom of the group, resting on the lower black shale, and consists of a set of grey and bluish shales, rather sandy and micaceous. ‘Thiese are well seen on either side of the arch of the lower black shales, between Minnigaff and the north edge of the Sheet. This anticline, as has been noticed in par. 17, dies out so rapidly to the south-west that neither the black shales, nor the lower beds of the (Jueensberry group are seen again south of the Cree. Above this shaly subdivision, as in the typical ground at Queensberry Hill, a succes- sion of thick massive grits, fine pebbly conglomerates and shale bands form the remainder and chief portions of the group. Their upper beds sometimes contain well-marked bands of blue shales and flags, as at Glen- luce, where they are quarried for roofing and paving purposes; but these are not at all constant, and, as a rule, the grits pass gradually up into the flaggy ereywackes, constituting the Dalveen group. 31. The lower shaly zone is well exposed on the craggy hills west of the New Galloway road at Talnotry, where a constantly ascending dip to the north-vest may be traced from the granite junction across the black shalvs into the (neensberry grits. It is here tilted up at anangle of from 65° to 80°, and covers a breadth of fully a quarter of amile. Unless folds or reversed dips shoul occur which have not been noticed, this dip would give the shalvs a thickness of fully 1200 feet. They thin out rapidly to the south-west however, and are entirely absent in the Cree section, where their place is taken by thick greywackes, with some flaggy bands. To the north-west these beds gradually swell out so as to cover twice the breadth of ground in Sheet 8, which they occupy here. From their appearance and position, they may be considered the representatives of what have been recognised as the “Grieston beds,” in Sheet 9, and the ground to the north-east. (See Explanation of Sheet 9, pars. 14 and 15.) The absence of these shales in the north-western portion of this region vannot be satisfactorily accounted for by any folding or other kind of structure which might have concealed them, for though the very lowest beds of the Queensberry group are several times brought up along lines of anticline, resting directly upon the black shales, yet the so-called “(rieston shales” nowhere reappear, their place cing occupied, as has been said, by well-bedded ereywackes. The beds on the south side of the anticline of black shales, along the New Galloway road, dip in the same direction as those on the north. That a is a reversed dip is indicated by the occurrence of the same zone of “ Grieston shales” on both sides. They have likewise been thrown into a small basin between Black- craig and the granite junction, so as to enclose some of the overlying thick massive grits which are well seen on Larg Hill, and on the moor south S Glenamour Loch, where they form prominent bare rocky hummocks, The 13 dips on the Map from Paluwre station round by Blackeraig to Larg show well the ending off of this trough. It must be remembered that between Larg and Glenamour and the black shales the dips are reversed. 22, The grits and thick beds forming the great mass of the Queensberry group can be advantageously examined in many natural sections in the present Sheet. With the exception of Cairnsmore, they form the chief ranges of hills—for instance, Eldrig, Culvennan, and Barskeoch Hills in Wigtownshire, and Glenmalloch Hill and Cumloden Deer Park in Kirk- cudbright. Along their south-west boundary rise the hills of Bennan, Mochrum, and Chang Fell; while over the intervening ground the coarser and more massive beds swell up here and there into prominences, such as Knock Fell, Craigeach, and Barraer Hill. ‘The section which perhaps best shows the characteristic features of those thick grits and massive grey- wackes, runs along a line of cliff called the Craigs of Garheugh, at the side of the road from Glenluce to Port-William. Cutting across the beds at right angles to their line of strike, it displays their well-defined parallel bedding, and their regular system of jointing. Another good section may be found in the valley of the Bladenoch Water, both in the channel of the stream and on the adjoining hill-sides. Few instances in this area can be seen where the pebbly grits pass into a rock coarse enough to be properly called a conglomerate. One patch of conglomerate lies on the west side of Craigeach Fell, but is only traceable for a few hundred yards. The pebbles are from $ inch up to 4 and 6 inches in diameter, and are com- posed of quartz, quartz-rock, greywacke, and hardened shale. A coarser conglomerate occurs at the head of the Straminoch and Coldstream Burns on Drannandow Moor, at the extreme north edge of the Map. It passes into Sheet 8, where it is traced in broken bands of varying breadth for over a mile. The stones vary from small pebbles up to boulders 1 foot in diameter, and are almost all of quartz and altered greywackes. 23. The prevailing colour of the strata of the Queensberry group is blue and grey; but on Barr Hill, south of Newton-Stewart, a set of massive grits, with bands of shale, are all stained of a deep red and purple colour, owing to the diffusion of iron through the mass. Some of the beds are so strongly ferruginous as to have given rise to a belief that hematite veins existed in the neighbourhood, but, though diligent search has been made in several localities, no trace of them has yet been found. 24. In a few localities a set of blue shales and flags occurs at the top of this group, occupying the place of the ‘‘ Barlae shales” in Sheet 9, of which they probably form a continuation. They may be best seen in the quarries and railway cutting immediately south of Glenluce, where they are largely worked for roofing purposes and pavements. DaALVEEN GROUP. 25. This set of beds, which comes on immediately above the group last described, is distinguished from it by the generalabsence of the characteristic thick grits, and by a less regular system of jointing. It consists of a set of greywacke beds, a good deal broken up by joints, with bands of flags and grey shales. Sometimes the shales occur in bands of considerable thick- ness, though generally they take the form merely of thin beds and partings between the greywackes and flags. The greywackes also occasionally form thick masses with bands of grit and thin shale partings. The zone of coarse grit passing into pebbly conglomerate, so well developed in Sheet 15, and known as the “ Haggis Rock,” also occurs in this district. It has a coarse pebbly texture, the pebbles sometimes being } inch in diameter, and it passes into a fine conglomerate, with stones from the size of a pea up 14 to 2 and 3 inches in length, The component pebbles of the “ Haggis Rock” consist, for the mostJpart, of fragments of quartz, Lydian stone, and altered greywacke. The most important feature in this conspicuous band is its occasionally fossiliferous character. A few encrinite fragments have heen obtained by the Geological Survey from the fine conglomerate near the village of Knowe, but they are badly preserved. (See Explana- tion to Sheet 9, par. 19.) 26. This group occupies a comparatively limited area in the present Map. It crosses the north-west corner in two bands, one on each side of the synclinal trough in which the upper black shales lie. In the southern band the beds are well exposed at Carscreuch and Grennan, north-east of Glenluce, and in the Tarf Water at Mark Broom. They have a very con- stant dip to the north-west, at high angles of from 60° to 80°, and are traced by Ballochadee and Barfad to the north edge of the Sheet at Wood of Cree. Along this outcrop they consist of grey shales and greywackes, with a few thick gritty bands. On the northern outcrop they rise from underneath the Lowther shale group with a south-easterly dip, and extend from Kilhern, at the west edge of the Map, north-eastward to Glas- sock Fell. The beds here are a good deal more massive than on the south side of the syncline; the shales occur in thinner bands, and, where the grits become thickest and most numerous, as at Artfield Fell, prominent hills, as well as ridges and bosses, rise along their outcrop. The northern band of Dalveen beds is considerably broader than the southern. This arises from the fact that the strata have here been folded wp into an anti- cline, the axis of which runs from Drangower through Artfield Fell and Carseriggan Moor to the northern edge of the Sheet. To the north- west of this line the same beds are repeated with a north-west dip, until they again pass under the Lowther shales at Kilmacfadzean and High Eldrig. It is only along this final outcrop that the “Haggis Rock” appears. This conspicuous band is well exposed on the moor beside the village of Knowe, where it attains a thickness of about 100 feet, thinning out, however, before reaching the river Blailenoch. It reappears on the north side of Urrall Hill in two parallel bands, separated by greywackes and shales. These may be presumed to be the same band repeated by a small fold. It is again seen as a prominent feature on Eldrig Fell, and lastly crops up to the south-west through Artfield and Balmurrie Fells. In the present area, the Dalveen and Lowther groups pass so insensibly into each other, and have likewise been so plicated together, that no satis- factory estimate can here be made of the thickness of each group by itself. LowtuEr SHALE Grovr. 97. This group covers a still smaller area than that just described. It js seen on both sides of the synclinal trough of upper black shales (par. 26), and likewise in a third band further to the north. On the south side of the syncline, it is well seen between White Cairn and Camrie, one nile north of Glenluce, whence it extends across the Sheet to the north edge in a strip about half a mile broad. For three-fourths of this dis- tance the beds preserve a pretty constant dip to the north-west, but between Carseriggan and the north edge of the Map they are inclined to the south-east at a high angle. This is owing to some sharp crumplings of the beds which reverse the dip. _ Where’ typically developed, the Lowther shales, as their name implies, consist mainly of shaly beds. These are generally fine-grained argillaceous, grey, brownish-ycllow, and bluish in colow, with some brown sandy beds, and a few thick gritty 15 bands. This is the appearance which they present towards the south- west, south of the syncline, as may be well seen about Camrie, Carscreugh Fell, and Mark Broom. To the north-east, however, by Carseriggan and Glenhapple Moor, along the same line of strike, they become much more thick bedded, with several bands of grit and massive greywackes. In this condition they are undistinguishable from the underlying Dalveen group. North of the syncline, they are seen flanking the upper black shales, below which they plunge with a constant inclination to the south- east the whole way across the Map. They are well exposed on Bught Fell, Gass Moor, and Carseriggan Moor, and in the Drumpail Burn, the Tarf and the Black Burn. They here present the same thick-bedded character which they assume on parts of their southern outcrop. They consist of flags and greywackes, sometimes very massive and coarse, with here and there zones of grey shales and grey and blue flags. This thickening of the group on the north side of the syncline is a marked feature of the Lowther series, from Port-Patrick on the Irish Channel, across Sheets 3, 4, and 8 into Sheet 16, and has been described in the Explanation to Sheet 3, where it is largely developed. (See par. 17 of that Explanation.) 28. The most northerly outcrop of the Lowther shales forms a narrow band on the further side of the anticline in the Dalveen group, and ex- tends from Kibnacfadzean by Eldrig Loch to where the Bladenoch enters the Sheet. It here consists of several bands of grey and brownish soft shales, with greywakees and flaggy beds passing insensibly into the underlying Dalveen group. Good sections are obtained on the moors near Kilmacfadzean and at Eldrig Moss and Dimeark. 29. Like the shaly zones in the Lower Silurian series of the south of Scotland, the Lowther group is here often much crumpled and folded over. Some of these folds are shown in the Map by the dips; but in many cases where the dip remains constant in one direction for a con- siderable distance, the same beds are observed to be brought up two or three times by sharp inverted folds. The whole series is shattered and broken up by joints in all directions, and veins of quartz are also numerous. The sides of the joints in many instances are coated with carbonate of lime, which also occurs here and there in veins. It has been already remarked that, owing to the similarity of the Lowther and Dalveen groups in this area, it has not been possible to divide them sufficiently to allow an estimate to be formed of the thickness of each separately. The thickness of the two groups together is estimated at from 2500 to 3000 feet. Upper or Leap Hits Buack Suate Grovp. 30. This group bears so strong a resemblance to the lower or Moffat black shales already described, that, but for the evidence of superposition, it might readily be identified with that band. It consists of dark blue flags, grey and blue greywackes and shales, with one or two bands of black anthracitic shale, which form the conspicuous feature of the group. The total thickness of these strata probably does not exceed 450 feet, of which the black shales perhaps do not form more than about 30 feet. This group, in spite of its general resemblance to the lower black shales, may be distinguished lithologically by the occurrence in it of bands of grey flinty flags and whitish cherts which almost invariably accompany the black shales. The beds are very much contorted and crumpled, and generally seamed in all directions with fine quartz veins. The black bands contain quantities of iron pyrites in crystals and nodules, Where- 16 ever exposed they are found to contain remains of graptolites. In some localities these are specially abundant, as in the Black Burn, near Drum- mabrennan. In other places, however, the black shales have been so much squeezel, crumpled, and broken, that traces of fossils are almost obliterated. The blue shales and flagey bands accompanying the black shales likewise yield sometimes a few graptolites. 31. This group crosses the north-west corner of the Map in two parallel bands. Of these, the more southerly forms the centre of the synclinal trough referred to in par. 26, has a breadth of from a quarter to half a mile, and stretches from Camrie 2 miles north of Glenluce, by Bal- minnoch and Glassock to Glenhapple on the Cree. On either side of this basin the black shales may be seen dipping towards the centre in two parallel interrupted lines, forming nearly the base of the group. They are overlaid by blue and grey shales, flags, and greywackes, while some hands of grit aj pear when the trough is deep and wide enough to hold the highest beds of the series. This syncline of the upper black shales is a very well-marked one, traceable continuously from Morroch Bay, south of Port- Patrick, across Sheets 3 and 4, into Sheet 8, where it is cut off by the Loch Dee granite. As will be seen from the present Map, however, the outcrop of the black shales cannot be followed without numerous inter- ruptions, arising no doubt chiefly, if not entirely, from the drift-covered or mossy nature of the surface. These strata are seen on both sides of the syncline at Glassock. They appear on the north margin near Carse- rigean, in Black Burn, at Drummabrennan, on the road side at Balmin- noch, and in one or two places between Garvilland and the edge of the Sheet; on the south margin at Ringdown and Camrie. But could the drift and peat be removed from the surface, it may be presumed that the syncline would be found flanked with a continuous strip of these very conspicuous black beds on either side across the whole Map. Generally only one single band of black shale occurs along the outcrop. On the north side of Carscreugh Hill, near Ringdown, however, there are three outcrops only separated by a few hundred feet of strata. From the vertical and intensely crumpled and twisted character of the strata, as well as from the similarity of the black shales at the different localities, it may be inferred that these three bands are merely repetitions of the usual single zone brought up by small sharp folds. The deepest part of the syncline lies at the north edge of the Sheet. There, on Glenhapple Fell, some thick massive bands of greywacke and grit rest on the black shale group. These grits become more developed along the same line of strike in Sheet 8, where the trough deepens for some distance. They form, therefore, the base of the next overlying portion of the Silurian serivs, to Which the name of the ‘‘Carsphairn group "has been given. (See Explanation to Sheet 9, par. 26.) 32. Lo the north of the synclinal trough the second bar of the black shale group runs continuously from Eldrig Moss to the north edge of the Sheet, As it lies against the anticline which repeats the Dalveen and Lowther groups, it has a prevalent north-westerly dip. The black bands are very much crumpled and twisted here, and full of fine quartz veins, as may be seen in several good sections south-west of Dirneark. a PAR WWE SOON Dopo pe Dee H Ooonr bo bo noe 59 Llandovery (‘Queensberry and Hawick’ Rocks.) 28, S. slope of Culcaigrie Hill, 44 miles E. by N. of Gatehouse-of-Fleet. 24, Burn, 150 yards E, of Benjarg Wood, 1} miles E.N.E. of do. 25. Quarry near wood, 500 yards 8. W. of Mailie’s Walls, Trowdale, 26. Railway Cutting at Halketleaths Mill, Castle-Douglas. 27, At Railway Station, Castle-Douglas. 28. Shore, 800 yards N. of Torrs Point, E, Side, Kirkcudbright Bay. Wenlock and Ludlow (?). 29, 300 yards S. of Bathing House, E, side of Kirkcudbright Bay. 30. Shore, immediately N. of Longrobin, i 6 31. ,, 8. of Longrobin, oe - 82. ,, below word ‘ bught’ on 1-inch map, ‘5 es 33. ,, immediately 8. of Witch Wife’s Haven, ,, i 34, ,, at Raven’s Nest, 6 a5 35. ,, N. side of Torrs Point, * ‘3 36. ,, 5S. ofdo., 09 - 37. ,, 8. of Gauger’s Loup, sii hi 38. ,, 8S. of word ‘Sapphire’ on l-inch map, ,, af 39. ,, 8. of Dirk Hatterick’s Cave, Yr i 40. ,, 8S. of Torrs Cove Bay, 55 a 41. ,, SS. of Red Rock, i _ 42. ,, immediately N. of Balmae Haven, sii 5 43. ,, ‘i 8. of do., i ¥ 44, ,, 8S. of Shawhole, W. side of Kirkcudbright Bay. 45. ,, N. side of Balmangan Bay, ‘6 ia 46. ,, E. side of Manor Hole, do., 5 ia 47, ,, Meikle Ross. 48. ,, 8. of Sugar Loaf, E. side of Meikle Ross. 49. ,, opposite Richardson’s Rock. 50. ,, Fallbogue Bay, W. side of Meikle Ross, 51. ,, E. side of Howell Bay, E. of Kirkcudbright Bay. 52. ,, Gipsy Point (North band of Conglomerate), 8 5 58. 45 is (South band of do.). - 54, ,, ‘ (from Limestone Nodules). ‘a re Carboniferous—Calciferous Sandstone Series. 55. Rascarrel Bay, near Auchencairn. 56. Shore, near Bathing House, Orroland, Dundrennan. 57. ,, at Waterfall, E. of Bathing House, do. 58. Abbey-burnfoot, Dundrennan. 59. Near Portowarren Bay, Colvend, Dalbeattie. 60. Glenstocking Quarry, do. Carboniferous—Calciferous Sandstone Series—Sheet 6. 61. Foot of Kirkbean Glen. 62. Shore, W.S,W. of Southerness Point, Arbigland. 68. ,, 8. of Thirlstane, do, 64. ,, near Gardeners Cottage and Borron Point, do. 60 II. LIST OF FOSSILS. In the following List of Organic Remains, the formations and beds are Class, etc. Amorphozoa, Hydrozou, Brachiopoda, i arranged in ascending order, Llandeilo-Caradoc, (‘ Glenkiln-Hartfell’ Shales.) Name. Locality Number. Radiolaria, , ; ‘ 1, 7, 8, 9, 10, 18. Coenograptus explanatus, —Lapw. “5 gracilis, —Hall. 158 2, 7, 8, 9, 10, oy nitidulus,—Lapw. 5 1, %, ss pertenuis.—Lapw. ‘ 1,%, i surcularis,—Hall, ; 1, x5 pe» ‘ ‘ 5 ge Me Didymograptus superstes. —Lapw, : « 1, 2, 6; 7,9, 15; a nov. Sp.—with dise,* « &; serratulus.—Hall. » ad, Thamnograptus typus.—Hali. ‘ 3 5D Diplograptus bimucronatus.—Nich. . I, 6, 10. i dentatus.—Brongn. . « I, 3 euglyphus.—Lapw. . nce ne foliaceus.—Murch. . ; Hoe a 10, a es mucronatus, — 1 a Coe ae 6, 7, 8, 9, 10, Carr. . : ; : . J 12, Rn truncatus.—Lapw. . ‘ ‘ Whitfieldii—Hall. . ; ; i % 9, 10. » Sp. ‘ 4 7 8, Climacograptus bicornis. —Hall, 12. By ie, 2, $5 var poltifer, =} ue 18, 15, $5 caudatus.—Lapw, : a By 8p 12, 55 celatus, var ae aes 7 ie h, 7, 9, 11. 5 Scharenbergi. —Lapw. 2, 5. , Sp. : 10. Glossograptus Hance —_Hopk. : 19 Retiolites fibratus.—Lapw. ‘ 2. Clathrograptus cuneiformis.—Lapw. 14, Ls Dicranograptus Clingani.—Carr. . 4 2. 5 Nicholsoni.—Hopk. » dy 28, i ramosus.—Hall. . 6 Ay bs a tardiusculus.—Lapw. 3 oda ‘i ziczac.—Lupw, . 2165, Sp. « 10. Dicellograptus anceps.—Wich. a 9: 3 Forchhammeri. —Geinite, a 1,26, 7% 45 flexuosus.—Lapw. . a Aye Bs - Moffatensis.—Carr. 3 { ah Gy ty By Ads patulosus.—Lapw. . 1, 6, 7. ie sextans.—Hall, 1, 2. Sp. . 1; Corynoides calicularis, — Nich, 10. Acrotreta Nicholsoni,—Dav. 15. Siphonotreta micula,—JZ vee) 1, 11. Bivalve crustacean, : : 2. 1 The presence of the dise at the initial point suggests a close affinity between Didymograptus and Tetragraptus, and the probable descent of the former from the latter. Class, etc. Hydroza, Crustacea, Brachiopoda, Hydrozoa, Crustacea, Incertee sedis, Hydrozoa, 61 Llandovery. (‘Birkhill’ Shales.) Name. Diplograptus acuminatus.—Wich, . Locality Number. 4, 16, 17, 18, 19, : * (20, 22. 45 (Petalograptus) palmeus, —| 4 Barr. . F ‘ : : as tamariscus.—Nich, . 5 : ms 19, 22, > vesiculosus.—Wich. . . 18, 93 Sp. . : . ‘ : «2 Dimorphograptus confertus.—Nich. io 17, 18, 19. a9 elongatus.—Lapw. . +0 Swanstoni. es . : th. Sp. ; . 14, 18, 22. Climacograptus innotatus.—Nich. ‘ : 16, normalis.—Lapw a a ak uy ; m 19, 20, 22. 5 Sp. : é - . . 19, Retiolites perlatus.x—Wich. . : : a 1% 5 a var, : : « At 9 Sp. 7 5 fs ‘ . 24, Monograptus attenuatus. —Hopk. 17, 18, 19. 55 gregarius.—Lapw. 16, 17, 19, 22, ” ” tached, 45 jaculum.—Lapw. . a leptotheca.—Lapw. . 25 lobiferus. —7/‘Coy. 6 Sedgwicki.—Portl, 55 tenuis,—Portl. 5 triangulatus. —Hark. Sp. : Dawsonia drnpicnitaian Wicks : Sicule of Graptolites, . s Discinocaris Browniana, — Woodw. Lingula striata.—Sow, . . Llandovery, with gonophore at- ‘je ; Ads : sit GL of 18, 19, 22. 6 "17,18, 19, 22. 17, 22. 21; 22, . 17, 18, 19. « 4,-16,.19, 17. 17. (‘ Queensberry’ and ‘ Hawick’ Rocks.) Petalograptus ovato-elongatus.—Kurch. palmeus.—Barr. Monograptus Becki.—Zarr. . ss exiguus.—Nich. 43 Halli.—Barr. 7 as Sedgwicki.—Portl. a3 tenuis,—Hopk. . 3 attenuatus.—Hopk. turriculatus.—Barr. Retiolites, Sp. Aptychopsis minus. — Barr (like glabra. — Woodw.). A , Protovirgularia Harknessi. —M Coy u Sp. Worm ‘Tracks ? ao, Wenlock and Ludlow (2). (a) Graptolite Shales. Crytograptus Murchisoni.—Carr. . Monograptus colonus ?—Barr. 45 Flemingii, —Salter. . 25. . 25. » 23, 25. . . 28, 24, . » 25z i’ 21; . or 1252 . . 25, . . 25. 24, 25. 26, 27, 28. 26, 27° . «23, 26, 28. e icced . 85,43, 48, 49, 51. 31, 32 29, 30, 31, 32, 33, 34, 35, 36, ‘+437, 38, 40, 41, 42, 43, 45, 50, 62 Class, ete. Name. Locality Number, Hydrozoa, . . Monograptus priodon.—Barr. . ‘ . rd a 2 Pk $i i Riccartonensis.—Lapw. . a vomerinus.—Vich. . : a 623 § Sea he nee BO AD Retiolites Geinitzianus’—Barr. , : » 45, 50. Dictyonema.—Sp. ; : : = Bhs Cephalope?i, . Orthoceras annulatum.—Sor. 383, 35 be var fimbriatum. _ Sow, “pa ‘e politum.—AfCoy. ; ‘ 1 Bas oe tenuicinctum.—Port?, . ‘ » 37, 43. iis subundulatum. —Port?. 33, 58, 37, 42, 43. Sy 81, 32, 33, 38, i PRS Fe) ek CR Ge 41, 42, 45, 47, Crustaced, . Aptychopsis oblata.—Jones. . 2 ‘ aa Ceratiocaris.— Sp, Bis Discinocaris (Carapace, allied to), . ; . 81, 40. (?) Trinucleus Benniei.—£th., Jnr. . BA, Incertce sedis, . Dictyocaris.—Sp. . § ‘ F 51. (b) From Fine Conglomerate Bands near Little Daliae. Actinviod, . . Favosites.—Sp. . ; ' ‘ o3, Heliolites.—Sp.. : . 58, Petraia bina.—Lonsd. . i , j « 52553: » elongata.—Phill, if ‘i ‘ « BR: Stenopora fibrosa,—Gol/r ‘ « 82, G8: Syringopora.—Sp, ; 5 i 2 33: Polyzoa, . . Ttilodictya.—Sp, : ‘ . s 5B. Brachiopode, . Leptena sericea,— Soi. : 3 ‘ ~ £2,538, Orthis calligramma.—Dalm. . ‘ ‘ 5S, », Bouchardi.—Dav. a ‘ . .. 2. eee ; ‘i ' F » 162) Lamellibranchiata, Pterinea.—Sp, i , ‘ f » 2,538) Ga steropoda, . Murchisonia.—‘p. ; 3 : ; 53, Echinoderinata, . Enerinite stems, . : 3 : (b2, 58s Annelidu, . . Cornulites.—Sp.. : « 353. Crustacea, . Phacops caudatus. —Briinn. . ‘“ : ao ORs Trilobite remains, ‘i js : ‘ a) OSs (c) From the Limestone Volules in Shale at Gipsy Potnt and Rueberry Castle. Brachiopoda, . Athyris.—Sp, é » 54 Atrypa (allied to A. hemispheri ic a), —Sow . 64, Leptwna transversalis.— Wahl. . : Bd. Rhynchonella—sp, , ‘ - a ds Strophomena.—Sp,. ‘ : i . 54, Lamellibranchiata, Ctenodonta.—sp, ¥ . a » “ots Cucullella.—Sp. , ‘ 5 . 54, Orthonota,—Sp. . ‘ i » 54, Gasteropoda, . Bellerophon acutus. —Sow. : : ‘ . 54, 3 trilobatus.—Sow. 2 ‘ s Beh Loxonema.—Sp, . ‘ 5 a. Dd: Murchisonia obscura.—Port?.. $ Bas Pteropoda, . . Hyolithes (like H, aduncus of Barr, yy » b4s Cephalopoda, . Orthoceras Etheridgei—Blahke. , : x Ba. 4 Ope ¥ . ‘ E . 54, Carboniferous. (Calciferous Sandstone Series.) Plante, . . Fern stems, . ‘ é 3 ; + 5S: Stumps of trees, . » 68, Actinozoa, . . Aulopora (Syringopora) paraiilosa: —Goldy, » 56. » yy Sp. . a > » oO 63 Class, etc. : : Name. Locality Number. Brachiopoda, . Athyris ambigua.— Sow. ‘i : : . 55, 56, », eXpansa,— Phill, ; ; : . 56. 53 Ses : ‘. . 56. Camarophoria erumena, ~ Mart. z . 56, 57. Productus semireticulatus,—Afart. : . 55, 56, 4 5 var Martini.— Sow, ‘i . 56, 57, Rhynchonella pleurodon.—Prill. . . 57, Spirifera trigonalis, var bisuleata.—Sow. . 56, 57 Lamellibranchiata, Aviculopecten.—Sp,. ‘ 5 . 55, Edmondia.—Sp. . . . : « B7s Modiola Hiscadavii, —Portl. : : ‘ . 56. 5, Mmodioliformis.—E£th., Jnr. . . 56, 59, Myalina crassa,—Flem. ‘ : ‘ > 56, 57. », lamellosa.—De Kon. , ‘3 » 56: », sublamellosa.—Zth., Jnr, ‘ . 66. Pteronites angustatus.—M/‘Coy. . 3 » “6: Schizodus Salteri. —Eth. - ; 55, 56, 57. (elongated variety), 3 bbs Gasteropoda, z Bellerophon Urei.—Flem. « 6, 59: Capulus (Platyceras) angustus, —Phill. . . 56, Euomphalus carbonarius.—Sow. . ‘ x “OMe 5 Spo. 3 : 5 ‘ . 56,57. Loxonema mand —Mart. : ¢ . 56. e é ‘ » 66; 57; Murchisonia iia form), : ‘ » 56. Naticopsis (Natica)plicistria. “Phill. ‘ > 56,57: Nov. sp... a » 56. Pleurotomaria Yvani. Tvs + F é : 56; Sp. ‘ ‘ : « 665 57s Turbo. ” 8p. F ‘ . 56. Cephalopoda, . Nautilus biangulatus, —Sow. ; é » 56. Orthoceras.—Sp. . . , és ‘ a 06, 5B Crustacea, . . Eurypterus, , 3 . 5 é 5 « 58. Pisces, . : . Rhizodus (scales of), . ‘ . Fi « 165; 58. Fish jaw with teeth, . 3 é : . 56. Palatal teeth of placoids? . ‘ ‘ » 56.5%, Calciferous Sandstone Series—Sheet 6. Actinozoa, . . Chetetes tumidus.—Phill. . j : . 64, Favosites parasitica.—Phill. . . : . 64. Clisiophyllum turbinatum.—I‘Coy, . » 64, Lithodendron affine. —Flem. . , ; 64. a irregulare.—Phill. . e . 64. junceum.—Flem. . : . 64. Lithostrotion basaltiforme.—Flem. . 64, 4 cylindricum, . ‘ . 64. ea Macoyanum, —J/. Edw. . » 64, a5 Portlocki.—M. Edw. . » 64, Stenopora arbuscula.—Goldf. : : . 64. Aulopora (Syringopora) campanulata, — MCoy. . . 64. = 53 gigas. —MU‘Coy. . 64, ramulosa, as . 63, 64. Syringopora cylindrica, ‘ . 64, Zaphrentis cylindrica, —Scouler sp. : . 64, Sp. fi . . 64, Polyzoa, . : Ceriopora interporosa. — Phill. 62, 64, Fenestella a elegans. enh Sp. 64. . » 63, 64. Brachiopoda, ‘ Athyris matte, — Sow. . : : . 62, 63, 64. », Royssi.—Lév. . ‘ i Fr . 64, Camarophoria crumena.—Afart. . . . 64. Chonetes Buchiana.—De Kon. 3 . . 64, 3 Laguessiana.—De Kon. . . 64, » politaa—AM‘Coy, . . . . 64, 64 Class, etc. Name. Locality Number. Brachiopoda, . Crania quadrata.—M‘Coy. . ‘ . « 62, 64, Discina nitida,—Phill, . . . 62, Lingula mytiloides.—Sow. . 3 . . 62, 63. Orthis Mitchelini.—Lév. ‘ . : . 64, Productus giganteus.— Mart. . . . 64, 5 longispinus.—Sow. r 5 . 64, punctatus.—AMart. r : « 62, 64. scabriculus.—Mart. é " . 64, a” » 3 oe ee aa _ . 62, 63, 64, undatus,—Defr. . . 64 Rhynchonella pleurodon.—Paill, 5 . 64, Spirifera cuspidata.x—King. . . : » 62, 9 lineata. —Mart. - : : . 62, », ovalis,x—Phill. 7 . . . 64, 1, pinguis.—Sow. » 64. », trigonalis, var bisulcata. —Sow. . 62, 64, Spiriferina cristata,—Sch/, . . - 62, 64, Streptorhynchus (Orthotetes) crenistria, — Phill. : : ‘ . 62, 64, Terebratula hastata,—Sow. . : » 64 Lamellibranchiata, Aviculopecten ceelatus.—J/‘Coy. . « 68. i dissimilis.—Flem. . . 64, 3 elongatus,—M‘Coy.. . 64, 5 Geikiei.— th., Jnr., ILS. . 63, 64, sis interstitialis. — Phill. 4 » 63, like A. macrotis.—I[‘Coy. . 638, 64. ” 53 sa -radiatus, —J es . . 64, 5 Nov. . 62, 64 Avicula Hendersoni, Bh. Jnr. sy 8 A « 638, 64, 5; ov. sp. « ‘ . . . 64, fe iis . ey 61, 63, 64 Hamada sulcata. “phil. . 7 3 ‘ os 64, Sp. , ‘ epitome clavatus. i Coy.” 5 é . 61, 63, costellatus.—JL‘Coy. . ‘ . 64, 2 Modiola Macadami.—Portl. . f ‘ . 62, », modioliformis.—Zih., Jnr. a . 64, Sp. : ‘ » 64, Myalina crassa. —Flem. . : ; 2 . 68, 64. » lamellosa.—De Kon. 7 : . 64, Nuceulana,—Sp. 5 - - 63, Pteronites an gosta —M ‘Cm ne F . 62, 5 sulcatus, —JZ ‘Coy. ‘ ‘i . 64, Sanguinolites ‘ridinoides, a ‘Coy, ‘ . 62, 64, a plicatus. —Porri/, ‘ - . 64, variabilis.—M‘Coy, . : . 64. Schizodus Salteri.—Evh. » 62, 64. pA (Axinus) axiniformis, —Phill, . 64. Solenopsis.—Sp. . 4 : : 3 . 64, Gasteropoda, . Bellerophon decussatus.x—Flem. : . 64, af hiulcus.—Sow, : ‘ » 64 Dentalium priscum. eae: ‘ : . 62, 64. Sp. ‘ . 64. Euomphalus acutus,—Sow. . é : . 63, 64, 55 carbonarius.—Sow. . ‘ . 64, “s i. ‘ - 2 64, Loxonema rugifera, — Phill, , é . . 64, large smooth, —Sp. . ‘ » 64, Naticopsis (Natica) plicatula, i r . 64, 3, licistria.— Phill, ; » 64, 58 yrata.—Phill. . . . 64, Capulus (Platyceras) angustus,—Phill, : » 62, Pteropoda, . . Conularia quadrisulcata,—Sow. . ‘ «62s Cephalopoda, . Orthoceras attenuatum.—Flem. . ; . 64, Muensterianum.—De Kon. . . 64, Sp. (with sipuncle sulcated), . 64, ” ” Class, ete. Echinodermata, Annelida, Crustacea, Pisces, 65 Name. Archecidaris Urei.—Flem. Crateriocrinus (Synbathocrinus) —De Kon. ‘ ‘ Crinoid stems and heads, Spirorbis carbonarius.—Murch sp. . 5 helicteres.— Salt, Annelide tubes, Entomostraca, % . Teeth and other remains of fishes, encrinoides, ere eee Locality Number. 64, 64. 63, 64. 63, 64. 64. 63. 61, 62, 63, 64. 61, 62, 64, 66 C. LIST OF PAPERS REFERRING TO THE GEOLOGY oF THE REGION UNDER Description. 1814, 1843, 1843. 1848. 1851. 1851. 1852, 1853. 1856. 1869. ‘Notes on the Geognosy of the Criffel, Kirkbean, and the Needle’s Eye, in Galloway,’ by Professor Jameson ; Memoirs of the Wernerian Soc., vol. iv., p. 541. ‘Geognostical Description of the Stewartry of Kirkcudbrightshire,’ by R. H. Cunningham ; High. Soc. Trans., new series, vol. viii., p. 697. ‘Remarks on the Geology of the Island of Little Ross, Kirkcudbrightshire,’ by Thomas Stevenson ; Edin, New Phil, Jour., vol. xxxv., p. 83. List of Fossils from the East Side of Kirkcudbright Bay, collected by Mr Fleming, and determined by J. W. Salter ; Quart. Jour. Geol. Soc., vol. iv., p. 206. ‘On the Silurian Rocks of Dumfriesshire and Kirkeudbrightshire,’ by R. Harkness ; Quart. Jour. Geol. Soc., vol. vii., p. 46. ‘Notice of a Sea Beach during the Silurian Epoch,’ by R. Harkness ; Annals and Mag. of Nat. Hist., vol. viii., second series, p. 106. ‘Description of some Graptolites from the South of Scotland,’ by J. W. Salter; Quart. Jour. Geol. Soc., vol. viii., p. 888. ‘On the Silurian Rocks of Kirkcudbrightshire, by R. Harkness; Quart. Jour. Geol. Soc., vol. ix., p. 181. ‘On the Lowest Sedimentary Rocks of the South of Scotland,’ by R. Hark- ness ; Quart. Jour, Geol. Soc., vol. xii., p. 238. ‘Notes on the Geology of Southerness, Kirkeudbrightshire,’ by W. Jolly ; Trans, Geol, Soc. Ldin., vol.i., p. 278. 1873-4. I. ‘On a Cave containing Bones and Objects of Human Workmanship at 1876. 1878, 1879. 1889. Borness, Kirkcudbrightshire,’ by A. J. Corrie, W. Bruce-Clarke, and A. R. Hunt. II. ‘On the Osseous Remains of the Borness Cave, Kirkcudbrightshire,’ by W. Bruce-Clarke and Randall J. Johnson ; Proceedings of the Soc. of Auntiquarics of Scotland, vol. a. ‘On Scottish Monograptide,’ by C. Lapworth; Gol. Maq., vol. iii, new series, pp. 308, 350, 499, 544. ‘The Moffat Series,’ by C. Lapworth ; Quart. Jour. Geol, Soc., vol. xxxiv., p. 240. ‘Observations on Roches Aloutonnées, and other Points of Geological Interest in the Valley of the Urr, Kirkcudbrightshire,’ by Alexander Somervail ; Trans. of the Geol, Soc, Edin., vol. iii., p. 247. ‘On the Ballantrae Rocks of South of Scotland, and their place in the Upland Sequence,’ by Professor Lapworth ; Geol. Alag., Decade IIL, vol. vi., pp. 20 and 59, INDEX. A ABBEY Bury, 31. Unconformity at, 31. Abbey Burnfoot, 32. Fossils from, 32. Sand and Gravel in Boulder-Clay at, 34, Agglomerate, 27. Alluvium, 38. Almorness, 10, 23. Altered Silurian Strata, 8, 27, 28, 56, 57. Amethyst, 27. Andesite, 27, 55, 56. Dykes, Petrology of, 55, 56, Aplites, 28-25, 42, 47, 49, 50. Arbigland, 30. List of Corals from, 30. Ardwell Beds, 17. Area embraced in Map, 7. Arenig, iv, v, 9. ae age of Ballantrae Rocks, iv, 1 Arenig Tuffs, 11. Argrennan Farm, 52. Arthur Loch, 7. Farm, 50. Auchencairn, 8, 19. Auchenfad, Hematite, 40. Hill, 49. Auchengate, 53. Auchenleck, 40. Bait Hriu Morarnes, 36. Baleary Point, 56. Balgerran, 12. Ballantrae, Rocks of, iv, 11, 12, 17. Ballig, 34. Balmae Burn, 10, 20, 21. Grit and Conglomerate, 20. Haven, 19. Balmangan Bay, 19. Barclay Hill, 27, 49, 55, 56. Barlay Burn, 16. Barlocco, 32, 40. Barytes Vein, 40. Carboniferous Fossils from, 32. Cave, 37. Barmofitty, 14. Barnbowie Sands, 38 Bar Point, 18. Barren Mudstones, 12-16. Barskeoch Hill, 53. Barytes Vein, 40. Basalt Dykes, 26, 55, 56. Lavas, 29, 55. Olivine, 55. Basic Inclusions in Granite, 23-25, 42, 47. Bellymack Farmhouse, 15. Bengairn, 7, 8, 10, 11, 19, 22, 25-27, 47, 48, 52-54. Benjarg Wood, 17. Bennane Head, 11. Bentuther, 22, 48, 52. Birkhill Shales, Lower, 7, 11, 14, 16. Upper, 17. Birrenswark, 29, Black Shale Outcrops, 12-17. Bennan Hill, 16. Clenoch, 16. Coal Heugh, 16. Dunance Farm, 15. Kilnotrie, 15, Lawrieston Burn, 17. Mountskip Plantation, N. of, 13, 14. South Quintenespie, 15. Tottlehams Burn, 18, 16, 17. Trowdale, 12, Borgue, 18. Borness Cliffs, 18, Cave and contents, 18, 37, 38, 66. Borron Point, 30. Boulder-Clay, 8, 9, 33, 34. Boulders, Distribution of, 35, 36. resting on Gravel Kames, 36. Brandy Craig, 21. Brick Clays, 37, 40. Bridgehouse Bay, 39. Sub-marine Peat in, 39. Bridge of Threave, 8. Bruce-Clarke, W., 37, 66. Burnside, 21. Cc CAIRNSMORE OF FLEET, Granite Mass of, 25, 43, 44, 50. Petrography of, 48, 44, 50. Calciferous Sandstones, 29-32. areas occupied by, 29. Calciferous Sandstones—continued. List of Fossils from (General), 62-65. Lower Division, 30. Upper Division, 30. Order of Strata at Southerness, 30, Outliers of, 10. Sub-divisions of, 9. Campbell, C. R., iii. Camptonites, 46, 54, 55. Caradoc, 9, 11. Carse Lands, 38. Castle Douglas, 8, 12, 17, 22. Castle Hill, 31. Point, 54, Castle Muir Point, Conglomerate, 32. Cataclastic Structure in Granite, 28, Caves and Cave Deposits, 37, 88. Chapmanton, 53. Chlorite, 29, Chrysotile, 27. Cleavage of Llandovery Rocks, 18, 19. Clenoch Burn, 16. Clinking Cove, 19, 21. Haven, 27. Coal Heugh, 16, 17. Colvend, List of Fossils from, 17. Colvend Shore, 7, 10, 19, 25, 26, 29, 31. Conformability of Llandovery and Wen- lock Rocks, 10. Contact Rocks, 56, 57. Contents, Table of, 6. Copper Ores, 40, Coralline Limestone of Arbigland, 9, 30. Corrie, A. J., 87, 66. Craigend Hill, 23. Hematite, 40. Craig Hill, 23. Craignair, 23. Quarry, 23, 47. Specific Gravities of Granite from, 42, Craigneuk Point, 51. Criffel, 7, 8, 10, 18, 20, 23, 25, 49-51, 53. Granite Mass of, 7, 22, 41-48, 45, 47-55. Area occupied by, 22. Age of, 28. Age of Strata pierced by, 22, Aplites of, 23, 42, 47, 49, 50. Basic Inclusions in, 28, 42. Characters of, 22, 23, 42. Dykes later than Foliation of, 25, 27, 44-46, 50-57. Extreme Phase of Foliation of, 25. Foliation of, 24, 25, 42, 43. Hornblendic Varieties from, 28. Microscopic Characters of Foli- ated Granite of, 25, 42, 48, 49, 50. Petrography of, 41-43, 47-50, Crofthead, 53. Crossmichael, 11, 14. Arenig Felsitic Tuff at, 15. Cuil Hill, 7, 33. Culeaigrie Hill, 17. Cushat Wood, 30. Cyrtograptus Murchisoni, 19, 61. D DALBEATTIE, 7, 8, 10, 26, 53. Davidson, Thomas, F.R.8., 58. Dee River, 7, 8, 10, 15, 16. Base Level of erosion by, 8. Estuary of, 18. Valley of, 18. Denudation of Criffel Granite in Upper Old Red Sandstone time, 10, Dicellograptus anceps, 16. Diorite Dykes, 25, 26, 46, 54, 55. Diplograptus acuminatus zone, 15. Distribution of Boulders of Criffel Granite, v, 35, 36. Doon, The, 18. Dornell Hills, 17. Drainage, Main Lines of, 7, 8. Drum, 29. ‘Drums,’ 34. Drumbuie Wood, 25, Drum Burn, 10. Drumglass, 17. Drumjohn, Kirkgunzeon, 50. Dundrennan, 18. Dunnance Farm, 15. Fossils from, 15. Dunrod Burn, 21. Dykes, 25-27, 44-46, 51-56. Classification of, 25, Petrography of, 44-46, 51-56, Andesites, 56. Basalts, 25, 26, 55, 56. Camptonites, 46. Diorites, 25, 26, 46, 54, 55. Mica-traps, 25, 26, 46. Minette, 55. Porphyrites, 25, 26, 44-46 51- 54. Economic MINERALS, 39, 40. Barytes, 40. Brick Clays, 40. Copper Ores, 40. Fuel, 40. Granite, 39. Grits, 39. Iron Ores, 40. Limestone, 39. Erratic Blocks, 35, 36 F Faubocve Bay, 18, 19. Felspar ‘ Eyes,’ 25. Fleet, The, 8, 18. Fleming, Mr, iii, 66. Foliation of Granites, etc,, 28, 24, 25, 27, 28, 42, 43, 49, 50. Form of Ground, 7-9. Formations, Table of, 9, 10. Fossil Lists, Appendix B., 60-65. Carboniferous, 30-82, 62, 65. Llandeilo-Caradoc, 12-15, 60. Llandovery, 13, 15, 16, 61. Wenlock and Ludlow, 19-22, 61, 62. Fossil Localities, List of, 58, 59. Fuel, 40. G GATEHOUSE-OF-FLEET, 7, 8, 16, 17, 50. Geological Structure, 10, Gipsy Point, 20. Glaciation, 32-36. Glaisters, 35. Burn, 33. Glengainoch Burn, 36. ‘Glenkiln’ Shales, 11-15. Glenkiln-Hartfell Shales, 12, 14, 15. Glenstocking Quarry, Coral from, 31. Granite, 7, 22, 23, 25, 28, 39, 41-44, 47-50. a hay of Fleet Mass, 25, 48, 44, 0, Criffel and Dalbeattie Mass, 25, 43, 44, 47-50, Foliation of, 23, 25, 27, 28, 42, 43, 49, 50. Petrography of, 41-44, 47-50. Specific Gravities of, 42. Granitite, 25. Granulite, 25. Graptolites, the Key to the Silurian Succession, iii, 11. Graptolite Bands (Wenlock), 19. Gravel Kames, 35, Green Hill, 26, 55. Grennan Hill, 51. Gutchers Isle, 31, 51. H HaMatirE, 40. Halketleaths Mill, 18. Harkness, Prof., ili, 19, 21, 22, 66. Hart Burn, 52. Hartfell Black Shale, 11, 13. Hawick Rocks, 17, 19. Hay Cunningham, R. H., iii, 27, 40, 66. Hensol Black Shale Crop, 15-17. List of Fossils from, 16. Hensol House, 15, 16. Hestan Isle, 40. Copper Ore from, 40. Highest Elevation in the District, 7. Hogus Point, 30. Howell Point, 19. Hunt, A. R., 37, 66. I IcE-FLow, 32, 33. Ice Sheet, Minimum thickness of, v, 33. Igneous Rocks, Table of, 10. Of Silurian Age, 22. Influence of Denudation, 8. Ingleston, 27, Volcanic Neck near, 27, Tron Ores, 40. Irvine, D. R., i. J JAMESON, PRor., 66. Johnson, Randall J., 38. Jolly, W., 66. K KameEs, 35. Kells Farmhouse, 25, 28, 49, 50, 56, 57. Kelton Kirk, 52. Ken River, 8. Viaduct, 16. Killywhan, 8, 55. Station, 7. Kilnotrie, 14, 15. Farmhouse, 15, List of Fossils from, 15. Volcanic Tuffs, 15. Kirkbean, 10, 18, 29, 30. Glen, 56. Village, 25, Kirkconnell, 22. Moor, 17. Moss, 23. Kirkcudbright, iii, 8, 11, 22. Bay, 10, 11, 17, 18, 19, 22. Shore, iii, 11, 22, Kirkgunzeon Lane, 7, 9. Kirkpatrick-Durham, 8. Knockbrex, 18. L LADYLAND Burn, 29. Glen, 51. Lamprophyre, 46. Lapworth, Prof., iii, 11, 17, 66. Laughenghie, 50, 54. Lavas, Carboniferous, 10, 29, 56. Lawrieston, 11, 15, 17. Black Shales at, 15, 17. Liggatcheek, 16. Limestone, 39. List of Fossils—vide Fossil Lists. Fossil Localities, 58, 59. Papers, 66. Rocks and Microscopic Sections 47-57. Little Ross, 19. Little Water of Fleet Viaduct, 50. Livingstone Hills, 17. Llandeilo, v, 9, 11. sana s Rocks, Table of Sub-divisions of, 9. Base of, 17. Best Section of, 18. Overlying Black Shales, 17, 18. Plication of, 18. Loch Hill, Loch Kinder, 48. Lochanhead Station, 23, 26. Long Fell, 7. Long Robin, 9, 26. Lot’s Wife, 51. Lotus Hill, 7. Ludlow Rocks, 12. of Gipsy Point, 20. Limestone Nodules of, 20. List of Fossils from, 22, 62. of Little Balmae, 22. Review of Paleontological Evidence for, 22. M MAINSRIDDLE, 10. Manganese Nodules, 13. Meikle Kirkland, 54, Meikle Ross, 18-19. Meikle Saddler’s Bay, 37. 70 Metamorphism of Silurian Rocks, 27, R 28, 56, 57. RADIOLARIA, 60. Character of, around Granite Masses, Radiolarian Cherts, 11-14. 27. Mudstones, 13. Extreme phases of, 27, 28. Organic Origin of, 11. Mica-traps, 26, 27, 46, 55. Raeberry Castle, 19, 21. Midhill, Screel, 49. Cliffs, 20. Midpark, 52. Point, 21. Millstones, 39. Raised Beaches, 36. Mines, Copper, 40. Brick Clays of, 37, 40. Minette, 46, 55. Old Cliff Line at Castle Muir, 37. Minimum thickness of Ice-sheet, v, 33. Rascarrel Bay, 22, 29, 32. Moffat Series, iii, 11, 14-17. Rastrites maximus, 18. Occurring on crests of Anticlines, | Redbank Farm, 53. 10, 11. Rerwick Shore, 31. Three Faunas of, 11. Carboniferous Rocks of, 31. Monograptus criguus zone, 14, 15, Riccarton, 11. gregarius zone, 15, 16, 17. Road Metal, 40. Sedgwickit, 17. Robb’s Crags, 21. vomerinus, 19, 21. Roches moutonnées, 82, 33. Moraines, 36. Rockcliffe, Colvend, 51. Mountskip Plantation, 12. Lists of Fossils from near, 13. 8 Glenkiln Fossils from, 14, 15. SALT FLATS, 48, 49, Llandovery Fossils from, 13. Salter, J. W., ili, 22, 66. Mulloch Bay, 19, 20, 21, 26, 55. Sands and Gravels, 34, 35. Areas of, 34, N Sandyhills, 51. Necxs or old Volcanic Chimneys, 26, 27. Sandyhills Bay, 9. Needle’s Eye, 54. Screel, 7, 10, 22, 27. Nether Clifton, 51. Hematite of, 40. Nether Howe Cottages, 48. Selkirk, Earl of, 22. Nether Linkens, 52. Shaw Hole, 19. Nun Mill, 55. Sheets of water in the District, 7. Shoulder 0’ Craig, 27. oO Silurian Rocks, 10-22. OLDHAM QuaRRY, 47. Sub-divisions of, 9. Orroland, 32. mainly of Llandovery Age, 10. Fossiliferous Strata at, 32. Skerrow Loch, iii, 8-17. Outliers of Calciferous Sandstone, 10. Slagnaw, 52, 55. Carboniferous, 31. Solway Firth, 7, 8, 18. Somervail, Alexander, 66. P Southerness, iii, 7, 30. Parton, 8. Southwick, 7, 8, 22-25, 28. Peat, 38, 89. Carboniferous Outlier of, 31. Fuel, 40. ; House, 31. Remains of Red Deer in, 39. Sphene, 23, 28 : , 28, 28. Sub-marine, 39, Spout Gill, 30. Trees in, 39, Stevenson, Thomas, 66. Pegmatite, 25. Striated Rock-Surfaces, 32, 33. Veins, 42. Stroan Loch, 8, 16. Petrography of Igneous Rocks, 41-57, Viaduct, 54. Piper’s Cove, 37. . Submarine Peat, 39. Bay, List of Fossils from, 31. Sypland, 52. Pleistocene and Recent, 32-39. Porpbyrites, 25, 26, 44-46, 51, 54. p Port Mary, 32, TABLE OF ForMATIONS, 9, 10. Port o” Waren, 10: Tarff Water, 16. Powillimount, 80. Tercbratula lacunosa, 21. 0 semisuleata, 21. QUARRIES: — = Terraces of Alluvium, 38, Barcloy, 31, 39. Thirlstane Sandstone, 30, 31. Craignair, 33. Tongueland Gorge, 8. Dalbeattie, 39. Torrorie, 29. Glenstocking, 31. Torr Point, 18, 19. Quartercake Burn, 21. Torr’s Cove, 87. Quartz Veins, 44. Torr’s Cove Bay, 19. Queensberry Grits, 17. Tottlehams Burn, 11-14. Quintenespie, South, 15. Felsitic Tuffs of, 14. List of Graptolites from, 15. List of Fossils from, 13, 14. Tottlehams Burn—continued, List of Fossils from—continwed. Birkhill, 18, Glenkiln-Hartfell, 13, 14. Hartfell, 14. Transverse and Longitudinal Valleys, 8, Trowdale Glen, v, 11, 12-15, 17. Bands of Black Shale, 12-15, Lists of Fossils from, 12, 13. Volcanic Tuff of, 12. Tunhill, 52. Twynholm Hill, 7, 8. U Untocu Hitt, 17. Underwood, Rev. Mr, iii, 22. Upper Old Red Sandstone, 9, 28, 29, Upper Tower of Glenstocking, 51. VEINS, Mineral :— Barytes, 32, 40. Copper, 40. Hematite, 40. Quartz and Calcspar, 27. Quartz, 18. 71 Vermioular Quartz, 44. Volcanic Necks, 10, 26, 27. W WALLTREES Moss, 35, Wenlock Fossils :— General List, 61, 62. Kirkbean Glen, 29. List from Little Balmae, 22. Review of Evidence afforded by, 22. Wenlock Rocks, 9, 18-22. Altered on Colvend Shore, 19. Brecciated Conglomerate of, 20. Plications of, 19, Reddened by Lower Carboniferous Rocks, 21. Sub-divisions of, 9, 18. West Glenarm, 54. Whinyeon Loch, 9. White Port, 18, 20. Woodhall Loch, 9. Z ZonAu Distribution of Graptolites, il. NEILL AND COMPANY, PRINTERS, EDINBURGH, LIST OF PUBLICATIONS OF THE GEOLOGICAL SURVEY OF SCOTLAND. I,—Maps on One-inch Scale. 1. Wigtownshire, Southern Districts. 4s, 2, Wigtownshire, South-Eastern Districts. 4s, 3, Wigtownshire, South-Western Districts, 6s. 4, Wigtownshire, East Park: Kirkendbright, portion of W, Division. 6s. 5, Kirkeudbrightshire, Southern Districts. 6s. 6. Kirkcudbrightshire, S.E.; Dumfriesshire, S. margin. 4s. 7. Ayrshire, South-Western Districts. 6s. 8. Kirkeudbright, Ayrshire, and Wigtownshire. 6s. 9, Kirkeudbrightshire, N.E.; Dumfriesshire, 5.W. 6s. 10. Dumfriesshire. 6s. 11. Roxburghshire and Dumfriesshire. 4s. 12. Argyleshire (Kintyre). 4s. 13. Ayrshire, Turnberry Point. 4s. 14. 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