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Les diagrammes suivants illustrent la methodo. 1 2 3 1 2 3 4 5 6 MKROCOPV RBOIUTION TBT CHART (ANSI and ISO TEST CHART No 2) |» 1^ 1^ 116 1*0 U(2.0 ■ 2.2 I 1.8 1.4 ^l^ ^ r^PPUEDjVHGE '653 Eojl M<:ir> SIrwl ("6) 4«2-03cO-P(,on, ("6) 2M-5989-fo, In *i- cf\. M, i(2z. jb^gAOA DEPARTMENT OF JjJJiES Htm. Loan Ccbbui. Mmtttu; R. W. Bmcs, Dbtutt MiMimi. GEOLOGICAL SURVEY I MEMOIR 60"! No. 47, Geological Skribs Arisaig-Antigonish District, Nova Scotia IT M. Y. WllUami OTTAWA GOVSBNMENT PRINnNO BUBBAU 1914 No. 1308 CANADA DEPARTMENT OF MINES Hon. Lovu Combu, Mimiitbb; R. W. Bbocs. Dinrrr MiNuna. GEOLOGICAL 8UBVBY Ml .VIOIRM No. 47, Gbolooical Sbubs Arisaig-Antigonish District, Nova Scotia n M. Y. WiUiuiM OTTAWA GovnunaiiT Pmmiia Buibas 1914 No. UN I CONTENTS. CHAPTER I. Introductioa Gciwnil ftatrmrnt and ■cknowledgmraii Location and area of Arinaif-AniigonUh dUtrict. General character o( Arl«aig-Antigoniih diatrkt . Meant of communication Paoi CHAPTER II. Previoui work. CHAPTER III. Summary and conrlutioiM General itatement Phyriography Obiervationt Conclu«ioM Sedimentary formation! Browns Mountain group. . . ObaervatiofW Conclusioni Malignant Cove formation. Obeervations Conclusions Aritaig series Observations Conclusions Knoydart formation Obeervations Conclusions McAras Brook formation. . Observations Conclusions Ardness formation Observations Age and correlation. . . Listmore formation Observations Conclusions 2S 25 35 25 26 26 26 26 27 27 27 28 IS 28 29 29 29 30 30 30 31 32 32 32 33 33 33 I. Qiwtcmary depoiita jj Obaerratioiw 3j ConcliuioM 3^ IlMoua intnuives and extnuivet 34 Acid rocka ' " ' ^ ObwrvatioiM '[ 34 Conclunons 3j Ba«c intnuivei '[ jj Obiervations 35 Conclusions 3ij Tuff and breccia ''[ 3^ Economic deposits ' _ 37 Copper '"" 3y Observations 37 Conclusions 37 Iron ore of Arisaig and Ross brooks 37 Observations 37 Conclusions 37 Iron ore of Doctors brook and Browns mountain 38 Observations 3g Conclusions 3g Oil-shale m Observations 39 Conclusions 39 Gypsum 39 Observations 39 Conclusions 39 Limestone ^ Observations 40 Conclusions ^q Gravel ^q Other economic deposits 40 CHAPTER IV. Physiography 44 Regional 4j Local ] 42 Land forms 42 General statement 42 Highlands 42 Lowlands 44 General statement 44 The shore front 44 Carboniferous lowlands 47 Drainage 49 iU. 1 I CHAPTER V. Paob. Stntigmphy 51 Introduction SI Table of formations 53 Remark! 53 Browns Mountain group 54 Extent and area 54 General character* 54 Mode of origin 54 Fossil contents and age 55 Correlation 55 James River formation 55 Baxters Brook formation 57 Malignant Cove formation 58 Ariaaig series 61 Extent and area 61 Character 61 Mode of origin 61 Fossil content 62 Divisions of Arisaig series 62 Age and correlation 62 Beechhill Cove formation 63 Ross Brook formation 64 McAdam formation 66 Moydart formation 69 Stonehouse formation 71 Knoydart formation 73 McAras Brook formation 75 Ardness formation 77 Listmore formation 79 Quaternary deposits 79 Pleistocene 79 Recent 80 CHAPTER VI. General and structural geology 82 Introduction 82 Browns Mountain group 84 Extent 84 Igneous intrusions in Browns Mountain group 84 Structure 84 Relation to older formations 85 Metamorphism 86 Malignant Covr formation ***?: Extent and characten "' Probable ftructural relationa .. Probable age " Aruaig series |' Extent and general relationa ao Structure f„ Upper contact Knoydart formation g\ Extent and general characters g. Structure ^ Post lower Devonian, pre-Mississippian fault. ...... 93 General description „, Age :::::::;:;:: 11 Character " McAras Brook fo.-mation „, Extent and area «. Structure and relations oa Ardness formation Extent and general characters gj Structure and relations [[[[ g, Listmore formation Extent and general characters on Structure " *g Recent deposits of Stream gravels IT 99 CHAPTER VII. Igneous geology General statement inn Table of igneous rocks ,«- James River granite ini Location and extent ini Petrologic characters loi Contacts of the granite .„■ Structural relations jn? Mode of origin ,_. Age '.'.:'.::::::'.::::::::: SJ Monzonite intrusives Location and extent .q. Petrologic characters jq^ Age and correlation jq^ Aporhyolite flow at the base of the Silurian section '. . . 107 Distribution and general characters jny Petrologic characters ing V. Structural relationa I jq Mode of origin j.. Age and correlation 112 Volcanic (?) breccia of Frenchman's Bam 112 Location and general characters jl2 Petrologic characters jji Mode of origin .., Acid intrusives .^ , ., Distribution .., Petrologic characters j j4 Structural relations ..5 Mode of origin j.^ Age and correlation ..y Volcanic tuff and breccia of Sugar Loaf area ng General location and extent Ug Petrologic characters j jg Age ^^////^'.'.'.'.'.'.'.'.'.'. 119 Diabase intrusives .jq Distribution . .n Petrologic characters j2i Structural relations j22 Method of intrusion j24 Age ^y^^'.^y.'.'.'.'.'.'.'.'. 124 Basalt, breccia dyke, etc j25 Location and extent I25 Petrologic characters j26 Manner of intrusion and relations i2g CHAPTER VIIL Historical geology j3q General statement .jn Lower Ordovician period j3q Middle Ordovician period J3j Silurian period .32 Lower Devonian period I34 Middle and upper Devonian period I35 Mississippian (Lower Carboniferous) period 135 Pennsylvanian (Upper Carboniferous) period 135 Cretaceous period J37 Tertiary era J3g Quaternary era J30 Pleistocene or glacial time 13g Recent events 139 CHAPTER IX. Eooaomic geology j4q Introductory (cmarla 14^ Copper 1^ Distribution and ntent 140 Procpecting 140 Similar copper occurrences elsewhere 141 Probable origin 142 Conclusions as to future possibilities 14a Silver 142 Iron ^ 142 Introductory remarks 142 Distribution, extent, and development 143 Composition I43 Relations to enclosing rocks 144 Descriptions of individual localities 145 Iron ore of Browns mountain 145 Iron ore of Doctors brook 145 Ore of Ariaaig and Ross brooks 147 Genesis of iron-ore deposits 143 Oil-shale 15q General character and distribution 150 Gypsum 151 Distribution and extent isi Character Ul Development fi:\d future possibilities 152 Limestone 1J2 Distribution and foimer development 152 Relations and general character 152 Future development I53 Gravel "'' I53 CHAPTER X. Bibliography I54 INOM 153 ILLUSTRATIONS. Geological map (138A), Arisaig-Antigonish district In pocket Geological map (137A), Ariaaig in pocLiet Arisaig-Antigonish District, Nova Scotia. CHAPTER I. INTRODUCTION. GENERAL STATEMENT AND ACKNOWLEDGMENTS. The subject matter of this work has to do with a geological district situated in Nova Scotia, which has already been given much careful attention by geologists. Wiuhin the area studied Ii« the key to the stratigraphy of a considerable region; here critical data bearing upon the inter-relations of formations rang- ing in age from lower Ordovician to Pennsylvanian (Upper Car- boniferous) may be sought and found. The purposes in further examining the district and making the present report, were mainly two-fold: first, to work out in greater detail than had hitherto been done, the stratigraphlc relations of the sedimentary formations to one another and by means of such relations and from palxontologic evidence to determine more c'-«jely the age of the sediments; and second, to classify and work out the relations and ages of the intrusive and extrusive igneous rocks of the district. In pursuit of data relating to the objects sought, the neces- sary surveys were made to permit the remapping of the geology of the district, and much information was secured relating to the geological problems of the region. Additional data were also obtained bearing upon the physiographic forms as described by previous writers. A careful survey was made of the iron-ore prospects near Doctors brook, and of the gypsum deposits south of the Intercolonial railway. The writer desires to acknowledge his indebtedness for advice and assistance to Professor Charies Schuchert of Yale Univer- sity and Prof. W. H. Twenhofel of the University of Kansas, who were present in the field during the eariy part of the work. Professor Schuchert has supervised the examiration of the fosuls collected from several formations by the writer, and of the de- tailed collection made by Professor Twenhofel from the Silurian section at Arisaig. The writer is also under obligations to the following professors of Yale University: L. V. Pirsson. under whose guidance the petrography of the district was worked out; Joseph Barrell whose advice and criticisms have been of great assistance in the structural studies undertaken; Isaiah Bowman, who has given useful suggestions and criticisms relating to physiographv; and J. D. Irving for criticisms on the economic conclusions presented herewith. Mr. George E. Corbitt gave assistance in the examination of the iron-ore prospects which were under his management. Owing to the entrenched nature of the stream courses, and the second-growth timber covering the higher lands, traversing was difficult and the pace and compass method seemed best adapted to the conditions. A 4-inch tripod compass was used Tra- verses were tied to definitely located points and wherever practicable, they were run between fixed locations. In the survey of the iron-ore prospects of Doctors brook, a careful compass and chain traverse was made. Barometric measure- ments were taken at many places to facilitate the study of the physiography of the region and the making of structure sec- tions. In the absence of a barograph, it was seldom possible to check the barometer readings oftener than morning and even- ing, and they are accordingly to be considered only approxi- mately correct. Work in the field was begun by the writer on June 22, 1910 and continued until September 20 of that year. Mr. M h' McLeod of Northeast Margaree, Cape Breton island, who acted as field assistant, began work on July 6 and continued in the neld until October 8. Mr. McLeod rendered valuable assistance in the mapping of the geological formations and took charge of the re. ision of the base map. 'I 3 LOCATION AND AREA OF ARISAIG-ANTIGONISH DISTRICT. The Arisaig-Antigonish district fronts on Northumberland •trait and is situated about one-third of the way from Cape Breton to Pictou harbour. The area studied includes 10 miles of coast line, with Arisaig point at its centre, and extends inland southeast about 11} miles to the Intercolonial railway, includ- ing also the gypsum deposits south of that railway. The approx- imate area of the district is 115 square miles. GENERAL CHARACTER OF ARISAIG-ANTIGONISH DISTRICT. The name of the district is derived from the small settlement along its front, whose name has long been associated with the Silurian formations of the vicinity; and from the town of An- tigonish, which is situated in the southeast comer of the dis- trict. With the exception of a small area along the southwest side, which is in Pictou county, the district is entirely within the county of Antigonish. This county was settled during the last quarter of the eighteenth century by Highland Scotch pioneers, whose descendants still occupy most of the farms. Besides farming, lobster, salmon, and mackerel fishing are important industries and some lumbering is still carried on although nearly all the timber is second-growth. Red spruce rapidly encroaches upon the cleared fields, especially along the shore, and hardwood including red maple, beech, and yellow birch commonly forms the deciduous growth of the highlands. Lobster canning and the manufacturing of dairy products are carried on to some extent in the district. MEANS OF COMMUNICATION. Communication is furnished along the south border of the area by the Intercolonial railway, and stage routes from East Merigomish and Pictou reach the interior and the shore settle- ments. Steamboat communication is somewhat irregularly inaintained between Arisaig and Malignant cove, and Pictou and Cape Breton ports. CHAPTER II. PREVIOUS WORK. A* a reault of its favourable location on Northumberland ■trait, Antigonish county was easUy accessible to naturalists and was one of the first parU of Canada to be studied geologically. As early as 1827, Francis Alger, a mineralogist from Massa- chusetts, commenced work on the iron ores and mineralogy about the Bay of Fundy. For several years following, Alger and Charles F. Jackson, who later became State Geologist of Maine, New Hampshire, and Rhode Island, continued the work m Nova Scotia, extending it to cover the broader geological fwtures of the whole province. These gentlemen, along with r«,'^ °^ Canadian geologists, Abraham Gesner, Sir J. W. Dawson, and Reverend D. Honeyman, were the pathfinders ui the geological study of northeastern Nova Scotia. They were followed in the work by Hugh Retcher, H. M. Ami, and R. W. Ells. aU of them officers of die Geological Survey of Canada. The fossils obtained from time to time were described by E. Billings and J. F. Whiteaves, palaeontok)gi8t8 to tiie GeoktgicaJ Survey of Canada, and James Hall of the Geological Survey of New York State. Otiier investigators whose work has added to tiie geological knowledge of tiiis district are: Professor R. A. Daly, of Harvard- Professor J. E. Woodman, of New York City Univereity; Pro- fessor W. H. Twenhofel, of the University of Kansas; and Pro- fessor Charles Schuchert, of Yale University. The first systematic geological study of Nova Scotia was made by Francis Alger during his exploration of tiie iron ores of Annap- ohs county. Besides the iron ores, various mineral and rock oaairrences were described and remarks were made on the erosive action of the tides, etc. His results were published in 1827 under thetitie "Mineralogy of Nova Scotia." « Two years later, Jack- • Alscr, Francis. Amer. Jour. Sd. and Am, Vol. XII, itp. 227-233, 1827. ■on and Alger' published an account of their more extended explorations, and also a geological map of the whole province. Their geological subdivisions, which were fourteen in number, were baaed on lithological distinctions; the occurrence of beds of gypsum, iron ore, or coal; the presence of marine fossils, lime- stone, etc. It is evident from the text that their more detailed explorations extended into Plctou county, but stopped short of what is now Antigonidi county. The metamorphic lower Or- dovidan formations of the uplands, together with intrusive igneous rocks and some younger Palaeozoics, were mapped as 'Transition Clay Slate." The younger Palteozoics, as a class ranging from Silurian to Lower Carboniferous, were included under "Red and Grey Sandstone alternating with black and red shale containing impressions of vegetables, beds of coal, etc." The above were respectively divisions III and IV and as mapped were rather inaccurately bounded. A number of locations of gypsum, iron ore, and coal were fixed, giving the map a practical value. Notes on the topography of the country occurred in the text. The "South Mountains" were described as passing \ito Pictou district, while the remaining uplands of Pictou and those of Cumberland county and Colchester district were described as "rounded hills of inconsiderable elevation." In a later publication* "gypsum of piactical worth" was described as occurring near th« head of the "Basin of Minas" and also near Windsor. Limestone containing marine shells was mentioned as occurring at the latter place. Among many other interesting observations is one on the relations of what are now known to be Carboniferous sandstones and the metamorphic lower Ordovidan rocks, seen at East river (of Pictou). Because of the high dip of the "clay slate" to the northwest and the gentle dip of the sandstone, the relative ages of the formations were determined although no contact was observed. Jackson and Alger continued work in Nova Scotia for a short time longer; a new edition of their report appeared in 1833*; * Jackwn. C. F., and A^, Frandt. Am. Jour. Sd. and Arte, VoL XIV, pp. 305-^30, 1828. ' Jackaon, Charles F., and Alfcr, Ffands. Amer. Jour. Sd. and Arts, Vol. XV, pp. 132-160; 201-217, 1829. ' . Mem. Amer. Acad. Arta and Sd., 1S33. •nd their new geoloficd map wu publidwd in Botton in 1841. Their later work wi« not concerned with problenu reUting to the dtttnct now under oontideration and eo need not be reviewed Bere. The firit man of Britiih birth to underuke the taik of unravel- Ung the geology of Nova Scotia waa Abraham Ge«ier. a native of the provmce. whow birthplace waa at ComwaUia. By profea- •ion a physician and wrgeon. he became more and more inter- ested m geology and finally waa made provincial geologist of er entitled "Remarks on the Geology and Mineralogy of Nova Scotia" was published at Halifax. Aftw the work of Jackson and Alger tiiis was the first treatment of ti>e subject. It gave a fairly accurate impresMon of the geology of the province as it was then known and set forth some original Ideas relating to tiie district about Arisaig. In the geological map of the province the rocks were divided in descending order into: (1) Red sandstone. (2) slate, greywacke. and greywacke Slate, and (3) pnmary granite, gneiss, and mica slate. The high- lands of Antigonish, composed of lower Ordovician and igneous rocks, were included in the slate, and the remainder were put in the n^ sandstone division. It was also noted that coal occurred near Pictou, south of Antigonish harbour, and elsewhere. An 18-foot bed of iron ore occurring south of Pictou was described as containing marine organic remains. These are men- tioned (page 61), but from the names there used no correlation can be made. The ore and containing greywacke held the same fossils nd were recognized as being of the same age. It waa suggested that the ore bed was a deposit of iron-bearing sand 8u<. 1 as occurred on Sable island. Greywacke and greywacke-slate were described as extending from the East river of Merigomish to Arisaig pier, where they were penetrated by a bed of porphyry. The last statement is very interesting, for if the reference be to the volcanic rocks, as It doubtiess is, Gesner was the one man among all the eariy work era to recognize die true origin of the old rhyolite flow, so com- monly described in later reports as an altered sedimentary. The derivation of the Carl jtiiferoiu oongloaMratca from the older formatUma waa iccocnized, and the materiala were thought to be worn down and depoaited by curranta in the depreisiona of the older rocka. Geaner described the limestone and gypaum of Windsor and Antigonish, recognizing their stratigraphic relations and men- tioning the sink holes and general Icarst topography accompany- ing them. The formations were named in ascending order: Old Red sandstone, Carboniferot 'Tiestone, Millstone Grit, and coal. These ft the late literature are known respectively aa Horton and Riversdale formations, Windsor group, Millstone Grit, and Coal Measures; the first two divisions being referred to the Lower Carboniferous and the other two to the Upper Car- boniferous or Pennsylvanian. Bom (1820) and brought up at Pictou, Nova Scotia, J. W. Dawson received his early training at the Pictou Academy. After graduating from the University of Edinburgh, Scotland, he returned to his native land in 1847. Even before thit. he had w'tten on the coal formation '' his home county with which he was so familiar. During the period between 1855 and 1893, Dawson w-\s principal of McGill University, also holding the chair of natural history. During his life he published many books pnd articles relating to the geology of northern Nova Scot' ■. From among thum those will be considered which are most directly related to the problems in hand. In 1845' Dawson published his first work on northeastern Nova Scotia, accompanying it with a map by Gesner. The article contained a concise account of the "coal formation" and the "gypsiferous formation," giving their general geological rela- tions and their relations to other groups. Of the sections illus- trated and described, the one extending from Merigomish to Malignant cove is of special interest to us. The band of Car- boniferous rocks included between the shores of the gulf and the hills to the southward, was described as having a thickness amounting to 10,000 or 12,000 feet. ' Dawson, Sir William. 35, 1845. Quart. Jour. Geol. Soc., London, Vol. I, pp. 26- o»n««iing ot two beds having an aggn-gaie thitkm-M of M) r^.* dupl.ca,«>n by faulting not having ien reciS Nu^^u: b^k nnl JL 7y«^-'°"'«l "-"P" at the mouth of McAra. brook were n.entioned a. probably underlying the CarLifcro« The Kction between McAra. brook and Ariwig. Daw«>n wmt, .^th^t LTti!? *";*' conglomerate. The« rocks dip k-" ir the „ri» ,h.„ .he I,.. «.r .* mS™ J^ktC n^^ irrr^' ,. "^ '" P™"'»°« »» mentioned a< bein. r rrert^r:2L^Ter?^2:HS" "-"'^'' ^^"^ theh„, , .eeSandso^ttoSignTnt'^ve" "™^ °" with an?!^'^'"""' "^^ °^ ^r '*°"'^ *'^''»"' ^"^ then dealt with and a section wa« given of the strata exposed along Righu nver. Dawson also noted an outcrop of gypsum nearly 200 C lin h""'";!!."^ "' '^^ °"*'^* «^ ORdens laE, which ITenius^aS and descnbed in considerable detail mustrated (2)^rRirrH''l"*'^"' ^T ^°''" '"^°= ('> C°-' Measures, and s^riat Td U W '"^ ^>'P«:^-°"» «"«■ ^ Metamorphic ana biiunan and (4) Igneous rocks. Within divisions 1 and 2 the Ansaig-Antigonish district is included. ' It will be Men that in this paper, DawMMi laid a Arm foundation for the more detailed geology which waa later tupplicd by Honey* man, Fletcher, and others. In 1847I a letter written by Dawaon to Profeaaor Johnion, gave a careful treatment of the geological age and relations of the gypsum of Nova Scotia, with descriptions of sections as exposed at Ogdens point, in Antigonish harbour, and elsewhere. In sum- ming up Dawson wrote: — "Its constant association with limestone of the Carboniferous system containing marine fossils proves that it was deposited in the sea, and ft>m the present relations of the Carboniferous rocks to older sybtems, in this province, it is probable that the sea basins in which the gypsum was deposited were not very exten- sive. In these sea basins the deposition of gypsum alternated with mechanical deposits of sand and m.irl and with the growth of shells and corals; but the conditions which produced beds of gypsum were unfavorable both to the transport of sediment and the existence of animals or plants." Following these apt remarks were suggestions that "springs and rivers" bearing free sulphuric acid from decaying iron pyrites may have flowed into seas where lime had been deposited and thus gypsum was thrown down. As an inst^ nee of such rivers the Rio Vinaigre of South America was cited. In a paper entitled "On the MeUm^rphic and Metalliferous Rocks of Eastern Nova Scotia,"* published in 1850, Dawson made mention of the Arisaig rocks and stated that a small col- lection of fossils from their upper beds had been sent to Pro- fessor Hall of Albany, who gave it as his opinion that \.tiey belonged to the age of the Hamilton and Chemung groups. T*"'s correla- tion Hall himself later showed to be wrong, referring ' i . rocks to the Silurian. A description was also given in .his paper of the ■lates, quartzites, and igneous rocks of Cape George, and the Antigonish and Merigomish hills. In the first edition of the "Acadian Geology," Dawson briefly descri bed the Arisaig region and stated that some fossils obtained ' Uawnri, Sir William. Proc. Acad. Nat. Sci., Phila., Vol. Ill, pp. 271- 274, 1847. * Dawson, Sir WtUiam. Quart. Jour. Geo!. Soc., London, Vol. VI, pp. 347-361, 1850. 10 Dawson classed these nvlr. o. n ^ ™''- ^" ''»» "»P In 186n. n '*"*'" " ^*^°"'^" and Upper Silurian. War..^:rSiS^ ?* Gold-bearingsenesof Nov. also. T;re..si;;:ran°-td'^E^o";L^^^^^^^^ The Arisaig Silurian strata were referred tn o. 'u„ r .l date " Lists of foSf '^ • "^*"' *'^P °^ Carboniferous wWch thtm tI ''T ^'''"' ^°"« ^"'' ^« horizons from rrh. V^-^ . ^"^ ^""" *h^ 'o^^' «haly beds were placed 572%^^ T""^ '^'''°" °^ '^^ "A'^^'an Geology" (1868 paeea Sxhuchert, Charle.. Amer. Jour. Sci.. (4). Vol. XXVIII. p. 163. 1909. 1^1 ^1 '4 I 11 upper Arisaig series were thought to be equal to the Clinton of New York and the Upper Llandovery of England and perhaps a portion of the time represented by Wenlock and Niagara. He stated that the strata of the lower part of Doctors brook might be equivalent to an older member of the "Upper Silurian," but probably was not so low as the Medina and Oneida of New York or the Lower Llandovery of England. Dawson still referred most of the rocks of the Cobequid moun- tains to the Arisaig series, basing his opinion upon fossils col- lected at Earlton and New Annan. In 1875, writing on the "Geological Relations of the Iron Ores of Nova Scotia,"' Dawson described a 30-foot bed of laminated, more often oolitic iron ore occurring on the East branch of East river. The rocks contained characteristic fossils of the "Arisaig group" and were thought to be equivalent to the American Lower Helderberg or the English Ludlow. Peroxide of iron was found in minute concretions enveloping grains of sand and the ore graded into ferruginous sandstone. The iron content of the ore was 43-54 per cent. Writing in 1878, in the third edition of the "Acadian Geology" (page 58), on the Post-Pliocene period, Dawson recognized the following deposits in descending order: — (1) Gravel and sand beds, and ancient ridges and beaches,' indicating the action of shallow water and strong currents and waves. (2) Stratified clay with shells, indicating quiet deposition. (3) Unstratified boulder clay, showing united action of ice and water. (4) Peaty deposits of land surface before deposition of boulder clay. The account included the directions of a number of glacial scratches, tending mostly to the south and southeast. Floating ice and glacial action were considered as possible agents produc- ing the deposits noted, but Dawson favoured the theory that the deposits were due to the action of floating ice during maritime conditions of the land, and explains "horse backs" and "boars' backs" ridges as due to currents during the retreat of the sea. ' Dawaon, Sir William. Can. Nat., new ser., Vol. VII, pp. 129-138, 1875. the top of the Silul« N?, ^ °* .'"" '^'' ■^"'wtia,, to their clearness. The aj of hU r ,Z "V-^P^"^"^ because of Cambrian." '=°"^'"«'°»' Dawson referred them to the "Siluro- The Carbo.u.erous system was divided into:- glomeratr" """' °^ '^'''' Carboniferous shales and con- (3) Sst; Gr? " '°^^^ ^^''-"^^-- «— (4) Coal formation. ^Dawson^WilHam. Can. Nat., new ser.. Vol. IX. pp. 315-314 1881 816. im. • ^"'^*- J°"^- ^~'- Soc.. London. V^XLIV. pj 797- 13 ll> 1 it 1 e n e i 1 » 1 The areas of Carboniferous strata were described and the earth movements bringing about the varying conditions of sedimen- tation were compared with those movements which produced the great unconformities below and above this system. To explain irregularities in sedimentation within the system itself, current action was odled upon. Under Pleistocene, Dawson discussed rock scratches and trans- ported materials, explaining them by supposed denudation of the lower lands, which were "traversed by northern currents of ice- cold water, bearing floating ice throughout the year." Local glaciers were supposed to have existed on the hills but the author says, "I fail to find, either in the Acadian Provinces or in Canada proper, any indication of a great continental glacier." He made the statement that "Glacial striation is very frequent wherever fresh surfaces of rock are exposed." Thei. followed a table giv- ing the location and direction of fourteen examples of such stria- . on, with the statement that there is "a tendency to a southerly and southeasterly direction, which accords with the prevailing course in most ports of northeastern America." Taking the Pleistocene of Prince Edward Island as an illus- tration, Dawson stated that the deposits here consisted of "Post- Pliocene boulder clay composed of red sand and clay derived from the waste of the red sandstones, * filled with boulders of red sandstone derived from the harder beds." The latter were described as being "more or less rounded, often glaciated, with striae in the direction of their longer axis." Later the text went on, "No marine remains were observed in the boulder clay; but at Campbellton, above the boulder clay * * * there is a limited area occupied with the beds of str?.tif^ed sand and gravel, at an elevation of about 50 feet above hi sea, and in one of the beds there are shells of Tellina Graenlandica." Boulders on the surface of the country were referred to a newer "boulder drift" and were correlated with the Saxicava sand. Some of the boulders were supposed to have come from Labrador, others from Cape Breton, and still others from the mainland of Nova Scotia. The existence of the boulder clay and native boulders was thought to be due to one of two hypothetical processes. Either W 14 m snow and ice to affn^i « thoroughly enve oped t«u,de. dHft w:: arf:;iToTrrJ'o1.-7-; ^'^ '^' ;lt; ^n-o^f --- "P -e cS^°/.,TA^-reS: Js- Si'^rtht;^^^^^^^ --^h a discussion of of Europe, and its dec'S'Lnt:^^^";^ ''?^"«^ *° *»>-* of Canada or the United Sta?« a I , ' ^"^'"^ °^ ^''^ "^^ for the region was appSdcrf "'"' ^^'"^ °^ formations begt tZTo;"ca7:rist'::r ^ *T °' ^"^^^°-''- -<» the interesting rocks ateLthr A '°"''*°' °^ ^°««"« «niong the r., .eo4c"prbSstf%t"J,„^^^^^^ En^htened as tf editionof Dawson's-AcadianGeolo.^'" ?^K y '^^'^'"^ '''^ '^f ance with its author. ^nTy^T^or^^^'^'^'"'' ''^-'^''^'^ accuracy. He published many ^Z^^f ""j '" P"^ and Ansaig region in various srient.r " ^~'°«y °' t'^* called f«>n, his pastoS duSn Lr^^T' ""^ ''"^lly was Nova Scotia Department ar^hl "^"^ "«*. »« '"Perintend the Becoming acquai^tS^^th - L"'!''°" '" ^"^°" '" ^862. to European colle.SonrionevCn^'^^^'i""'' ''"^"8 access the task of corn^latin^he SiLrTan f ''*'*'^ '"''""^'f ^^P'y '" of the Atlantic oc an "sad^"! formations on the two sides the Silurian formai ^f Arit T.' °' *"" ^"«''«'- ^^"dies as set forth on^oth" tge ^'^ ""* '"'^'^'^«' '^^ Ave zones. thi cSian°(SS S^:? " h1 °' ^^'^^-^ --ty ^or the Pn>vi„dal Mu'Slm a'SkT'i™"':'^'"^'''^"^^ he made extensive studies nn i, ,* • ?? **"' °ty as a centre, with which Phasi o gtTo^hTsTat't?;'^'^ ^"' «'^'^'^''°" Honeyman-s first eeolSl n. Kr ^*'"^ '""'^'y ^^al. contained a some^ha^^Tu^r Pubhcafon. appearing in 1859.. their contained o'ans™ Of th?r' f *'' ^""'^ ''^^ and ganisms. Of the fossils mentioned, Prod«<:/,„ ' Honeynuui, D, 10-29, 18S9. Tr«u. Nov. Scotiaa Lit. and Sd. Sec., Halifax, pp. ich !re ed er 'y tit It St 18 i I } 15 depressa (^ Leptaena rhomboidatis), Spirifer elantus, Calymene blutnenbachii, and Homalonotus are the only ones that are now •ignificant. From the prevalence of Calymene hlumenbachii and Homalonotus and the general resemblance of the fauna to that of the Upper Ludlow, the author rightly concluded that the rocks were of "Upper Silurian" age. Five years later > fresh from his studies and comparisons in England and Europe, this persevering worker published the results of one of the most important pieces of geologic work done on the Silurian rocks of Nova Scotia. Having consulted Salter, an English palaeontologist, Honeyman proceeded to divide the Silurian rocks into five subdivisions, which he designated by let- ters and correlated in ascending order as follows: — A. The approximate equivalent of the Mayhill sandstone. B and B'. The equivalent of the Lower Ludlow of England. C. The equivalent of Aymestry limestone. D. The equivalent of Upper Ludlow. According to this correlation the Wenlock group or the whole M'ddle Silurian, is missing between divisions A and B. Dawson agreed to the above with the exception of D, which he considered equivalent to the Lower Helderberg of New York State. Honeyman traced his divisions inland and carefully mapped them. Three crose-sections were added to interpret the struc- ture. The synclinal arrangement was recognized, but was some- what perplexing to the author who believed it to be due to the intrusion of the "augitic trap" seen along the shore. Thicknesses of the various divisions were estimated, and many fossils were named with the localities from which they were obtained. Daw- son's theory that the old volcanics were metamorphosed sedi- ments was perpetuated in this article, and these rocks were thought to belong to division A. In 1866* the strata extending up from the mouth of McAras brook were recognized by Honeyman as lying unconformably • Honeyman, D. Quart. Jour. Geol. Soc., London, \r'.. XX, pp. 33i- 345, 1864. * Honeyman, D. Nova Scotian Inst. Nat. Sci., Vol. I, pt. IV. dd. 106- 120. 1866. . w ««- 16 fim recognition of acZr^^oJlT T '^"- '^^'' *« ^he F«rt of the pi^vince. Tthe r'lL"?' '"•"'" northeastern Hall and Lyell turned out trS |?,„Hr""" ^°"""*'°"« <>' -rtre ro-fci^dtirr ^^^^^^^ -r and at the Sugar T^rh-iiK;-- ^^^ ^^"^ °^ J-^ a-SnSr^^^^^^^^^^ the sea subsidence was responsible t^Sea^l^r*^ *''"^ ^°"*'""«' the lack of recognition of a^y ^L , „ l""^" ^«^^"« °f S'lunan and Devonian for^atTol no " °™ ^^ ^'^^'^ ^he was thought to hav- occS un.h f.^l* "P'*'* °^ ^^e land Devonian sediments. Then^olfolf '' ""' ^"P^^'^'"" °^ ^^e erosion interval was r^ogSed tl^ r?'"'^^' ^" ''"P^^ant •trata were la' ' down. The uplift Z ^''"' ^^'^^niferous the .^ntrusion of the trap shits 2^/^"^^ *° "^ •■^'^*^ ^° brook The extensions of th? Ca^"? """""'^ "^ ^^"^ eluded limestone and gynsum ^ ^ ^'■°"' '°^^ ^'th the in- tigonish were discu^T„rf T'^J ^^"' the town of A^- Doctors brook an?tSicTfiedconr'''"^ '™"*°"^' ^'- oi -re referred to the Car^ro^ 7hTL°' ''^"■^"^"* ~- Ordoyican age. as will be shown later in ..' '' ^'^^^^'^ °f 'lescnpt.on of the Malignant cZ Z:;,:^'' "'"^ ""^^ ^'"^ Ma^vlXettit^X^^ ^k/--' --^« o' the "intervales" or flarbottomT^? ^'^^^ «'^'^'^' °ri«in. and town of Antigonish were thoTg^rtt .^^^^^ ^"* "^^' ^^ ^^e probably equivalent in time to the '-^ °' f ' ^""^ ^«^' being Cape Breton, in which the theh L ^^fVf' °' ^'dd'^ ^ver found. *"«'' '^ne of Mastodon Ohioticus wai 17 I so the em of ■er, )e. les ea xl of le d e t s > rocks containing the dawn animal or Eotoon, east of Malignant cove. Passing over some publications in which little new material was given, we shall consider Honeyman's paper of 1875.' Not confining himself to the shore lowlands, he described ten sections including much of the plateau to the south of Arisaig with its metamorphic sedimentaries and varied igneous rocks. The Silu- rian strata of Doctors brook were found to be fossiliferous. Those near the shore road were recognized, from north to south, as belonging to A, B, and B' divisions of the Arisaig series, and across a syncline nearer the Hollow, strata of B', B, and A divi- sions were found. Honeyman observed on the Old road south of Arisaig, a syn- cline axis and thought the strata were higher than D or Upper Ludlow, calling this division E. Mention was made of salt springs near the town of Antigonish, which had been tested but were found not to be permanent. Later papers appearing before 1888 added little information. In a publication of that date' Honeyman discussed the super- ficial geology of Nova Scotia, dividing the country for convenience into five topographic districts. He described moraines, perched boulders, and the clay under the town of Antigonish bearing fossil plants, etc. The gravel hills near Maryvale were classified as of Champlain age, a classification based upon certain types of valley formations and the northward transportation of material. The "intervale" of Antigonish, along with the marshes and dyke land of Amherst and Grand Pre, was considered of recent origin. In 1860* James Hall described thirty-seven "New Species of Fossils from the Silurian Rocks of Nova Scotia" accompanying his publication with twenty illustrations. On other occasions he gave valuable opinions on the fossils from Silurian localities, and assisted Dawson and Honeyman in fixing the age of the rocks. In I860* E. Billings described a new starfish found by Honey- man at Arisaig in his zone C, and named it Palaester parviusculus. ' Honeyman, D. Nova Scotian Inst., Vol. IV, pp. 47-79, 1875. ' Honeyman, D. Nova Scotian Inst., Vol. VII, pp. 131-141, 1888. ' Hall, James. Can. Nat. and Jour. Sci., Vol. V, pp. 144-150, I860. * Billings, E. Can. Nat. and Geol., Vol. V, pp. 69-70, 1860. It 'ron, the An.aig 41^^" "*'' "^^ <'' LanieJlibrancS west a, the East river 7^^''''' '"^ ''^ •°'"«' -°^<^ as Ti' dc^yon^;;^^^^^^^^^^^ yea, he .ve a .Hef of volcanic activity; and «mLS?w ' ''"u?""*^ two period, rocks present on the coast of Ari J ^' "^'"''"^" °' Silurian part of the volume of th^on^Lf"r*'*Pr"^^ ""'^ « ""all «;«.ng in the counties of Sou a„H A '."'''* C«'»«nife«.u. In I886» Fletcher in h- ° Antigonish. Guysborough. Antigonish': rnTpiru""*''-'"' exploration, in account of the geology of tht ? • ° *»""»>«, gave a detailed onish district. Thel^neral .. ^°" '""'"^''"^ *''« Arisaig-AntiT ph^s of the g«„:^^s rfS ii:rT' ^"^^ ---^^ maps and reports were so relirbTe thL I *"'' "^"^ Fletcher's fonnatirs. "^^Z.^^ 7^ ^-^^ ^ ^"e Silurian fully mapped, Honeyman'I work 1^- ^""^'^ «"« were care- ever, the formation-nam^ of mL T^ "*^ •" ^ ^^^^ How- ton. Niagara, and Lowe7 HeS^r^t"" "^'L"^""' ^PP^'cS- «ons A. B, B-. C, and D of Ho„! ^ ^^* substituted for divi- instead of Arisai^ irfes FWr""!!:. *''"* '°^ '^^ whole grZ section along the^bTaTw!^^ e " "'^J'^'^ '*'"" ^"""an. ^rSe Jesuits for the first threeZ LT wS Th ST^'^' ^^' ^^ Honeyman. did not quite agrTJtul '^ ^" '"^asured by boundary between the Lowe^anH n ' P"^^""' ^°^k. The h-Rher than the boundary ^^eerl!^"''' ?"*°" ^^ P'acS n^ ry Between divisions B and B' of Honeys 19 illut. chiata been since «ton, is far brief ioda Irian nail 'OU8 in e- V- 1- i- P e e r Fletcher named no foaails found at Arindg but it may be inferred from the report that the correlation (and hence the names) of the formations was based upon evidence obtained from the collections made for the Geological Survey of Canada by Honeyman, Wes- ton, and Robert. In his interpretation of the structure, Fletcher agreed essen- tially with Honeyman. He recognized, however, an up-thrust block between Smith brook and a point east of the Trunk road and thought it was bounded by two north and south faults. It is worth noting that Fletcher divided the "Cambro-Silurian" rocks (included by Dawson in the Cobequid series and thought to be of Siluro-Cambrian age) into three formations. These were in ascending order: — "(1) The lower flinty slates, quartzites, and 'whin'-like rocks of James river and Eigg mountain. "(2) The soft reddish and olivaceous slates of Baxters brook and Brian Dalys brook. "(3) The reddish and grey sandstone, grit, and conglomerate of Bears brook." The red slates of the metamorphic area south of Doctors brook were placed in the second division and the silicified conglomerate of Malignant cove was referred with sohie doubt, to either divi- sion 2 or 3. Fletcher thought that in some localities he recog- nized an uncoHiomiity below division 2. The Carboniferous rocks were divided, in ascending order, into, Carboniferous conglomerate, Carboniferous limestone, and Millstone Grit formations. Two sections of these rocks were carefully measured and described. The first extended from the ponds of Merigomish to Knoydart, and the second was along Baileys brook. The igneous rocks of the region were described as they occurred in the field. The volcanic rocks of Arisaig point and Frenchman's Bam were described as being felsitic, but Fletcher was non- committal as to their origin, being content to say that they "have been regarded both as metamorphosed sedimentary and as vol- canic rocks." He did, however, recognize that the trap of McAras brook was intrusive and not interbedded as affirmed by Dawson. The Devonian rocks were described and many other 20 topict were dealt with m„nU - • above .y„op.i. Srl^rp^ '."'''"' °™' '''-' »>"» the the pre«nt «udy of the Vri JKmTJoTl!'."'""' •""»««« '» prehen«ve treats on the g"d^v " 'fh ^'"""- ^' « ^o™" a handbook for a .tudent entZ^ ,h J'.?*^."" ^''^"•^ «"d » work yet published. * ""^ '^'''^ »''•' » by far the be.t f,^"^'^^^^^^^^ expo^d th.ckne« of 683 feet of rcxk wi ^l u **• '" ^" ''^- ^''""^ « or summit of the formatbn rThe l^"""* •?" '^''''er the ba« an article by Ami- publish.^ in I JS)?^'' *°''' *" '"<='"ded in A» palaeontologist to the n^t^- • ^ Ami ha, publishtl a numbe^^T' ^"^'^°^ ^"^^a- H- M. near Ari«ig and ha, Ze much 1^:"^" °' '°""' ~"«^ted relationships. "'■'*^'' »° "'ork out the stratigraphic .trita oTLSrig""-""^ ^ "- °^ ^-•'- ^ound i„ the Silurian In 1900» in an articio on ••'i,.\^- • • -n Eastern Canada." Amilaht^;h"rr' ''^ ^-»-"'^-o"- by previous writers, and attempt^ to fi/^'^'"'°"' '«ogn«ed tions. Ami used the term Zf>r f ' ^^^ ^"'^ ~"«'a- hmestones with the acco.^„y ^^^^ ^T"''"" ^°' '^' '"^""e he stated, overlay unconf^rmaWv th^iT" '""^ "''"'«' *''''^b. formations. I„ this he sim^Ty fdlowi ^hT" '"^ ^'"*^"^^'<^ who ,n h.s Handbook of 1889 aoS^K ""^^^ °^ ^^«^«>n. to the limestones, sandstonT and st. ^"^ ^'"^"^^ ««rie, R.versdale formations and S^w tt M-^ ""' '^' ^"'°" and and River^lale formations, o-^rheej^'ir? """'• ""'^ ■^'"■°" remams. were placed by Ami n t^ r"t, .^""^ ^"^ P'ant White was quoted as confirm na h' ^f^^^^'^^'ous and David sure whether the WinS^r forZ.' °'''"'°"' ^^' ^mi wa« not meso-Carboniferous." The m2T. T "^-^"bonifcrous o formation, but although an un^"„? ^"' °^''^^y the Winder !^ber. Ami found iln" rc^Z^L^Jr^^^ ' *• "• 2. pp. 162-178. 1900. 21 ndered the Union and Riveradale formations, aa well aa the Millstone Grit and Coal Measures, to be of estuarine origin, while he recognized the Windsor formation as marine. In the same year' Ami proposed a new subdivision of the Silu- rian rocks of Arisaig. In descending order his proposed forma- tion names were Stonehouse, Moydart. McAdam. and Arisaig, a terminology reuined to this day with the exception of the last name which has been used by the present writer to designate the whole group. Ami did not definitely fix j boundaries of his ■ubdivisiuns and so no exact correlations with the previous sub- divisions can be given. In an article* dealing with the t)evonian strata, Ami discussed the question of their correlation and age. On the basis of fossil evidence obtained during a pala»ntological survey of tiie Silurian and Devonian rocks made by Weston and Robert, he decided that the Devonian correlated *'ith the "Old Red Sandstone" of Europe and proposed the n.une Knoydart formation for the strata exposed along McAras brook. The fossil fish remains referred to were identified by A. Smith Woodward and Henry Woodward of the British Museum as Pterygotus, Onchus murchisoni Agassiz, Pteraspis cf. crouchii, Psammosteus cf. anglicus Traquair, and Cephakupis n. sp. ?; impressions made by a pair of sharp organs probably pertaining to a fish were named Ichthyoidkhnites acadiensis. In his report, Smith Woodward stated that "the McAras Brook specimens represent the base of the Lower Old Red Sandstone of Britain," and the fossils oresent "seem to indicate clearly the presence of a fauna precistiy similar in facies to that of the Hereford beds, referable to the lower Devonian (Old Red Sandstone) or Corn- stone." On the evidence of Ptetaspis, which was considered closely allied to if not identical with P. crouchii, the horizon indi- cated was thought to be low down in the Devonian and not far from the summit of the Silurian.* From faunal and lithologic characters. Ami correlated the Knoydart formation with the strata near Ledbury in Hereford- shire^ rather than with the American Dev^.aan. I Ami, H. M. Trans. Royal Soc., Canada, Vol. VI, Sect. 4, p. 203, 1900. ^ Ami, H. M. Bull. Geol. Soc. America, Vol. XH, pp. 303-312, 1900. For a fuller diacussion by Ami, see Knoydart formation below. •nd • large number of otheTSnh. '^Jril^r *!ll*"* °' **•'• to be of about the ,tni^7al.:v., •*'» '*^*» *•• held York and the L^k^^^'^ ^ eL^" P'^'^'''^'' °' ^^ quoted It i. .een thaTthrAriLSi ^^Li ""^ r"* ■''^>' the Ludlow. ' ^*" '*«*''• ""ch eariier than recognized DevorL bS. aTiS ' «nd J.thologlc evidence. The work of Daw«n iS!, ^^^°"te harbour and Moo« river, di^^veringlhe^:; "j^Z^/^:'^' .^^-^ Weston in* formations in Nova Scotia w«. I- « *he age of the Devonian bined hTr^'ultSr^^r^rtS^^^^^^^^^ to pve a comprehenrive accoun of »K ""/''' ^ ^^^ *» featu«,of NovrScotia^nd S^";^"!,:^:,--" Phyiographic f^:'^^r^^ ^^--.. He dealt Cretaceous peneplain ^S Ind T"' Z '^' '^''■^'"^- ^he the upland ^ate" ^ S at. btl 'T "^^ T '•^P^««> - and were developed mS uli The r' T^'*^' '" '^''^^^^^^^ rocks. ^ "P°" ^he Carboniferous and Triassic 1901 ' Sir:: {: P S„^; ^"^^ ¥•• "''• «<^"' »''■ * Daly R A M. ^' *" •^•' ^°'- X. Pp. 402-412 1899 a'y. R. A. Mu.eum Co.p. Zool, Bull.. VoUXXXVIli. pp -ya-lOS. 23 The fMturM of Acadia are to Mincitive of the topographic fonm of New England that attention ihould be directed to the appended tat)le showing "Homologies of Land-Form and of the Determining Structures in Acadia and New England." This table is remarkable for the way in which it brings out the close resemblance of the region' xmipared. In his report on the iron ore depodta of Nova Scotia (Pt. I),' J. E. Woodman described the occurrence of ore in the Silurian rocks near Arisaig and also the ore beds in the lower Orao/ician rocks of the Doctors and Iron Brooks area. Thicknesses of ore, results of assays, etc., were given, making the report of economic value. In his summary report of 1908, R. W. Ells, wno was working for the Geological Survey on the oil-shales of Canada, made mention of the occurrence of oil-shale at Big Marsh, Antigonish county. Nova Scotia; and quoted How's "Mineralogy ot Nova Scotia" (1868) as a reference on thickness of the formation and the yield of oil per ton of shale. Besides How, Honeyman and Fletcher had described this occurrence of oil-shale. In 1910* a fuller description was given by Ells of the two groups of oil- bearing shale underlying the Lower Carboniferous limestone. The lower group, 70-80 feet in thickness, consisted of 20 feet of good oil-shale and 5 feet of curly cannel, rich in oil. The upper was ISO feet thick and contained a large percentage of oil. It was in immediate contact with limestone. The black shales were found to be associated with light grey micaceous shales containing impressions of broken plants. In places the strata were much faulted and sometimes steeply in- dined. During the summer of 1908 W. H. Twenhofel made a careful zonal collection of fossils from the rocks of the Arisaig series exposed along the shore east and west from Arisaig point. Fos- sils were gathered from over 200 horizons representing a thick- ness of 3,465 feet. In the following year' he described the struc- ' Woodman, J. E. Canada, Dept. Mines, Mines Branch, 1909. * Ells, R. W. Oil-shales of New Brunswick and Nova Scotia, Canada, Dept. Mines, 1910. •Twenhofel, W. H. Amer. Jour. Sci. (4), Vol. XXVIII, pp. 143-164, 1909. 24 ture and the i»>n»n>i — i . accepted, but a lower fo"..'^''""'.^'"''^ ""^'^ of 1901 was described in detail the various lolt """^ "^^"^- Twenhofel ^onec, and their contain JS°™^^'°"^' ^^^''^g '" all with 41 The "volcanic rorlrs" o* «.i. ■ gatc^ 'n.-croscopicaCand chl T. °^ '^' ^"""^" ^^^^ ^nvesti- volcanic ori,i„ ,,, e's titrt? 'fint»' ^''^"^"'^ ^"^^ ^^^^ Puted question as to the oriS of it'' T"''"^ " """^^ ^is- thought to l,e metamorphosed sechmir "^'''' ^'"■*^'' ^^^«^ 'ong careful petrologic work L^nTh 7' "'" 7'''^ ^^« ^l^^ "rs? Nova Scotia. °" ^"^ '^"^ous rocks of northeastern Twenhofel's article w^e by Charles Schuche D ^isirr^'i^' 'f ^ '^^^-'^^-n "ote -dence for its correlation ti h rS' '"^ T^'" "« ^--! was regarded as of Clinton or We7l f J'"^ °^ ^'"^ ^"'^ and n or the Arisaig formation, wa th. utt"^T^ ''"" ^^-'-^n 'ower b«ls of the eastern ^ ?„ 'u r r «^q"'valent to the -'i possibly a part of the U^l' [ "T "'' ^" of the Lower described by Kiaer). Division m ^'^"/'°^^'> of Norway (as -- held to be best corrd t^r^th thT r'^"'^^'^'" ^--'^'on Llandovery, including probahir^ i I '^"^'^^'^tcr and the Upper ' «'on IVa or the Moyd/rt Tori' '*' '^' ''°"^' ^'^"'«^k. D^ ^"■valent in time to the rdd rN-"" ''°"''^ '" '^^ ^^^^t I-u.s..,,e formations, and the UpLvv'T".' ?' ^^''l™" -d s'on IVb or the Stonehouse form^ Ln"'''°^ ^°™^y- ^^vi- Ludlow, having its nearest tiZ ■ T' '■"^'"^lated with the •nterior America. '""" "^^^'valent in the Guelph of <^^^^I::?nrtatIIy r ^-^ ^^^^^-^^^ ■•-^'-e.y pre lllil^eport is the outcome. ' '"""^ ""^^ '" ^^'0.. of whTh '^--Surv. Canada. S..„3rv Kept.. .,o.p, ,«-... 25 CHAPTER III. SUMMARY AND CONCLUSIONS. CENiLRA h C^A TEMENT. In order to ' iciliiate thi- nnderstanding of the succeeding longer and more <) t-M^xJ chapt<.- betis, interrupted by rapids and falls, are followed to the fault scarp of the Hollow. Here the smaller streams cascade down rocky beds worn but a few rods back from the scarp front. The larger streams have come more nearly to grade and flow across the Hollow or turn along it without irregularity in their beds. From the Hollow onwards, the stream channels are well graded, until they approach the shore, although all brooks flow through rocky ravines in crossing the Devonian and Silurian hills. Near the shore, rapids and falls occur over which the water tumbles on its way to the ocean. In the larger streams these falls are frequently one-half mile inland, but the smaller streams of local origin in many cases tumble over the present sea cliff. Gravel flood-plain deposits have already been described in relation to the raised terraces. There is plenty of evidence that spring freshets carry down considerable volumes of gravel and deposit it along the lower graded portions of the streams. The south flowing streams start from the highland divide near the heads of the north flowing streams. They make their way southward across the plateau for several miles and then collect in the tributaries of the West river, which flows eastward through Antigonish harbour into George bay. On the plateau the stream courses are comparatively straight and appear to be consequent upon a tilt of the old peneplain surface. As a result of uplift of the region they have become incised, often occupying narrow valleys 100 feet or more in depth. Rapids and falls are common in the upper reaches, particularly where tributary streams join the main channels. The highest known fall is that on the James so river whid with the rapids below, is 75 feet. The lower por- tions of the streams, before reaching the lowlands, are well grade^l an ' !>. the case of James and Rights rivers full of mean- ders. Oil hi Carboniferous lowlands, some of the streams be- C(imc lost in tin karstcd country, but most of them meander to the eastward < 'tr gravel beds flanked by grass grown bottom Unds. Nf-ar /»rtip )iii' various streams unite with West river. At the ji '■ , I .1:. 1 !■ r some distance up these streams, the bottom lands 4. ■ •' uic a:^^ being very fertile yield large crops of farm and ga (1< . in* I ice. These rich bottom lands are lf»cally known "ii i<- ales," a ward common in the early literature of this 'ii trie \i Antif. mish and to the east, the intervales •' ^,. ' iisunces from the river and no a origin seems necessary than that i.ich have received the finer deposits •creams during flood or during a period ivcly nearer the level of the water than become m^ r !i> c. further • xi>ia,i.i ion uf they a i ' ■<,-/,, brought a wn b; ti i when the • nd v/i ^ u at present Malignant brook is an example of a stream flowing fi location and extent will be brief and no more will be said about structure than is essential to the understanding of the relationships of the formations to each other. The gen- eral and structural geology will be dealt with in the succeeding chapter. 52 h II S •' ^5 o O a ■sis II til ^ § u 11 •> f « ill ^ B sl OM o o ^ jO OS t- u (■ Hi a II L r g ¥ d II r l! Is ^1 i sa l_ III! a m S7 avi a I " a C t-i >•" = ? 5% aw h h S3 REMARKS. In the accompanying table, a number of new formational names have been used instead of the older terms of Fletcher. For the most part the stratigraphy and larger questions of geo- logical structure as described by Fletcher, are adhered to, but since the old formational names, in certain cases, imply the acceptance of views concerning correlation and general geo- logical conditions that are not supported by the information at hand, it has seemed best to adopt the proposed scheme of nomen- clature. In the table the older usage of Fletcher is indicated. For the metamorphic rocks of the highlands the term Browns Mountain group is proposed. The formational names James river and Baxters brook are retained, as Fletcher quite clearly defined his terms and included these rocks specifically under them in his report of 1886. Fletcher himself was not sure that any of his Bears Brook formation occurred within the Arisaig- Antigonish district and Malignant Cove is proposed as the name of the formation represented by conglomerates and grits at the place of that name. Arisaig series is retained, in the sense used by Dawson, to include all the formations of Silurian age. For the lowest mem- ber of the Arisaig series, the name Beechhill Cove formation (from the place where the best expiisures occur) is proposed instead of the term Medina used by Fletcher. For the next formation the term Arisaig proposed by Ami has to be discarded in order to retain it for the name of the series, and the name Ross Brook is proposed in its stead (near the mouth of this brook the formation is well exposed). For the upper three formations the names McAdam, Moydart, and Stonehouse as proposed by Ami and defined by Twenhofel are adopted. Ami's term Knoydart is likewise used as he defined it, as the formation name of the De- vonian rocks of McAras brook. For Fletcher's Carboniferous Conglomerate and Limestone formations, the names McAras Brook and Ardness are respect- ively applied. The latter is certainly equivalent to a portion of the Windsor series as defined by Dawson and Ami; but because of local variations and uncertainty as to limits, and because of 54 the various interpretations connected with the older terms, it seems best to use local formational names. Likewise, instead of Millstone Grit as used by Fletcher for the formation above his Carboniferous limestone (Ardness), the term Listmore proposed. ' IS BROWNS MOUNTAIN GROUP. EXTENT AND AREA. The rocks of the Browns Mountain group occupy the plateau areas of the district, that is, the central and western part and the southeast comer. Their lower contacts have not been ob- served, but they everywhere unconformably underlie the younger formations. The greywacke, slate, etc., of the group are highly metamorphosed and have long been recognized as forming a metamorphic province. GENERAL CHARACTERS. The Browns Mountain rocks consist of a lower member of great thickness (estimated at 1 mile!) of greywacke varying to impure quartzite, interbedded with banded slate of a very sili- ceous nature; and an upper member, perhaps 500 feet thick, of red slates, and some sandstone. These rocks have been intruded by a granite stock at James river, by a monzonite stock east of Malignant cove, by rhyolite and quartz-porphyry necks south of Malignant cove, and at various places by irregular intrusions of diabase and basalt, and by rhyolite and diabase dykes. MODE OF ORIGIN. The alternation of greywacke and slate suggests that these thick deposits were the work of a transgressing sea. The red slates of the upper division may be the result of a change from a cooler and moister to a warmer and drier climate, so that the 55 land waste was oxidized before it reached the sea, as the fine, even character of the slates hardly suggests subaSrial conditions of deposition. FOSSIL CONTENTS AND AGE. Fossils were obtained from the iron ore zone placed in the lower but situated near the boundary of the two divisions. Both the iron ore north of the Little hollow, and a schistose, micaceous sandstone associated with the ore on the East Branch of Doctors brook furnished fossils. These have been deter- mined by Professor Schuchert as Obolus {Lingulobus) spissa and LinguleUa ( ?). The former occurs at Belle isle in Conception bay, Newfoundland, in strata which are of lower Ordovician age.* The lower division (James River formation) is, therefore, regarded as belonging to lower Ordovician time; and because of the con- ormable succession of the upper division and the position of the fossils close to its lower contact, there seems little doubt that the Browns Mountain group all belongs to this period of deposition. 'Ml CORRELATION. Dawson (see "Historical Geology") included the Browns Moun- tain group in his Cobequid series, which was made up of a lower group of volcanic and intrusive rocks and an upper group of altered sedimentaries. Fletcher has referred the group to the Cambro-Silurian system, using Silurian in the sense of "Lower Silurian" or Ordovician. JAMES RIVER FORMATION. The James River formation underlies all the area of the meta- morphic province excepting a belt south of Malignant cove, ' Since the preparation of this manuscript A. O. Hayes has found Didy- mograptus nitiius along with OMus (Liiiiulobus) spissa in the iron ore horizon of Belle isle, Newfoundland, and consequently the age of the formation is to be considered lower Ordovician. w m 56 which is occupied by the next higher formation and by igneous rocks, and areas at James ilver and elsewhere occupied by intrusive rocks. Granite, monzonite, rhyolite, diabase, and basalt cut the James River formation. From the broad surface extent of strata that are thrown into great regional folds, it is estimi-ted that this formation is at least 1 mile in thickness. The James River formation is thought to be the same as the James River division of the "Cambro-Silurian" rocks as de- scribed by Fletcher. With the exception of the grits of Rogers brook, he clearly included in his division all the rocks at present described under this heading. The grits of Rogers brook were correlated with the grits and conglomerates of Malignant cove. However, the writer cannot agree with such a correlation, as the Malignant Cove formation is clearly unconformable with the James River slates, whereas the Rogers Brook grits are inter- bedded with those slates and in reality never reach a conglom- eratic stage, being little coarser than some of the greywacke else- where observed. The James River rocks consist of interbedded greywacke and slate, the latter probably predominating. Towards the top of the formation and also probably at a lower horizon, iron ore beds occur, and in one instance a tuff bed is associated with the iron. The greywacke varies from impure grey-green and occasion- ally nearly white quartzite, to a rather coarse grit showing small points or angular grains of jasper ( ?). The gr«y phase when studied microscopically, may be seen to consist of small rounded to sub-angular quartz fragments about O'lmm. across, similar fragments of plagioclase (andesine was recognized) occasionally as coarse as 0-2 mm. across, and finer quartz, mica, and other materials. The slate is usually banded, dark grey and light olive grey alternating in layers less than 1 inch in thickness. In places the colour is entirely greenish grey. The texture is very fine and even, and as a result of silidfication the slate is in many cases harder than steel. Jointing is common, but cleavage usually follows the bedding planes. 57 Iron-ore "beds" occur near Browns Mountain settlement and in the vicinity of Doctors brook. The ore "beds" of Browns mountain are exposed in a limited number of prospect trenches and are two or more in number. The western exposures repre- sent a broad zone of coarse grit perhaps 20 feet thick, impreg- nated with hematite. The "beds" exposed to the east are only a few feet thick and are less siliceous than those farther west. In the vicinity of Doctors brook at least three "beds" of iron ore have been discovered and although varying greatly in thickness from place to place, the "leads" have been shown to extend in a northeast-southwest direction a distance of more than 3 miles. These "beds" vary from 10 feet to less than 1 foot in thickness, the thicker "beds" consisting of iron impregnated grit, and the thinner "beds" being made up of oolitic hematite occasionally containing fossils and always more or less siliceous. On the hill where an old wooden tram-way previously terminated, vol- canic breccia occurs in association with iron ore and is apparently interbedded with it. The writer obtained fossils from ore north of the Little hollow and Woodman (1909) mentioned the ore as containing "shells" at several places. The wide extent of the iron ore, its oolitic character in many of the "beds," and its con- tent of marine fossils show a marked similarity to the well known Clinton iron ores which are now regarded by the best authorities' as of contemporaneous deposition with the sedi- mentary formations. BAXTERS BROOK FORMATION. The rocks of this formation are confined to a portion of the metamorphic province south of Malignant cove, extending about 5 miles east and west and 1} miles north and south at its widest part. They are interrupted by belts of the James River forma- * Eckel, E. C. U. S. Geol. Surv., Bull. 400, pp. 26-39, 1910. Newland, D. H. Amer. Inst. Mn. Engr*., Bull. 27, pp. 265-283, 1909. N. v. State Mm., Bull. 123, pp. 1-18, 41-S3, 1908. Smyth, C. H., Jr. Amer. Jour. Sci. (3), Vol. XLIII, p. 487 et aeq.. 1892. McCaUie, S. W. Geol. Surv. Ga., BuU. 17, pp. 29-35, 104-194, 1908. 58 tion and by many intrusive bodies, including rhyolite, quartz- porphyry, diabase, and basalt. The thickness of the formation is estimated to be approximately 500 feet as here represented. The red slates and sandstones of this area agree with Fletcher's description of his Baxters Brook rocks and were included by him in his description of that formation (1886, pp. 25-26 P). Many igneous rocks and grits are also described under this formation, but in the present work the term is restricted so as to include only the red slates (and leached slates of light creamy colour) with thin beds of sandstone and sandy schist as repre- sented in the area described. The red slates are of fine texture and readily deavable. In the vicinity of intrusive bodies they are frequently much twisted and contorted. In some of the streams, notably a small brook northwest of Maryvale, the colour of the slates has disappeared, evidently as a result of reduction and leaching of the iron during weathering. In the vicinity of the iron ore "beds," greenish-grey, micaceous, schistose sandstone occurs and in McNeils brook, brown grits and fine grained sandstone are found. It was in the schistose sandstone that linguloids were seen and this is probably near the base of the Baxters Brook formation. Fletcher has also in- cluded the iron-ore "beds" in this formation, but because of the constant presence of greywacke, generally on both sides of the iron ore, the ore "beds" are included in the James River formation. MALIGNANT COVE FORMATION. This formation of coarse conglomerates and grits, outcrops east of the pond at Malignant cove and for one-half mile south of the cove along the Gulf road. It rests, as seen at the pond, upon cleavage surfaces of James River slate, the contact dipping south- west at a high angle. The observed thickness of these sediments is about 20 ± feet, but the original thickness was probably much greater. Along the Gulf road irregular basalt dykes have cut the grit and conglomerate, and diabase has penetrated it at Malignant pond. 59 The coarse conglomerates lie in irregular beds, exhibiting pockets of finer material and cross bedding. Almost no sorting is to be seen, although the cobbles and pebbles are well rounded. The grits to the south are of uniform character and no bedding could be distinguished. The formation is of a dark red, or purple colour. The above characters suggest subaCrial deposi- tion, marked at first by strong current action and later by quieter, less turbulent stream conditions. The coarse conglomerate is made up of rounded cobbles, some as large as 6-8 inches in diameter, mixed with fine gravel and sand. The coarse material consists of purple rhyolite, pink quartz, greywacke, etc. The finer grit, when studied under the microscope, is seen to consist of sub-angular fragments of rhyo- lite, quartz, tuff, and greywacke, besides isolated fragments of micropegmatite and plagioclase feldspar. Many of the frag- ments show evidence of crushing. The secondary products are iron oxide, chlorite, calcite, sericite, and much fine interstitial quartz. This formation was included by Fletcher in his "Cambro- Silurian" system and was thought by him to belong either to the Bears Brook or the Baxters Brook division (1886, pp. 19 P and 24 P). Because of the lapse of time between the James River deposition and that of the Malignant Cove formation as represented by the unconformable contact along cleavage planes of James River slate, it does not seem probable that this forma- tion was deposited during eariiest Ordovician time. On the other hand, in degree of silicification the Malignant Cove con- glomerates and grits resemble no other rocks of the region so closely as those of the Browns Mountain group. Until further evidence of the age of these rocks is produced they will be classi- fied provisionally as belonging to the middle part of the Ordo- vician period. Fletcher compares these rocks with conglomerates and grits at Georgeville and at Marshy Hope, but as the writer has not seen these occurrences definite correlation cannot be made at the present time. 60 111 I ijllli 11^ W I I !| IM lU i iNft 2 111 S S 11- HI'* M I i II 11 lli 3] h i B^ist II ot« « ^ g ^B* llhl ljs"I III •1 ARISAIG SERIES. UTKNT AND AUA. The rockt of the Ariuig wries occurring in th« Ariaaig-Antigo. nith di»trict, occupy an area along Northumberland strait from Malignant cove west to McAras brook. On the aoutheaat they are cut off from the lower Ordovidan formaticms by the great fault along the Hollow, and on the weat and aouth they are overlain by Carboniferous and Devonian strata. The area extends 6 miles along the shore and is about li miles wide. CHAKACTEK. The formations of the series are composed of shales, thin bedded sandstones, and arenaceous and argillaceous limestones. Near the base of division III is a bed of hematite containing many fossils. The shales vary in character from black and car- Kuaceous with papery cleavage, to grey or red with coarse arenaceous texture. The limestones are rarely pure and aiv grey to greyish green in colour. The conformable relations of the formations and the gradual evdution of the entombed faunas are evidence that the 3,S00± feet of the Arisaig series were formed during one continuous period of sedimentation. MODE OF ORIGIN. The arenaceous character of nearly all the sediments, the lenticular deposits of fine-grained sandstone, together with cross bedding, red shales and many examples of ripple-marks, espe- cially in the higher formations, indicate varying degrees of shal- low water, littoral conditions. 62 FOSSIL COHTENT. Twenhofel sayi of the foHil content of the aeries: — "The rocks, in general, are fossiliferous throughout; only one stratum, the 'Red Stratum' of authors, being without organic remains. They are particularly abundant in the upper red shales and flags, and at many horizons in the middle and lower shales. The impure limestones as a whole contain few fossils, but a series of intercalated nearly pure limestone lenses have them in more than ordinary abundance. These lenses are of two classes: the one wide, but thin, conains merely fragments; the other, about three times as wide as thick, contains many well preserved fossils, usually of only one species." DIVISIONS OF ARISAIG SERIES. Following the work of Twenhofel, the Arisaig series is divided into five formations. The boundaries of these were examined with Twenhofel, in the field, and are used as he delimited them. Most of the fossils have been re-examined by the present writer, but until a complete description of all the new species is at hand, and especially of the lamellibranchs, there are no new palaeontologic data to offer. The species as named below and the stratigraphy as worked out are based directly upon the previous work of Twenhofel and Schuchert. AGE AND CORRELATION. As is given in considerable detail in the discussion in Chapter II of the work of Honeyman and Dawson, the age of the Arisaig formations was early recognized as Silurian, but the fossils were found to be more closely related to European than to American species. Later, due to the presence of certain fossils from the higher beds, both American and English palaeontologists decided that these rocks were of Devonian age, and Dawson was con- strained to accept their view. Still later, however (1868), he returned to his previous opinion and decided that the Lower 63 AriMig division wm of Clinton or Upper Llandovery age, and hit Upper Arisaig was of Lower Helderberg or Ludlow age. Honeyman in 1864 correlated his division A with the Mayhill sandstone, divisions B and B' with the Lower Ludlow, and division C with the Aymestry limestone. In 1886 Fletcher, using what were eaaentially Honcyman's divisions, correlated and named them in ascending order as follows: Medina, Lower Clinton, Upper Clinton, Niagara, Lower Helderberg. Thus the matter stood until the work of Twenhofel and Schuchert in 1909. As a result of their work the age of the series is fixed between the Lower Llandovery of Europe or the Clinton of America, and the Ludlow of Europe or the Guelph of interior America. As there are no Helderbergian fos«iils in the Arisaig series it is con- cluded that no strata occur here of this time, which is earliest Devonian. The lower Devonian of the Arisaig region, or Knoy- dart formation, rests with an angular unconformity upon the Silurian strata. DIVISION I, BEECHHILL COVE FORMATION. On the shore at Beechhill cove, 160 feet (Twenhofel) of cal- careous sandstone and thick-bedded limestone are exposed. These strata of the Beechhill Cove formation sUnd nearly verti- cal and are succeeded by black shales of division II similar to those exposed on the shore near the mouth of Ross brook. East of Frenchman's Bam at an exposure recently made by the sea, the sandstone and limestone strata are seen to overlie the vol- canic rocks unconformably. The surface of the volcanics has been irregulariy eroded and the shales bend around the irregu- larities. The flexures are probably the result of movement along the conUct, but the unconformable relation between the shales and the volcanics is dear. At Doctors brook upwards of 200 feet of neariy vertical sandstone and limestone strata occur between the volcanic rocks and the overiying black shales. The contact of the sandstone with the volcanic flow is marked by a conglomerate derived from the volcanics. How much of this fragmental material is really erosion conglomerate and how much of it is the volcanic breccia which normally overiies the volcanic Wi flow (aporhyoiite), ia hard to determine. The well water worn pebbles of rhyolite. however, at the bate of the shale furnish food evidence that there is present at least some con«iomerate that is the result of erosion. The sandstones and impure limestones at the base of the Ari- aaig series, with the associated volcanic rocks, were included in Honeyman's division A. By him the formatioai was thought to be approximately equivalent to the Mayhill sandstone of Exif- land. The Beechhill Cove formation was tfi^l^iiid in Dawson's Lower Arisaig division, and was corrcl«Pi «itt ^ Clinton of America or the Upper Llandovery of Eam,,^^ Fletcher thought these beds were of Medina age and aamed them the Medina formation. Twenhofel and Sdiuchert found no evidence for fdadng the formation in the Medina and referred it to Clinton time, separating it as a formation on lithologic grounds. Schu« chert regarded the time represented as Clinton or Lower Llan< dovery and stated: "As yet no Anoplotheca kemisplurica havt been gathered here, but the other fossils are those of Division 11" (1909, p. 160). There is no faunal break between this and the succeeding formation, the separation being baaed merely on the change in sedimenution. Clear water and limy conditions were char- acteristic of the time during which the Beechhill Cove formation was deposited; but muddy waters were characteristic of the time represented by the overiying formation. The characteristic fossils of the formation as collected from the upper 75 feet of straU exposed at Beechhill cove are: Za- Mentis cf. bilateralis, Lingula cf. tfMmca, OrbicuMdea, Dal- maneUa eUganttda, and ComutiUs flexuostu. Helopora (2 sp.) Corntdites, and TenlacuUUs were obtained from green micaceous shales about three-quarters of a mile up from the mouth of Doctors brook. These straU protnbly belong near the base of the Beechhill Cove formation. DIVISION II, loss BROOK FORMATION. The second division of the Arisaig series, or the Ross Brook formation, consisU of more than 800 feet of dark carbonaceous paper shales, with some green shales and fine-grained sandstones near the top. The contact of this formation with division I i« beet exposed at Doctors brook and Beachhill cove. The forma- tion itself is exposed in section on the sJkore between a point a little west of the mouth of Ross brook and a fault tone about KK) yards west of the mouth of Smiths brook. A portion of the section outcrops along lower Ariaaig brook, being separated from the iron-ore tone by a vertical northeast-southwest fault. The beds of this formation are tilted at high angles and have suffered much crumpling. The toul thickness of the formation is, as Twenhofel suggcsU, probably more than the 833 feet observed along tiw shore, as some thickness was k)st by faulting. The Ross brook formatwn coincides with Honeynun's divi- sions B and B' which he correlated with the Lower Ludknr of England; includes a portion of Ouwson's Lower Arisaig, corre- lated by him as Clinton or Upper IJandovery; includes some- what more than Fletcher's Upper and Lower Clinton; forms the upper part of the Arisaig formation of Ami; and is the same as the Arisaig formation defined hy 1 wenhofel. The guide fossils of the Ross UrtwW inmiavm are: Mono- iroptus cUnkmnms, M. prwionc luifmancasis, RetiolUt t geittit- aianus venosus, ChontUt tenuiitrialux, Anabata anticostiafta, A. deprusa i^Atrypadeprusa Sowerhy). Anopi UtcM hemisphtrica, ComuliUs distant, and Acaste dawntngtae. As hiu already been stoted by Schuchert (1909, p. 161), "the time equivalent of these fossils is clearly Clinton. • • • Division II is thought to be equivalent to the lower beds of the eastern New York Clinton, i.e., beds having Anolootkeca hemispherica, and all of the Lower and possibly a part of the Upper Llandovery of Norway as re- cently described by Kiaer (Das Obersilur im Kristianiagebiett. 1908)." Division II has been subdivided by Twenhofel into twelve zones. In the present work but three subdivisions will be made and these are based upon faunal differences. Zone 2 (including zones 2, 3, and 4 of Twenhofel) consists of black carbonaceous shales and dark grey and green shales, and has an approximate thickness of 415 feet. In the first 100 feet fossils are scarce, but higher up they are plentiful. They are: Monograptus cUntonensis, Lingula cf. oblonga, Anabaia anti- 66 eostiana. Anophlkeca hemispherica, ComulUes fiexuosus, Calymau ci. tuberculata, and Acaste dmmingiae. ^^ Zone 3 (including zones 5. 6. and 7 of Twenhofel) consists of papery shales with some hard bands, dark grey splintery shale and green arenaceous shales and fine-grained sandstones in beds up to 6 inches thick. The appearance of a variety of species of graptohtes besides Orbiculoidm, Dalmandla, SchucherUlla, and Lhonetes, distinguishes this zone from the lower ones The fossils present are: Monograptus clintonmsii, M. priodon chap- manensts, Rettohtes geiniteianus venosus, Lingula oblonga. Or- biculoidea tenuilamellata, Dalmanella elegantula, SchucherUlla T" .; i^'"\ t'^^iltriatus, Camarotoechia near equiradiata, Anoplotheca hemvsphertca, Anabaia anticostiana, A. depressa CornuhUs fiexuosus C. distans, Avicula emacerata, fragments of Valmanttes sp. and Eurypterus. Zone 4 (including zones 8. 9. 10. 11. and 12 of Twenhofel) consists of green shales and lenticular fine-grained sandstones arenaceous shales, ight green papery shales, greenish-grey shales, and dark grey shales. The zone is marked by the first appear- ance olLeptaerta rhomboidalis and Modiolopsis ( ?) cf. primigenia. The other fossils present are: Monograptus clintonensis, M. Prtodon chapmanensis, Retiolites geinitzianus venosus. Lingula oblonga?, Orbtculoidea tenuUamellata, Schizocrania n. sp cf helderbergta, Pholidops implicataf, Dalmanella eUgantula. ChoneUs t^uistrtatu^ Camarotoechia near equiradiata, C. cf. obtusiplicata Rhynchonella cf. robusta, Wilsonia cf. saffordi, Atrypa marginalis, Anoplotheca hemtspherica, Serpulites cf. dissolutus, Cornulites dtstans Avtcula cf. rhomboidea. Pterinea honeymani, Modiolopsis (?) cf prtrntgenm, Conularia, Calymene, Dalmanites sp.. and Eurypterus fragments. DIVISION III, MCADAII FORMATION. The strata of the McAdam formation consist of arenaceous shales, a 2J foot bed of fossiliferous iron ore. and argillaceous and arenaceous limestones, mixed with carbonaceous and arena- ceous shales The section measured by Twenhofel was 1.020 feet thick and the thickness of the iron-ore zone is estimated at 67 100 feet ±, making the whole thickness of the formation more than 1,100 feet. Besides the section exposed along the shore of Northumberland ■trait from the fault at the top of division II west of Smiths brook to a point about 300 yards west of McAdam brook, there is also a section of these rocks containing the bed of iron ore, exposed in the valley of Arisaig brook. The strata here stand on edge and have been apparently much reduced in thickness by strike faults. This formation includes approximately the lower three- quarters of Honeyman's division C which he correlated with the Aymestry limestone. In his description' of the section passing across the area from north to south along Arisaig brook, he clearly placed the iron-ore zone in division C, making the formation begin at the hard shales below the iron ore. Thus the lower boundary as recognized by Honeyman both on the shore and in McAras brook is the same as that here adopted. The McAdam formation includes about three-fourths of Fletcher's Niagara although it does not start quite so low in the shore section. However, Fletcher included within the Niagara the iron-ore zone. This formation is thought to coincide in the njain with the McAdam formation of Ami and is the same as that of Twenhofel excepting that it includes the iron-ore horizon of Arisaig and Ross brooks. Throughout this and the succeeding formations the faunas are of one continuous development. Following, however, a previous subdivision based on lithologic differences, the strata consisting essentially of shales, have been retained as the McAdam forma- tion. The fauna is not large, but contains many pelecypods, not yet described. The guide fossils of division III are: Mono- graptus riccartoensis, Camarotoechia neglecta, C. cf. obtusiplicata, Dalmanella cf. edgelliana (sometimes compared with D. sub- carinata), Chonetes tenuislriatus, Spirifer crispus, and Atrypa reticularis. As stated by Schuchert, "these fossils, and the absence of the guide Clinton or Lower Llandovery fossils, seem ' H<>neyman, D. 1864, p. 340, line 10. 68 to indicate that Division III is to be correlated with the Roches- ter (probably within the lower Rochester) and the Upper Llan- dovery including probably also the Lower Wenlock" (1909, p. 162). Twenhofel subdivided the McAdam formation for descrip- tion purposes into fifteen zones. In the present work but three zones will be described, the iron-ore horizon being dealt with by itself and the first nine and the last six zones of Twenhofel being described together. The latter division is mainly one for con- venience, but is also based on faunal and stratigraphic differ- ences. The zones 15-21 of the former work consist of alter- nating limestones and shales with Camarotoechia cf. obtusiplicata as their distinctive fossil. Zones 22-27 consist of concretionary and slaty shales giving place to impure limestones. Camaro- toechia obtusiplicata is still found in zone 22, but that is its last appearance, and in the same zone Spirifer crispus makes its first appearance and extends through the fossil bearing strata of the remainder of the formation. Zone 5, or the iron-ore zone, as exposed in the gorge of Arisaig brook, consists of firm shales and thin-bedded sandstones with 2 feet 3 inches of ferruginous shale and weathered hematite. Ore obtained from a prospect drift was firm and dense, but many fossils were present throughout the bed. The fossils obtained are: ( ?) DaimaneUa elegatUula, Leptaena rhomboidalis, Camarotoeckia, sp. undet., Homoeospira (well developed form), Meristina n. sp. very large near M. oblata, Cornulites pruprius ( ?) or fiexuosus ( ?) TentacuUtes. Of these the Camarotoeckia resembles C. neglecta as found in the McAdam formation much more closely than C. obtusiplicata or C. equiradiata of the lower zones. The Comu- Utes and TentacuUtes resemble species fo«nd in the McAdam zones. Altogether on the fossil evidence, backed by strati- graphic position, the iron-ore zone appears to belong to the base of the MrAdam formation, representing beds that were cut out of the section on the shore by the fault between di^nsions II and III. Zone 6 (including Twenhofel's zones 13-2P consists of grey, greenish-grey, and blue-grey argillaceous and arenaceous lime- stones interbedded with shales. The latter vary from splintery and micaceous-arenaceous shaJcs. to crumbling shales, shales splitting into dagger-like fragments, and at tlM- top soft papery arbonaceous shales. The thickness of this zone as determined by Twenhofel is 574 feet. The fossils present are: Pkolidops imphcata, OrhicuMdea tenuiltmeUata, DalmaneUa eUgantuh Dalrjanella n. sp. (intermediate between polygnmma (Sow.) var Penttandtca (Dav.), and subcarinata) , Lepuuna rhomboidoHs, LkmeUs tenutslriatus, Comarotoechia negkcta, C. cf. obtusiplicata Atrypa rehcuiaris, Tmtaculites, BucarMa Srthbata. Hcmalonotui aawsont ?. Zone 8 (including Twenhofel's zones 22-27) consists of 446 feet of dark mostly soft carbonaceous shales containing lenses and concretions of sandstone, which are succeeded by 71 feet of greenish-grey argiMaceous and arenaceous limestonej. The zone w marked by the presence of Spirifer crispus. The fossils present are: DalmantUm eUgantula, Leptaena rhomboidaUs, Ckonetes lenutstnatus. Camarotoechia negUcta, C. obtusiplicata, Atrypa rettcularxs, Granmysia (small form), BuconeUa trilobala, Calymene tuberculata. DIVISION IV, MOYDART FOUIATION. tVll T^^ °' **** Moydart formation consist in ascending order of 250 feet of greenish-grey impure limestones alternating with bluish to greenish grey shales, and succeeded by 32 feet of brick red shale known as the "Red Stratum;" the total thickness t^ being, according to Twenhofel, 282 feet. The formation has been best recognized in the section on the rfiore between the top of division III and the top of the Red Stratum. The dip here is nearly south varying from 30"*-37° In the gorge of Arisaig brook the formation is also exposed and the Red Stratum may be with difficulty located. The straU here dip to the north at high angles. Along the OW road east of Arisaig brook, the Red Stratum is quite clearly exposed, dipping to the northwest about 75». There is either a faulted syndine or else an overturn to the north of these north dips. I he thicknesses of strata favour the first h>TX)the8is and, there- fore, It is thought strata belonging to the Movd«rt formation also outcrop north of those of division V lower down in the stream valley. 70 The Mcydart formation includes the upper part of Honeyman's division C which he correlated with the Aymestry limestone, and also the Red Stratum which Honeyman did not clearly in- dude in either division C or D. The formation probably includes the upper part of Dawson's Lower Arisaig division, and the top of Fletcher's Niagara along with the Red Stratum which Fletcher placed at the base of the Lower Helderberg. It is thought to include the lower portion of Ami's Moydart, which extended both above and below the "Red Stratum," and coincides with Twenhofel's division IVa, or Moydart formation. Division IV is not faunally distinct from either division III or division V, and is retained as a separate formation as a mat- ter of convenience in description. However, the unfossiliferous "Red Stratum" forms a suitable upper member. Chonetes wnu- scotica first appears where the base of the Moydart is here drawn and extends, with ever increasing size, into division V, finally becoming 1 inch wide on the hinge line. "Spirifer crispus of Division III is succeeded in IV by 5. suhsuUattu and this gives rise to 5. rugaecosta that attains to typical development and large size in Division V" (Twenhofel). The guide fossils to the Moydart formation are Chonetes novascoticas, Wilsonia wil- soni; "a rhynchonelloid suggestion Eatonia medialis, but has a lamellose instead of a striate surface;" Camarotoechia cf. borealis or formosa; Spirifer subsukalus; large Spirifer crispus; Homoeo- spira acadiae; Orlhoceras suggesting the Ludlow 0. striatum; Homalonotus dawsoni and Calymene tubercidata. The age of the formation is thought to be middle Niagaran; or about the time of the Waldron and Louisville faunas of America. It corre- sponds most closely to the Wenlock of Norway. Twenhofel has divided this formation into four zones, but for the present description only two subdivisions will be made, the first induding all the fossiliferous strata and the second the "Red Stratum." Zone 9 (including zones 28, 30, and 31 of Twenhofel, who does not describe 29) consists of 250 feet of strata induding greenish- grey arenaceous-argillaceous limestones with small thicknesses of bluish to greenish-grey shales. Towards the top the li. ".- stones are heavy-bedded and some beds are nearly pure. The 7! fossils of this zone are: DalmantUa elegantula; Chonetes nova- scolica; Camaroloechia cf. formosa or borealis; Homoeospira cf. acadiae, H. cf . evax; Spirifer subsulcatus; Serpulites cf. dissolutus; Pterinea emacerata; Grammysia acadica; CornulUes proprius; Diaphorostoma cf. niagarensis; Calymene tuberculata; Homalono- tus dawsoni. Zone 10 or the "Red Stratum" of previous writers consists of 32 feet of shale described by Twenhofel as follov s:— "A brick-red shale of which the upper thirty feet is prismatic and locally nodular. Shows little evidence of stratification ex- cept near its base. It is rather sharply differentiated from the overlying green shales, but grades into the subjacent zone. Twenty feet below the top is a nodular band ten inches thick. The nodules are bright green to greenish-white in color and have their longer axes transverse to the bedding. The same color shows along the fracture lines. At the base are included twenty- seven inches of thin beds of ferruginous limestone and shale which form the transition to Zone 31" (1909, p. 156). ^VISION V, STONEHOUSE FORMATION. The Stonehouse formation consists of arenaceous and argil- laceous limestones interbedded with arenaceous shales. In the lower part of the formation the sediments are of a bluish-green or greenish-grey colour, but near the top the colour is grey and red with bright-green patches. The green strata are often rip- ple-nurked. The total thickness of this formation measured by Twenhofel is 1,075 feet. The Stonehouse formation is exposed in the section along the riiore from tlw Red Stratum to the intrusive trap sheets just east of the mouth of McAras brook. This is probably all of the formation that is preserved as above the trap Mississippian strata occur. The Stonehouse strata exposed in Arisaig brook probably represent much less than the original thickness, due to loss by faulting, as they probably form the centre of a faulted syncline. The strata on the shore dip nearly south at angles of 35MQ°. 72 This formation coincides with Honeyman's division D which he correlated with the Upper Ludlow; probably includes most of Dawson's Upper Arisaig division which he correlated with the Lower Helderberg or Ludlow; corresponds to Fletcher's Lower Helderberg above the "Red Stratum" and include, part of Ami's Moydart and all of his Stonehouse formation. Divi- won V, or the Stonehouse formation, is the same as Twenhofel's division IVb, or Stonehouse formation. As already stated division V represents in fauna a further development of that of division IV. The guide fossils are- Pholidops tmplicala: Rhynchonella nucula, Spirifer subsulcatus S. rugaecosta, SchucherttUa subplana, CornuliUs flexuosus. Gram- mysm acadta, G. ruslica, Goniophora transiens, PteronUella venusla P. curia, Bucanella Irilobala, Beyrichia pttstulosa, B. aequilatera, Acaste logam, Calymene tuberculata, and Homalonotus dawsoni By means of the above fossils the Stonehouse formation is corre- lated with the Ludlow, and is thought to have its nearest Ume equivalent in the Guelph of interior America. Twenhofel subdivided the Stonehouse formation into eight zones In the present work only two divisions will be made. The div.ding line is drawn where the trilobite fauna first becomes common. Zone 11 (including zones 33-36 of Twenhofel) consists of 665 feet of limestone with some shale. The limestone is grey to bluish-green in colour, is arenaceous-argillaceous in character and IS frequently ripple-marked. The shale which is mostly in the lower part of the zone is deep-green in colour and contains some thin lenses of limestone. The fossils of zone 11 are: Leptaena rhomboidalis, Chonetes novascottca, A try pa reticularis, Spirifer subsulcatus (larg>^), 5. rugaecosta, Homoespira cf. evax. Grammysia acadica, Pteronitella vefiusta. Zone 12 (including zones 37-40 of Twenhofer, consists of 410 f.ct of mterbedded shales and limestones. The lower l)eds are grecnish-grey in colour, the upper are mostly red with some greyish-green and greyish-blue strata. Among tlie upper beds the "tnlohite bed" is found. Throughout the zone trilobites are numerous. 73 The fossils of zone 12 are: Pholidops implicata, Srhuchertella subplana, Chonetes nmnscotica, Camarototchia cf. borenlis, C. cf. nucula, Spirifer rugaecosta, S. subsulcatus, Ptrronitella venusla, ComuHtes proprius ( ?), Grammysia, Goniophora transiens, Orthonota afiRiiHfera ( ?), Bucanella trilobaia, Beyrichia aequilntera, B. pustulosa. Acasle lonani, Calymene tuberculata, Ilomalonotus dawsoni, Eurypierus or PUrygotus fragment. KNOYDART FORMATION. The strata of the Knoydart formation underlie an area alx)ut 7 milcA long by an average of 1 J miles wide, extending southwest from the Arisaig scries which they overlie with a marked erosional unconformity. From the Browns Mountain group on the south this formation is separatetl by the great fault located along the Hollow. Westward the Knoydart strata are overlain uncon- formably by the Mississippian formations. Fletcher measured 683 feet of outcrops of the Knoydart formation without recog- nizing either base or summit. The true thickness is probably much greater, possibly reaching 1,000 feet. The present usage of the formation name is that defined by Ami (1901, pp. 301-312). From the evidence of the red sediments and the contained fossils, which although considered as representing fresh water forms, may have been derived in some cases from marine sources, the deposition of the Knoydart formation is thought to have been on the flood-plains of a Devonian river, probably along the estu- ary and on the delta. The climate of the time was probably one of seasonal rainfall, which would give rise to a periodic fluctua- tion in the level of the river's surface. The interbedded grey impure sandstone probably represents deposits which were carried to scaw.-ird beyond the reach of the atmosphere or else deposits laid down in lakes of temporary existence. Lacustrine origin for the whole formation was suggested by Ami, who followed in this the opinion of R. Murchison. The latter believed that the Old Red and the Devonian rocks projier differed because of different geographical conditions during the same period. Ami cited evidence of volcanic activity at the time of sedimentation expres«d in volcanic ash found in the sandstone. This corre- T4 •ponded to conditions such at he found in the Devonian of Chaleur bay and he postulated two lakes, Pictou and Chaleur, to allow for the necessary conditions of sedimentation. Thus Ami considered all the deposits of lacustrine origin. As seen below, the writer finds no evidence to support the supposition that ash deposits were mixed with the sediments. The strata consist mainly of fine grained arenaceous slates of a bright brick-r«d colour (described as argillaceous shale by Fletcher). Thty ire soft but firm and often considerably cleaved , so that bedding is hard to detect. These slates form the basal member seen in McAras brook not far from the Arisaig contact and again near the contact in McAdam brook. No fossils have been reported from them. The firr I rjey sandstones make up a minor part of the Knoy- dart formation. They are of a dirty gre>' colour and consist of a mixture of materials. Under the microscope the composition is seen to be that of a greywacke, the components being fairly well rounded quartzes about 0-1 mm. across, surrounded by fine fragments of quartz 0-02 mm. across, mica, and undefined material. The specimen examined was taken from an exposure about 4 or 5 rods north of the strata at McAras Brook bridge from which the fossils mentioned below were obtained. Ami (1906, p. 310) has published a note by Barlow giving the result of a microscopic examination of the so-called "ash bed" (from locality 6, No. 44 of Fletcher's section) in which the fossils were embedded. In part the note is as follows: — "Rock of McAras brook * * greywacke. • • * It is composed for the most part of angular, subangular and rounded grains of quartz and feldspar embedded in a matrix of the same material but in a finer state of division. • • • The rock is probably of tufaceous origin." It will be seen that other than the feldspathic character of the deposit there is no clear evidence cited to show that the rock i: made up of ash or tuff. Glass shards are not mentioned and Barlow himself qualified his statement by "probably." The writer has found no evidence of igneous activity during the Devonian period (see page 134), and wishes to call attention to the fact that the case as stated by previous writers is not proved IS ■o far M the locality under ditcuMion ia concerned. That auch activity may have occurred it tupported by the opinion of Dr. Barlow, a geologist and petrographer of recognized merit. The foaails from the Knoydart formation at mentioned by Ami were collected from the grey tandttone or greywacke (de- ■cribed by him as an ash bed) outcropping to the south of the •hore road along the west bank of McAraa brook. As identified by A. Smith Woodward and Henry Woodward, both of the British Museum, the species were: (1) Plerygotus sp.; (2) Onchus murcki3tnii Agassiz; (3) Ptertupis sp. cf. P. crouckH; (4) Psam- mosteus sp. cf. P. anglicus Traquair; (S) CtphaUupis n. sp. ?; (6) IcklhyoHickniUs acadiensis, impressions made by a pair of sharp pointed organs or spines, probably those of a fish. In his report Smith Woodward wrote: "On the whole, I should place the McAras brook beds on the same horizon as the Lower Old Red Sandstones-Comstones of the Hereford district of England above the passage beds." Because of its continenul origin, Ami compared the Knoydart fon nation with the European Old Red Sandstone rather than with the marine Devonian of America, and from a faunal list given by Prestwich he correlated this formation with the straU near Ledbury, in Herefordshire, belonging to the Lower Old Red Sandstone. Fletcher (1886, p. 49 P) considered the Devonian rocks of McAras brook as representing the highest member of a series which extend in a broad belt "from the Strait of Canso to Locha- ber— thence keeping south of the East river of Pictou to strike the Intercolonial railway near Glengarry, form the high land south of Truro, and pass unconformably beneath the Carbon- iferous of Stewiacke river." The correlation of the Knoydart formation with the Devonian strata of Chaleur bay by Ami has already been cited. McARAS BROOK FORMATION. The red conglomerates and sandstones of the McAras Brook formation occupy a small area wesi of Mu\ris brook, a narrow belt along the Intercolonial railway in the south, and a broad 76 area in the '-entral and eastern part of the district. Every- where thet>< itrau rest with a marked anKular unconformity upon the older rocks, and are overlain, conformably so far as evidence obtainetl Irom this district shows, by the Ardness formation. The colour and cross-beddinK of these strata suggest conti- nental or littoral sedimentation which Rave place to marine con- ditions as is shown by the presence of ihe overlying limestones. Limy conditions appear to have been common throughout the deposition, as show n by the linie present in the sediments. The conglomerates conti. fragments from the nearby formations, and often from the rocks which ihey directly overtie. For tVe most part these fragments are well roi ded, but where the ma- terial is of local origin, as .liong the J sues River granite stock, it is decidedly angular. The finer materials are covered with iron oxide as are many of the coarser fragmrnts. In places the older rocks beneath the formation have also bet n stained red. At Pleasant valley and in the vicinity of Marvxaie and east of the border of the district of study, y\z., at Big marsh, thia formation conuins bods of oil-shale. According to Ells (1910), who quotes How's "Mineralogy of Nova Scotia," the shales "underlie the Lower Carboniferous limestone at Big Marsh" and may be divided into a lo*' r group "70-80 feet thick including 20 feet of good oil-shale, 5 feet of which are curly cannei, rich in oil ;" and an upper group "ISO feet thick in immediate contact with the limestone and containing a large percentage of oil." These shales are associated with light grey micaceous shale con- taining fragments of plants. The McAras Brook formation waa called the Carboniferous Conglomerate by Fletcher (1886, p. 69 P), who atoted that it lay unconformably beneath the "Carboniferous limestone." backing his conclusion by the statemei.t that "the great difference of thickness in so many places in adjoining areas cannot, in absence of faults, be explained otherwise than by unconformity." For the district now being described neither great variations in thickness nor other evidence of unconformity were found by the writer. The bedding planes of the two formations at the many contacts examined corresponded in attitude, and if any 77 U, «e of time ii here represented it is marlced by a disconformity rather than an unconformity. It is admitted that this area may represent local conditions which do not correspond to ihoHt- of the broader field from which Fletcher drew his conclusions. From the apparent conformability of the McAras Brook forma- tion with the overlying limestones of undoubted \Vin.l«>r age, from the limy condition of much of the formation, and i(^ close reaemhiance to the strata succeeiling the limestones, the writer has concluded that the age of the McAras Bror.k formation is essentially that of the Windsor rocks; that is. these strata were deposited in the Mississippian period a short time before the Windsor series. ARDNESS FORMATION. The Ardness strata underlie a narrow belt of land extending •outhwest from a point near the northwest corner of the Arisaig- Antigonish district. On the south the formation extends from a short disunce north of the railway southward far beyond the bounds of the district. On th. shore of Northumberland strait the Ardness limestone overlies, apparently conformably, the McAras Brook conglomer- ate and is in turn overlain, with apparent conformability. by the Listmore formation. The thickness here represented is about 2,045 feet. On the south the limestone holds the same relations to the underlying formation, but is succeeded by red sandstone and grits and higher up by a thick bed of gypsum, followed agam by red sandstone and shale. The totol thickness is not definitely known. The basal limestone containing marine fossils indicates that the deposition took place beneath the sea. Red sand and grit deposits suggest a return to subaCrial conditions of sedimenta- tion, or to the deposition of previously oxidized land waste along a littoral zone, and the gypsum beds are evidence of shallow water pans or lagoons which had periodic connexions with the •ea during a time of intense evaporation, probably due to a hot dry climate. MICROCOTY nSOlUTKM TBT CHART (ANSI and ISO TEST CHART No. 2) __^ /APPLIED IM/1GE I ^^^ 1653 East Mom Stf««t ^^ Rochester, .4ew York 14609 USA %i^a (^'6J *82 - 0300 - Phone ^S ('16) 288- 5989 Fa« 78 The limestones at the base of the formation are thin-bedded near the top and the bottom, but are massive at the centre. The thickness seen on the shore is about 20 feet. At the base are dark grey beds about 1 inch thick, some of which contain numerous brachiopods and ostracods. The massive limestone near the middle is dark grey and compact, and does not appear to be fossiliferous. Near the top light brown resistant layers occur and in these brachiopods have been found. In the section observed along the shore west of McAras brook, the remainder of the formation (2,024 feet as measured by Fletcher) consists of thin-bedded sandstone, marl, and shale. For a few feet above the limestone, grey and green are the pre- vailing colours, but higher up red is predominant. Ripple- marking is common except in the lower beds, and near the top, plant remains, associated with copper carbonate, are found in green concretionary beds. In the south, 200 feet of red sand- stone and shale are estimated to overlie the limestone and these are succeeded by about 200 feet (estimated from outcrops, etc.) of gypsum deposits. The gypsum as seen in the cliffs along the railway near Brierly brook is white to greyish-white and shows very little evidence of bedding. Dawson (1847) described a section observed by him at Ogdens point, Antigonish, as con- sisting in ascending order of white gypsum (containing some carbonate of lime) and reddish foliated gypsum, more than 100 feet thick; succeeded by alternations of thin beds of gypsum and grey earthy limestone; overlain by a thick bed of grey brecciated limestone and reddish sandstones and shales. The age of the Ardness formation was determined by a study of the fossils obtained by the writer from the limestone west of McAras brtxjk. These were identified by Professor Schuchert as follows: "Beecheria davidsoni Hall and Clarke {Terebratula sac- culus Davidson), Martinia glabra (Martin), both of which are characteristic and common species at Windsor. Pugnax, sp. undet., is rare, while Productus cf. doubleti Beede is very common. Productus dawsoni Beede, one of the P. cora group, is also pres- ent." All these forms occur either in the dolomite at Windsor in close association with this well known gypsum horizon of Nova Scotia, or in the Windsor series of the Magdalen islands (see 79 Beede and Clarke report). The evidence is, therefore, decidedly in favour r( correlating the Ardness formation directly with the l-.iestone and gypsum outcropping at Windsor. Thus this formation represents for Antigonish county at least part of the Windsor series of limestones, gypsum, and shales occurring else- where in Nova Scotia. LISTMORE FORMATION. The Listmore strata extend westward from a point on the shore of Northumberland strait about one-half mile within the west boundary of the Arisaig-Antigonish district. So far as evidence from the contact observed goes, there is no apparent unconform- ity between this and the Ardness formation. The sandstones are greyer in colour and contain more plant remains than those of the Ardness formation, but in other respects show similar characters. As measured by Fletcher, this formation is 582 feet thick. The plant remains, cross-bedding, and frequency of red beds in this formation suggest strongly that the deposits are of con- tinental origin. The plant remains are probably Stigmaria (as reported by Fletcher) and Catamites. Other than that these represent Car- boniferous time, no direct correlation value can be attached to them. The Listmore formation was called the Millstone Grit by Fletcher (1886) and if these strata are the same in age as the Millstone Grit formation of other parts of Nova Scotia and New Brunswick, they probably belong to the Pennsylvanian system, as the Millstone Grit underlies the Coal Measures. Fletcher described the Millstone Grit as having an uncoiiformable rela- tion to the "Carboniferous Limestone" strata, but Ami failed to find any evidence of this in the Cumberiand basin (1900). QUATERNARY DEPOSITS. PLEISTOCENE. Deposits of Pleistocene or Glacial age cover the lowlands of the Arisaig-Antigonish district to a greater or less depth, and occur in considerable thicknesses over parts of the plateau under- lain by Browns Mountain rocks. fiii 80 These deposits of clay and clay-gravel bear evidence of glacial origin in their unsorted character and sub-angular and occasion- ally scratched pebbles. The oldest of the deposits thought to be of Pleistocene age are firm red, marly clays seen in McNeils brook between the road and the shore. They lie in a nearly horizontal position and are overlain by brownish-red unstratified sandy clay. Such clay was observed about one-half mile up McNeils brook, in the small brook to the east, and again in Vameys brook. The thickness of the red marly clay was not determined as the base was only seen far up the stream where it rested on James River strata. The brownish-red clay, however, attains a thickness of about 12 fer.c in McNeils brook. Unconformably overlying the brownish-red clay are unsorted clay and gravel deposits of a reddish-brown colour, which reach a thickness in McNeils brook of about 40 feet. Near the top the gravel is roughly sorted. Such deposits are common along the shore of Northumberland strait, and are probably of the same glacial origin as the many gravel knolls seen at Arisaig, Maryvale, James river, and elsewhere. Sub-angular pebbles are everywhere present and scratched pebbles were obtained from a number of localities. The debris is for the most part of local derivation, but occasionally " travelled fragments " may be recognized. Generally only the upper part of the till shows sorting and bedding such as results from water action, but occasionally bedded gravels occur of several feet in thickness. Such a deposit may be seen on a western tributary of James river about 620 feet above sea-level. RECENT. Flood-plain deposits of stream-worn gravels have accumulated in the graded portions of the brook channels. The thickest obi-erved deposits were those of Knoydart brook. Here e' out 15 feet or more of deposits had accumulated in a broad flood- plain, before the stream cut down to its present level where it is forming a narrower flood-plain. 81 Near the town of Antigonish the streams which have come to grade several miles higher up their courses, have deposited silt and other fine materials, iralcing rich bottom lands known as "intervales." These deposits have received additions of organic material resulting from the decay of vegetation growing on them. The soils of the district are of considerable depth, but although largely consisting of glacial material show a decided relation to the underlying formations, as may be observed in their relative productivity. The Carboniferous lowlands have by far the deepest and most fertile soils. 82 CHAPTER VI. GENERAL AND STRUCTURAL GEOLOGY. INTRODUCTION. Northeastern Nova Scotia, lying between the Gold-bearing series of the Atlantic shore and Northumberland strait and George bay, is underlain by rocks ranging in age from lower Ordovician to Permian. The lower Ordovidan rocks underiie plateau-like areas, but the youn^'er formations of Silurian, De- vonian, and Carboniferous age are confined almost without excep- tion to the lowlands. These later sedimentary rocks occupy great 'lepressions in the formations of the uplands, depressions probably originated by erosion and supplemented by crustal warping and faulting. The oldest rocks generally included in the "Cobequid series" and called the "Cambro-Silurian" formations by previous writers, are exposed in many places over the highlands of the region! They consist of metamorphic rocks, including quartzites, silici- fied slates, indurated sandstones, conglomerates, etc. Folding and faulting are features of these formations, but because of the lack of consecutive exposures little detailed work has been done on their structure. Igneous rocks of various kinds and ages have cut the metamorphic seriimentaries, and were included by Dawson in his Cobequid series. Rocks of undoubted Ordovician age have not before been recognized in Nova Scotia, but it has been thought by previous workers that portions of the "Cambro- Silurian" strata would prove to be "Lower Silurian" or Ordovician. The Silurian formations, or the Arisaig series, occupy a num- ber of small areas in the region about Arisaig. Thfise rocks con- sist of shales, sandstones, and impure limestones, which uncon- formably overiie the lower Ordovician formations. The age of the Arisaig series has been determined from the numerous fossils 83 which it contains, as representing nearly the whole of Silurian time. However, the fossil species are much more nearly related to the Silurian faunas of Europe than they are to those of the rest of America, and the formations cannot be directly corre- lated with those that are typically American. The lower Devonian series of conglomerate, sandstone, and red slate occupy upland areas of considerable extent between the Strait of Canso and the town of Truro. These rocks overlie the older formations unconformably. The formations of Carboniferous age (Mississippian and Penn- sylvanian), include the Union and Riversdale formations, the Windsor series, the Millstone Grit (of Nova Scotia and New Brunswick), and the Coal Measures of former writers, and occupy by far the greater part of northeastern Nova Scotia. The differ- ent formations consist of conglomerates, limestones and gypsum, sandstone, grits, and beds of coal, and represent a long cycle of sedimentation which continued during varying relations of the land to the sea, and during varying climatic conditions. Above the Coal Measures are the Permo-Carboniferous or Permian formations, which occupy considerable areas in the northern part of Pictou county and to the westward. These strata consist of a basal conglomerate, and grits and sandstones "containing plants of Permian aspect."' They are the youngest rocks known in northern Nova Scotia. Of Quaternary deposits, stratified clay containing marine shells, unstratified boulder clay, gravel containing scratched stones, and stratified sands and gravels have been recognized. Within the Arisaig-Antigonish district of northeastern Nova Scotia, the formations of the region are represented probably as high as the "Millstone Grit" (Listmore of present nomenclature). It is the purpose of this chapter to deal primarily with the general relations and structure of the formations present, the detailed lithologic characters, palaeontology, mode of origin, age. and correlation having been treated in the chapter on "Stratigraphy." ' Fletcher, Hujh. Geol. Surv., Canada, Ann. Rent., 1886, VoL II, a. 94 P, 1887. '^ til 111 84 BROWNS MOUNTAIN GROUP {LOWER ORDOVICIAtJ). EXTENT. The metamorphic rocks belonging to the James River and Baxters Brook formations of the Browns Mountain group under- lie the great central plateau of the tlistrict and the smaller plateau in the southeast corner. The greywacke and induratetl, banded slates of the James River formation occupy the whole meta- morphic area except the region in the vicinity of the igneous rocks south of Malignant cove. Here the greywacke and grey slate are interbedded with red slate and finally give place along the axis of a syncline to the red slates, sandstone, and sandy schist of the Baxters Brook formation. IGNEOUS INTRUSIONS IN BROWNS MOUNTAIN GROUP. The James River formation is intruded by a granite stock at James river. Both members of the Browns Mountain group are cut by small rhyolite dykes and diabase dykes of much later date. The Baxters Brook formation is intruded also by quartz porphyry and rhyolite necks and irregular basaltic bodies. STRUCTURE. Because of the lack of exposures of the rocks of the Browns Mountain ^roup and the complexities arising from igneous in- trusions, the complete structure of the formations has not been deciphered. The best recognized fold of the region is the great syncline whose axis extends from near the headwaters of Vameys brook in the west, eastward to the headwaters of a small stream empty- ing into Malignant brook about 2 miles north of Maryvale. From the recorded attitude of the strata the syncline appears to be regular along its central part. To the east the slates of the Baxters Brook formation are held in a structural trough, which does not correspond in direction to the great syncline but ex- S5 tends in a crescentic northwest nrj then west direction. In thi« region of numerous intrusions regional structure has Riven plae- to confused warpings related no doubt to the igneous activity' An anticlinal axis begins in the west of the district about 1 mile south of Browns Mountain settlement and about 2J miles south of the probable axis of the great syncline. This extends eastward to the border of the lowlands about 1 mile north of Brierly Brook station. Folds with north and south axes occupy the y-shaped space between the axis of the anticline on the south and that of the syncline on the north. The strata exposed along the South Branch of Rights river stand at high angles and probably represent more than one compressed and truncated anticline and syncline. Farther east the folds are more open. A succession of three syndines and two anticlines probably com- prise the structure of the Browns Mountain rocks, from a point 1 mile east of the forks on the South Branch of Rights river east- ward be'ow the McAras Brook conglomerates and across the uplands as far as the Sugar Loaf hill of Antigonish. About this diabase centre, the structure is confused. Much faulting on a small scale is common where the iron ore of Doctors brook has been investigated, but because of the lack o. opportunity for detailed investigation it has not been deter- mined whether or not faulting is a regional feature of the meta- morphic rocks. The great fault separating these rocks from the younger formations to the north will be discussed under a sepa- rate ^leading. The trend of the greater folds and the major fault of the Browns Mountain rocks corresponds to the general directions the axes of the anticlines and synclines of the gold-bearing •-ks of southern Nova Scotia, which may be of Lower Cambrian ^ but are probably older. Thus it is seen that the regional -olding extended to the north coast of Nova Scotia. RELATION TO OLDER FORMATIONS. What the relations are between the gold-bearing series and the Browns Mountain formations is largely a matter of conjecture. The two groups of nietamorphic formations are separated sur- ficially by many miles of younger formations. The nature of the relations is. therefore, in doubt. 86 The two group* of lockn havt many rimilaritiet in character of sedimentB and in degree of liUdfication. On the other hand the slates of the Gold-bearing series are much more fissile .". n those of the Browns Mountain rocks, indicating a greater degree of dynamic metamorphism. The rocks of the Gulf of St. Uw- rence definitely rocogniie^l as Lower Cambrian do not appear to have suffered severe metamorphism, and for this and other rea- sons the rocks of the Gold-bearing series have been considered of Pre-Cambrian age. In view of the relative shallowness of the depressions holding the younger formations, it does not seem probable that any undiscovered group of rocks can lie between the Gold-bearing series and the Browns MounUin formations, and, therefore, so far as the evidence goes, the Gold-bearing series may be Cambrian. IIETAIIOKFBISM. Jointing is everywhere common in the Browns Mountain grey- wacke and slates. The number of measurements taken was not more than twenty but these are sufficient to show that the joint planes all dip at angles greater than 45" with the honzonUl. more than two-ti irds of those examined dipping at angles greater than W. The strike direction of the joint systems fall mto northwest-southeast and northeast-southwest groups, most of the dips being northeriy rather than southeriy. Such jointing must have originated deep down in the zone of fracture. The James River rocks include greywacke, or impure quartzite and flinty slate. Under the microscope the greywacke •■ -ly b'^ seen to consist of grains of quartz and feldspar (andesiu. and orthoclase were determined in one section), about 0-2 mm. across and anguhr in shape. Secondary silica has filled in the pore-spares. The slate is fine ^rained and very siliceous, reseni- bling navaculite in megascopic characters. Such regional silici- fication is probably to be ascribed to the readjustment of the silica of quartz and the silicates, which is favoured by conditions of great pressure and high temperature, such as exist some thousands of feet below the surface of the earth. The silicifica- tion probably took place before the joint pUnes of the region were •7 established, at these planes cut across the grain of the rock and do not show quartz accumulations on their surfaces, as might be expected had they existed previous to tiie chemical readjust- ments among the minerals of the formations. MALIGNANT COVE FORMATION. JX'tNT AND CHABACTERS. Along Malignant brook for the last 1} miles of iu course, and on the east side of Malignant pond, fine silicified red grit and (at the pond) coarse, cross-bedded, silicified conglomerate over- lie the James River rocks. At the pond the formation may be seen to lie upon cleavage surfaces of grey slate, portions of which are contained in the conglomerate, among fragmento of quartz, purple rhyolite, sand, and fine gravel. Cross-bedding is very marked, a coarse bed of conglomerate with cobbles 6 inches in diameter, overlying finer conglomerate containing pockets of coarser pebbles. Up the brook the conglomerates are replaced by fine silicified grits of a dark red colour, resen-blng igneous rocks very closely in appearance. Under the microscope the conglomerate is seen to be composed of partially rounded fragments of rhyolite, tuff, quartz, grey- wacke, micropegmatite, and feldspar. Many fragments show evidence of subsequent crushing and shearing. Secondar>- prod- ucla are iron oxide, chlorite, calcite, seriate, and silica. The silica has filled in the pore-spaces of the rock, making it hard and resistant in character. PROBABLE STRUCTURAL RELATIONS. The • proximity of the Malignant Cove conglomerate to the An, .g series, makes it seem probable that it may elsewhere underlie these rocks and so belong to the interval between the deposition of the Browns Mountain formations and fKe laying down of the Silurian strata. It contains, however, fragments of rhyolite that have the characteristics of the aporhyolite at the base of the Arisaig series. Here ar.8es a difficulty. The con- M'i M gbmeratc !■ evidentl> younger than the aporhyolite flow, but the latter is overlain by the AriM'K Mrie*, with apparently no great unronformity to far as local evidence goes. Turning to ■imilar formations elsewhere, we find that Fletcher* deacrit J conglomerate near Georgeville overlying "the slates from which It is largely derived. • • • Thi« conglomerate is the same M that of Malignant cove and probably not higher in the series than the Baxters Brook group." Later Fletcher thought that these strata might be correlated with the Bears Brook con- glomerate. According to his description of the Baxters Brook group as "soft reddish and olivaceous slates" and his interpre- Utions elsewhere, the Malignant Cove conglomerate cannot be correlated with that group. Fletcher's description of the relations of the Bears Brook con- glomerate, sandsiune, etc., is not very clear and for that reason and beiiusc he was not certain in his correlation of the formation under discussion, a new name has been applied to the conglomer- ate at Malignant cove. Dawson* mentioned conglomerate dis- covered near Fictou which he thought formed the base of the Silurian. PROBABLE ACE. The petrographic evidence that the Malignant Cove conglom- erate is younger than the aporhyolite flow seems pretty secure. The flow is not known elsewhere in the district and was probably a remnant of a much larger sheet. The Arisaig basal rocks con- tain fragments of aporhyolite, showing that here was an ero- sion interval betwe< n the volcunic activity and the sedimenta- tion of Silurian time, and owing to the hardness of the volcanics this interval may have been much longer than the evidence at the contacts would suggest. It is to this period of erosion and local sedimentation that the Malignant Cove conglomerate prob- ably belongs. The silicified character of the conglomerate cor- relates "^ much more nearly with the Browns Mountain meta- * Fletcher, Hrgh. Geol. Surv., Can., Ann. Kept., 1886, Vol. II. p. 19 P, 1887. 'f . • DawK)", J. Can. Nat., Vol. IX, p. 338. 1881. morphic roclu than with later lediincntii. Fur the rcaimn* given, the age of thia formation in thought to be Ordoviciuii. with a probability that it dates back to »'ie middle part of the period. ARISAIC SERIES. EXTENT AND GENERAL RELATIONS. Within the Arisaig-Antigonish district the formations making up the Arisaig series are confined to an area between the Ho lo« and the shore, and extending from Malignant cove about 6 miles southwest to McAras brook. The age of the rocks is Silurian, ranging in American equivalents from lower Clinton to Guelph. They occupy a down-faulted position in relation to the lower Ordovidan formations to the south, and rest upon a flow of aporhyolite a? '■ eir base. The relations of the sedimentaries to the lava may be studied at the exposures west of Frenchman's Bam or in Doctors brook. At the former locality the rhyolite has had porti-ms of its surface removed along planes of flowage. The beds of shale here are flexed and have probably suffered from later movement which destroyed the original conditions. In Doctors brook no angular unconformity was noted, but conglomerate composed for the most part of volcanic material forms the base of the sedimentary series. The irregularities in the underlying surface and the basal conglomerate are interpreted as evidence of an uncnnfor- mity which or reasons given in the description , *he Mali^.iant Cove formation (page 87) is thought to repres ■• a long time interval. STRUCTURE. The Arisaig series has h en (divided in-o five formations which are described in the chai>. . on "Stratigraphy" (page 51). The divisions are important because in mapping their areal ex- tent much structure was deciphered. It was recognized by the early workers in the district that the Arisaig rocks lay in an asymmetric syncline pitching southwest. 90 Fletcher' also recognized that there was an upthrown block be- tween "Smith brook and a point east of the Trunk road." The previous interpretation is true so far as it goes. When an at- tempt is made, however, to unite the boundaries of the divisions recognized definitely along the shore, on Arisaig brook. Doctors brook, and elsewhere, it is found to be an impossibility without doing violence to known thicknesses and relations of beds, or else introducing a series of displacements. Thus, the boun- daries of the formations recognized along Arisaig brook are so far south and strike and dip in such a way that they cannot be continuous with those on the shore. Eastward a similar dis- continuity is recognized by an offset in hard strata and an iron- ore bed. In this manner the upthrust block mentioned by Fletcher is established. In locating the bounding faults, the line of offsets on the west had to be followed and this line passed directly through the break in the aporhyolite flow at Arisaig point. The offset here, however, is too great to be accounted for by the one fault, and for this reason and because of the loca- tion of observed discontinuity in the strike of strata, the fault on the west is thought to meet that along the east, on the shore, making the upthrust block triangular. Fossils found in the iron ore ak)ng Arisaig brook show it to belong to strata between the top of the Ross brook and the base of the McAdam formations as seen on the shore, and the displacement there observed is consequently extended inland to allow for a down faulting of the McAdam sufficient to eliminate its lower beds. Insufficiency in the thicknesses of formations along Arisaig brook has to be accounted for by faults simUar to one observed at the iron ore, which follows the strike of the beds but is vertical, thus differing a few degrees from the dip of the strata. Hence three fault blocks have been set off, being successfully down-faulted to the north except in the case of the last which was upthrust relatively to the adjoining block. At a sharp bend to the north in Doctors brook, fossils were obtain«Hl which belong to the lowest part of the Beechhill Cove formation. The age of the strata to the south and west is not ' Fletcher, Hugh. Loe. Cit., p. 41 P. 91 certain, but from Honeyman's interpretations and from litho- logical characters, they appear to belong to the Ross Brook for- mation. It will thus be seen that a fault with down-throw to the south has to be postulated to explain the relations. When the divisions from the east are projected to meet those from the west they fail to harmonize and the location of a fault, with down-throw to the east, passing through the gap in the outcrops on the beach seems very probable. There is a decided offset in the aporhyolite to the east of the mouth of Doctors brook, and the evidence of faulting is dear in the truncation of the rock out- crops. This displacement with down-throw to the east is thought to extend inland as represented. At McNeils brook the rhyolite breccia outcrops along the west of the brook only and a fault here with down-throw to the east seems probable. The information at hand makes it clear that some such sys- tem of faulting as the above is necessary. That much crushing and complicated faulting not represented has taken place is most probable. This opinion is supported by the evidence of small faults and flexures occurring at many places along the shore. Where the great down-faulting of the area took place, the soft shales and thin arenaceous limestones were unable to withstand the great stresses set up and much minor readjust- ment necessarily followed. UPPER CONTACT. The question as to the amount of the unconformity repre- sented where the Arisaig series is overlain by the Knoydart for- mation on the west, is of considerable importance. Ami' con- tended on fossil evidence that it was not great. Both series of strata are much deformed, but the upper is found to rest on different underlying Arisaig formations. A study of the attitude of the beds outcropping along Mc- Adams brook shows the degree of dip not only to be reversed on crossing the contact (which might be explained by the existence of an anticline), but the strata of the Knoydart formation to be ' See Ami under "Previous Work." ,^i 92 much more disturbed than is the case with the Arisaig rocks. Fortunately other evidence is available. At the mouth of Mc- Aras brook, the Stonehouse formation is overlain by the Knoy- dart. At McAdams brook the Moydart is probably the basal formation. The presence of the Moydart formation along the upper part of McAdams brook is based mainly upon structural evidence, taking into account the attitude of the strata and the thickness of the Stonehouse formation. Thus there is a prob- able unconformity ranging through several hundred feet of strata within a mile of horizontal measurement. The McAras Brook conglomerate is separated from the Upper Arisaig rocks by an intrusive diabase sheet which confuses the contact relations. Evidence here is not needed, however, as the attitude of the strata of the two formations indicates an angular unconformity of more than 45°, and only a short dis- tance up the stream the McAras Brook rocks overlie the Knoy- dart formation. On the East Branch of Doctors brook, the Ardness limestone, underlain perhaps by some McAras Brook conglomerate, forms a small outlier above what are probably Ross Brook strata. KNOYDART FORMATION. EXTENT AND GENERAL CHARACTERS. The lower Devonian strata of McAras brook, overlying the Arisaig series on the east and disappearing below Mississippian rocks about 2 miles west of the area studied, were named the Knoydart formation by Ami. As measured by Fletcher, the thickness of exposed beds was 683 feet, but its total thickness is evidently much more. This formation is cut by numerous small diabase dykes. STRUCTURE. Exposures of Knoydart strata are not numerous except along the lower parts of the brooks, but enough measurements have been taken to indicate that the structure of the formation is that 93 of an asymmetric and probably faulted syndine which pitches to the southwest. As in the case of the Arisaig series, it origi- nated during the movement along the great fault at the Hollow. To the westward, the Knoydart formation is overlain uncon- formably by the McAras Brook, and farther west by the ArdnesB formation. POST LOWER DEVONIAN, PRE-MISSISSTPPIAN FA ULT. GENERAL DESCRIPTION. A great fault extends to the southwest from Malignant cove, in line with the shore from Cape George. Its location is marked by a steep scarp several hundred feet in height, forming the south side of a U-shaped valley. The scarp and valley extend across the front of the Arisaig-Antigonish district and appear as an im- portant topographic feature for a number of miles beyond. On the south are the highlands underlain by the metamorphic rocks of lower Ordovician age; on the north, from east to west, are the lowlands and rolling uplands of the Silurian, Devonian, and Mississippian (Lower Carboniferous) areas. '=t| AGE. The fault originated in pre-Mississippian time, as shown by the fact that the Mississippian rocks are but little disturbed and have evidently been deposited against the fault scarp, which they overlap in some cases to the westward, as appears from the work of Fletcher. The lower Devonian formations are down- faulted and thus the age of the fault is most probably later De- vonian (See also "Historical Geology'). CHARACTER. It will be seen that the faulting was normal and to the north- west along a fault plane dipping at a steep angle. Taking into account the tenacity of the metamorphic slates and greywacn-e 94 and the friction incident upon such faulting, the dip of the fault plane or fault zone is estimated to be about 70° from the horizontal. The throw of the fault appears to have been least in the east and greatest in the west. At Malignant cove it is probable that the lowest beds of the Arisaig series lie next the fault zone. What lay directly below the lava flow at the base of these rocks we do not know, and it seems probable that the Malignant Cove conglomerate was elsewhere beneath the Arisaig series and above the Browns Mountain group. The conglomerate at Malignant pond is exposed about 20 feet above the level of the sea, and here rests upon James River slate. Thus the eroded surface of the James River rocks and the base of the Arisaig series are at the same level, and from the evidence at hand the throw of the fault is to be measured by an unknown quantity, the thickness of the strata once lying between these two formations. The fault scarp is clearly defined i mile to the west but is not so well marked here. From the evidence it is possible that Malignant cove is situated at a node in the fault where the throw was considerable (for the shore to the east is very straight and doubtless dependent upon faulting), but not nearly oo (Fieat as farther west. The rocks of the Arisaig series, consisting of soft shales and thin limestones, suffered much secondary faulting during the general disturbance and their throw is not readily determined. As the Knoydart formation to the west overlies the Arisaig rocks and suffered little complex faulting, the throw of the great fault may be best studied in relation to it. Although at Malignant cove the base of the younger rocks appears to have been near the present sea-level, as is the case with the Malignant Cove forma- tion, and so may have originally been low compared to the pla- teau level, there is no evidence that such relations held for the Knoydan. formation. Younger and older formations are sepa- rat> d by a clean straight fault scarp and structural valley, the top of the Knoydart formation lying probably 300 feet below the level of the Cretaceous peneplain underlain by raetamorphic rocks. Twenhofel has measured 3,465 feet of Arisaig strata, and to this must be added the thickness of the iron-ore zone, prob- 95 ably 100 feet ±. Fletcher measured 683 feet of Knoydart beds without recognizing either the top or the bottom of the forma- tion. From structural evidence it is probable that this is much less than the true thickness. The Knoydart formation overlies the Arisaig series uncon- formably, resting upon the Stonehouse and Moydart at places little more than 1 mile apart. The value of the unconformity may be conservatively considered as equal to half the thickness of the Stonehouse formation. Assuming the base of the Arisaig series to have been at least as high as the plateau level whose rocks it may have overlain and neglecting the attitude of the for- mations to each other, the throw of the fault along the Knoydart formation may be estimated as follows: the thickness of the Arisaig series, plus the thickness of the Knoydart formation, plus the height of the plateau above the Knoydart formation, less the value of the unconformity between the Arisaig series and the Knoydart formation. The result is, in rouiii numbers, 4,000 feet. To arrive at the minimum estimate of the throw it may be assumed that the base of the Arisaig series was never so high as the plateau top but lay near the present level of the sea. In this case, the throw would be reduced by the height of the plateau, or about 1,000 feet, leaving a result of 3,000 feet. That faulting of this order «-.f magnitude has taken place is evident to the casual observer of the physiographic and geologic relations along the Hollow. McARAS BROOK FORMATION. EXTENT AND AREA. The McAras Brook conglomerate and grits of Mississip- pian age, occupy a small area northwest of the Knoydart formation. As measured by Fletcher along the shore they are 1,145 feet thick. The same strata occupy the eastern and central part of the Arisaig-Antigonish district and also a narrow belt along the south. With the exception of the intrusive diabase sheets at McAras brook and some irregular diabase 96 and basalt i* at the outlier of Doctors brook, the relations of which are in doubt, no igneous rocks cut the McAras Brook formation within the district. STRUCTURE AND RELATIONS. Everywhere these rocks overlie unconformably the < Ider formations, containing much debris derived from them. In the case of the Browns Mountain formations the contacts are sinuous and usually dip. very steeply, comr.ionly at 40-50' from the horizontal. The contact surface of the metamorphic rocks usually rises as a scarp with high inclination to the plateau level. The conglomerate beds for some distance from the older formations dip at angles depending upon the contacts. Where independent of border relations, the dips are low, with exceptions occurring in limited areas. From the above evidence it appears that the McAras Brook conglomerate was deposited by current action in old erosion valleys. These valleys were probably dependent on the structure, but probably were not wholly controlled by it. They were broad and may have been within reach of the in- iluonce of the tides. Cross-bedding is a common feature of the conglomerates and marine conditions followed their de- position as will be seen when the next formation is considered. Some time after the deposition of the conglomerates, regional compression probably took place and down-flexing was doubt- less influenced by the initial dips at the edges of the basins of sedimentation. As a result the dips at the contacts were in- creased and the beds were flexed into gentle synclinal struc- tures. Shrinkage in the thickness of beds, due to solidification, may have also accentuated these basin structures. Elevation has caused the erosion of the deposits so that we are now near the bottom of the basins. This may be seen in Rights river about 1 mile southeast of North Grant. Here a flat erosion surface on James River quartzite is exposed for a few square feet by the stripping away of the overlying conglomerate. 97 ARDNESS FORMATION. EXTENT AND GENERAL CHARACTERS. The Ardness limestone, gypsum, sandy shale, sandstone, etc., are of Mississippian age, being equivalent to at least a part of the Windsor group. The formation extends west- ward 1 mile along the shore from the top of the McAras Brook formation, and occupies the southern border of the district. Fletcher found the formation to have a thickness of 2,110 feet along the shore. In this he included the thickness of the lime- stone and underlying beds of marl three times. These are now known to be one bed faulted twice, and as a result 65 feet must be subtracted from 2,110, leaving the real thickness 2,045 feet. No gypsum is present in this section and the total thickness of the southern section including the gypsum is not known. The formation contains no intrusive rocks. STRUCTURE AND RELATIONS. The Ardness formation Las at its base a limestone member 20 feet or more in thickness, which, wherever observed, over- lies the McAras Brook formation conformably. The upper beds of the conglomerate are very even and for a few inches below the limestone are very calcareous. At the base of the overlying formation are thin-bedded limestones containing pebbles from the conglomerate, and these are overlain by the massive lime- stone. Then after an estimated thickness of 200 feet of red sandstone and shale, the gypsum beds occur. They are prob- ably about 200 feet thick and are overlain by red sandstone and shale. The Ardness formation ovr-lies the Knoydart along its western extent, and holds a similar relation to the James River quartzites at the southeastern corner of the district. The Ardness strata dip gently away from their boun- .ies and show very few evidences of disturbance. y,-m I ill] i m n LI ST MORE FORMATION. EXTENT AND GENERAL CHARACTEKS. The Liatmore formation was recognized by Fletcher as overlying the Ardness near the mouth of Knoydart brook. From here it extends westward a number of miles beyond the boundaries of the district with which we are concerned. If it is to be correlated with the "Millstone Grit" formation of Nova Scotia and New Brunswick, it is probably of Pennsyl- vania (Upper Carboniferous) age. STRUCTURE. There is no marked change in the characters of the sedi- ments of this formation from those of the formation directly below. A small fault with down-throw to the southwest occurs at the lower contact seen on the shore, but the zone of faulting is narrow, the strata on both sides have the same strike and dip, and no unconformity has been observed. The dip of the Listmore formation, like that of the Ardness below it, is about 30* to the northwest. RECENT DEPOSITS. Red marly clay underlies thick deposits of clay and till at the mouth of McNeils brook and elsewhere. This material is several feet thick, appears to be flat-lying, and grades upward into softer clay which is overlain unconformably by unsorted clay and gravel deposits. Near Malignant cove the till is 50 feet thick and shows some rough sorting near the top. West of Knoydart point well sorted beds are occasionally observed above the till, and these also occur along James river and the Intercolonial railway. The debris is usually of local origin, although some travelled pebbles are found. The shape is generally subangular, and scratching may be occasionally ob- served. Hog-back ridges and knolls are common in the vicinity of Maryvale and Arisaig and exist to a less extent over the 99 whole district. Three instances of glacial strije were noted on the plateau, having an average direction of S. 34° E. true bearing. One was situated north of James river and two were southeast of Arisaig. The extreme measurements were only 5" apart. Two other observations, however, were made on the lower lands to the north; one on the Arsiaig rocks of the OW road had a bearing S. 55" W.. and another uken on the north side of the Su^ar Loaf hill of Malignant cove had a bear- ing S.73»W. STREAM GRAVELS. The deposits along the lower graded portions of the streams have already been mentioned under "Physiography"; they reach considerable thicknesses in some instances, as in Vameys brook. They are, however, generally local in extent. The rich deposits of the "intervales" or bottom lands about Anti^onish may be correlated with the stream gravel deposite. In the case of the "intervales," the streams are long and h-ve deposited their coarser debris far back, carrying only the finer material to their lower courses. m 100 CHAPTER VII. IGNEOUS GEOLOGY. GENERAL STATEMENT. A glance at the geologic map of the Arisaig-Antigonish district will be sufficient to show that while igneous rocks occupy only a ■mall fraction of the area, they are of wide-spread occurrence in all except the Mississippian (Lower Carboniferous) formations and are of various kinds. The order followed in describing these rocks will be: (1) deep seated intrusions, (a) granite, (b) monzonite; (2) acid intrusion* and extrusions, beginning with aporhyolite because of i*s pre- vious interest to geologists, and then taking up rhyolite and quartz-porphyry necks, etc., and finally rhyolite dykes, breccias, tuffs, etc.; (3) diabase intrusions, (a) necks, (b) dykes; (4) basaltic rocks and a dyke of breccia character. Tabk of Igneous Rocks, (Descending Order). Post-McAras Brook, pre-Ardness. . . Diabase necks, dykes, ai>d intrusive sheets. Basaltic ( ?) intrusions and red dyke of breccia character. Rhyolite intrusions. Post-Baxters Brook, pre-Malignant I Quartz porphyry. Cove I Rhyolite dykes. [Altered tuffs (?) Post-James River (probably of age offGranite. above group \Monzonite. Pre-Beechhill Cove (probably of agef Aporhyolite flow, of above group) \F1ow breccia, etc. 101 JAMES RIVER GRANITE. LOCATION AND EXTENT. The James River granite area is situated about one-half mile north of James River station on the Intercolonial railway, and extends probably 3 miles east and west with an average width of about 1 mile. The granite is best seen along James river and its branching tribuury from \ . west. The only observed cont.T-t with the country rock is situated near the headwaters of a small brook flowing south across the railway about one-half mile east of James River station. Eastward and westward the granite boun- daries are obscured by drift. PETROUXilC CHAKACTERS. The specimen chosen as the type of ihe James River granite was taken only ?0 feet away from the contact already mentioned. The grain of the rock in this sample is fully as coarse as that of specimens taken from the centie of the igneous area. The granite is of a bright, flesh-red colour, is tough, and frac- tures in an irregular to sub-conchoidal manner, lepending doubt- less in these physical characters upon the texture which is dense but visibly granular. Feldspar is present both as bright red and as flesh-coloured crystals. Quartz occurs in irregular grains, generally under 2 mm. in diameter, and is clear or milky in appearance. Numerous irregular green patches of chlorite are scattered through the rock, indicating considerable weathering. Alkalic feldspar and quartz are the essential minerals, and from a comparison of several slides they are estimated to occur in the approximate proportions of 2 of feldspar to 1 of quartz. The accessory minerals are biotite (altered to chlorite), epidote, and plagiocla&e. The alkalic feldspar consists of the intimate intergrowth of orthoclase and albite forming microperthite, which may be recog- nized by its flecked appearance when seen between crossed nicols. Quartz is anhedral, occurring in irr^ular grair : and 102 mawws. The ptagioclaae (eldBpar, u determined by Michd Levy's method, ii andetine, varying in proportion ol the albite and anorthite moieculea from a compoaition o( AbiAni to AUAni. The andeaine ia present in conaiderable qua-'Mty. Chlorite prcaerving the structure of biotite, indicatea the original presence of that mineral. It occurs in small amount. In texture the rock is granitoid with a strong tendency towards pegmatitic intergrowths of quaru and feldspar. Quartt crysUls frequently extinguish together over considerable areas. Even in the normal specimens graphic intergrowths of quartx and feldapar are sometimes seen, while contact specimens show beautiful micrographic structure, as is described below. In general, the texture correaponds to that of a rock which is not far from a con- tact, and indicates the presence of plenty of water vapour during crystaliixation. CONTACTS OF THK GtANITB. At the obeerved contact with the country rock no diminution from the normal siie of the granite grain could be detected. However, at a contact between two masses of granite, exposed on James river, finer grain in the rock was obstrvcti and a micro- scoiNC examination of a specimen taken 2 or 3 feet away hows beautifully developed micrographic intergrowthf cf quartz and feldspar. The quartz takes the form of hollow triangles, hooks, etc., up to 0'04 mm. across and rodsuptoO'6 mm. in length with a breadth of 0-04 mm. Small veinlets of quarU cut the country rock near the north contact of the granite. As seen in thin section under the micro- scope, these conbist of quartz seams carrying a small amount of feldspar. They penetrate a shattered wall rock consisting of hornstone or greywacke. The larger quartz uniu show wavy extinction and very complete granulation. STRUCTURAL RELATIONS. The granite has intruded the James River (lower Ordo- vician) formation. The one contact examined was nearly vertical and that this is the general relation of the stock to 103 tht country rock may be inferred from the absence of other than insignificant dykai or ofTahoott from the parent maw. If the granite proj«!cted beneath a cover of icdimentary rocic it might reatonabiy be expected that numeroui acid dylces would be found extending considerable distances from the surface boundaries of the stock. Such intrusives are rare. South of the granite and west of the map boundary, an outcrop of pink intrusive rhyolite about 30 yards across occurs. Eastward about 2) miles, a few small dykes of similar character are exposed in l stream bed. No other fcldspathtc intrusives were noted in the vicinity excepting the small dykelets to the north already described. The debris scattered over the granite consists for the most part of glacial gravels, the surface of which corresponds in elevation and topography to the table-land to the north. Still a tendency towards radial drainage as e.xprcs8ed by the streams shows clearly that the top of the granite stock is slightly dome- shaped. This may have arisen in one of two ways; either we may have here what is practically the dome-shaped top of the stock from which little more than the roof with certain irregularities in the surface of the granite has been stripped; or the doming may be due to the greater resistance offered to erosion by the central part of the granite mass than would be offered by the somewhat shattered contact zone. The lack of anythii.g approaching channels cut into the granite; the small amount of granite debris either above the igneous rock or mixed with the glacial materials to the south; and more particularly the dense contact character of the granite itself, favour the first explanation. On the other hand, at the gran' • contacu with the Mc- Aras Brook formation, the oldest cI che Mississippian system found in the district, granite fragments ranging from angular to rounded pebbles are packed into the basal conglomerate. This establishes the erosion of the granite as far back as Mis- sissippian time. However, as the contacts noted are along steep decliviti. which were probably shore-lines, the erosion was most probably due to wave and current action and may not have affected the top of the stock. The long period dur- 10* ing which the granite has been exposed to erosion, and the probable steep character of its contacts, make it seem probable that the domed surface is due to the differential erosion during the progress of peneplanation and the later glacial abrasion. Still the texture of the granite favours the conclusion that no great thickness of the upper part of the mass has been removed. The observations made on the jointing of the granite, when plotted, suggest two joint systems, one dipping to the north and northeast, the other to the south and southeast. The angles of dip vary between 66° and 9G' from the horizontal. Cor- responding jointing was observed in the country rock showing the systems to be regional. Numerous small diabase dykes have wedged into the granite along its joint planes. MODE OP ORIGIN. Little evidence is at hand relating to the method of the intrusion of the granite magma. Sheeting was observed in the granite from 1 to U feet from the contact. This is com- monly found where igneous material has been injected into cold rock. Again the regional system of joint planes, frequently meeting at approximately right angles and making high angles with the horizontal, would indicate that this structure was developed hundreds of feet deep in the zone of fracture. The complete jointing of that zone would be expressed along four planes at right angles to each other and making angles of 45° with the direction of maximum force. More commonly two planes are set up instead of four, and the angles vary with the values of the different forces acting. Inferring that the granite was deep seated when the joint planes were formed, we may conclude that the intrusives took place at considerable depth in the earth, whence the granite was uplifted and exposed at the surface by erosion. AGE. Other than the James River granif, no granite is known in the area studied, with the exception of an obscure exposure lOS in a small stream flowing into Malignant cove east of McNeils brook. Here, caught between irregular acid intrusives is a badly crushed and altered granite, penetrated by calcite. This appears to have been a small intrusion into the Baxters Brook formation. Thus we have the intrusion of the granite positively fixed as younger than the James River slates and quartzites and older than the lowest of the Mississippian formations, which contains granite debris. No other formations have given us any relationships unless it be the Malignant Cove conglomerate, of probable middle Ordovidan age. Upon microscopic ex- amination this rock has been found to contain micropegmatite similar to that observed in the granite of James river. The localities are 12 miles apart, but a previous drainage system may have carried granite debris from its source to the location of the conglomerate beds. No other micropegmatite capable of producing such fragments is known in the district, although similar rocks may be found among the varied intrusions oc- curring eastward toward Cape George. If the fragments are part of the granite, the intrusion took place after James River and before Malignant Cove time or about the close of lower Ordovician time. This would correspond to the probable time of intrusion and extrusion of the acid rocks south of Malignant cove, which, as explained where they are discussed, may be related in a general way to the granitic intrusion. MONZONITE INTRUSIVES. LOCATION AND EXTENT. Commencing on the seashore about one-half mile east of the pier at Malignant cove, and extending to the eastward are a number of exposures of dioritic rock cut by irregular intrusives of diabase. Inland a few deeply weathered outcrops indicate that the intrusion is probably in the form of a stock extending southward about 1} miles. 106 No contacts with the enclosing rock were observed. The surface, for the most part mantled by drift, is rounded and con- forms to the general topography of the lower Ordovician rocki as seen east of Malignant cove. PETROLOGIC CHARACTERS. The type specimen was taken from an exposure on the sea- shore about one-half mile east of Malignant cove. The rock is medium granular and of a mottled green and white colour, de- pending mainly on the presence of green hornblende and white feldspar. Light and dark minerals are present in about equal amounts. The feldspar, which occurs in masses up to 5 mm. across, assumes a delicate pink colour on weathered surfaces, especially where these are wave-worn. Considerable chlorite is present. The essenual minerals of the rock are: hornblende, plagio- dase and orthoclase feldspars, and biotite. The accessory minerals are: iron ore, apatite, zircon, and quartz. The hornblende is a dark green variety. It is comi. ij euhedral in more or less perfect prisms, but here and there con- forms to the shape of the plagioclase. Occasional cores are present which are non-pleochroic and from their high extinction angle appear to be augite. The hornblende is thus probably present as a secondary mineral after augite. The plagioclase, determined by Michel Levy's method, varies in composition from AbrAnt to AbtAni and so is an andesine. Here and there this mineral tends to be euhedral, controlling the shape of the hornblende, and thus there is an approach to ophitic texture. Orthoclase, recognized by lack of twinning and small extinction angle from the cleavage on the 010 face, is an important con- stituent of the rock. Biotite occurs in rather irregular masses and is common. It is of a rich brown colour, strongly resembling brown hornblende. Magnetite is present s scattered irregular or rounded grains, included in hornblende. A few apatite prisms are included in hornblende and feldspar. Zircon is rare, occur- ring as more or less rounded prisms. 107 A thin section representing a boulder lying above the igneous mass, shows the rock to be made up of labradorite (AbiAni) and basaltic hornblende, with considerable secondary actinolite. In veinlets a mineral occurs which from its optical properties appears to be phrenite. The specimen as represented in thin section consists of the following approximate mineral composi- tion: plagioclase and orthoclase each 25 per cent, hornblende 30 per cent, biotite 15 per cent, and small percentages of apatite, zircon, and quartz. Thus in classification it falls between syenite on the one hand with predominant orthoclase feldspar, and diorite on the other hand with a predominance of plagioclase. The intermediate name monzonite is thus most suitable. It differs from the type, however, in the substitution of hornblende for augite and so may be called hornblende monzonite. AGE AND CORRELATION. As the monzonite lies off the area mapped, only little attention was given it in the field other t*">n to determine its character and possible extent within the area. An examination of the expo- sures extending eastward along the shore towards Cape George might yield information bearing upon the general relations of this intrusion. It is cut by diabase similar to that seen else- where in the region. Feldspar fragments similar in character to the plagioclase of the monzonite occur in the conglomerate of Malignant cove. This evidence, so far as it goes, favours the supposition that the monzonite intrusion may have belonged to the general igneous activity at the close of the lower Ordovician. APORHYOLITE FLOW AT THE BASE OF THE SILURIAN SECTION. DISTRIBUTION AND GENERAL CHARACTERS. The upturned edge of a rhyolite flow which has been of great interest to former writers extends eastward, with two interrup- tions, from Arisaig pier to McNeils brook, a distanc of about 3 miles. The first break occurs a short distance east of 108 Arisaig point where for a Uttle more than a quarter of a mile no volcanic rocks outcrop; again at Beechhill cove for a haH mile the sea sweeps without interruption against the lower beds of the Silurian system, which overlie the rhyolite. The aporhyolite forms a low ridge with nearly vertical con- tacts and reaches its greatest physiographic expression m French- man's Barn, an irregular rock rising about 60 feet above the sea. with a base measuring about 150 yards east and west by 40 yards north and south. The lower part of the sheet vanes in colour from pink to green to brown, and shows well developed flow structure, /is is best seen in the quarry along the road extend- ing to Arisaig pier, the rhyolite passes by gradations into a How breccia. At Frenchman's Bam breccia of finer nature is over- lain by the coarse breccia. Adding further interest to these striking lithologic characters, younger intrusives consisting of dark green diabase and a red tufaceous dyke have penetrated the volcanic rocks along the whole extent of their visible outcrops. PETROLOGIC CHARACTERS. The type sn- ..^n was taken from the quarry near Arisaig point. It has a decided platy parting, which coinddes with rusty-red bands in the otherwise flesh-coloured rock. These bandb are on an average 2 mm. apart. The material between the bands is of felsitic texture and may be seen, even with the unaided eye, to consist of rounded masses like small shot, closely packed and more or less welded together. On parting surfaces these Uttle bodies project, giving an irregular oolite-hke appear- ance. By means oi the microscope the rounded mass^ prove to be spherulites with characteristic radial structure. The dark parting planes are situated along cracks fiUed in with secondary quartz and iron oxide. As seen in the hand specimen thrae fine bands or layers have been determined by flow structure, and have no relation to sedimentary origin, which they were formerly thought to indicate. In general characters the rhyolite corresponds to moderr. acid lavas from the Lipari islands and the Yellowstone park as seen on a comparison of hand specimens. Iddings states 109 if .« I IS % a in his work on the geology of the Yellowstone park* that lami- nation in the case of the lithidite at Obsidian cliff depends upon the different amounts of water vapour in the layers, which cause different degrees of crystallization or the formation of bands full of gas cavities. In the lava under discussion the secondary minerals along the parting planes have masked the original texture, but in favourable places narrow bands of finer spheru- lites may be observed, as described by Twenhofel.' The finest material appears micro-feisitic in character. The parting takes place along the cracks originated during crystallization and filled with the secondary minerals mentioned above. No structure that could indicate the former presence of gas cavi- ties has been observed. Where the aporhyolite does, however, decidedly differ from the recent lavas mentioned, is in its complete felsitic texture, although all the structures point to its once having been partly glassy. Layers of spherulites averaging about 0-5 mm. across, compose nearly the whole rock mass, while the small amounts of glass once present have been devitrified. A similar oc- currence is described by Professor F. Bascom in her publication on "The Structure, Origin, and Nomenclature of the Acid Volcanic Rocks of South Mountain, Pennsylvania."* Fol- lowing her suggestion of the name aporhyolite as being mob suitable for a devitrified add lava, the name has been adopted as best designating the rhyolite under discussion. Some specimens representing certain bands of the rhyolite lava flow are fine-grained, flinty looking felsites of light green or pink colour. They possess conchoidal fracture. • Iddings, J. S. U. S. Geol. Surv., Mono. XXXII, Pt. II, pp. 424-5, 1899. ' Twenhofel, W. H. Amer. Jour. Sci. (4), XXVIII, p. 159, 1909. » Bascom, F. Jour. Geol., I, pp. 813-832, 1893. See also: Weidnian, Samuel. Wisconsin Geol. Nat. Hist. Surv., Bull. Ill, Sd. Ser. No. ?. pp. 1-63, 1898. Clements, J. M. Jour. Geol., Ill, pp. 800-822, 1895. Hobbs, W. H. and Leith, C. K. Univ. Wisconsin, Bull. 158, Sci. Ser. No. 6, pp. 247-27?, 1907. i tl 110 The flow bfecda forming the upper portion of the rhyolite sheet contains rounded fragments of rhyolite and has a grit- like texture. In general it is light grey-green in colour. The essential minerals of the rock, represented by the spherulites. are quartz and alkalic feldspar. Secondary quartz and iron oxide are prominent along the parting planes. The texture, in general spherulitic, varies to microgranitic. In one slide representing a bomb taken from a fine-grained red-brown breccia at Frenchman's Bam, a microfelsitic ground- mass is very general, showing spherulites only under very high magnification. Sericite is abundant and is probably the cause of simultaneous extinction, or approach to extinction, over oval or pt.itagonal art as when the section is studied between crossed nicols. These areas are seen in the hand specimen to be sections through small facetted grains into which the rock has become divided. The development of sericite is probably re- sponsible for the separation, which may be described as a perlitic parting. . , , . Sections of the rhyolite obtained by Twenhofel show, as described by him, a flow structure expressed in different sizes of microlites. He says of the minerals in the less dense bands: "These consist of quartz and alkalic feldspar, the quartz actmg as a sort of sponge for the feldspar and giving what is known as micropoikilitic structure."' An examination ot the slides confirms this statement. (His chemical analyses also confirm our classification). STRUCTURAL RELATIONS. Rough columnar jointing with axes about perpendicular to the contacts is common in both rhyolite and breccia. Sheet- ing is orescnt in many cases where the rhyolite and breccia merge, being more noticeable in the breccia. The sheets vary in thickness from 6 inches to 2 feet. The rhyolite sheet lies below the Beechhill Cove formation, the lowest of the Siluran system. Debris from the volcanics » Twenhofel, W. H. Loc. Cit., p. 159. Ill is included in the baaal sedimentaries, as may be seen at the contact exposed in Doctors brook. At Beechhill cove storms have recently exposed a contact where the sedimentary beds are flexed around an irregularity in the rhyolite. Near by small dykes deeply weathered and of uncertain character, cut the sediments. The relations point clearly to the latter having been deposited over an uneven surface, in this case where a lava bed has been partly removed. Later move- ment was most concentrated at the contact of hard and soft rocks and flexed beds resulted in the shales. The dykes are doubtless representatives of the soft weathering basaltic ( ?) intrusives everywhere abundant along the rhyolitic exposures, and are connected with the contact only in that the latter afforded a zone of weakness where intrusion was relatively easy. In Doctors brook the overlying shales are finely jointed and micaceous near the contact; no other changes were noted. Diabase nearly always occurs with the rhyolite, cutting into it mostly from the seaward or under side. Here and there it penetrates the lava along joint planes. Besides the dark green diabase, a brown, fissile, irregular, red dyke is present almost everywhere with the rhyolite and cuts both it and the diabase.' MODE OF ORIGIN. The aporhyolite was originally described as an altered sedi- mentary but as Twenhofei has pointed out, its characters and relations show that it is without doubt a lava flow which was poured out upon a surface existing before the Beechhill Cove for- mation was deposited. At first the flow was homogeneous, but as thickness increased, cooling lowered the fluidity of the ma- terial and all gradations resulted between lava with flow struc- ture, and flow breccia consisting of lava blocks surrounded by a fine cryptocrystalline' rock mass. ' For the above intrusives see "Diabase and Basaltic Intrusives." * The microscope shows quartz crystals usually less than 1 mm. across, having wavy or rolling extinction and frequently broken more than once. Ml 112 That the pouring out of the lav. wm accompanied by some explosive action and the depo?' -'ju of fragmental rocks may be inferred from the character of the breccia seen at Frenchman'^ Bam. In the opinion of the writer, however, this is also a flow breccia. A part of the flow breccia may also consist of tuff or bomb deposits, but the field evidence does not strongly favour this supposition. AGE AND CORRELATION. The rhyolite flow is at least older than the Beechhill Cove for- mation as exposed on the shore. On the other hand, the Malig- nant Cove conglomerate contains fragments of rhyolite similar to that under discussion. This would make the aporhyolite of pre-Malignant Cove age. While it cannot be conclusively shown that the extrusion of the aporhyolite belonged to the same period of acitvity as the intrusion of the quartz porphyry, rhyolite dykes and purple rhyo- lite of the Sugar Loaf area south of Malignant cove, still from similar characters and close association these various rocks appear related. If this could be proven, then the extrusion of aporhyolite would be limited to the time intervening between the deposition of the Baxters Brook slates and the Malignant Cove conglomerate, or to what was probably the close of the lower Ordovician period. VOLCANIC (?) BRECCIA OF FRENCHMAITS BARN. LOCATION AND GENERAL CHARACTERS. Just west of the prominent rock known as Frenchman's Bam, a dark red bed of fissile material (discussed under basalt) over- lies the flow rhyolite. It is about 10 feet thick and is succeeded to the south by a dense red rock which contains some blocks of rhyolite as large as 1 foot across, but which apparently consists mainly of fine felsitic groundmass with angular red fragments 1 mm. and less in size. Above lies a thick bed of dark green 113 rock showing lighter bands. This may be traced for a consid* erable distance eastward and has been described by Twenhofel as a volcanic breccia. PETKOLOGIC CHARACTERS. Seen in the hand specimen, this rock is dense, has a felsitic texture, and is of a chocolate brown colour, with purplish varia- tions. The fracture is conchoidal. Scattered through the mass are a few, small angular brick-red fragments, and greenish colora- tion seems to indicate other fragments. Microscopic examination of the dense red breccia shows it to consist of a fine-grained groundmass containing angular frag- ments of quartz about 2 mm. across, and under very high magni- fication the groundmast appears to have an exceedingly fine micro-granitic texture. Low magnification brings out an ar- rangement of the groundmass suggesting either flow or irregular bedding. No shards of glass or other material are present. MODE OF ORIGIN. The characters aktd relationships of the breccia beds would indicate that they formed one phase of the volcanic activity dur- ing which the aporhyolite was poured out. While the upper beds of rhyolite at Arisaig point were coming to rest as flow breccia, similar action was taking place near Frenchman's Barn, but here, in the case of the lower beds, finer fragments appear to have resulted, while the upper beds differ but little from the breccia farther west. The inconclusive character of the dense red breccia leaves some doubt whether after all, at this eastern locality, the rock is not made up of true volcanic tuff and breccia. ACID INTRUSIVES. DISTRIBUTION. The picturesque Sugar Loaf hill of Malignant cove is a centre from which extends dark coloured rhyolite breaking through the 114 •late cover, quarts porphyry protruding here and there, and ■mall light coloured rhyolite (feltite) dykea penetrating the country rock in very irregular fashion. Only the dykes extend to any considerable distance and they are for the most part in- cluded within the southwest quadrant of a circle of 3} miles radius, with centre at the Sugar Loaf. At the so-called marble quarry of Browns mountain, at a place about three-fourths of a mile northwest from Browns Mountain post- office, and at two or three isolated areas near the James River granite stock, and also, in one instance, within the granite itself, rhyolite dykes occur. PETROLOGIC CH^RACTIiKS OF THE ACID INTRUSIVBS. The rhyolite terming the neck of the conical hill known as the Sugar Loaf, and many irregular intrusions about it, all of which belong to the zone of transition between flow and intrusion, is a dense dark purple rock so weathered as to be unidentifiable in the field. To the westward it is replaced by quartz porphyry, which has been observed to grade directly into it. Across the transition zone the groundmass of the porphyry becomes suc- cessively darker, the feldspar phenocrysts decrease in number, and finally the dense purple rhyolite shows only an occasional oval quartz to indicate its relationship to the porphyry. The quartz disappears also within a short distance. At one or two localities rhyolite flow-breccia is p'esent. In general it has the purple colour and dense texture of the intrusive variety, but contains angular fragments, usually less than 1 cm. across, of grey-weathering material. Flow lines are well brought out on weathered surfaces. The quartz porphyry when fresh consists of z purple grey groundmass rather thickly set with large oval phenocrysts of flesh-red feldspar, and occasional round or oval patches of quartz. The feldspar phenocrysts may be as much as l-S cm. long, while the quartz is usually less than half that size. The fracture of the rock is uneven and hackly. The rhyolite of the dykes is of a light flesh colour, and usually shows small irregular patches of chlorite. It is of very dense, feisitic texture and 115 hat a conchoidal to hackly fracture. Very much altered and often femiginout dykeleU occurring in a small brook north- west of Maryvale, and again along the northern part of the Okl road of Maple ridge and elsewhere, are probably weathered dykes of this group. A slide fror> the rhyolite of the Sugar Loaf shows under the microscope a micro-felsitic groundmass, containing felds- pathic rods. These are probably orthoclase for the most part, but a little plagiodase is , .fsent as is shown by distinct albite twinning. As no Carlsbad twins could be found the nature of the plagiodase is uncertain. Serpentine and caldte are com- mon alteration products. A spedmen taken from near the slate contact with the r /o- lite of the neck shows much fragmental material consisting of broken laths of feldspar and rounded fragments and shards of quartz. Bunches of material are separated and appear to have been rolled together. Some fragments show small oval mmygdules filled with an isotropic mineral having radia! lines and what was originally a cavity in the centre. Shards of isotropic material as well as those of quartz are preac^nt, but can frequently be traced to their apparent source in material of similar characters showing remnants of a vesicular nature. A fine groundmass surrounds the fragments, and so far as can be seen is microgranitic in texture. Small euhedral, or hollow squares of magnetite are common. Kaolin and fine iroa oxide obscure the original structures. A spedmen of quartz porphyry taVan from an outcrop a short distance southwest of the Sugar Loaf, proves upon micro- scopic examination to consist of a microfelsitic groundmass of quartz and feldspar containing a number of large pheno- crysts of orthoclase with some plagiodase and a few large rounded quartz masses. The latter fade off at the margins into the groundmass. Alteration to kaolin and chlorite is common. The type specimen from the rhyolite dykes was taken from an exposure in the bed uf a small brook about three-quarters of a mile south of the Sugar Loaf. Microscopic examination shows the rocks to be made up of quartz, orthoclase, and plagio- claw feldBptr, in about the profwrtion common in granitt. The texture it microgranitic. The grain is equidimen- •ional and of an average diameter of 0-1 mm. With high magnification piagioclaw laths were observed about 0-09 mm. across. The extinction angles were about 13*-I8* from the albite twinning plane. One feldspar also showed Carlsbad twinning by means of which it was determined as andesinc. The extinction angles given above would bear out this de- termination. Specimens from the dykes in the James River granite show characters similar to those just described. A slide representing a dyke cutting the granite, contains a little scattered magnetite in grains about 0>02 mm. acrosa, and has a microgranitic texture. Some well developed quarti and orthoclase and plagioclase feklspars are present. A sample of rhyolite dyke-rock from northwest of Browns Mountain post-office, consists of a groundmass exhibiting apherulitic texture, and phenocrysu of orthoclase and plagio- clase feMspar. The latter has large angles of extinction, and as determined in one case, by Michel Levy's method, is labra- dorite. Flow structure is clearly present as shown by broken quartz crystals, broken pieces of feldspar, and by a general flow arrangement of the groundmass about the ohenocrysU. The pink colour of the rock is largely due to strings and shreds of iron oxide which are scattered through the groundmass. STRUCTURAL RELATIONS. The acid intrusives, with the exception of the dykes cutting the James River granite, cut either James River or Baxters Brook formations of lower Ordovician age. The rhyolite of the Sugar Loaf forms a nearly vertical, but irregular neck standing high at its east and west extremities. Against the sides and nearly overlap, =ng the central portion are twisted and more or less stretched red slates. The same rhyolite outcrops in many mounds to the westward, often little more than breaking through the slate, which overlies it generally at a low angle of dip. 117 The quartx porphyry beara in general the Mme relationa to the enclottng rocks m doce the purple rhyoUte and forms an irregular neck outcropping in McNeil's moUntain, one of the highest eminences in the area. The porphyry appears to represent aii intrusion more deeply cut than the rhyolite and has, so fs*- ss indications go, steep conUcU. The rhyolite dykes are usually small and cut the country rock along lines of weakness such as bedding und joint planes. In one case they were observed to flow around quartz por- phyry. The dykes near James river have the same general characters as those just discussed, while the intrusions of Browns mountain are somewhat irregu^tr though probably of the nature of dykes. MODE OP ORIGIN. The fine-grained texture of these rocks and their manner of breaking through the older formations indicate that they were intruded near the surface. The occurrence of flow breccia and tuff shows that they had extrusive phases, which have scarcely been removed by erosion. In one exposure a triangular block of slate 3 feet by 4 feet has settled into the rhyolite. This would indicate that overhead stoping had played a part at least in the imiptive processes. AGE AND CORRELATION. That the purple rhyolite and the quartz porphyry are merely phases of tht. same intrusion seems to rest upon safe evidence in the case ol the observed gradation of the one into the other. The rhyolite dykes are evidently younger as they are known to curve about the quartz porphyry. However, their close petro- graphic resemblances point to their common origin and seem to indicate that the difference in the ages is not great. The rhyo- lite dykes of Browns Mountain and the James River granite area are probably a little younger than the granite, but appear to be of the »s»me magmatic origin. Their close petrologic resem- blance to the acid intrusives of Malignant cove and their pres- ence in the same sedimentary formation, favour the theory that 118 all these intrusives are really of one general age. H we include also the aporhyolite flow at the base of the Silurian formations, which is closely allied in petrologic characters, we may seek for an epoch of activity agreeing with the accumulated data derived from the separate study of these various rocks. Such an epoch is found between the deposition of the Baxters Brook slates and the Malignant Cove conglomerate, probably corresponding in time to the close of the lower Ordovician. All the acid intru- sives have been shown to be younger than the James River for- mation, while the Sugar Loaf intrusions cut the Baxters Brook slates and so are younger than these. These intrusives do not cut the Malignant Cove conglomerate; and fragments of rhyo- lite of microgranitic texture are found in this formation. The aporhyolite is certainly older than the basal Silurian and most probably older than the Malignant Cove conglomerate which contains fragments of similar material. There seems no good reason for placing its age farther back in time than the lower Ordovician to which belong the oldest formations known in the district. The weight of evidence thus favours one general period of intrusive and extrusive activity for the acid irruptives; and this being granted, the time of activity must have been previous to the deposition of the Malignant Cove conglomerate but after the Baxters Brook slates and sandstones were deposited. A time interval is here represented by an unconformity between the formations named which probably marked the close of lower Ordovician sedimentation. If the Malignant Cove conglom- erate is of Ordovician age the igneous activity may be consid- ered as belonging to the close of the lower Ordovician. VOLCANIC TUFF AND BRECCIA OF SUGAR LOAF AREA. GENERAL LOCATION AND EXTENT. In several localities within the igneous area of the Sugar Loaf hill south of Malignant cove, soft purple schist or light green breccia rocks were observed. For the most part, outcrops are of insignificant size, extensions being m sked. 119 PETROLOGIC CHARACTERS. A specimen of soft green rock weathering so as to show a breccia nature was obtained from an outcrop near hematite prospects north of the Little Hollow. Megascopicaliy it is clearly very calcareous. Other specimens of similar rock differ in be'.-, ', fine grained and of a purple colour. Those tested e- .T vesce Ircf ly vrHh acid. Under the inicrocope iron oxide is seen to be rather fieely s.; itt( rod through the calcite, which makes up the greater part of t-i. t -Kk. In Uie arrangement of the oxide and in the peculiar globules of caicke present a former tufaceous structure is thought to have been recognized. The purple schist seen under the microscope shows similar characters. AGE. :■ -■; ] As already indicated, there is some uncertainty as to the real character and relation of these tufaceous rocks, because of their great alteration. The specimen described represents the south wall-rock of a bed of iron ore, and Woodman states (1909, p. 194) that "tuff-agglomerate" has also been observed to form the south wall of an iron ore bed at Iron brook and elsewhere. If this be tuff and be really interbedded with the James River strata, as it appears to be, it becomes the earliest evidence of igneous activity that has been found in the district. The neces- sary conclusion would be that extrusive volcanic eruptions oc- curred during that part of lower Ordovician time represented by the deposition of the James River greywacke and slate. DIABASE INTRUSIVES. DISTRIBUTION. Series of diabase dykes are of common occurrence cutting rocks of all ages from the lower Ordovician to the Mississippian. In almost every stream, excepting those flowing through the upper divisions of the Carboniferous rocks, ui^right projections 120 of diabase mark the intersection of these dykes by the water course. They are in many cases so weathered as to be with difficulty disting-iished from the enclosing rocks. For the most part the dykes are small, being less than 15 feet in width. Quite a number, however, are of fair size, some reach- ing a thickness of 40 or more yards. In general they conform to the main direction of faulting and folding in the region, and extend in a northeasterly and southwesterly direction, with a tendency in the Devonian area to swing n' «; nearly north and south. The dip usually varies but a few degrees from the verti- cal, but there are exceptions as in the case of the amygdaloidal diabase at the mouth of McAras brook. Here the intrusive sheets dip to the north of west at from 40° to 49°. In the meta- morphic area of lower Ordovician rocks the regional jointing for the most part controls the form and direction of the dykes. Numerous small dykes have also wedged into the James River granite along the jointing. In one instance four dykes varying from 1 to 20 feet in width and separated by similar widths of granite, are exposed in parallel arrangement across the bed of the western branch of James river. Generally longitudinal extensions of the dykes are obscured and dyke terminations occurring in the stream beds would indi- cate that there are frequent interruptions along their length. However, extending eastward from Arisaig point, diabase may be observed in connexion with the aporhyolite flow for about 3 miles a!' ng the shore. This appears to be a continuous intrusion, although outcrops are occasionally lacking. The dia- base occurs as an irregular dyke partly following the bedding of the flow, partly breaking across it, and nearly always lying at the base of the lava sheet whence it extends into the ocean form- ing numerous reefs several rods from shore. Besides the dykes there are a few irregular intrusions of dia- base. One of the best examples of these occurs as a neck in the Sugar Loaf hill about IJ miles nearly due north of the town of Antigonish. This prominent physiographic feature is an oval knob about one-fourth of a mile north and south, measured along its major axis. Its top, according to Fletcher's map, reaches an elevation of 760 feet above sea-level. 121 On its summit, weathered diabase outcrops in the form of an oval with a narrow projection to the south. On the north a precipice of 25 feet marks the contact of the James River rocks with the diabase from which the slate has fallen away. Else- where the slopes are more gentle, although still steep down to the plateau level. The slate at the contact is very hard and is frequently jointed into small blocks. The diabase forms the core of the hill and is the cause of its preservation, both the diabase and the metamorphosed slates about it being very resistant to erosive agencies. Within a circle of 1 mile small diabase dykes are of commom occurrence. PETROLOGIC CHARACTERS. Certain of the diabase intrusions, notably the sheets cutting the McAras Brook formation (Mississippian), are decidedly amygdaloidal for several feet both from the upper and lower con- tacts. Fillings of calcite have been observed that measured an inch in diameter. Similar diabase occurs along the shore east of Arisaig point and amygdaloidal character has been noted elsewhere. Other than this physical difference no natural divi- sion of the diabase intrusions has been found and they will be described together. The type specimen was taken from an irregular dyke exposed along the Old Road about 2) miles south of Arisaig point. The rock is visibly granular, but dense. Its colour is lark green-grey with lighter spots due to more or less distinct, . II, light-green laths of waxy-looking plagioclase feldspar. :tered through the mass are numerous irregular patches of iron pyrites. Jointing is well developed and much chlorite is present along the joint planes. Some specimens are so dense that no grain can be seen, while others appro." ~h pegmatitic structure and show well developed feldspar crystals of a pink-brown colour. The latter characters may be observed at the forks of the upper branches of the South Branch of Rights river. A" seen under the microscope the essential minerals are augite a ^io^odase feldspar; the accessory ones being magnetite and pyrite. The texture is characteristically ophitic. il 122 The magnetite occurs in idiomorphic crystals about 0-27 mm. across, while pyrite is present in irregular grains. The plagio- clase feldspar has crystallized in laths about 0-2 mm. wide and 2 mm. long. By means of the Michel Levy method these laths were found to vary in composition from Ab»Any to AbiAn,, and so belong to the labradorite-bytownite series. Augite has developed partly before but mostly after the plagioclase, com- monly appearing as laths more or less parallel with the feldspar, and more larely torming irregular masses. Actinolite, chlorite, and epidote have replaced much of the augite. The rock composition is approximately augite one- third, plagio- clase one-half, and magnetite one-tenth, while the remainder is made up of alteration products. The composition and texture of the rock determine it as diabase. The more feldspathic specimens show some quartz to be pres- ent. A sample taken from the intrusion on Rights river, already mentioned, cor tains considerable quartz, while the feldspar belongs to the andesine-labradorite group. A specimen from a small stream north of James River statio.i shows in thin section considerable quartz and also r> tendency towards micrographic structure. STRUCTURAL RELATIONS. In many cases the diabase dykes show systems of jointing. Sheeting parallel to the contacts extends into the body of the dyke for a short distance and is replaced by rough columnal jointing with axes perpendicular to the contact planes. The two systems may be observed at the mouth of McAras brook. The columnal jointing here has prism faces from 1 to 2 feet in width. In the case of the smaller dykes, only little jointing is present. No sheeting has taken place at the contacts with the country rock, but it is found that here the grain of the diabase is finer than at the centre of the dykes. As the diabase sheets at the base of the McAras Brook (Mis- sLssippian) formation have been described by Dawson as ex- trusive flows laid down in water during the deposition of the con- glomerate, a rather full description will be given of the character 123 of these intrusives and their relations to the sedimentary forma- tions. The author did not find any evidence of fragments of diabase in the conglomerate as described by Dawson. The diabase is for the most part intruded either along contact or bedding planes. The lowest sheet occurs at the top of the Silurian section and flexes the shale beds, forming a 'x:al syn- cline. For 5 feet below the "trap" all bedding is destroyed. Tongues of diabase containing fragments of shale penetrate across the direction of bedding for f feet or more. For 12 feet beneath the lower igneous contact the shales have become uni- form iron-red in colour, and in places assume a submetallic lustre. A trap sheet passes very near the contact of the Mississippian conglomerate with the Devonian shales, leaving but little con- glomerate below it. In all cases the lower contacts of the diabase sheets with the McAras Brook conglomerata show, in the sedimentaries, dis- coloration, baking or hardening, and fissility parallel to the contacts. The upper contacts show practically the same char- acters. In one exposure the trap has an uneven surface; 3 inches of gouge overlies this; the conglomerate is hard for about 3 inches and is finely jointed for about 3 feet more before it becomes normal. In another case the intrusive rock uplifts the conglomerate beds and breaks r ;ross their strata "s much as 2 feet. At one upper contact shale fragments are '^ontained in the diabase for 6 feet down, one a foot from the contact being 3 feet long. The diabase is amygdaloidal for considerable dis- tances from both the top and bottom. This amygdaloidal nature suggests intrusion near the surface, an inference supported by the observation that the intrusives do not cut the formation above and hence probably came to place before the Ardness sediments were deposited. In the older formations the intrusives affect the wall rock but little. In the Devonian rocks sheeting has been observed parallel to the contact. Where the diabase cuts the aporhyolite east of Arisaig point the dyke material flows around and into v.ie joints and fractures of the lava in a very irregular way. In some cases blocks of 124 rhyolite are dislodged and contained in the diabase. Little con- tact eflfect upon the wall rock could be observed, but the "trap" is always very dense. In the case of the James River granite where the diabase is intruded along joint planes, discoloration of the granite is often marked at the contacts. METHOD OF INTRUSION. As already mentioned the wide-spread regional structure con- sisting of jointing, faulting, etc., has for the most part controlled the mode and directions of the diabase intrusions. Usually joint planes have been the passageways for the molten material, but bedding planes have also been followed as in the case of the Mississippian formations and the rhyolite flows. A few small irregular masses appear to be more or less independent of struc- ture and were probably related to minor centres of disturbance. This seems to be true in the case of the Sugar Loaf, near the town of Antigonish, with its set of dykes on the south and west. AGE. No good reason has been found for considering the diabase dykes to be of more than one period of intrusion. In not a single instance was diabase observed to cut diabase. On the other hand diabase is known to cut representatives of all the other intrusive rocks. As already noted the sheets of diabase cut the McAras Brook conglomerate but do not cut the Ardness, the overlying forma- tion. They were then, in all probability, intruded during early Mississippian period after the deposition of the McAras Brook formation, but before the laying down of the Ardness limestones, sandstones, etc. For the reasons given it seems probable that the other diabase intrusions of tlie region also belong to the early part of the Lower Carboniferous or Mississippian period. 125 BASALT, BRECCIA DYKE, ETC. LOCATION AND EXTENT. A number of the irregular basic intrusives scattered over the area are of basaltic rather than of diabase character. Examples of this class are to be found associated with the purple rhyolite south of Malignant cove. Of such a chara er are the purple intrusives along the Gulf road for the first miie south of the shore and also the amygdaloidal rocks north of Rogers brook, a tributary of Rights river. An altered intrusive In the Silurian rocks of Doctors brook and soft clayey dykes near the small Carboniferous area on the east branch of this brook, are prob- ably basalt. The long red dyke mentioned in connexion with the intrusives east of Arisaig point, is so friable as to be with difficulty deter- mined. It appears to be a very fine breccia in nature, but amygdaloid associated with it is basaltic. With the exception of breaks common to all the rocks along the shore, this dyke has been traced for nearly 3 miles. At Arisaig point to the east of the Lighthouse, diabase pene- trates the aporhyolite in the form of irregular dykes of bmall size. Near one of these, brown fissile to powdery material ca*s into the rhyolite as small dykes with rounded terminations, and in one case as an almost circular pipe of about 1 foot diameter. This soft-weathering imcrusive has a fissility parallel with the contacts, while vesicular nature was present in one case. The rhyolite was faulted previous to intrusion as the diabase follows the fault line. The acid lava also shows a pitchstone character and fine sheeting parallel to the fault line. West of the base of the rock known as Frenchman's Barn, a lO-fc"* sheet of red fissile rock separates rhyolite-breccia on the south from rhyolite showing flow structure on the north. This sheet is directly in line with the red dyke to the eastward which leaves the aporhyo- lite and cuts into the diabase. At Frenchman's Barn rounded masses of red material are contained in the mass of the sheet, while rhyolite blocks are enclosed farther east. In places the red material is amygdaloidal. Eastward the red dyke cuts 126 across the sheeting of the volcanic breccia and still farther to the east it is found entirely within the diabase, in places throw- ing ofT branches for several feet along the joint planes of the older intrusive. Due to its soft nature, long tide-washed lanes are here and there left with a floor of dyke material and high walls of diabase. West of Doctors brook two small re(* dykes are present part of the way, while in some places no d> .ce can be seen. However, to the end of the exposures of diabase east of Doctors brook evidences of the dyke are present. PETROLOGIC CHARACTERS. Four specimens have been selected for special description. The first was taken from an area south of the Hollow and north of Iron brook. It is very dense, of a purple colour, and has a conchoidal to uneven fracture. The second to be considered is a sample of the red shaly rock occurring west of Frenchman's Bam. This is of a bright iron red colour, with irregular white patches scattered through it. These look at first like sheared amygdules. The texture is fine and the rock is fissile and slaty in appearance. Rounded nodules of the same material cause the fissility to pass around them; some fragments of aporhyolite are present. The third specimen is taken from the irregular red dyke as exposed east of Beechhill cove. In general only crumbly detris can be obtained, but the specimen is of slaty texture, dark red colour, and fine, even grain. A cleavage parallel with the con- tacts is very marked. The fourti; rock sample was taken from an r.nygdaloidal dyke penetrated by the fissile red material last described. It is purplish red in colour, and has light green amygdules about 3 mm. across. These are considerably flattened out and sheared. Under the microscope, the first rock, although very much altered, from secondary products and remains of crystal forms, may be shown to have contained olivine and feldspar as the best developed minerals. The feldspar had the form of laths twinned according to the albite law and where best preserved these show nearly parallel extinction. These characters determine the feld- 127 •par to have been oligoclase. The olivine has altered almost completely to serpentine and iron oxide. It is by the marginal arrangement of the oxide that the original character of the mineral may be determined. Glass and undifferentiated augite were probably present. Secondary quartz is common. A slide from the intrusives along the Gulf road shows considerable augite to be still present as irregular grains, and crystals pene- trated by feldspar laths. Secondary chlorite, iron oxide, cal- cite, and chalcedony are present. Flow structure is marked. In spite of alteration typical pilotaxitic texture is well preserved. It was originally expressed in the crowding together of micro- STopic laths of feldspar, with olivine, augite, and probably some glass between. A microscopic examination of a specimen of red material west of Frenchman's Barn clearly shows it to be made up of a fine groundmass containing irregular fragments of rhyolite measur- ing on an average 0-1 mm. by 1 mm. Some quartz fragments are also present. The rock is filled with iron oxide and little can be said of the oriftinal character of the groundmass. It appears to have been made I'p of fine fragments of some kind. Twenhofel considered this rock in all probability to be of sedimentary origin, basing his opinion upon his unpublished chemical analyses which show the average content of alkalis to be \atO, 2-54 per cent, and KjO, 2-92 per cent. It is evident that these percentages are greater than would be the case if the rock were of normal sedimentary origin. On the other hand, they correspond to the average percentages found in igneous rocks of intermediate feldspathic character. As the specimens studied show almost complete setting free of the combined iron so that it now fills the rock as iron oxide, it is reasonable to expect that the alkalis have to a large measure been leached out. The third specimen, which is from the red dyke, is difficult to determine under the microscope. It consists mainly of finely divided iron oxide, with small grains of quartz and some magne- tite. The average grain of the rock is about • 02 mm. in diame- ter. Some unquestionable shards of quartz are present, and the original rock was clearly made up of line clastic components. 128 The laat tpecimen, reprewnting the purple amygdaloid, ia •Imoat completely changed from ita original minetal compoei* tion, yet paeudomorphs of feldapar latha atill exhibit albite twinning and ahow that the original mineral waa plagiorlaae. Magnetite waa alao a primary conatituent, aa shown by the de- velopment of feldapara around it. In the place of the earlier minerala, chlorite, iron oxide, kaolin, opal, and chalcedony now make up the bulk of th<; rock, the chalcedony forming the amyg> dulea. Pilotaxitic atructure is. however, well preaerved. The feldapar latha were on an average 0-15 mm. acroaa, and were doaely packed together. MANNER OF INTRUSION AND RELATIONS. The basalt of Rogers brook, the igneoua area south of Malig- nant cove and elsewhere, appears to have been merely a surface phase of the diabaac intrusions, and may have been in part extrusive. The red dyke along the shore cuts the diabase and the aporhyo- lite and so is the youngest igneous rock known in the district. In some cases it appears as pipes and small dykes cutting through the diabase. At other places it includes large blocks of diabase. At Frenchman's Tarn it has the characters of a sheet intruded between the homogeneous aporhyolite flow and the breccia above. Aa might be expected, fragments of the enclosing rock are contained in the intrusive. It is well to note here that at this one locality the shi^t might almost equally well be inter- preted as a normal tuff overlain by breccia. It is because of the apparent continuity and alignment with the red dyke that the first interpretation is thought to be correct. Eastward fro. Frenchman's Bam there is no question as to the dyke nature of the fissile red rock. It passes entirely into the diabase, branches and splits, includes rhyolite, diabase, and basalt as only a dyke possibly can. That such dykes occur elsewhere is shown by observations made by various geologists.' ' In the Quarterly Journal of the Geological Society of Ix>ndon, Volume 57, 1901, pages 479-489, Jame» Robinson Kilroe and Alexander McHenry, M. R. I. A., have described as dykes rocks occurring in Waterford and Wex- 129 Some evidence bearing upon the origin of the red dyke it afforded by the character of the purple amygdaloidal dyke asao- dated with it. The amygdaloid ia entirely distinct from the diabaae and occurs along the tame line of intrusion as does the red dyke. It is somewhat older as the red material flows into it and around portions of it. The suggestion seems to be that the amygdaloid repreaenU the first pulse of intrusion, and the brecciated material later pulsations. The conditions must essen- tially have been those close to the surface. As the activity was confined to the vicinity of the diabase, it may well have been an after phase of the diabase intrusion. ford counties, Irebnd, that had previoutly been considered volcanic tuffs •nd breccia*. They find them cutting ■edimentariea and containing many fragmenti of the country rock*. Thu* ilate of Llandeilo age and Bala lime- •toae are intruded. Even the dykelet* retain tufaceoui character. Inform tlie intrusion* are either (ill* or dykes. An instance was noted where granite grsdca into felsite and this into breccia, and finally intrusive tuff is found. The explanation offered ia that fracturing occurred in connexion with continued intrusion after portions of the invading magma had solidified in smaller vein*. Pumice i* explained by the audden opening out of fi**ures, etc. 130 CHAPTER VIII. HISTORICAL GEOLOGY. GENERAL STATEMENT. From lower Ordovician to Penniylvanian time, the geological history of the Arisatg-Antigonish region is imperfectly written in the aedimentary records, but there are also important chap- ters dealing with igneous intrusions, lava flows, and erosion intervals. From Fennsylvanian to Quaternary time, there probably warn little or no sedimentary record, the interval being apparently one of long and continuous erosion. The erosion cycles are clearly indicated but arc limited in number and not readily placed in the chronology except by analogy with other physio- graphic provinces. Quaternary time is meagrely represented in sedimentary records. LOWER ORDOVICIAN PERIOn. The history of the region opens in lower Ordovician time with a long period of sedimentation. Whether or not these sedi- ments were laid down upon the Gold-bearinj; series, often stated to be of Cambrian age and sometimes thought to belong to Pre- Cambrian time, we do not know. The thick deposits of ^^ ywacke or impure quartzite inter-bed- decl with banded slate imply the existence of a shallow transgressing sea during the deposition of the James River formation, the older of the two formations here constituting the lower Ordovician record. The minor variations, such as those seen in the band- ing of the slate, may represent cyclic climatic changes. When the upper part of the James River formation was being laid down, there existed conditions favourable for the deposition of iron, such as a shallow sea rich in iron solutions. Between beds of impure sand, oolitic iron oxide was deposited in beds none of which 131 exceeded 20 feet in thicknew In thr muddy fcrruginoui watrrt of this time a few linguloi>t brachiopods were able to live, and they are our only guides for the age determination of thcw deposits. The red slates and thin sandstones of the Baxters Brook forma- tion, which constitute here the higher beds of the lower t)nlo- vician, commence only a short distance above the iron ore beds and probably represent shallow water conditions of wide extent during which oxidized sediments were washed in from the land along with some clean sands. Following the solidification of the Baxters Brook strata there was a negative movement of the strand-line, annsiderable beds of oil-shale containing impressions of fern- like leaves and plant stems. Higher up in the formation grey 10 136 and green bands are found evidently indicating the encroach- ment of the sea, as the deposition of marine limestone followed, marking the base of the next formation. Igneous activity occurred probably during the later part of the McAras Brook deposition, and diabase intrusions in the form of necks, small dykes, and intrusive sheets penetrated all the formations of the region. Some phases of the activity were probably represented by basaltic dykes and flows, while others appear to have been of more explosive violence, forming breccia dykes and possibly tuff deposits. Along the base of the Arisaig series, a basaltic dyke came to rest, probably with pulsating injections, and assumed a breccia or tufaceous character. Within the Arisaig-Antigonish district no break in sedimenta- tion was detected between the McAras Brook conglomerate and the Ardness limestone. Submergence and marine conditions followed subaerial and possibly estuarine conditions. In a sea of clear water, high in lime content, organisms secreting calcareous ■hells, such as ostracods and brachiopods, lived, and on dying contributed to the limy deposits on the sea-bottom. These con- ditions, however, did not last long. The waste brought in from the land probably pushed the sea back, at all events shallow water conditions followed during which red and grey sands, red marl, and later ripple-marked sands were deposited. At some localities lagoons and shallow water-pans were partially shut off from the sea, and in them upwards of 200 feet of gypsum was precipitated as a result of evaporation and occasional inflow of salt water. The characters and colours of the other sediments are those suggesting subaerial conditions and this conclusion is borne out by the plant remains present in the upper beds. At times, swamps existed in which flourished thickets of CalamiUs and other Carboniferous plants. Finally, continental conditions again prevailed and marked the passing of Ardness sedimentation which represents the closing stage of Windsor time in this district. PENNSYLVANIAN (UPPER CARBONIFEROUS) PERIOD. The continental conditions that set in near the close of the last formation continued without interruption into the time rep- 137 resented by the Listmore formation. Considerable sorting was accomplished by the streams of the time and the deposits con- sist mostly of fine to ccarse, grey or white sandstone with some red shaly sandstone near the base. The remains of Stigmaria and Calamius indicate that condi- tions were at least locally favourable to plant growth. The sea was probably wholly excluded and fresh water was the trans- porting agent for the sediments. Its work is recorded in false- bedding and round concretionary forms similar to deposits fill- ing river pot-holes to-day. With the advent of fresh-water sedimentation, an emergence began which probably was a part of the closing Palaeozoic uplift known as the Appalachian revohaion. If the Listmore formation is equivalent to the Millstone Grit, it represents an unconformable relation with the Ardness forma- tion, but no such relation has been detected by the writer. In other places the unconformity is said to be marked between the Windsor series and the Millstone Grit, although Ami failed to find it in the Cumberland basin. CRETACEOUS PERIOD. Although Permian and Triassic time are represented in some part- ' Nova Scotia by continental deposits, the geological his- tok. - Arisaig-Antigonish district during the remainder of Palaeozo id all of Mesozoic and Tertiary time, is written in the negaiive terms of erosion. These negative terms may, however, have very definite values and such is the case in the result of CreUceous erosion. Long continued denudation must have swept away vast quantities of rock debris of varying resistance and left finally a plain of very gentle relief, traversed by rivers meandering over the flat flood- plains. From analogy with other districts, the flat top of the Cobequid mountains is thought to have gained its older surface features during a peneplanation cycle completed in the Cre- taceous period. 138 TERTIARY ERA. In Tertiary time the land stood high and the erosive agents started to unmake the products of their long activity. Naturally the softer formations suffered most and were gradually etched out below the upland surface. During the Tertiary era a secondary base-level was formed on the Carboniferous rocks and the elevation of the surfaces of the Silurian and Devonian rocks was much reduced. But on the metamorphic and igneous rocks erosion did little more than entrench the stream channels. The age of this base-level is fixed by analogy with regions else- where and there is some evidence at hand from this district. Glacial striae have been recognized upon the Arisaig rocks and upon the Baxters Brook slate of the Sugar Loaf hill south of Malignant cove. The locations are situated approximately 500 and 400 feet below the plateau level, and show that the ice met in the plateau scarp a barrier that caused it to swing to the south- west. The amount of erosion implied is far too great to be ex- plained by glaciation and the alternative view is that Tertiary erosion was effective in reducing greatly even such hard rocks as the upper slates and limestones of the Arisaig series and the metamorphic slate of the Sugar Loaf. If this were true, the softer rocks would be much more reduced, even assuming a surface of low relief. QUATERNARY ERA. Pleistocene or Glacial Time. By the time the "ice age" took possession of the region, the surface rocks had apparently become much decayed and dis- integrated, forming a regolith over the surface of the land. The continental ice sheet passed over the district in an average direction of 10° east of south, and redistributed the land waste, sweeping the plateau bare of all thick deposits and laying down red marly clay and unsorted clay-gravel-boulder deposits in the valleys of streams and as moraines along the margins of the low- lands. During the retreat of the ice the glacial deposits took 139 on their characteristic forms and may at the same time have been modified near their surfaces by outwash from the melting ice, so that bedded gravels resulted. At James river, near the Intercolonial railway, such bedded deposits occur at an eleva- tion of about 180 feet above the sea. Near the headwaters of the western branch of James river bedded gravels dipping 13' to the eastward occur about 670 feet above the sea. Recent Events. Since the Glacial period, terraces have been formed along the coast probably during a decided negative movement of the strand- line. Three well-preserved terraces occur, the highest being at an elevation of more than 120 feet. Each probably marks a major halt in the movement of the strand-line. Recently thin deposits of stream gravels have been formed and it is thought that movement is still taking place, causing the streams to cut down. 140 CHAPTER IX. ECONOMIC GEOLOGY. INTRODUCTORY REMARKS. The economic mineral resources of the Ansaig-Antigonish dis- trict are neither of great variety nor have they proven so far of great commercial value. Most important are the iron-ore de- posits which were first prospected many years ago. Next in importance are the gypsum depos:ts which as white cliffs form a noticeable landscape feature along the Intercolonial railway. Oil-shales have been found in limited quantities and signs of copper occur at a number of localities. Indications of silver have been previously reported, but no evidence of its presence has been recently found. Limestone, formerly quarried to some extent for the manufacture of quicklime, .^ present in consider- able quantity, and stream gravels suitable for concrete work form local deposits along the streams. The economic deposits will be dealt with in the following order: copper, silver, iron, oil-shale, gypsum, limestone, and gravel. COPPER. DISTRIBUTION AND EXTENT. At a number of localities signs of copper occur in the Missis- sippian formations. These consist of green stains in the con- glomerate and sandstone, and wherever observed were inti- mately connected with plant remains. Although considerable prospecting has been done no workable deposits of copper ore have been found. PROSPECTING. Some insignificant digging has been done along the seashore and in the brooks where the formations bearing the [copper stains 141 outcrop, but the only undersround work is that at Brierly brook IcM than ooCKiuarter mile north of the Intercolonial railway and nearly 1 mile southwest from Brierly Brook station. Here in the McAras Brook conglomerate two shafts have been sunk and a tunnel has been driven. The workings were filled with water when the vicinity was visited, but the shafts were said to be about 30 feet deep and the tunnel about 60 feet long. It was from the eastern shaft that copper ore was said to have been obtained, but the dump showed only scanty traces of coooer stain. *^*^ SIMILAR COPPEK OCCURItENCES ELSEWHERE. Deposits of copper sulphides in sedimentary formations, hav- ing characters similar to those supposed to be present in this district, occur at many places. Lindgren* has described the oc- oirrences of such ores in the Permian. Jurassic, and Triassic of Europe, Asia, North and South America, and Africa. They are usually found in fractured or brecdated beds or in proximity to plant fMsils, and are characterized by blue and green colours due to the presence of azurite and malachite. In North America copper deposits such as the above occur in the Red Beds of south- ""^S^^f • P*^^'"^' New Mexico, Arizona. Colorado, Utah, and Idaho, but they are most succrasfully exploited in New Mexico. The containing strata are probably of Upper Carbon- iferous, Permian. Triassic, and Jurassic age, and are thought to have b«!n accumulated in shallow seas or as land deposits as the result of a process of rapid degradation of the adjacent land areas ol the Rocky Mountain region. In New Mexico production has been achieved from picked ore at Naciminto. The copper is nearly all found in the basal 25 feet of strata consisting of reddish-white sandstone rich in fossil wood which is largely chalcocitized. One tree trunk 60 feet long by 2§ feet in diameter is said to be almost wholly converted into copper glance. Malachite, azurite, and chrysocolla are also pnaent. The underiying beds are Pre-Cambrian granitic rocks wnich contain much older copper deposits. • Lindgren, W. Econ. Geol. VoL VI, pp. 568-581, 1911. 143 ..indgren considers that the copper has probably been a con- centration of the scattered particles of copper ore contained in the sediments. Atmospheric water containing sodium chloride or sodium sulphate would readily dissolve the disseminated ores and carry them into contact with the plants, where they would be reduced to the sulphides, etr. Later, weathering would pro- duce malachite and azuritc stains. PROBABLE ORir.IN. The occurrences of copper stain in the Arisaig-Antigonish dis- trict represent, on a small scale, the conditions described above, excepting that the older rocks have not been found to contain copper ores. Consequently the powibie explanation of the cop- per stains is that sm" il quantities of copper sulphate, generally present in both sea and river water, were reduced to the sul- phides during the deposition of the sediments, by the action of decaying vegetable matter. Later these small sulphide deposits were changed to the carbonates by the weathering action of surface water and have given the insignificant stains already noted. CONCLUSIONS AS TO FUTURE POSSIBILITIES. Workable deposits of such an origin are not to be expected, especially where plant remains are small and scarce, as is the case in the Mississippian formations of this district. SILVER. Although silver has been indicated - previous maps of the district, no traces of it were found f .1 locations marked or elsewhere. IRON. INTRODUCTORY REMARKS. The iron ores in the vicinity of Arisaig were carefully described in detail by J. E. Woodman,' in 1909. However, the field work ^ See bibliography. 14J of 1910 has added new information relating to the age and extent of the on bodiet and hai also included one occurrence not pre- viouMy d:!«cribed. Therefore, this report will deal mainly with the geological problems relating to the ore, its age and origin, and will only describe in a general way the prospects, individual outcrops, ore analyses, etc., all of which may be found in the report already referred to. DISTRIBUTION, EXTENT, AND DEVELOPMENT. Iron-ore beds have long been known to exist in both the metamoi-phic rocks of the plateau (now known to be of lower Ordovician age), M>uth of Doctors brook, and in the rocks of Silurian age south of Arisaig. More recently iron has been din- covered on the plateau at Browns mountain. Prospecting has been done in many places and some ore was formerly shipped, more especially from the Doctors Brook area, but work wasdis- continued probably because of the low grade and siliceous char- •cter of the ore. Recent development has been carried on under the management of Mr. George E. Corbitt, in the hope that mining might once more be undertaken. The development work in the iron-ore areas has been in neariy every case in the form of surface stripping, and trenching. One or more shafts were sunk in the earlier work. In the sum- mer of 1910, Mr. Corbitt drove a tunnel 70 feet into the north- sloping hillside a short distance east of the western brook flow- ing out of the Little hollow. A small outcropping of ore south of the tunnel was the surface indication depended upon. When last word was received no ore was met with and attention is called to the fact that the ore zone here is cut off by the tlope of the hill, and the ore seen is probably a remnant of the southern- most bed. Tunnel development to be successful must be started farther east. At Arisaig and Ross brooks, tunnels were run in on the vertical ore beds for short distances. COMPOSITION. In the better samples from the lower Ordovician horizons, the ore consists of oolitic hematite having a fine grain resem- IM 1 ling flaxseed; in other umpies the grunii comparatively coarw. The finer ore occasionally contains foMtU. The poorer varie. tjrs conitist of a coarM grit impregnated with hematite. Fre. qui .itly wcondary quarts forming maiaet of conuderable aiie ^1a^ »je detected with the naked eye. According to Wood- man (lie asaayt of the better claat of ore run on an average 4f 4^ ,)er cent metallic iron. J-r -r. the above description it will be seen that the ore closely .CH. "lb; «s the Clinton ores and this is confirmed by comparison . .^^fT|-les. However, the silidfication due to secondary region 4 not found in the Clinton ons of the Appalachian 'i"h(. crt! I/.' or" Jr'-:i: !• >"*'e xposed to the weather. Certain bands .''•••' J i ' : .uMils and readily crumble down. Farther > ' ce the ore is compact hematite, showing a fine- C' i-: character. According to Woodman (page 183) ment of ore sent to the Dominion Iron and Steel Lomp.iu>, g.ive the following analysis: Fe-52-930 per cent, SiO, - 1 1 • 620 r)er cent, AI|Oi - 7 • 460 per cent, P -= • 495 per cent. This ore very closely resembles the Clinton ores and has not suffered secondary silidfication. RELATIONS TO ENCLOSING ROCKS. Wherever observed the "beds" of hematite are interstrati- fied with the endosing rocks. The contacts of the denser ore are sharper than is the case with the impregnated grits. In the latter the contacts are often very pooriy defined, the iron being present in decreasing quantity for the last foot or more of the ore zone. No cases were noted where the ore pene- trated the wall rock as veins, but in the Doctors Brook area the "beds" occasionally split into two thinner "beds." us DRSCMPTION or INDIVIDUAL U)CAUTIB9. Iron Ort of Browns Mountain. In an area about 1 mile northeait of Browns Mountain poat-office, ore ha* been exposed by prospect trenches at pointt about five-eighths of a mile apart. In the western prospect an ore •one more than 20 feet acrou has been uncovertJ The "bed" dips nearly south at about 60° and the contained ore consists of coarse grit impregnated with hematite. In the walls the grit is finer than in the ore, In the eastern exposure the "lied" strikes nearly north and south and is only about 5 feet across, and the ore is more compact and of higher grade. Possibly two "beds" are present here, '^p'cimens are said to have as- »y«l «• high as 30 per cent nciallic iron. The iron ore of tWs vicinity appears to belong to a lower horizon in the James River formation (the lower formation of the Browns Moun- tain group) than thitt which contains the ore beds of Doctors brook. Iron Ore of Doctors Brook. The most important ore belt of the district extends south- westerly for neariy 4 miles from a point about three-quarters of a mile southwest of Malignant cove. Many igneous intrusions have interrupted the ore leads in their northeastern extent, but be- tween the East Branch of Doctors brook and the western brook flowing north from the Little hollow, few intrusions are present. Numerous trenches and prospect pits have been dug and the ore zone more extensively disclosed in this locality than elsewhere. However, the trenchts for the most part cross the ore "leads" and the relations of ore to wall rock are frequently obscured. Three ore "beds" have been recognized with widths from 2 to 8 feet. From place to place th« widths of indi- vidual leads vary and many small faults have been discovered which offset the ore 1, 2, or more feet. The "betJs" strike in a northeast direction and are approximately vertical in dip. 146 The following table gives a summary of the chief characters of the ore leads according to Woodman. Lead. Average thickness at Iron brook west. Character of ore. Assay, % of meuUic iron. 5 feet Compact oolitic ore in part resembling peb- Locality. 1 2 3 48- 174% 46-213% 47-302% Intermediate 4 feet Fine-grained ore 45-94% 41 •177%43-5S8% 10 feet Grit impregnated with hematite. 35 167% Average of all obtainable analyses. Insoluble matter. Metallic iron. Mines Branch. 20-884% 1 38-186% All others 28-655% 1 42-514% According to Woodman's carefully wrought-out summary (page 202), "The ore is uniformly free from sulphur ** • but it is high in phosphorus. Silica and general insoluble matter stand unfortunately high, the average of all Mines Branch an- alyses being 20-884, and all the others obtainable at present, 28-655%. In iron the general quality is low, the average of Mines Branch analyses being 38-186, that of all others ob- tainable, 42-514%." The exposures of the contacts are not always clear, but the wall rock appears to be generally quartzite. Where this is the case no difference has been noted in the north and south contacts. A breccia was found to form the south wall of a "bed" near Iron brook, and although there is some uncertainty as to the identification of the altered rocks along the extent of what is probably the same "bed," the indications are that the association of ore and breccia may be continuous for nearly their whole extent. 147 The breccia has been so changed to caldte and in places dis- coloured by iron stain that little can be said about its origin other than that it may be volcanic. Grey slate has also been noted in contact with one "bed." A short distance south of the ore zone, red slate occurs marking the lower boundary of the Baxters Brook formation. The iron-ore zone appears to hold a definite relation to the base of this formation, which appar- ently lies in a closed syncline. No iron is found on the south of this syncline, but whether this is due to lack of systematic prospecting, to the thinning out of the ore beds, or to faulting has not been determined. As already stated the surface extension of the ore beds is quite definitely known. Woodman has stated (page 203) that although the ore "beds" have not been identified as being identical from one end of the property to the other, certain beds have been followed for long distances. "The greatest distance over which any single ore 'bed' has been found is 6,750 feet." This was his Tunnel lead and he says, "the coarse lead is probably continuous for at least as great a distance." On the east, intrusion has interrupted the continuity of the ore, and on the west it is off-set by faults. The displacements appear to be along vertical planes, but it is not clearly estab- lished that horizontal breaks may not also occur. Because of the close jlding which probably exists, the same vertical attitude of the beds probably holds downwards for several hundred feet. From the distribution o the igneous rocks it is not probable that serious disturbances will be met with, due to their presence, in the area between the East Branch of Doctors brook and the small western brook flowing out of the Little hollow. Small dykes do occur but they are not apt to do more than sever the ore bed. Ore of Arisaii and Ross Brooks. In Arisaig and Ross brooks a bed of hematite between 2 and 3 feet thick outcrops. Two exposures occur on Ross brook, but there is evidence of faulting in the vicinity and the bed has probably been off-set along a fault zone. Wherever seen 148 the strata stand nearly vertical. The wall rocks consist of shales and thin-bedded, arenaceous limestones and in places the surface of the wall rock is chloritized. It is probable that the ore bed is continuous or nearly so between Arisaig brook and Ross brook, but beyond these limits, particularly to the westward, the probability of disturbance is great. A fault zone, about 20 yards north of the iron ore in Arisaig brook, paral- lels the ore bed and by a slight change of dip this may cut the ore off in depth. The thicknesses of the formations lo the south are thought to have been diminished by similar faults. GENESIS OF IRON-ORE DEPOSITS. The ore beds of the lower Ordovician and Silurian formations are, in general, similar and their origins will be discussed tc^ther. The ore leads of the lower Ordovician for the most part follow the rock stratification. Woodman speaks of them as being "broadly of the bedded type although departing from the rock stratification in a few places, sometimes through irregular replacement, sometimes proceeding for a very short distance along fissures." So far as the observations made by the writer go, they do not clearly depart from the strati- fication although the contacts are irregular in places. In one or two instances the bed branches, but whether this is due to an inter- fingering of sedimentary layers, or to other causes was not clearly determined. It is clear, however, that the outcrops of ore extend in general alignment for long distances, and repre- sent a definite number of leads. The horizon followed by the ore is constant, but whether there is a migration from layer to layer could not be definitely told. In the Silurian strata the iron ore is exposed at only two places, but is of nearly constant width and appears to hold a definite horizon. It is fossiliferous and at Arisaig brook where fossils were collected, contains a fauna related to that of the enclosing sediments, but of very distinct development. The metamorphic rocks of lower Ordovician age are nearly unfossiliferous, but the iron ore, and a schist associated with 149 it contain iinguloids. Thus it seems fairly clear that the iron- ore strata differed during the time of their deposition from the precedmg or succeeding sediments. The indications are too, that the iron ore of the lower Ordovidan rocks was deposited before the rocks were disturbed either by intrusion or faulting and if the mterpretations given in this report be correct, the earliest mtrusions took place at about the close of lower Ordo- vician time. In age, the Silurian iron-bearing sediments are probably eariy Rochester or a Uttle later than upper Clinton, correlating, however, with some of the "Clinton ores" of the Appalachian region, which are now considered by the best authorities to be of sedimentary origin (See under "Stratigraphy," page 68). The iron ore of Doctors brook contains Iinguloids (see page 55). which not only fix the age of the formation as lower Ordovician. but correlate tiie ore horizon directiy with that of the deposits of Belle isle, Newfoundland, generally considered to be of sedimentary origin. In the case of the Silurian iron ore there is littie doubt tiiat It is of sedimentary origin, and was formed as were any of the other strata, but under conditions favourable to the deposition of iron oxide. The same statement may be made with less assurance, in the rase of the lower Ordovician iron ores, for the writer wishes to admit tiie difficulty of explaining the filling of fissures as described by Woodman, by a sedimentary deposit. Then, too, the gradual diminution of iron from the ore to the ferru- ginous enclosing rocks is what might be expected if the orewer« of secondary origin. There is no reason, however, why iron deposited as a sediment should not mix to some extent with the sediments above and below it. The varying tiiickness of the ore beds is only what might be expectec! in tiie case of any strata, and is of common occurrence in sedimentary beds of sandstone, shale, etc. Although all the information required for a complete dis- cussion of these ore deposits is not available, much is defi- nitely known. Their great extent along a more or less definitely recognized horizon; tiieir independence of igneous intrusions; 150 their distinctive faunal character; their oolitic character and resemblance to the "Clinton ores"; and their metamorphosed condition corresponding to that of the enclosing rocks, all make the conclusion very probable that they are of sedimentary origin and hence are of the same age as the rocks in which they occur. However, in a formation where metamorphism is a characteristic feature, it is not impossible that some second- ary concentration or transfer of iron oxide has taken place at the borders of the iron ore beds. OIL-SHALE. GENER.\L CHARACTER AND DISTRIBUTION. A short distance east of Maryvale, and outside of the Arisaig- Antigonish district, drilling and mining have proven the ex- istence of considerable beds of oil-shale. Ells in his report of 1910 describes these and quotes an older authority (How's "Mineralogy of Nova Scotia," 1868) for the statement that the shales are found in two groups, "The lower 70-80 feet in thickness, including 20 feet of good oil-shale, S feet of which are curly cannel, rich in oil ; the upper 150 feet thick, in immediate contact with the limestone, and containing a large percentage of oil. Of the 5 foot seam of curly cannel, he (How) states that it will yield at least 40 gallons of crude per ton, and IS feet of the remainder will yield at least 20 gallons." In the vicinity of Maryvale and Pleasant valley, oil-shale has been exposed in a number of pits and prospecting is said to have been carried on by a core drill. The formation at Maryvale and Pleasant valley is the Ard- ness, the same as that containing the oil-shale at Big Marsh, and is probably of Mississippian age; but the upper part of the formation and probably the upper oil-shale zone has been stripped away by erosion. At Pleasant valley and south of Maryvale the strata appear to lie at low angles and the oil- shale is probably not deeply buried. North of Maryvale near the contact with the metamorphic rocks, considerable dis- 151 •"I^!! i" *'•* ^"^""^ formation may be expected as i. GYPSUM. DISTRIBUTION AND EXTENT. the^'lT *'I^ T*'' °' *''^ Arisaig-Antigonish district along the In erco!on.al railway, pond holes, sink-holes, or gy^um mSetide ?he^Ji:r'' r J°"? ""^ °"^-^'«''*h '° one-quarter ™ he total ih^fT'K!"^^ °^ ^^P^""" °«^"Py '««« than half a wL on th^ I ^'*' r ""^"«^ '"^"'y ^t B-^^rfy brook. «n5^- .1? • '^''''^y '""'■^ *''^" * "»*'« west of Antigonish and m the vicmity of Antigonish harbour. ^""Konish, CHARACTER. tt,J^*5'^"'" '" ^"^'^"y °* ^ «^™bly nature as exposed at .•» nf ^ "^ ^"'■^^^ ^''^ SyP^""" « firm and compact a sLlllrountT""''*'- ~'°"^' ^"'^ ^PP-" ^° ~"Sn only a small amount of impurities. As described by previous in been anhydnte. but weathering has left little of this mS • K "J"^' ^''' °^ '^^ ^^Po^'ts. At Ogdens point i^Antr gonish harbour. Dawson* observed more than IwSetof Cw te and reddish gypsum, containing some calcite. overiaS by dt^ S ^r^H^K ""7""""' '"P"" '••"-*°-- -•>-" were su<^ ed by reddish sandstones and shales. From the breadth S^. Sni':i\jr-"^^-'""^^ ^"^ sink-hot^'r oS ^^ckness of the gypsum horizon is thought to be neariy - calTf ?k"' "^^ ""'"■'''^ ^'^^ KyP^"™ i" ""ost places o •- ^nally the gypsum cliffs are uncovered and have aSumed 1847 II 'Dawson. J. W. Proc. Acad. Nat. Sci.. Phila.. Vol. III. pp. 271-274. 152 a peculiar honey-comb surface aspect due to water aolution. Much sand falls into the channels made by the water and thus the deposits have become more or less mixed with sand and earthy materials. However, much nearly pure gypeum is to be found. DEVEUJPMENT AND FUTURE POSSIBILITIES. Quarrying is carried on to a very small extent at Brierly brook. The proximity of the railway and the ease with which the gypsum is quarried should make this region the location of a large gypsum industry so soon as the demand for the raw product is sufBdently great. LIMESTONE. DISTRIBUTION AND FORMER DEVELOPMENT. Along the limestwie horizon generally about one-quarter mile north of the Intercolonial railway, a number of old lime kilns and lime quarries mark the existence of a former industry. The lime burnt in this vicinity is said to have been of good quality. RELATIONS AND GENERAL CHARACTER. The limestone forms the basal stratum of the Aruness for- mation and is under 20 feet in thickness. Only one bed occurs ; the second outcrop of limestone north of the town of Antigonish being due to a local syndine which has brought the limestone to the surface along its south limb. Limestone also occurs on the shore of Northumberland strait and in an isolated out- crop on Doctors brook. In both these instances the age of the limestone is the same as of that already described. Limestone of Silurian age has not been burnt because of its impure character. 15J FUTURE DEVELOPMENT. The limestone bed usually dips at an angle of about 30' and IS not exposed at the surface except at a few places genenUly in the creek vaUeys. Here, however, quarrying might be readily earned on by following the strike of the beds. Plenty of wood for fuel is near at hand and should demand warrant It, a hme industry of considerable importance couW be started along the railway. GRA VEL. Deposits of water worn gravel are found in many of the stream courses. For road-metal and concrete work this gravel IS well adapted. 154 CHAPTER X. BIBLIOGRAPHY. Alger, Francis. — 1827. — Notes on the mineralc^y of Nova Scotia, Amer. Jour. Sci.. Vol. XII, pp. 227-232. Ami, H. M. — 1892. — Catalogue of Silurian fossils from Ari- saig, Nova Scotia, Nova Scctia Inst. Nat. Sci., new ser., Vol. I. pp. 185-192. 1895. — Notes on a collection of Silurian fossils from Cape George, Antigonish county. Nova Scotia, with descrip- tions of four new species. Ibid., Vol. VIII, pp. 411-415. 1899. — On the subdivisions of the Carboniferous system in certain portions of Nova Scotia, Brit. Assoc. Adv. Sd., Rept., pp. 755-756. 1900. — Notes on some of the formations belonging to the Carboniferous system in eastern Canada, Can. Rec. Sd., Vol. VIII, pp. 149-163. 1900a. — ^Synopsis of the geology of Canada, Royal Soc. Canada, Trans., Vol. VI., Sect. 4, p. 203. 1900b. — Notes bearing on the Devono-Carboniferous prob- lem in Nova Scotia and New Brunswick, Ottawa Nat., Vol. XIV, pp. 121-127. 1900c. — Notes on fossils and formations of Silurian at Ari- saig, Nova Scotia, Geol. Surv. Canada, Summary Rept., p. 180 A. 1900d. — On the subdivisions of the Carboniferous system in eastern Canada, with special reference to the position of the Union and Riversdale formations of Nova Scotia, referred to the Devonian system by some Canadian g^eo- logists. Nova Scotian Inst. Nat. Sci., new ser., Vol. X, pt. II, pp. yj?-n3. 1901. — Description of tracks from the fine-grained sili- ceous mud-stones of the Knoydart formation. Ibid., pp. 330-332. 155 1901a.-Stratipaphical note (Devonian and Silurian near Ansaig. Nova Scotia). Science, March 8. 1901. pp 3M-3m 1901b.— The Knoydart formation of Nova Scotia— a w* l!>03.-Me«vCartjonifcpoi» a- ^'>»<'- vS: Baa<»m Flo«„ce.-1893.-Structure. origin, and nomenclature of the acd volcanic rocks of South Mountain. Pennsvl! vania. Jour. Geo!.. Vol. I. pp. 813-832. i-ennsyi- ^^f'J-^^^J^^P^on of a new Pal««oic starfish IfJ.iT^'^, *' "*^ 'P*^" °' Ari«ug lamellibranchs; ^'"^S Jr mT- ^'^T"^" ^''^^''^^ °^ the Michigamme distnct of Michigan. Jour. Geol.. Vol. III. pp. 801-822 Daly R. A -190L-The physiography of Acadia. Mumsum Comp. Zool.. Bull.. Vol. XXXVIII. pp. 73-103. Dawson. J. W.-1845.-On the Lower Carboniferous rocks or gypsiferous formation of Nova Scotia, with geological' ^^^ i, ."''^ ^''^ ^y A''^*'" Gesner. Quart. Z^ Geol. Soc. London. Vol. I, pp. 26-34. l^li^^ letter from Dawson to Prof. Johnson, describ- Sfi™. i^"^*^*'^*" °^ Nova Scotia. Acad. Nat. Sci Philadelphia. Proc.. Vol. Ill, pp. 271-274. 18S0.-On the metamorphic and metalliferous rocks of IM DawKM, J. W.— (continued.) 18SS.— Acadian geology, firat edition, Edinburgh. I860.— On the Silurian and Devonian rocka of Nova Scotia, Can. Nat. and Geol., Vol. V, pp. 132-143. 1860ia.— Notes on the fowiliferoui Silurian of eastern Nova Scotia, Ibid., pp. 297-299. 1868.— Acadian geology, second edition, London, (a) p. 316, (b) pp. 565-8, 572-3: (a) Description of Carboniferous rocks of Pictou county. Nova Scotia, with reference to amygdak>id as interetratified beds of trap; (b) Description of Silurian system as represented on the east coast of Nova Scotia, noting resemblances to other American occurrences. 1873. — Impressions, footprints, etc., on Carboniferous rocks, Amer. Jour. Sci., (3), Vol. V, pp. 16-24. 1875. — On the geological relatioru of the iron ores of Nova Scotia, Can. Nat., new ser., Vol. VII, pp. 129-138. 1878.— Acadian geology, third edition, London, p. 497. Unconformity between Devonian and Carboniferous noted and remarks made on stratigraphy of the Devonian; granite intrusions thought to be of late Devonian age. 1881.— Remarks on recent papers on the geology of Nova Scotia, Can. Nat., new ser., Vol. IX., pp. 1-16. 1881a.— New facts respecting the geological relations and fossil remains of the Silurian iron ores of Pictou, Nova Scotia, Ibid., pp. 313-314. 332-344. 1888.— On the Eozoic and Palaeozoic rocks of the Atlantic coast of Canada, in comparison with those of western Europe and of the interior of America, Quart. Jour. Geol. Soc. London, Vol. XLIV, pp. 797-817. 1889. — Hand book of Acadian geology, Montreal. 1891. — ^Acadian geology, fourth edition, London. Eckel, E. C— 1905.— The Clinton hematite, Eng. and Mg. Jour., Vol. LXXIX, pp. 897-898. ^'*?;f rJT**?""*^'. ^ F.-1910.-Ch«wter of ore, U.S. Ged. Surv.. Bull. 400. pp. 26-28, 38. EU.. R. W-IMO.-C«rboniferou, and Devonian of Gaape V?":5L"'!^"''"'" '" Nova Scotia and New tirun.. wiclt, Ibid., Summary Rept., pp. 132-142. I910.-Bituminou. or oil-Aale. of New Brun«rick and Nova Scotia (mduding notea on the oil-rfiale industry of Scotland). Canada, Dept. of Mines. Mines Branch and Geo- logical Survey, joint report. Fktcher, Hugh.-1886.-Nova Scotia. Geol. Surv.. Canada Ann. Report.. Vol. I. p. 62 A. 1887.— Report on geological surveys and explorations in 2! """,!'f? of Guysborough, Antigonish, and Pictou, Nova Scotia. Ibid., Vol. II, pp. 5-128 P. IWO.-Geolopcal nomenclature in Nova Scotia, Nova Scotwn Inst. Nat, Sci., new ser.. Vol. X. Pt. 2, pp. 235-244. ^^^ Abraham.--1836.-Remarks on geology and mineral- ogy of Nova Scotia (with map), Halifax. ^^^H: ^;r**?^ -P* '°'^'"« °' '^"^ Carboniferous strata in c ? Maritime Provinces of Canada (abstract). Can. Rer Sc.., VoKT pp. 14-15. Cf. also Royal Soc. Canada. Proc.,' Vol. I, Sect. 4, pp. 137-142, 1883. ^"^Vr^rr'^'^^T '°""' °' ^°^* Scotia. Can. Nat. and Geol., Vol. V, pp. 144-159. Hartt, C Fred.-1868.-On the subdivision of the Acadian Carbomferous limestones, with a description of a section across these rocks at Windsor. Nova Scotia, Can Nat new ser., Vol. III. pp. 212-224. 158 Hobb«, W. H. and Leith. C. K.— 1907.— The Pre-Cambrisn vol- canic and intrusive rocka of the Fox River valley, Wia- conain, Univ. Wiaconain, Bull. 1S8. Sd. Ser., No. 6, pp. 247-274. Honeyman, Rev. D.— 1859.— On the foaailiferoua rocka o( Ariaaig, Lit. and Sci. Soc., Halifax, Tram., pp. 19-29. I860.— On new kcalitiea of foanliferoua rocka in eaatern Nova Siotia, Cm, .«lat. a»d Ged. Vol. V, pp. 293-298. 1864.— On Hi ^poUijio of Ariaaig, .Mova Scotia, Quart. Jour. Ged. 4^^ i>ondon, Vol. XX, pp. J33-34S. 186^'— Geology of Antigoniah county. Nova Scotia, Nova Scotian In»t. Nat. Sd., Vol. I, Pt. IV, pp. 106-120. 1870.— Note on the geokigy of Ariaaig, Nova Scotia, Quart. Jour. Geol. Soc. London, Vol. XXVI, pp. 490-492. 1870a.— Lauren tian rocks of Nova Scotia, Amer. Jour. Sd., (2), Vol. I, p. 417. 1874.— Record of observations on Nova Scotian geok>gy, Nova Scotian Inat. Nat. Sd., Vol. Ill, pp. 6-18. 1876.— On glaciation in Nova Scota (abatract), Amer. Phil. Soc., Proc., Vol. XVI, p. 237. 1878.— Nova Scotian geology. Nova Scotian Inst. Nat. Sd., Vol. IV, pp. 47-79. 439-488. 1882.— Nova Scotian geology. Ibid., Vol. V, pp. 64-65, 197-204. 1886.— A revision of the geology of Antigonish, Nova Scotia, Ibid., Vol. VI, pp. 308-325. 1887.— Notes on the examination of the Silurian collection of the provindal Museum by James Hall, Ibid., Vol. VII, pp. 14-17. 1888.— Glacial geology of Nova Scotia, Ibid., pp. 73-85. 1888a. — Nova Scotian superiidal geology, Ibid., pp. 131-141. Iddings, J. S.— 1899.— Geology of the Yellowstone National Park, U.S. Geol. Surv., Mono. XXXII, Pt. II, pp. 424-425. 189 Jacl»on, C T and Alger. Frandi.-1828.-A oteMrriphon of the minerdogy „d geology of a part of Nova da Amer. Jour. Sd.. Vol. XIV. pp. 305-330. and map. ^*^-\'^'^^P^ion of the mineralogy and gw)l,«y of a part at Nova Scotia. Ibid.. Vol. XV. 132-160 207217 KI«er^M.-lW8.-Da. Ober«lur in Kri.ti.niagebie«. Christi- '^''Tuff^lil,'*' •""'' '^'"""y* Alexander.-1901.-On .ntrunive tuff.Iil« ,Kn^. rock, and breccia, in Ireland, Quart. Jour. Col. Soc. London. Vol. LVII. pp. 479-489, Undgren. W.-1911.-Copper. .ilver. lead, vanadium. a«d ur- jrSwS'" "^ ""* ""^ '^'^' ^~"- ^'' V*^ VI. ''^"p.T«0. '"''''""'***' "''"'""■'' •" ^°^^ ^'^'^' Vol- 11. Description ot ^yp,urn of Winder and Shubenacadie. with notes <.n CarlK .lifcrou. strata and "trappean rock..' ^"^S"' n ^-''^'-''^^ -- o^ of Georgia. Geol. Surv. Ga.. Bull. 17, pp. 29-35. 104-174. Newland. D. H^-1908.-Iron ores of the Clinto. form.K:.>. 41-53 ^^ ^'^"' ^'"'- ^""- '"^ '• ' " ''■- 1909.— The Clinton ore. of New York Star- '^.h- iii,. Mg. Engrs., Bull. No. 27. pp. 265-283. Smyths C. H.. Jr.-1892.-On the Clinton iron ore. A.v. j,, . . Sa., (3). Vol. XLIII. pp. 487-496. "^"'Nnt' W "rJ^-The Silurian action at Ari«ig. ThT ^ V r'S * ~"*'**'°" "°*« by Charle. Schuchert. Ibid.. (4). Vol. XXVIII. pp. 143-169. 160 Weidman, Samuel.— 1898.— A contribution to the geology o.' the Pre-Cambrian igneous rocks of the Fox River valley, Wisconsin, Wisconsin Geol. Nat. Hist. Surv., Bull. Ill, Sci. Ser., No. 2, pp. 1-63. White, David.— 1901.— Some palaeobotanical aspects of the Upper Palaiozoic in Nova Scotia, Can. Rec. Sci., Vol. VIII, pp. 271-280. 1902.— Stratigraphy versus palaeontology in Nova Scotia, Science, new ser., Aug. 8, 1902, pp. 232-235. Whiteaves, J. F.— 1883.— Recent discoveries of fossil fishes in the Devonian rocks of Canada (abstract), Amer. Assoc. Adv. Sci., Rept. 3l8t meeting, pp. 353-356. 1897. — Note on a fish tooth from the Upper Arisaig series of Nova Scotia, Brit. Assoc. Adv. Sci., Rept. 1897, pp. 656-657. 1899.— The Devonian system in Canada, Science, new ser., Sept. 22, 1899, pp. 402-412. Williams, G. H.— 1894.— The distribution of ancient volcanic rocks along the eastern border of North America, Jour. Geol., Vol. II, pp. 1-31, Abstracts, Amer. Jour. Sci. (3), Vol. XLVII, pp. 140-141. 1894; Amer. Geol. Vol. XII', pp. 212-213, 1894. Williams, M. V.— 1910.— The Arisaig-Antigonish district. Nova Scotia, Geol. Surv., Canada. Summary Rept., pp. 238-247. 1912.— Am. Jour. Sci. (4), Vol. XXXIV, pp. 242-250. Woodman, J. E.— 1909.— Report on the iron ore deposits of Nova Scotia, Part I, Canada, Dept. of Mines, Mines Branch. 161 ADDENDA. Beede. J. W. and Clarke, J. M.-1911.-Report of the Director for 1910, N.Y. Sute Mus., Bull. 149. Beede, The Carbonic fauna of the Magdalen islands, pp. 156-186; Clarke, Observations on the Magdalen islands pp. 146-150. Schuchert. Charle8.-1910.-Pala!Ogeography of North America, Bull. Geol. Soc. Am. Vol. 20, pp. 526-578. 163 INDEX AMdkn geology by Damon . Acatte dnwniiin I'Aoa , 10, II 1.^ logani 65, «6 Ma intniaves described. .". ".73 • rocki 113 Acknowledgmenu. ... H Actinolite 1 Alger, FrancH 122 Amherst 4 Ami. H. M Vi. ■ . ■ ■ '7 Amradaloidia trap 4.20,53. 73. 79,91 Amygdules. « ,■.•, 8 Anabaia amicostiina '• "^' '^l. 123s 126. 128 A Jy«. ^f?r"oL^ ^'^^ '"P^- Sowerby). .. . . ! ! . 'J; « Anhydrite 144, 146 Anoplotheca hrniKpherica '5' Anticline 65, 66 Antigonish county 85 ' harbour. .'. ". 3. 18. 48 I hills 49 Nova Scotia ' Apatite 3 Aoorhyolite. . . ^- IW •^ flow at iho baai oJ the ^lurUn »*-fi„n aJ^I^ ^' *'• "**'• '" Appalachian revolution "*"""• ^^^>*>^ 107 Ardness forinalion. . . ij ii i^ V. ,V ^, *^' " described. 32, 3*. 3«, S3, 76. 93. 123, ISO " limpHtone '••'" Area of Arisaig-Antigonish district '^' '^*' '^ Anaaig . 3 " brook ... 98. 143 * formation . . . ' ! ! „ , "•,^' ^' '♦7. 1« of Ami 21.23.24.28.53.94.132 ^ I ' , "Twenhofd... :::.::..; « Lower, of Dawson 0. «2. 19. 22. 82. 83 Lower '* " lowlands .; plants .« Upper 136 Cephalaspis. .... v.- •. ^- '8 Chalcedony 21. 75. 134 Champlain age 127, 128 Chemung group 17 ch!^le»:;:; •;:;::::•:•••■■• ■■- • novaacotica •,^'j}H\ *H * tenuistriatud «' «' J?' I« CUy, boulder. . 65, 66. 67. 69 Clays • • • • . 13 Ointoa group :;,• _•*''• '*• 138 • tower 10. 24, 29, 64, 63 " • of Fletcher.;;:::::;:; if • series of New York *? Upper 11 ccai ^. ...:;;:;;:; : is " formation **t 31 * Measures 12 Cobequid mountain i,^ .. 'Al ' plateau 10. 41, 137 " series. ... '1 Communicatioa. means of;. V. 12, 55. 82 Continental deiMaits i • • 3 Conularia °''^" 79. 136. 137 cop-r. ..■;;:::: „ 66 ^^carbonate 37. 140 ; depaatsdescribMl " ore '♦0 Corals 20 Corbitt. Gao. E. .;; ■ ; ,132 Comulites ■■■ • • 2, 143 " disun... :;; **. 132. 133 • flexuoaus 65, 66 I proprius. ...■;::::::;::::::::::: ^'i^'ll c«ta«ous ''>-««"«-(?) .:::::::::::::::::: "'Il Crin^.is...'*^'*''"'^"'- •■•••••■•• •••^ 137 ci;^'^*'* ■ •■••■■•••■•:-::-:::;;;;;;;-6i.79.87;96.i3s 25 D. Dairy products Dalmanella 3 • cf.edgeiiiana;; ;;;.;; ^^ '32 Dalmanites sp. ^ Daiy.R.A.:^;.;;;;;;^^;;.y 166 Kai Kenti. 4. 7. 53. 55. 62, 70, 78. 82. sT*!?! Devonian 22 . period. Lower, history of *' •"• "' '"' "' "' ^' "' «. " D«h,- """ <**'«»'"•' and Upper) history of. . ! . .' : . ! . , « ^'^"nVrusive.. de«:ribed. •• ''' "' **• ''■ '«■ «*" '«>• »°^; '»."'*. ^ Diaphonxitoma cf. niagarentis 'i; DidymoKreptui nitidus H Diaconformity. '" Doctors brook. ... Va io ' ii • :<-,' '^v • ■ '^ Drainage 16. 38. 57. 63. 65, 143, 152 Dykes. 49 100 Earlton East river 11 Eatonia 11 " medialia 133 Economic deposits 7" ElJs, R. W. . 37 Eo/oon 4, 23, 76, 150 Epidote 13 Eurypterids '"L 122 Eurypierus 132 66. 73 False-bedding K^uhing described ''' ''' '°' ''' "' «' ^^' 'W- «. 98. 135.145, 147. {« "'''•''^'aikalic ^' "' «^' '^°''' i»2. 106; 114, 116, 121, 126 Fishing... 110 Flow'st'r'uctu're- *' ''' ''' "■ '''''•''• '^'^ '^- "• rS.^S,' w! 88; W, 97. 4 '^'^'l^tK^S^S'^^'^'^^'^"-";"'"-"."^»M32;,33.}ll Frenchman's Barn 62 63, 108, 112 G. Gene^l characters of Arisaig-Antigonish district. . , Geoogicalrclationsof the iron ores by Dawson ,? Oeology, economic H " general iJO * historical °2 " igneous 130 " structural 100 fieorge bay 82 Gesner, Abraham! ...........'. 49 Gesner s map 4, 6 Glacial age. . 8 " is ;::;:::;::;:: ' ^^ " striation .■ ■ ■ • • ■ „ 34 " time, history of ...'..■.,.:;..:.■,■ 13. 20, 90, ug loo 167 Glactation Pace. Glacier, continental. .'. . •* Gold-bearing leries '3 Goniophwa ■ '30 " transiena , '-'^ (iorgea 72, 73 Grammysia 42 acadia. '.;::.'::;: «», 7.1 " nutica 71, 72 Grand Prt 72 Granite V« .; 17 GraptoUtea 34. 54, 56, 84, 100, 131 Gravel ■ 66, 132 . • deposit, described 40. 80, QQ. 139, 140 ('Uelph formation "^ V.uU road 29 Guysborough county. . ! ! '* Gypsum ,• ■ ^ ■ ;.- " • deposits 5. 8. 32. 39. 78. 136 " described::;;;:;;:::;:;:::::;:;;;;;;;; \^ m. Hall, James Hamilton group 4. <>,17 hIv'^^O ^"*'''«n Geology by Dawson ; ,' Helderberg. i.ower ^^ „. " " of Fletcher.;;: ;;;;; ., '? Helopora /O, 72 Hematite .;!■;;.••.. ** Hoilow ... 27, 38, 57, 61, 68. 143 Homaionotus ;::;;;;:;;;;;;;;;; 29,44,46.93,95,135 * dawsoni ^^^ Homoeospira . . ; ; 69, 70, 7 1 . 72. 73 * acadiac 68, 133 cf.evax 7". 71 Honeyman, D. . . , . - 71, 72 Hornblende 4, 14. 62, 65, 67, 70. 72 Horton formation. J06 7, 12 1. [chthyoidichnites acadiensis ,, „ Iddmgs. J. .S 21, 75 Igneous activity, history or ; ; ; '08 intrusiona 136 '■ intrusivcs and extrusives $f nxka 34 Intercoloaial railway '• ''• "2 Intervale. . . 39, 47, 151 Iron brook 17. SO, 81 " deposits described. . ' " 12 168 Paoi. Iron art, analyiia of. Me iinlym. " " depmits 140 " " " bedded type t4S !! - I.. " T""*"^ «« " " hiatory of 132 " " uf Ariiaig and Roei brooke 37 " "•«.«• dMcribed 147 ' * * Browns mounuin d ae c ri bed 14S " " " Doctors brook deicribed 145 " * ' " * and Browne mounuin 3> Iron-ore lone 6g Iron orea 4, 6, II, 12, 20, U, 27, 36, 56, 57, 66, 67, M, 119, 130 ' oxide 87. 110, lis, 119, 127, 128. 135 Irving, J. D 2 Jackson, Charlea F 4 amea river 16, 49, 54 " River formation 53. 55, 102. 116. 130 " " ' described 55 ' " granite |20 • described 101 " " quarUites 9J " rocks 94, 121 " " station 101 Jointing 56, 86, 104. 120. 121. 122 Kaolin 115, 128 Karst topography 47 Knoydan brook 80 " formation 21, 29, 53, 94, 97, 134 • described 73,92 Land forina 42 Lametlibnuichiata 18 Laurenttan rocks 16 Lava Ill, 112, 125 Leptaena rhomboklalis 66, 68, 69, 72 Lime 140 Limestone 40 * deposits deacritied 152 Lindgren, W 141 Lingula cf. oblonga 64, 65, 66 Lingulella (?) 53 Linguloid 58, 1j2. 149 Liatmore formation 33. 54, 137 • • described 79, 98 Location of Arisaig-Antigonish district 3 Lowtand 25, 41. 44 Lumbering 3 Lyell. Charles. Sir 9 169 M. Magdalen Manda •**«• Maanctite ;X»' iim ' ".•.. .1? Mall|nant brook '*• '"• »". >J7 ' '^'^iSar''';::;:..- : poild ' '^'^ ■::::::::::::::: -"rV^ Maple ridge . ....■::.':;,':'.':: , j* Martinia glabra Martin "f Maryvale Vb '«. . . Maalodon Ohioticua ♦». W, J50 McAdanis brook j* McAdam formation j. i: i, «. *; deicribed 21. 24. S3. 00.132 " " ofAml ** w/ ^\ " Twenhofd " McAras brook it, n at I Brook conglomerate 92 121 141 • - °""?""'' ^rih^ 30. 36. 39. 53. 121. 122. 124. 135 McLeod.M.H ^"^ ". W McNeils brook ' ' ; gn oV o« in? • mountain 80.91.98,107 Meanders... ** Medina formation ii ,, 59 Marigomiah hiila 18. 53, 64 Merbtina. n. ip • ' Mtorfitea.".-. . :.::::. ■ •;;.'::.w. 101.106,134 Micropagnaatite ''2 Microparthite '' MferoiwikiUtic ttructuie. ... JVA Mill brook ']0 Millatone Grit 7 ii ii « ^ ' "of Fletcher ',12.21.33.54 Minmlogy of Nova Scotia, report'on! ^? Mia»».pp„n ^^^. . . . , ... 32. 36. 37. 771 83. 93. 97. ioo. ,24 Modiolopsis (?) cf. primigenia ii Mono^ptus clintonensis 6S 66 priodon chapmanenaia m'm. nccartoenaia '^ Monaonite «\i ««'inn li! „ " intruaiveadcacribed. 35. 54. 56. 100, 131 Moraines i7 }« Moydart formation ii «»' oi i .i : , - de«:ribed 21.33.92.133 H. Navaculite Necka. . . 86 100 170 Paob. Ntw Annan 10 N«w Red *»ndito«r U.IO Hhmu* -, ^ '.'.'.'.'.'.'.'.'.'.'.'.'.'*1,n ^f o( Ftatcher 'ij^ Northumbcrlnml .irait *•• ""• '■"• 7t Ohotui (Mngulobu«l iipMM. Ogdeni lake . • point Oil-Ahate ■ • • deiKi-iitii 'tttcnbed Old ed sandmonf On'll,:"M«.mor,,' .nd Metamteou.Rotk.ol EMttn. Nov. Scotia ^^ ^9 Onthu* murchisor 1 AgaBtiK 'j2g Oiwl..,. ,; "'.'.'.'.'.'.'.'.'.'.'.'.'.'■'■'■'.'■■■ (^,66 23, 31, ». 76. IM. 140 ISO 21 127 OrbicutoMca Ordovician (ormation , „■ 66, W tenuilaniellaw 5, 82 K" '" . ... . 10, 16, 23. is; S5. 107. 112. 120. 130. \*»^\W • Middle -, 130 period. l...wef.hi«oijr(,r ■•■■•• ,3, • • Middtc, " ! ...70,'M Orthocerai ' 73 Orilionota aiwuHlera 30. 134 Ostr^rodern n»he» 32, 74, 136 Onlr^-nds , M Outliet . , 17 PalMMCr pwiUKUlM 57 132, 133 Pelecy "ida ° . . .26. 44, 94 Peneplain 137 PenepUnatipn 7. 79. 83. 98. 130 Penn.jrlv.nun ^^^ carbonilerou.) period. hUtory o( ^ \f^ Pentacutite. ! 82. 8J, 137 Permian 133 Pholidopfi ... 66, 69, 72. 73 * ''mplicata r . . 25, 41 Physiogr.tphy ; ; ig", 48 Pictou county 127, 128 Pilotaxitic. . 2 PttMon,L.V 12s Pitchatone 25. 47, 50, 80 Plains, flood 25, 41, 43 Plateau. 39, 48, 135, ISO Pleaiant valley 13 Pleistocene 79 • depoMt... ,. 138 Porpi-yrT. ;i::;;^''.v.::v.;.;;:^.^. . •. .. -3^^ »♦• "' 171 Paob. PkMi-PHareiw (wriod II, IJ PrtviotM work 4 Productutcf. doublcti Bmi» 7S ■ dawMNii BMdc 71 • Martini S PMmmoatew c(. anflicu* Traquair 21 * M>. c(. P. angiculu* Traquair 7S PxmufAa 134 • d. GTOuchii 21 • i(». cf. p. erouehU 75 Ptcrinca honcymani M Ptaronitella 133 • curtt 72 • venuMa 72, 73 PtcniMa emacerata 71 Pterygotuf 21, 73, 75, 134 Pugnas tp. undct 78 Pyrite 121 Q. Quatamary 130 • depoMt* 33, 83 • • diwrilied 7« " era, hintory of 131 Quartz 56, 5Q, »6, 101, 106, 110, 113. 114, 122, 127, !44 R. Recent depoaita W) " deacribcd 98 Recent events 139 Red and grry landatone S Red iitratum 69, 70 Rejuvenation 26, 28, 131 Remark* on the Geology and Minerakigy of Nova Scotia 6 Replacement 148 Retiolitet geinittianui venoaua 65, 66 Rhynchonella 133 • nucula 72 • cf. robuMa 66 Rhyolite 28, 29, 34, 43. 54, 56, 58, 84, 91, 100, 103, 113, 125, 131 Right! river 50, 96, 121 Ripplr-marka 28, 30, 61, 71, 78, 132, 133, 136 Riverodale fomution 7, 20, 21 Robert, Mr 21 Rogers brook 56, 128 Ross brook 147 • Brook formatioa S3, 90l 91, 132 • • • described 64 Salt springs Scarp Schixocrania n. sp. cf. helderbergia. 17 28 66 MICROCOfY *ES01UT»N TBT CHART lANSI ond ISO TEST CHART No 2| ■ 23 ■ a? 140 Ki 2.0 1.8 ^^ A ^jPPUEDJM^E '653 East Mom Slrwt Boci,«sltf. Ne. York 14609 USA (716) «82 - 0300 - Ptar. (716) 288- 5989 - ro« 172 Page. Schuchen. Charl«. P.O. L 2. 4. 10. 24. 55. 62. «. 65.^67.^8 Schuchertella. . . • • • 72, 73 " aubplana 26, 51 Sedimentary formatioM ■.]'.■.■.'.'. .59, 87, 110 Sericite ^^I'JV, Serpentine. .■•,.••■• 66, 71 Serpulites cf. dusolutus 44 Shore front §7 ISan formation: : : : ! ,: : : ibi 12; 18. 2i; 24. 37. 62. 82. 89. 143. 148. 149, 152 " period, history of 10, 15 « Upper ■.".'.'."....'.'.. 40, 140, 142 saver '.'.'.'.'.'.'.'.'.'■ , ,5 South mountains 116 Sperulitic texture 108 Spherulites 132, 133 Spirifer 67, 69, 70 • ctisput 8 « gUbra .... 70, 72, 73 • rugaecosta ! . . .70, 71, 72, 73 • subsulcatus 79, 137 Stigmaria 34 St^k ; 21.24.53.133 Stonehouseformation^.^^.....-- ••■••• 71 « « of Fletcher 117 Stoping »- 5i Stratigraphy 25. W Streams *J " conseauent 41 « meandering {5^ 43^ 99, 113. 118. 120 Sugar Loaf hill 9 Sulphuric aad • ; ^5 Summary and conclusions 2 Survey methods 8 Syenite greenstone 84 Syncline •. 89, 93 ■ asymmetric T. 52, 60 Table of formations. ' ; 100 « " igneous rocks 131 Taconic revolution '.'.'.'.'.'...... ^. [I Tellina eraenlandica 64, 69 TentacuUtes 25. 45, 139 Terraces 22 Tertiary ; 1^° « era, history of 26 « ero^on 4 Tides 80.98 Till ^. ' deposits 2 Transition clay slate ■ " • 22, 137 Triassic 1** Trilobite bed 173 Page. TrilobhM 72, 132, 133 Tuff 36, 56. 100, 112, 117, 118. 136 " und breccia 36 Twenhofel, W. H., Prof. . .1, 4, 23, 45. 53. 62. 63, 65, 68. 69. 70, 71, 72, 94. 109, 113. 127 V. Unconformity 77. 89, 91. 92. 95, 137 Union formation 20, 21 Valley, structural 94 • U-shaped 93 Vameys brook ._ W Volcanic ( ?) breccia of Frenchman's Barn, described 112 « rocks 8, 10, 12, 19, 24, 63 " tuff and breccia of Sugar Loaf area, described 118 W. West river 16, 49, 50 Weston, T.C 21 White, David 20 Whiteaves. J. F 4, 22 Wilsonia 133 • cf. saffordi 66 " wilsoni 70 Windsor age 77 « KTOup 7, 12, 20, 21, 32, 78, 97 " time 136 Woodman, J. E., Prof 4, 23, 142, 148 Woodward, A. Smith 21, 75 Henry 21, 75 Worm tubes 132 Zaphrentis cf. bilateralis. Zircon 64 1()6 LIST OF RECENT REPORTS OF GEOLOGICAL SURVEY Since 1910, reports issued by the Geological Survey have been called memoirs and have been numbered Memoir 1, Memoir 2, etc. Owing to delays incidental to the publishing of reports and their accompanying maps, not all of the reports have been called memoirs, and the memoirs have not been issued in the order of their assigned numbers, and, therefore, the following list has been prepared to prevent any misconceptions arising on this account. The titles of all other important publications of the Geological Survey are incorporated in this list. Memoirs and Reports Published During 1910. REPORTS. Report on a geologiral reconnaisaance of the r^on travened by the National Transcontinental railway between Lake Nipigon and Clay lake, Ont— by W. H. Collins. No. 1059. Report on the geological position and characteristics of the oil-shale deposits of Canada— by R. W. Ells. No. 1107. A reconnaissance across the Mackenzie mountains on the Pelly, Ron, and Gravel rivers, Yukon and North West Territories— by Joseph Keele. No. 1097. Summary Report for the calendar year 1?«.^. No. 1120. MEMOIRS— GEOLOGICAL SERIES. Memoir 1. No. 1, Geological Series. (Geology of the Nipigon basin, Ontario —by Alfred W. G. Wilson. Mbmoid 2. No. 2, Geological Series. Geology and ore deposits of Hedley mining Jistrict, British Columbia — by Charles Camsell. Memoir 3. No. 3, Geological Series. Palaeoniscoid fishes from the Albert shales of New Brunswick — by Lawrence M. I^mbe. Memoir S. No. 4, Geological Series. Preliminary memoir on the Lewes and Nordenskiold Rivers coal district, Yukon Territory — by D. D. Cairnes. Memoir 6. No. 5, Geological Series. Geology of the Haliburton and Ban- croft areas, Province of Ontario — by Frank D. Adams and Alfred E. Barlow. Memoir 7. No. 6, Geological series. Geology of Si. Bruno mountain. Province of Quebec — by John A. Dresser. MEMOIRS— TOPOGRAPHICAL SERIES. Memoir 11. No. 1, Topographical Series. Triangulation and spirit levelling of Vancouver island, B.C., 1909— by R. H. Chapman. Memoirs and Reports Published During 1911. REPORTS. Report on a traverse through tne southern part of the North West Ter- ritories, from Lac Seul to Cat lake, in 1902 — by Alfred W. G. Wilson. No. 1006. Report on a part of the North West Territories drained by the Winisk and Upper Attawapiskat rivers — by W. Mclnnes. No. 1080. Report on the geology of an area adjoining the east side of Lake Timiskam- ing — by Morley E. Wilson. No. 1064. Summary Report for the calendar year 1910. No. 1170. MEMOIRS— GEOLOGICAL SERIES. Memoir 4. No. 7, Ceolo.'ical Series. Geological reconnaissance along the line of the National Transcontinental railway in western Quebec — by \V. J. Wilson. Memoir 8. No. 8, Geological Se.ies. The Ednonton coal field. Alberta — by D. B. DowHng. m Mbmoir 9. No. 9, Geological Series. Bighorn coal basin, Alberta— by G. S. Malloch. Memoib 10. No. 10, Oeolofical Series. An inatrumenUl survey of th« ghore-linei of the extinct lakes Ah^onquin and Nipissing; in Aouthwettern Ontario — by J. W. GoUlthwait. Memoo 12. No. 11, Geological Series. Insects from the Tertiary lake deposits ot the southern interior of British Columbia, collected by Mr. Lawrence M. Lambe, in 1906— by Anton Handlirsch. Memoir 15. No. 12, Geological Series. On a Trenton Echinoderm fauna at Kirkfield, Ontario— by Frank Springer. Memoir 16. No. 13, Geological Series. The clay and shale deposits of Nova Scotia and portions of New Brunswick— by Heinrich Ries, assisted by Joseph Keele. MEMOIRS— BIOLOfilCAL SERIES. Memoir 14. No. I, Biological Series. New species of shells collected by Mr. John Macoun at Barkley sound, Vancouver island, British Columbia— by William H. Dall and Paul Bartsch. Memoirs and Reports Published During 1912. REPORTS. Summary Report for the calendar year 1911. No. 1218. MEMOIRS— GEOLOGICAL SERIES. Memoir 13. No. 14, Geological Series. Southern Vancouver island— by Charles H. Clapp. Memoir 21. No. 15, Geological Series. The geology and ore deposits of Phoenix, Boundary district, British Columbia— by O. E. LeRoy. ^ , Memoir 24. No. 16 Geological Series. Preliminary report on the clay and shale deposits of the western provinces — by Heinrich Ries and Joseph Keele. Memoir 27. No. IT, Geological Series. Report of the Commission appointed to investigate Turtle mountain, Frank, Alberta, 1911. Memoir 28. No. 18, Geological Series. The geology of Steeprock lake, Ontario — by Andrew C. Lawson. Notes on fossils from limestone of Steeprock lake, Ontario — by Charles D. Walcott. Memoirs and Reports Publislied During 1913. REPORTS, ETC. Museum bulletin No. 1 • contains articles Nos. 1 to 1 2 of the Geological Series of Museum Bulletins, articles Nos. 1 to 3 of the Biologic. ' Series of Museum Bulletins, and article No. 1 of the Anthropological >crie^ ' Museum Bulletins. . ,•...• Guide Book No. 1. Excursions m eastern Quebec and t.ie Maritime Provinces, parts 1 and 2 . . „ ^ , . , ,^ , Guide Book No. 2. Excursions in the Eastern Townships of Quet)ec and the eastern part of Ontario. Guide Book No. 3. Ottawa. (iuide Book No. 4. Guide Pook No. 5. Manitoulin island. Guide BiKik No. 8 Excuniont in the neighbourhood u( Montreal aad tCxruriioni in louthweRtern Ontario. Kxcursions in the western peninnula of Ontario aad Toronto to Victoria and return via Canadian Pacific and Canadian Northern railways: parts 1, 2, and 3. Guide Book No. 9. Toronto to Victoria and return via Canadian Pacific, Grand Trunk Pacific, and National Transcontinental railway*. Guide Hook No. 10. Kxcursions in Northern British Columbia aad Yukon Ferritory and aUmg the north Pacific coast. .MEMOIRS— GEOLOGICAL SERIES. Memoir 17. ^0. 28, Geological Series. Geology and economic resources of the Larder Lake district, Ont., and adjoining portions of Pontiac county, Que. — by Morley E. Wilson. Mbuoir 18. No. 19, Ceologicai Series. Bathurst district. New Brunswick — by G. A. V'oung. Memoir 26. No. 34, Geological Series. Geology and mineral deposits of the Tulameen district, B.C. — by C. Can.sell. Memoir 29. No. 32, Geological Series. Oil and ^a!> prospects of the north- west provinces of Canada — by U . Malcolm. Memoir 31. No. 20, ecological Series. Wheaton district, Yukon Territory — by D. D. Cairnes. Memoir 33. No. 30, Geological Series. The geology of (jowganda Mining Division — by W. H. Collins. Memoir 35. No. 29, Geological Series. Reconnaissance along the National Transcontinental railway in southern Quebe^— by John A. Dresser. Memoir 37. No. 22, Geolcgieal Series. Portions of Atlin district, B.C. — by D. D. Cairnes. Memoir 38. No. 31, Geological .Series. Geology of the North American Cordillera at the forty-ninth parallel. Parts I and II — by Reginald Aldworth Daly. Memoirs and Reports Published Durinj} 1914. REPORTS, ETC. Summ iry Report for the calendar year 1912. No. 1305. Museum Bulletin No. 1: contains articles Nos. 13 to 18 of the Geological Series of Museum Butleiins, and article No. 2 of the Anthropological Scries of Museum Bulletins. Prospector's Handbook No. 1: Notes on radium-bearing minerals — by Wyatt Malcolm. MUSEUM GUIDE BOOKS. The archaeological collection from the southern interior of British Colum- bia—by Harlan I. Smith. No. 1290. MEMOIRS-GEOLOGICAL SERIES. Memoir 23. No. 23, Geological Series. Geology of the coast and islands between the Strait of Georgia and Queen Charlotte sound, B.C. — by J. Austen Bancroft. Mkmoii 25. Mkiioik 30. Mkmoir 20. Mbmuin 36. MuMoiK 52. Mi'iMoik 43. Mkmoir 44. Mkmoim 22. MkMOIK ^2. Mrmdir 47. Memoir 40. Memoir 19. Memoir 39. Memoir 48. Memoir 45. Memoir 49. .Vi> il, Oeolotital Striei. Report on the clay unci iha'r ilr- pusitd of the weitern province! (Pan III) — by ilcinriih Kic* and Joneph Kit-it.. No. 40, GeotogieJ .Sfrirs. The batint o( Nelnun ami Chun hill rivers — by William Mclnnes. No. 41, Geological Serits. GoM fields ot Nova Scotia -by W. Malcolm. iVu. 33, Geological Series. Geoiofty o( the Victoria ami Suinirli map-ureas, Vancouver island, B.C. — by C. H. Clapp. No. 42, Geological Series. Geological notes to arcoiiipaiiy maji of Sheep River gas and oil field, Albcrt.i — by L). U. DnwIiiiK. No. 36, Geological Series. St. Hilaire (Beloeil) and Ri.ugeinont mountains, (Juebcc— by J. I. O'Neil. No. 37, Geolvxical Series. Clay and shale depo.sin of New Brunswick— by J. Kecle. No 27, Geological Series. Preliminary report on the ■eriK-ni ines and associatefl rocks, in southern Qucljec^by J. A. Uresser. No. 25, Geological Series. Portions of Portland Canal and Skeena Mining divisions, Skeena district, B.C. — by R. (j. McConnell. No. 39, Geolofical Series. Clay and shale deposits of the western provinces. Part III — by Heinrich Ries. No. 24, Geological Series. The Archican geology of Rainy lake — by Andrew C. Lawson. No. 2(1, Geological Series, tleology of Mother Lotlc and Sunset mines, Boundary district, B.C. — by (). E. LeRoy. No. 35, Geological Series. Kewagama Lake map-urea, Quebec -by M. E. Wilson. MEMOIRS— ANTHROPOLOGICAL SERIES. No. 2, Anthropological Series. Some myihs ami talcs of the Ojibwa of southeastern Ontario — collerted by Paul Radin. No. 3, Anthropological Series. The invitintj-in feast of the Abska Eskimo — by E. VV. Hawkcs. No. 4, Anthropological Series. Malecite tales — by W. H. Mechling. Memoirs and Reports in Press, September 10, 1914. Memoir 41. No. 38, Geological Series. The "Fern Ledges" Carboniferous flora of St. John, New Brunswick — by Marie C. Slopes. Memoir 51. No. 43, Geological Series. Geology of the Nanaimo map-area — by C. H. Clapp. Memoir 53. No. 44, Geological Series. Coal fields of Manitoba, Saskatche- wan, Alberta, and eastern British Columbia (revised edition) — by D. B. IJowling. Memoir 61. No. 45, Geological Series. Moose Mountain district, southern Alberta (second edition) — by D. D. Cairnes. Memoir 55. No. 46, Geological Series. Geology of Field map-area, Briiish Columbia and Alberta — by John A. Allan. Memoir 58. No. 4S, Geological Series. Texada island — by R. G. McConnell. Memoir 60. No. 47, Geological Series. .^risaig-Antigonish district — b\ M. Y. Williams. Memoir 50. No. , Geological Series. Lpper White River district, \'iikon — by D. D. Cairnes. Mbmoir 56. No. , Cfol0)ical Stru$. OeoloKy ot Franklin Mining camp, IVC— by I hai. W. IJryiwIali'. MttMuiR 42. A'o. /, AHlkf'ipoloiual Series. The V Kraiik <.. S|)i!ck. Memoir 62. No. 5, AnthrotHiln"Hal Serirs. .Abnormal ly|)e» of gpcK*- '' .\ika~ by K. -^.ipir, . . , , Memoir 63. No. n, AnthriipoloxiaU .Serirs. Nmin rfiluplicaimn in C omox, a S.ilish utii(uaK<' of N'anoiuvcr i^l.iml bv IC. Sapir. Memoir 46. No. 7. Anlknip'lniiiciil .Series. l'l.i with sc.bjcclive pronominal pri-fixes — by C. M. li.irlHMij Memoir 54. No. Z, Hmtogiral Series. Annotaliil li»i i>( Howtring pUntt ami fiTPii '>< I'oint I'elee, (hit., and iii-iKl>l>ourink Uigtrict*— by ('. K Dmige. Summary Report for the calendar year I'HS. I LEGEND lA PtNNSVLVANIANI^I 3 O Wf i 9^ ■ i !■ «Mf .lit ■>, !■ ; ""Ttss^'issr U ^MISSISSIPPIAN ^ "^'tdSi OdOOVICIAN y ^^^^Sa-?- MfArM 1 SILURIAN -< 1:^1 I, 1**1 ■■iiijawii - Awfc — -sSEi-, -«*^^y ' ORDOVICIAM ^vMtr— 'AR C»»ll ^t«l> iiiiiiliiiy 1 1 ♦ I ClISniMal, ITi , pi arf OUa^ J -■■.y ») ' M iiii i *r M.r.n lipaitment of iRmcs Hon L Co[)fRHK, Minis-i «. h G.M' ( (.iNstLu.Dt-PuTv MiNir.tEP OeOLOOICAL SURVEY OUTLINE MAP ARISAiG. ANTIGONISH COUNTY. NOVA SCOTIA -1 L. LEtlKNII OS PtNNSVLVANlAN LIstivarr "'T'^' Ty *"' OBOOVICIAN (A 3 o z o CD MISSISSIPPIAN -> K < Suall diakur Ol •l« l f» Rivvr KvniholH IHp and ali-ikr IkTAraa Krmali Wnti'Hl Mi-HM LEVONIAN c <;itH-iiii miiir SILURIAN RuuMditry oa Makninu I'ov O TDOVICIAN (■.♦ISrm*.-*! . MiMafti Iquuliufiu itfBntt •lOMCicAi mhviv OUTLINC MAP fOMTMI'MMKHI. A.VO It T II A I T ^RISAIG-ANTIGONISH. ANTIGONISH COUNTY. NOVA SCOTIA •rsir at MUp«