Science, Faculty of
Earth, Ocean and Atmospheric Sciences, Department of
DSpace
UBCV
Carbonneau, Come
Master of Applied Science - MASc
University of British Columbia
This thesis is the result of information obtained during the field seasons of 1947 and 1948. The writer was an assistant on a geological survey party for the Quebec Bureau of Mines, working in the area. The thesis contains a description of the rock formations and an interpretation of the regional structures. Much of the information had to be obtained from the literature previously published on the district. The geological sketch-map accompanying this paper is drawn at the scale of one mile to the Inch. It is a compilation of the previous geological work In Gaspe completed and modified with the aid of personal notes. In order to give a better picture of the structures, a portion of this map was drawn at a scale of half a mile to the Inch. All the important exposures of rocks situated south of the Shickshook series were visited, but only two weeks were spent on the northern contact of this series with the North Coast sediments. Consequently more attention will be given to the Geology south of the Shickshooks than can be given to the northern part of the area.
L £ 5 * 7 if-i 1 R 7 Car STRATIGRAPHY AMD STRUCTURE OF A PORTION OF THE SHIGKSHOCK MOUNTAINS, GASPB _P gNimULA. A thesis submitted in pa r t i a l f u l -filment of the requirements for the course leading to the degree of Master of Applied Science In Geological Engineering at the University of B r i t i s h Columbia. Come Garbonneau University of B r i t i s h Columbia. A p r i l , 1949 • CONTENTS. Page. Foreword 1 Abstract I l l INTRODUCTION 1 Location of area 2 Means of access 2 Previous work 3 PHYSICAL FEATURES 5 Topography 5 Drainage 8 Geomorphic History 10 Glaciation 10 STRATIGRAPHY 20 Ordovician 20 Sedimentary rocks 20 Shickshock series 24 Silur ian 33 LIthology 33 Paleontology 38 Correlation 44 Devonian 47 Gaspe limestone series 477 Gaspe sandstone series 50 Basic volcanics and basic dykes 53 INTRUSIVE ROCKS 55 Serpentine 55 Granite 60 Diori te 61 STRUCTURE 61 Structure north of the Shickshock ser ies . . . 61 Structure in the Shickshock series 63 St ru^ t re south of the Shickshock se r i e s . . . 64. BIBLIOGRAPHY 66 MAPS. . . . . i n pocket. PIATES (After page 71) Frontispiece: Mount Albert . View from the west. Recently upl i f ted, peneplarted surface and g l ac i a l cirque. Contents (continued) PLATS 1 View looking southeast from a high point in the Shickshock mountains. Foreground: South Mountain. Center: Squaw Gap and Barn-shaped mountains. Background: level-crested surface of the lower plateau. PLATE 11 A view from the Shlckshock to the northern plateau. Background: St. Lawrence r i ve r . PLATE 111 Ground moraine along the Bathurst road in the eastern part of the area. PLATE IV On top of Mount Albert, angular debris or felsenmeer. PLATE V Jointing in the serpentine of South Mountain. PLATE VI Interior of a g l a c i a l cirque on the south flank of Mount Albert . PLATE V l l An exposure of competent, S i lur ian limestone beds dipping north. Seventeen-Mile brook. (South branch) PLATE V l l l North-dipping beds of S i lu r ian doldn-ite exposed along the Salmon Branch of the Cascapedia r i ve r . PLATE IX Slickensides in Devonian rocks exposed along Seventeen-Mile brook (South branch). 1 FOREWORD. This thesis i s the result of information obtained during the f i e l d seasons of 1947 and 1 9 4 8 . The writer was an assistant on a geological survey party for the Quebec Bureau of Mines, working in the area. The thesis contains a description of the rock formations and an Inter-pretation of the regional structures. Much of the Information had to be obtained from the l i tera ture previously published on the d i s t r i c t . The geological sketch-map accompanying this paper is drawn at the scale of one mile to the Inch. It i s a compilation of the previous geological work In Gaspe completed and modified with the aid of personal notes. In order to give a better picture of the structures, a portion of this map waa drawn at a acale of ha l f a mile to the Inch. A l l the important exposures of rocks situated aouth of the Shickshook series were via i ted, but only two weeks were spent on the northern contact of this series with the North Coaat sediments. Consequently more attention w i l l be given to the Geology aouth of the Shickahocka than can be given to the northern part of the area. The writer i s much indebted to Dr. H.W. /fc Gerrigle, under whom he has worked, for the advice received, for the opportunity to v i s i t the exposures In the f i e l d and for the use of notes and map a of the previous years. The present paper could not have been written without Dr. /Ac Gerrigle 'a a id . The writer i s also deeply grateful to 11 Dr. V . J . Okulltch for his suggestions and cri t icisms during the preparation of this thesis and for his very-great helir in the ident i f icat ion of the f o s s i l s . Sincere thanks are extended also to Dr. H.O. Gunning and Dr. K. Watson for their suggestions in the study of the t h i n-3sctions. I l l ABSTRACT. The Shickahook mountains form a belt of highlands extending para l le l to the axis of the Gaspe Peninsula in South-eastern Quebec. They represent remnants of a peneplain completed by late-Tertiary time and greatly modified by stream erosion in recent geological time. Local glaciers developed in the summit areas during the Pleistocene Epoch. A short review of the controversy on the possible continental glaciation i s given. New findings are added to the evidence for continental glaciat ion. The area under consideration l i e s a few miles north-west of the geographic center of the Peninsula. The rocks range in age from possibly Cambrian to Middle Devonian. They consist mainly of sedimentary rocks intruded by granite, d ior i te and serpentine. Two major volcanic flows are inter-bedded with the sedimentary rocks. A description of the various types of rocks is given and a correlation is made with belts of similar rocks exposed elsewhere In Gaspe. A small f o s s i l fauna collected in the Si lur ian limestone is described. As a result of the present geological work, the age of a serpentine, previously thought to be Ordovician, ia questioned. No data can be added for the determination of the age of a volcanic series apparently overlying Ordovician limestones and slates. IV The structure, where i t could be determined, is one of repeated small anticlines and synclines with possible development of high-angle thrust faults near the crests of the folds. -1-INTRODUGTION . Gaspe Peninsula is located in the south-eastern part of the Province of Quebec. The Peninsula forms a tongue of land/ which extends into the Gulf of St. Lawrence. From i t s western boundary, the valley of the Matapedia r ive r , to the Bay of Gaspe, i t has a length of approximately 150 miles; i t s width between the St . Lawrence estuary and the.Bay of Chaleurs varies between 70 and 90 miles. 2-Location of Area. Means of acceaa. The region dealt with in this paper i s situated west of the Mont-Albert Map-area, approximately in the center of the Peninsula, between latitudes 66° 15' and 66° 30' and paral lels 48° 40' and 49°. The northern half of the area includes part of the national park of Gaspe. The southern l imi t of the area roughly follows the Lake Branch of the same r iver , whereas the St . Anne r iver i n part of i t s course marks almost i t s northern boundary. The southeast corner of the map-area is easi ly reached by a motor road from Grand Cascapedia on the Bay of Chaleurs. This road runs north along the Cascapedia r iver and leads to the Federal Mine Camp, pasaing within three miles of the area. From the Mining Camp a new motor road, bui l t by the Bathurst Pulp Company, runs north almost to Mount Albert , then turns west and crosses the whole width of the area in i t s central part. The southern half of the area is reaaonably well provided with old paths and t r a i l s associated with the former lumber exploitat ion, but north of the Bathurst road auch t r a i l a are completely lacking except for a few miles along the Salmon Branch. This lack of t r a i l s and the heavily wooded condition of the region render3 back-packing t rave l l ing par t icular ly arduous. Another, much shorter road may be uaed to enter the area from St. Anne des Monta, a v i l lage aituated on the n o r t h c o a s t . T h i s motor r o a d runs s o u t h e r l y f o r 10 m i l e s and t h e n t u r n s e a s t I n t o t h e v a l l e y of the S t . Anne r i v e r I n t h e n o r t h e r n p a r t o f the a r e a . However, from t h e r e t h e a s c e n t t o the t o p of t h e S h i c k s h o c k brow i s so s t e e p t h a t t h i s approach t o t h e r e g i o n i s v e r y l i t t l e u s e d . P r e v i o u s Vifork. S e v e r a l g e o l o g i s t s worked i n t h e v i c i n i t y of t h e a r e a under c o n s i d e r a t i o n . I n 1843, S i r l<?illiam Logan ascended th e Cap Chat r i v e r , c r o s s e d over the S h i c k s h o c k M o u n t a i n s , r e a c h e d t h e M i n e r brook i n t h e m i d d l e of t h e P e n i n s u l a and went down t o t h e C h a l e u r Bay by the Lake B r a n c h and the main C a s c a p e d i a r i v e r , making a complete c r o s s - s e c t i o n of Gaspe west of t h e p r e s e n t a r e a . A y e a r a f t e r , A l e x a n d e r Murray made a t o p o g r a p h i c a l and g e o l o g i c a l s u r v e y of t h e S t . Anne r i v e r . I n 1858, R i c h a r d s o n ascended the same r i v e r t o t h e f i r s t main f o r k and t h e n t r a v e l l e d f o r 20 m i l e s s o u t h e a s t t o Barn-shaped M o u n t a i n . I n 1883, E l l s e x p l o r e d and mapped the Lake and Salmon branches o f t h e Grand C a s c a p e d i a r i v e r . The n e x t p e r i o d w h i c h may be d e s c r i b e d as modern g e o l o g i c a l mapping began w i t h A. M a i l h o t who worked out t h e g e o l o g y of a p a r t of the Lemieux t o w n s h i p and o f t h e Mount A l b e r t a r e a , d u r i n g the summers of 1917 and 1918. At t h e same t i m e , Coleman was i n v e s t i g a t i n g t h e g l a c i a l g e o l o g y of the P e n i n s u l a . P . J . A l c o c k spent the seasons of 1921,. 1922 and 1923 s t u d y i n g t h e Geology of Lemieux-itownship and Mount A l b e r t s he wrote perhaps t h e most c l a s s i c a l r e p o r t on -4-Gaspe under the t i t l e , "Mount A l b e r t Map-area". Between 1 Q 2 9 and 1 9 3 7 , I.W. Jones mapped a l a r g e p a r t of the i n t e r i o r of the P e n i n s u l a . Prom 1 9 4 2 t o 1 9 4 5 , as a p a r t of a b r o a d - s c a l e reconnaissance program of g e o l o g i c a l mapping, H.W. M c G e r r i g l e covered most of the ground of t h i s area. Other workers concerned w i t h the P l e i s t o c e n e h i s t o r y , v i s i t e d the neighbouring areas'. T h i s w i l l be t r e a t e d i n the s e c t i o n under G l a c i a t i o n . A p a r t i a l survey of other works concerning Gaspe may be found i n the b i b l i o g r a p h y . -5-1. PHYSICAL FEATURES. Topography. Gaspe Peninsula forms the northern extension of that great geomorphic unit known as the Appalachian Province, which extends inland pa ra l l e l to the Atlant ic Coast from the state of Alabama to Newfoundland. Consequently, Gaspe is a region of mountains and folded structures. In the present area, the general trend of the ridges and valleys i s east-west or, generally, follows the l ine of the north coast. The elevation of the country rise3 gradually from south to north u n t i l the northern boundary of the Shickshocks i s reached. A sudden drop to the bottom of the St. Anne valley follows and from there the level of the country rises again for a few miles and becomes subdued close to the St. Lawrence r i ve r . For anybody standing on a high summit, the topography appears to be d iv i s ib l e into three units: f i r s t , a lower southern plateau which, in the area, extends from the Shickshocks to the Bay of Ghaleurs (Plate 1). Second, a higher plateau developed on the harder metamorphics of the Shickshock Mountains and th i rd , an intermediate plateau which rises between the same mountains and the St. Lawrence r iver (Plate 11). This threefold divis ion of the topography, f i r s t made by Alcock, ia based on physical featurea which characterize the Appalachian region as a whole: the l eve l -crested mountaina, the plateau5and areas of accordant h i l l tops at varioua elevations. -6-The flat-topped character of many of the summits and the several level led surfaces standing at different elevations constitute certainly a s t r ik ing topographical feature of Gaspe. These facts are well I l lustrated "by the perfect f l a t surface of Mount Albert and the level led horizon l ine of the Tabletop both standing east of the present area. (Frontispiece). From the valley f loors, however, the region does not appear as being formed by this three-stepped plateau. In the lower southern plateau, the area is f i r s t crossed by a broad, east-west valley occupied by the Lake Branch of the Cascapedia r i ve r . The valley stands between 500 and 600 feet above sea-level. Immediately north of i t , a low ridge, also running east-west, reaches an elevation of 1200 feet. Further north, a gently r o l l i n g swampy surface developed on York River type of sandstone, r ises gradually from 800 to 1200 feet in a distance of approximately two miles. As we go farther nofcth into the region underlain-ed by the more resistant Gaspe limestone series, the topography becomes more rugged. The in t e r f luv ia l areas are narrower. The streams flow swift ly by cascades and rapids in deeply entrenched valleys and even in small gorges. Often large angular fragments of rocks block the beds of minor streams. Near their headwaters, the tr ibutary streams have a tendency to disappear and flow underground. In the eastern part of this bel t , two prominent granitic bodies j| Barn-shaped and Squaw Cap Mountains) reach an elevation of 3000 feet. -7-Elsewhere, the country stands between 1200 and 2500 feet above sea-level. Just north of the Faribeault-Richard township line and pa ra l l e l to i t , there is another broad, f l a t , swampy trough bounded in the north by the f i r s t range of the Shickshock Mountains and by two masses of serpentinized peridot i t e, the easternmost of which is known as South Mountain. The Shickshock Mountains form a chain of highlands which extend for 50 miles from the Matapedia valley to the Table4*top Mountains, a l i t t l e north of the central axis of the Peninsula. They are the continuation towards the west of the Notre-Dame Mountains which r i se In southern Quebec. In the present area, the northern boundary of the Shickchock Mountains is marked by an abrupt escarpment which roughly follows the convexity of the north coast about 12 miles inland. Eight miles south of the escarpment they lose their identi ty and merge with the lower plateau and the r o l l i n g h i l l s developed on softer rocks. The Shickshocks stand at an aver-age elevation of 3000 feet but a few summits i n the Tabletop Mountain group reach an elevation of 4000 feet. Mount Albert has an elevation of 3775 feet. In the map-area, as elsewhere, this higher plateau country i s very rugged and much dissected. The i n t e r f l uv i a l areas are often f la t and some contain small ponds and s?/amps. The valleys are commonly steep sided. No exact information is available as to the elevation of a l l the summits in the area but at many places the ve r t i ca l drop from the divides to the valley bottom is over 1 0 0 0 feet. As a general rule , the gradients are gentle near the headwaters on the tributary streams, North of the Shickshock Mountains, across the trench of the St. Anne r ive r , the th i rd unit shows a more subdued topography and is characterized, within the map-area, by more extensive summits and i n t e r f l uv i a l areas. This northern plateau reaches an elevation over 2 0 0 0 feet above sea-level. Drainage. The whole area i s almost ent irely drained by the Grand Cascapedia r iver which flows southerly to the Bay of Chaleurs. Three main tr ibutaries of that r iver constitute the hydrographic system. The Go-a-shore brook flows in the South-western part of the area into the La.1® Branch which joins the main Salmon Branch near the south-east corner. From the point where i t leaves the area to the mouth of the Seventeen-Mile brook, the Salmon Branch Is already a swift stream with several rapids. It has an average width of 2 0 0 feet in this stretch. Just below the mouth of Seventeen-Mile brook, the r iver f a l l s 25 feet over a s i l l of d io r i t e . Two miles above Seventeen-Mile brook, where the r iver flows on the hard volcanics of the Shickshock Mountains, the valley i s narrower. Rapids and f a l l s become numerous. In this section the r iver flows over huge blocks of detached rocks or on bedrock with numerous pot-holes. The r iver has i t s source in the somewhat f la t te r ground north and west of Lake Paul and in the trough occupied by Lake Cascapedia, a beautiful body of water about three miles long and half a mile wide. In some places, mcr e resistant beds have caused temporary base-levels to form and one finds small gravel bars and small flood plains even in the stretches where the stream normally would be very swift. The Lake Branch and the Go-A-Shore brook possess the same general features, and the same description holds for these t r ibu-tar ies , but on a smaller scale. Other major streams flowing into the Salmon Branch are the Fourteen-Mile and the Seventeen-Mile Brooks. The northernmost part of the area is drained by the St. Anne r ive r . Fast flowing obsequent brooks f a l l down the escarpment, which terminates the Shickshock Mountains, and join immediately the St. Anne r i ve r . A l l the way along this front, there is a general tendency for the streams flowing north to capture the headwaters of the streams flowing south. The piracy of the headwaters of Seventeen-Mile brook by the Ruisseau du Gros Volume is Imminent. Furthermore the present area In that respect seems to be behind the two adjacant areas east and west (Alcock 1923). Both the Cap Chat r iver and the St . Anne r iver include in their headwater basin waters which formerlv K/ flowed southerly to the Bay of Chaleurs. -10-Geomorphic History. Alcock (1922, 1926, 1935) believe*that the f la t summits of Shickshook Mountains (including Mount Albert and the Tablet op) represent remnants of a plain completed by early Tertiary times. Upl i f t in the early Tertiary caused a new cycle of erosion to begin and a mature surface was developed on the limestones, shales and sandstones of the present southern plateau. In late Tertiary times, elevation took place again and a second cycle of erosion was inaugurated. The present Shickshock range was formed by the dissection of th is la te-Tertiary uplif ted surface. Renewed up l i f t occurred again in late Pliocene times, Inaugurating the present cycle of erosion. F ina l l y there was a temporary depression due to the weight of the ice during the Glac ia l period. Recent up l i f t Is presently going on but, as yet, has been insuff-icient to offset the depression caused by the Pleistocene glacia t ion. GlaciatIon. The g l ac i a l features in the present area cannot - l a -bs treated without considering the problem of the glaciation as a whole for the f u l l length of the Shickshocks. Much haa been written about the Pleistocene ice-age in Gaape Peninsula, the problem being whether the Labradorean ice-3heet had covered the highest part of the region or whether only small loca l glaciers had spread from the alopea of the major mountaina. U n t i l 1942 the general opinion, based on geolo-g ica l inveatigation made by Chalmera, Coleman, Alcock and Jones, was that the continental ice-aheet had never croased the Interior of Gaape. Chalmers ( I 9 0 4 . p .254) states that: "the glaciation and the transportation of the dr i f t in the Gaspe Peninsula are entirely l o c a l , except auch material aa I 3 due to f loating ice on the north shore". As a reault of two aeasons f i e l d work in Gaape, Coleman (1922) atated that the Labradorean glacier had never overridden Gaspe and that the loca l glaciera had never taken their sources at an a l t i -tude higher than 2500 feet, I .e . the central part of the Peninaula above an elevation of 2500 feet was never covered by any Ice. Hia concluaions, which were reasonable at that time, were baaed on the following features: lack of g l ac i a l grooves, s tr iae, polished or rounded surfaces at an al t i tude above 2500j occurrence on the summit surfaces of angular rock debris (felsenmeer) of the aame character as the underlying rock; ahape and couraes of the r iver valleya which are V-shaped and have zigzag couraes. Furthermore according to Coleman, i f the Torngat mountaina of Northern Labrador, v i s i ted by - 1 2 -him two years previously, had never been glaciated, i t was highly plausible that the Interior of Gaspe with mountains of similar height had never been covered by a continental glacier . The facts which favour a loca l glaciat ion are: the occurrence of small g l ac i a l lakes and cirques in the Tabletop Mountains and on the flanks of Mount Albert , the occurrence, on the two Goasts, of pebbles and boulder clay derived from local rocks or from the Shickshock Mountains. Alcock ( 1 9 2 6 ) , mapping Mount Albert a few years la ter , agreed with Coleman that there was no evidence of continental glaciat ion, but he brought the l imi t of l oca l glaciat ion up to 3200 feet on the basis of a large erratic found at this a l t i tude. U n t i l 1935 a l l other workers in the region accepted Coleman's views that the Labrador glacier , on approaching Gaspe divided into two tongues; one flowing eastward towards the Gulf of St.Lawrence, the other advancing southeastward through the val ley of Matapedia r iver and continuing eastward into the Bay of Chaleurs trough. However, prior to Coleman, Mailhot (I9I8-P.I46) in his report on the Geology of Mount Albert, wrote in favour of a continental glaciat ion. "Certain portions of the summit (Mount Albert) are absolutely flat and present a true g l a c i a l surface with here and there some gantle undulations or rocky knolls which have been spared by the g lac iers . In general these small knolls present a gentle slope towards the north and an abrupt face towards the south, and this feature would -13-prove that the glaciers were advancing from north to south. On the summit plateau are found a few errat ic blocks of granite and hornblende schist which certainly represent remnants of ancient g l ac i a l moraines". Prom 1935 u n t i l now, Mailhot 's views were strengthened by new observations of Alcock (1935-p«125 and 1944), Jones (1939), F l i n t , Desmorest and Was/burn (1942 and 1944) and H.W. McGerrigle. (1) Local errat ics, g l ac i a l striae and polished surfaces were found at different elevations up to 3700 feet, leaving a margin of 500 feet in the Tablet op Mountains where no trace of glacier passage San be observed. Errat ics were found on top of Mount Albert and at various lower elevations. However, according to F l i n t , Desmorest aid Wasburn, these features and facts are not a direct proof of the passage of the Labradorean ice-sheet over the highest part of central Gaspe. The Precambriam anorthosite and the Laurentian gneisses were brought undoubtedly from the north shore of the St. Lawrence r iver by the i ce . But this ice-sheet may have been of low elevation and may have possessed just enough strength to cross the Peninsula through the valleys. Deposition would have occurred on the valley f loors . I t i s conceivable but hardly probable that later debris was transported from the valley bottoms up to the top of Mount Albert and elsewhere by the action of l oca l glaciers . According to these prominent glaciologls ts , a 1. Personal communication. -14-direct protf of glaciat ion would consist in the finding of an erratic lying on the top of the highest summit. I f the g l a c i a l features of the present area are to be considered by themselves, very l i t t l e can be e done to dtcipher the problem. On the contrary, much confu-sion would be thrown i n . The dis t r ibut ion of the rock debris indicates movement of the ice almost i n every d i rec t ion . However, the prevailing tendency is for the rock erratics to come from the north. Throughout the area, i t seems that £ g l ac i a l feature^ such as grooves, striae and polished surfaces lacking. This may be explained i n part by the scarcity of rock exposures in some parts of the region and by the type of outcrops which, almost entlreljr, occur as c l i f f s on the valley sides or form the beds of the streams. In the southern part of Richard township, the re la t ive abundance of the Shickshocks type of rock debris increases aa we come closer to the Shickshock seriea. Occaaionally a aerpentine boulder from Mount Albert or South Mountain is found mixed with other type a of rock. However, generally, the rock fragments are of the same nature aa the underlying bedrock and, In many casea, thia feature may be used to map the contacts of the rock formations in areaa where the expoaures are rare. In central eaatern part of the area, at least two ground morainea were uncovered during the conatruction of a new road. (Plate 111) These moraines were thoroughly examined, but very l i t t l e information concerning the character of the glaciat ion could be obtained. A typ ica l -15-laurentian gneiss boulder was found near a moraine standing at an elevation of 2000 feet. This boulder was almost perfectly spherical and about one foot in diameter. A l i t t l e farther west, amongst the debris covering the bottom of the Seventeen-Mile brook, another similar erratic was found. There i s l i t t l e doubt about the provenance of such boulders; they appear to be derived from the granit ic orthogneisses which outcrop on the north shore of the St. Lawrence from Tadoussac to the Mingan Islands (Paessler 1940). No such boulders were found in the northern part of the area within the Shickshock range i t s e l f . Furthermore, in this region the erratics are indicative of a south to north dement of the glaciers and both the d i s t r i -bution and the provenance of those erratics i s very obscure. On the north shore of Lake Cascapedia, there i s a large, angular slab of Grand Greve limestone about s ix feet in diameter and one foot thick. The nearest formation of Grand Greve limestone i n the area l i e s about three miles south of Lake Cascapedia. Between the lake and the formation, there i s a secondary mountain range standing at higher ele-vation than the limestone h i l l . To explain how this slab of rock could have passed over this range of mountains is a puzzling problem. It has been said before that the northern boundary of the Shickshocks Is an abrupt eqcarpment. The erosion i s so active from the top to the bottom of this ve r t i ca l wal l that any g l a c i a l feature would have l i t t l e -16-chance to be preserved. This may pa r t i a l l y explains the lack of g l ac i a l features. In connection with the same problem, Mount Albert was v i s i t ed in the area immediately to the east. The surface of this peridotite intrusive i s rough and i s covered with angular pieces of rock. At f i r s t glance It certainly does not resemble a g l a c i a l floor (Plate IV). However, as pointed out by F l i n t , Desmorest and Washburn, these conditions do not necessarily mean the absence of glaciation and can be explained by severe frost action on the strong joint ing which exists in the peridotite mass. (Plate V) On the other hand, certain features can possibly be attributed to a glacier working i t s way to the south-east. For instance, a knol l or roche moutonnee (|)f Mailhot 1918) lying about 200 feet from the top shows a gentle slope towards the north-west and a steep face towards the south-east. However, joint ing and frost action can be responsible for such a feature. Different kinds of erratics were collected at an elevation above 3400 feet. Most of them come from the Shickshock series, a few from the granite intrusive of the Tablet op mountains. Three small pebbles suggest granite gneisses from the north shore of the St. Lawrence r ive r , but the weathering of the pebbles prevents an accurate determination. Some amphibollte pebbles were also found within 200 feet ve r t i c a l l y from the top of Mount Albert . These amphibollte fragments appeared to be s imilar to the amphibollte ring which encircles the peridotite -17-intrusion at a lower elevation. Consequently a glacier must be responsible for the transportation of these erratics to the highest part of the mountain. No polished, grooved or striated surfaces characteristic of glaciated regions could be aeen i n the parts v i s i t ed . However, evidence of loca l glaciation can eaally be obaerved on the western and aouthern sides of the mountain where g l ac i a l cirquea were carved out from the mountain sidea. (Frontispiece and Plate VI ) . At the end of the 1947 f i e l d seaaon, in the hope of finding other erratica, eapecially gneissea and anorthoaite boulders, a. 50 mile t r i p wa8 made in the in te r ior of the Peninsula. On this occasion, the party lef t the Federal Mine in the center of the Lemieux townahip, went northeasterly through the southern part of the Tabletop mountaina, croased the headwaters of the L i t t l e Cascapedia, Madeleine, Beland rivers and ended the t r i p aeven milea west of Copper Mountain situated at the head of the York r i v e r . The results of thia investigation were very poor. The debris was found to belong exclusively to the underlying bedrock or to formations situated to the north. At the sources of the L i t t l e Cascapedia r iver , a calcareoua aandatone lying at an elevation of 1800 feet, shows a series of g lac ia l striae running at 175°. Theae striae do not give any information as to whether a local or a continental glacier paaaed over the Peninsula, but i t may be noted that they trend almost at right angle to the direction of a local glacier -18-that came down the slopes of the Tablet op Mountains. This section oft he paper on glaciation shows the scarcity of g lac ia l features in Gaspe. However, the few foreign gneissic and anorthosite boulders found at e different elevations and especially the gneisses found on the summit of Mount Albert (Alcock 1942) seem to prove that the Labradorean i c e - 3 h e e t overrode the Interior of Gaspe. I t i s d i f f i c u l t to explain otherwise the preseaoe of erratics lying on the top of one of the highest mountains. Since fire retreat of the continental g lacier , many factors may have contributed to erase or hide the effects of Glaciat ion. Amonst these factors are: the loca l glaciers which followed the Labradorean ice-sheet, and the processes of mass-wasting and stream erosion which must have been very active during deglaciation. Furthermore, the fact that the Labradorean glacier had to cross the deep trough of the St. Lawrence r iver and to override the escarpment of the Shickshocks suggests that the or ig ina l deposition might have been of a very small extent. Therefore, i t seems reasonable to conclude, as F l in t do§s in his latest work. (1944 p.82) that the continental ice-sheet did override the Gaspe Peninsula as i t did Newfoundland in the east and the rest of Quebec in the west. The parallel ism cited by Coleman between the Shickshock mountains and the Torngat mountains now may be brought as a point of favour of continental glaciat ion, since new observations have enabled Dr. N1E. Odell to write on the -ts-subject: " While there Is no definite evidence of more than one glaciation in northern Labrador, i t seems to be clear that during the greatest advance of the ice from the Labrador center the Torngat and the Kaumajet ranges were both entirely submerged". (Am. Geog. S o c , Spec. Publ. No. 22 P.206). 111. GENERAL GEOLOGY. The rock formations in the area range in age from probably Cambrian to Middle Devonian. They consist mostly of sedimentary rocks invaded at different periods by intrusives. The Intrusive rocks vary from ultrabaslc to ac id ic . Two thick volcanic flows are interbedded with the sedimentary rocks. Sequence of formations: Periods. Series. Formations. Li thologica l Characters. Middle Devon-ian Granite, Dior i t e . Acid Volcanips Basic Volcanlcs. Basic dykes. Gaspe sand-stone Series Battery Point Mediom to fine grained sandstones and shales. Dominantly red in colour. York River Coarse to fine-grained greenish to brownish grey sandstones and shales. Lower Devon-ian Gaspe lime-stone Series Grand Greve Fine-grained, hard, s i l i -ceous and calcareous s i l t stones. Cap Bon Dark grey, soft, arenac-eous magnesian limestone. Si lur ian Arenaceous limestone, limestone conglomerate, calcareous shale, fine-grained sandstone. Ordovi-cian and in part Cambrian? Serpentine intrusives. (Age in doubt) Shickshock Series. (Age in doubt) Shale, Schistose shale, slate, limestone, limestone conglomerate, quartzite. -20-STRATIG-RAPHY. Cambrian (?) and Ordovlcian. Dis t r ibut ion: Ordovlcian and Cambrian (?) rocks cover the northern part of the area. They outcrop in many places on the banks of the St. Anne r iver and Its t r ibutar ies . Very good exposures can be found in the Shickshock range In mountain c l i f f s , but elsewhere in the Ordovlcian rocks the exposures are restr icted to the valleys of the main streams. Lithology: The Ordovlcian and Cambrian (?) rocks comprise two main divis ions: a series of sedimentary rocks in the North and a series composed essentially of volcanic rocks in the South. The southern Series i s known as the Shickshock Series. Sedimentary Rocks. The northern series consist of highly folded shale, sandstone, quartzlte, limeBtone, limestone conglomerate and slate . These rocks are so strongly folded, and the structural relationship so obscure, that any further sub-divis ion into formations i s impossible. It can be noted, however, that there Is a predominance of slates and shaly schists south of the St. Anne r iver whereas the limostone members become more numerous to the North. The slate zone consists of thin-bedded, black to brown-weathering dark -21-slates and shaly schists invaded by numerous quartz and calci te stringers. These stringers are generally less than two inches wide; they follow the bedding and cleavage planes and have been twisted and folded with the beds. The slaty seems cleavage vto be para l l e l to the bedding in this zone. A f a i r amount of thin-bedded, dark-weathering, dark-grey limstone is interbedded with the slates. Some beds of grey quartzite, weathering l ight brown to rusty brownish-grey can also be found. At one place, on du Gros Volume brook, some thin beds of yellowish grey slates are interbedded with the quartzite. Some r e l a t i v e l y massive beds of red and green sandy shales occur within half a mile north of the contact with the Shickshock Series. These beds appear to be similar to some red and green fades of the S i l l e r y formation as can be seen near Quebec Ci ty or Riviere du Loup. The same sequence of rocks continues north of the St. Anne r iver , but as mentioned before, the proportion of interbeds of massive, greeriwJLsh grey limestone increase northward. There are fewer quartz and ca lc i te stringers in this zone than i n the slate zone. Both the beds and the stringers are highly twisted and folded. Drag-folding i s common. In some places, the bedding, as detected by colour banding, was found to be different from the cleavage planes and in two instances, the relations between the two features suggested overturned beds. Another important member of this belt - the limestone conglomerate - i s not frequently exposed In the -22-area, but there is a par t icular ly good exposure on Gapsize brook, about half a mile upstream from the St. Anne r i v e r . The pebbles of this conglomerate consist mostly of irregularly-shaped, l ight grey limestone fragments: a few shale fragments are also present. They a l l show a tendency to follow a rough alignment. These grey-weathering pebbles offer a strong contrast to the brown-weathering, coarse-grained g r i t t y matrix. A few bands of similar brown-weathering gr i t are interbedded with the conglomerate. Correlation: Similar rocks are exposed to the west in Mount Albert Area, but they were most f u l l y described by Jones (1934) in the Marsoui area where they underlie almost the whole length of the map-sheet. They have been assigned by different geologists to the "Quebec Group". The group f i r s t appears in the v i c i n i t y of Quebec Ci ty , runs east along the south shore of the St. Lawrence r ive r , and extends possibly as far as Cap de Rosiers at the east end of Gaspe Peninsula. In the v i c i n i t y of Quebec Ci ty , these rocks were divided into the S i l l e r y and the Levis formations. Since no foss i l s were found in the present area, the correlation of these beds i s based on l i t ho log i ca l characterist ics. According to the meagre faunas (1) collected in various l oca l i t i e s along this belt , the bulk of these rocks i s Lower Ordovlcian (Beekmantown). However, recent (1) A good f o s s i l l i s t for this belt can be found in Volume 11. Geology of Quebec, pp. 306 - 308. -23-work (Jones 1935 and Kindle 1938) and some earl ier faunal l i s t s (2) suggest that rocks of Middle Ordovlcian age are also present and may he more common than was previously thought. In the Dartmouth River area, Jones (1935) collected from similar rocks a meagre fauna consisting of Agno3tus sp. and Asaphiscus sp. This fauna suggest5 the pre#enxj6 of Upper Cambrian beds. At various l oca l i t i e s between Quebec and Matane, Rasetti (1945, 1946) collected a r i ch fauna of Lower, Middle and Upper Cambrian t r i l ob i t e s In the pebbles of a conglomerate l i t h o l o g i c a l l y similar to the conglomerate described above-. He assigned the conglom-erate to a Lower Ordovician age. The place-of origin of these Cambrian pebbles and boulders has always been an interesting problem since no formation of Cambrian age and of this type Is known to occur in Quebec. The nearest Cambrian strata outcrop on the West and North Coast of Newfoundland and on Labrador near the straight of Belle I s le . -^Alcock (1926) noted that some of these boulders could not have travelled a long distance. Various explanations have been offered as to the provenance of these boulders, but the problem is s t i l l a matter of debate. In the f a l l of 1948, members of the department of Geology of Laval Univer-s i ty found a Middle Cambrian fauna in place In the v i c i n i t y of Levis . No definite information is available as yet, and any conclusions must be delayed u n t i l the publication of (2) These ear l ie r faunal l i s t were f i r s t c lass i f ied as Upper Ordovlcian but are now regarded as Middle Ordovlcian. -24-these findings. The occurrence of Middle Cambrian rocks in the "Quebec Group" would easily explain the provenance of the boulders In the conglomerate. This discussion shows that some of the rocks occurring in the present area may be of Cambrian age. However, the scarcity of foss i l s and the intr icate folding of these rocks leave l i t t l e hope as to the poss ib i l i ty of ever separating the Cambrian beds from the Ordovician beds. SHICKSHOCK SERIES. The Shickshock series which underlies the greater part of the Shickshock range is composed of basic volcanics with occasional interbeds of c las t ic sediments. It was assigned to the Precambrian by E l l s (1883) and to the Ordovician by Logan (1863) aid Alcock (1Q26). Its age is s t i l l uncertain and is tentatively placed in the Ordovician in this paper. As a rule, both the sediments and the basic volcanics are much altered. A pronounced schistosi ty, running approximately from south-west to north-east and dipping steeply south, i s developed almost everywhere in the series, but certain beds have remained f a i r l y massive. In the f i e l d the tendency was to c a l l the volcanics chlori te schists, but they are better described as greenstone. The eruptive character of the basic rocks is revealed by their composition and by the few volcanic textures observed In the f i e l d . Vesicles and amygdules occur, but these structures are re la t ive ly rare. Most amygdules are -25-f i l l e d with quartz while some contain ca l c i t e . The occurrence of amygdules containing feldspar crystals suggest that these features are not true amygdules but that they may represent remnants of or ig inal porphyritic textures. Some bands in the northern part of the series, consisting of a fine-grained material, exhibit a very fine volour banding. These bands have been referred to as tuffs (Alcock 1926) but the f i e l d evidence is not conclusive. Locally some yellow to yellowish-green epidote stringers follow the schistosi ty planes or form e l l i p t i c a l nodules; these nodules may represent altered pi l low lavas. The chemical composition of the rock gives more definite information as to the or iginal character of th i s series. As mentioned previously, the rock i s strongly altered and l i t t l e can be said about the originaly minerals, however, i t s average composition corresponds to that of basic volcanics. Because of their possible bearing as to the age of the series, part icular care was taken i n the f i e ld to find sedimentary beds which could be compared with the sediments of the northern Ordovician bel t . Unfortunately, however, except for a lens of quartz conglomerate and possibly some s e r i c i t i c schists, which w i l l be described la ter , no sedimentary rocks were found. Only four thin-sections were available for the study of the volcanics. The rock consists of a fe l t of secondary minerals that were d i f f i cu l t , to determine. These minerals are believed to be acid plagioclase, hornblende and -26-epidote. Chlorite Is present in smaller amount and there are some well developed crystals of carbonates. One section, which was taken from a bed believed to be a tuff , contains around 20 percent of quartz. Microscopic examination of three thin-section taken from rocks described in the f i e l d as mottled chlori te schist , were seen to consist of the following minerals: A. Porphyroblasts: 1. Amphiboles: variet ies: tremolite and ac t ino l i t e : varying from 30 to 55 percent. 2 . Chlor i te : in one thin-section, 4 percent. 3 . Plagioclase: variety, oligoclaseX less than 5 percent. B. G-roundmass: 1. Plagioclase: oligoclase. 15 to 25 percent. 2 . Epidcfe: from 10 to 15 percent. 3 . Amphibole: tremolite and ac t ino l i t e . Prom 5 to 20 percent. 4 . Chlor i te : less than 5 percent. 5. Leucoxene: less than 1 percent. 6. Carbonates: less than 1 percent. 7. Opaque mineral which may be magnetite or pyri te: less than 2 percent. 8. Quartz: In one section, 10 percent. The large amount of epldote and the general composition of the rock suggest that the s o J i d plagioclase grew at the expense of a more basic plagioclase. There is evidence also that the porphyroblastic amphibole takes part • -27-of i t s calcium from the plagioclase. The amphibole crystals exhibit a tendency to be In a sub-parallel alignment. The amphibole i s often sheared and in places, chlori te i s formed In the cleavage fractures. Because of the smaill number of thin-sections studied, any conclusion extended to the whole Shickshock series should not be considered as f i n a l . However, in view of the fact that the general appearance of t he rock i s uniform throughout the Series, the following inference can be made. F i r s t , there i s l i t t l e doubt that these rocks were or ig ina l ly volcanics. Second, they were affected by a re la t ive ly Intense metamorphism. The development of schist-osity suggest that they were the product of dynamic rather than thermal metamorpMsm. I t can be seelr*- also why the rock should be called hornblende schist or amphibolite (greenstone in the f i e l d ) . The re la t ive ly small amount of chlori te does not warrant the appellation of ehlorite schist . Some other types of rock can be found in the same series. On the Salmon Branch of the Cascapedia r ive r , west of South Mountain, a poorly exposed granite gneiss was seen intruding the greenstone. At the contact, the greenstone is altered to a dark, coarse-grained hornblende schist different in texture and in composition from the hornblende schists described above. The grani t ic body which i s only 4 feet wide is too poorly exposed to show whether i t intrudes the greenstone as a dyke or as a s i l l . The study of a thin-section from this outcrop of granite -28-showed the following composition: 1. Plagioclase: 50 percent. Altered to se r ic i te in the proportion of 80 percent. Ah 70 An 30. K-feldspars may he present but the alteration prevents an accurate determination. 2. Quartz: 30 percent. Last to c ry s t a l l i z e . 3. B io t i t e ; 10 percent. Flakes def ini te ly elongated In one di rect ion. Some are twisted. 4. Epidote: 5 percent. Appears to grow at the expense of the plagioclase. 5. Garnet: 2 percent. 6. Magnetite or pyri te: 2 percent. 7. Apatite: Traces. The hornblendic schist in contact with the granite, was seen to be composed of the following materials; 1. Hornblende: 60 percent. Large porphyroblastic crystals , showing a prominent geissic texture. 2. Quartz: 20 percentl F i l l i n g the interst ices between the hornblende crystals . 3. A lb i t e : 12 percent. One th i rd , altered to s e r i c i t e . Tendency to be lath-shaped and elongated pa ra l l e l to the hornblende crysta ls . Probably derived from a more calcic feldspar. 4. Epidote: 5 percent. Occur with the hornblende. 5. Chlor i te : 2 percent. Product of alteration of the hornblende. 6. Opaque mineral surrounded by an alteration product (Limonite?): 2 percent. -29-7. Anthophyllite: fibrous aggregate of very low birefringence, less than 2 percent. 8. Rut i le : a few crystals . There i s l i t t l e doubt as to the igeous origin of the granite gneiss. The hornblende schist has a composi-tion which may correspond to a meta-sedimentary rock. But since there i s no part icular reason in the f i e l d to believe so, the rock ia included in the Igneous complex. At the outlet of Lake Noir , about half a mile upstream from the Salmon Branch, a red diabase dyke was seen cutting the schistose rocks. Microscopic examination shows the rock to have an ophitic texture and to consist of the following minerals; 1. Plagioclase; 50 percent. Composition: Ab 50 An 50. Half the mineral altered to s e r i c i t e . Part of the ground mass i s made of altered, plumose, microlites of feldspars. 2. Pyroxene: 20 percent. Colourless to pale green. Variety: pigeonite. The mineral was seen reverting into b io t i te with iron minerals alteration around the crystals . 3. Iron minerals: limonite? 20 percent. Scattered through the section as an alteration product of the ferro-magnesians. 4. B io t i t e : 5 percent. Appears to be derived from the pyroxene. 5. Chlori te: 5 percent. Appears to be produced by alteration of the b io t i t e . -30-6. Epidote: less than 2 percent. Accompanies the b io t i t e in the process of transformation of the pyroxene into b io t i t e . 7. Carbonates: a few crystals . Due to the alteration of the primary minerals, this diabase dyke appears to have been intruded into the volcanics before the various periods of orogeny which affected the region. The diabase dykes intruding the Devonian rocks to the south are much fresher. The only rock known defini te ly to be a c las t ic sediment out^crops^a lens paral le l ing the south-wast shore of Lake Cascapedia. I t Is a conglomerate made of sub-rounded quartz fragments varying in size from half an inch to three inches. These fragments are embedded in a greyish-brown weathering arkosic matrix. This sedimentary member has the same general trend as the schistosity planes i n the volcanic rocks. Microscopic examination of the conglomerate shows the following composition: 1. Fragments: constituting 35 to 70 percent of the rock. 2. Quartz. 30 percent. ' Angular, fractured fragments. Some grains show undulatory extraction. 3. Plagioclase: as much as 35 percent in one thin section; lacking i n the others. Composition: Ab 91 An 9* Altered to scaly black material . Thin lamellae f i l l e d by dark, opaque, fine-grained streaks. A similar type of alteration on smaller crystals of microperthite in the matrix suggests that a f a i r amount of this plagioclase might be altered microperthit e. B. Matrix. 1. Quartz: 15 to 20 percent. Fractured. Shows undulatory extinction. Part of i t r ec rys ta l l i zed . 2. Plagioclase: up to 45 percent. Same composition as in the fragments but appears fresher at places. Some K-feldspars may be present but they cannot be ident i f ied with certainty. 3. Microperthite: up to 20 percent in one section. Usually occurs in f a i r l y large, angular, fractured fragments, with the albi te lamellae altered to a dark, opaque scaly material. 4. B io t i t e : less than 5 percent. Smeared along the contacts between the quartz and plagioclase crysta ls . F i l l i n g the fractures in the quartz grains, but not penetrating the plagioclase. 5. Chlori te : up to 7 percent in one section. Same occurrence as the b io t i t e of which i t appears to be an alteration product. 6. Carbonates: 10 to 20 percent. Sheared, smashed, angular crystals . Usually small but some are up to gr i t s i ze . In places, cement fractures in the plagioclase. 7. Ti tani te : a few euhedral crystals . 8. Opaque iron minerals: traces. The large percentage and relat ive freshness -32-of the feldspars In this conglomerate show clearly that the rock was derived from a nearby source. The pebbles and the matrix could easily be the product of disintegration of an original intermediate volcanic rock invaded by quartz stringers such as occurs south of th is sedimentary lens. I f such an assumption Is made, the deposition of this conglom-erate should obviously come after the Introduction of the quartz stringers into the volcanics. These quartz stringers, in such a case, would have intruded the volcanics not long after the consolidation of these rocks because the conglom-erate shows a degree of metamorphism very near the metamor-phism affecting the greenstone. On the other hand, i t i s d i f f i c u l t to account for another source of the quartz pebbles since no acid intrusive of Ordovlcian or pr ior age i s known to occur in Gaspe. In any case, this Intrusive would have to be f a i r l y close and i t does not appear to exis t . Another belt of rocks of the same series can possibly be of sedimentary or ig in . This belt which runs south-westerly north of Lake Cascapedia, consists of a s i lvery brown s e r i c i t i c quartz shist . The large percentage of quartz in this rock suggests a dedimentary or ig in . Quartz banding, however, occurs so extensively throughout the whole series that any speculation on the original character of a rock, based on this feature, should be made with caution. -33-SILURIAN. In the present area, the Si lur ian rocks form a belt which runs approximately east-west between the foot of the Shickshock mountains and the new Bathurst road. This belt has an average width of two miles. The rocks are best exposed on the Go-A-shore brook, the Salmon Branch and the South Branch of Seventeen-Mile brook. Good exposures can also be seen along the North Branch of Fourteen-Mile brook. Lithology. The S i lu r ian rocks of the present belt are recognised by a characteristic greenish cast. They consist e of greenish-grey, soft, argillaceous and arenaclous limestone weathering buff-brown. In several places, the limestone grades towards soft, greenish, calcareous shales and brownish-grey calcareous silts. In part the limestone is f ine ly banded and sub-crystall ine. It usually occurs in beds less than 4 inches thick, sometimes separated by th in ly bedded, dark, pure shale layers up to one inch thick. In the section along Go-A-ahore brook, where the rocks are less folded, acme f a i r l y pure, grey limestones are interbedded with th in-ap l l t t lng ahales and fine-grained calcareous sandstonea. Some ripple-marka occur in the arenaceous beds; they ahow that the currents flowed north. Some lenses of creamy brown-weathering limestone conglomerate are interbedded with the limestonea - 3 4 -and shales. The subjtngular fragments of this conglomerate are up to three inches in diameter. They consist mainly of l ight grey, in part f o l i t i c limestone weathering creamy brown. Some greenish-grey, arenaceous limaBbones aid brown-weathering doloun-^g constitute some of the pebbles. The matrix consists of a grey, crysta l l ine limestone. Near the intersection of the Farlbeault-Richard township l ine and the Salmon Branch of the Cascapedia r iver , the matrix of a conglomerate was seen to be made of recrys ta l l ized f o s s i l fragments. A similar lens of rock i s exposed south of the Bathurst Road in Lemieux township. The matri^ of the rock i s a crystal l ine limestone weathering l ight grey and i s entirely composed of comminuted f o s s i l fragments. On breaking, this rock yields a strong smell of o i l and sulphur. A pure white sandstone was also found i n the Si lur ian sequence of rocks. This sandstone may easi ly be taken for a quartzite but the boundaries between the quartz grains are s t i l l v is ib le aid the rock breaks along these boundaries. Fossi ls are s t i l l preserved in this sandstone. Red beds are present to a very small extent in the section along Go-A-3hore brook. They occur as a lens 3 5 feet thick, composed of brownish-red shale with some interbedded, thin , green shale layers. In Fpy the eastern part of the area, a series of outcrops, well-exposed along the South Branch of Seventeen-Mile brook and in the south cuts of the Bathurst Road, i ka -35-were f i r s t thought to he of Ordovician age. No foss i l s were found i n these rocks. The rocks are nearly as Intensely folded and sheared as the Ordovician rocks of the Northern be l t . The outcrops were found to consist of the following variety of beds: 1. Greenish, softnshales with Interbeds of greenish-grey limestone. 2 . Darkish-grey, well banded, arenaceous limestone. 3. Creamy brown weathering beds composed of pale brownish to greenish-grey limestone. 4. Small lenses of greyish, calcareous, coarse sandstone and black shaly limestone. 5. Conglomerate with pebbles of creamy brown-weathering limestone embedded in a matrix of shaly limestone, in places, recrys ta l l ized to ca l c i t e . Some of these rocks, on breaking, y i e ld a bituminous smell. Sometimes zones of crumpled, dark grey, argillaceous limestone and shale abut against more competent, th inly bedded, purer limestone.(Plate VII) Some drag-folding occurs in the incompetent zone but not as extensively as i n the Ordovician rocks of the Northern be l t . As a general rule , the highly folded and sheared character of this group of rock relates them with the Ordovician rocks. However, they have several l l t h o l o g i c a l characteris-t i cs In common with the typ ica l S i lu r i an beds. In both this group and the Si lur ian rocks, greenish-grey argillaceous limestones are present. Some lima stone pebbles weathering - 3 6 -crearay brown occur also in the Si lur ian conglomerate. The smell of o i l i s a common feature. The rocks in the eastern part of Seventeen-Mile brook are more severely folded and sheared than the typical S i lu r ian rocks but the shales are not transformed to slates. One must note also that they outcrop in proximity of the Serpentine intrusion of Mount Albert and the granite Intrusion of Barren Mountain. This may account for some folding and shearing. It may be noted also that the rocks along Seventeen-Mile brook produce crumpled, slumped exposures broken i n fragments while the Northern Ordovlcian rocks are exposed generally as compact, competent, t igh t ly folded beds. Moreover, i f these rocks were Ordovlcian, a very complex and at least unusual system of fault ing would hatoe to be inferred. Consequently this group is Included with the typica l Si lur ian rocks. Another problem i s raised on the occurrence of a dolomite (Plate V l l l ) exposed at various l oca l i t i e s within approxLoa te ly half a mile from the underlying Shickshock series. The age of this dolomite may be a matter of importance since i t appears to be cut by dykes of ser-pentine. The rock i s usually l ight grey to pink but contains also white cherty patches, in places crossed by green serpentine streaks. It weathers brown to red and Is coated with a layer of l imonit ic material approximately one eig&i of an inch thick or less . In thin-section, It was seen to consist of 80 percent calci te and dolomite and 20 percent v quartz occurring as small .reinules cutting the carbonates. -37-The rock may possibly be gerftically related to the serpentine masses of Mount Albert and South Mountain. Because of the lack of continuous exposures, It cannot be ascertained whether i t occurs as separate lenses or as a continuous band along the Shickshock series. On Go-A-shore brook, where re la t ive ly good exposures can be found, a l ight pinkish-grey, hard, doiomitic limestone i s met. This type of rock occurs close to the typ ica l dolomite and the Shickshock series in the north. The rock is s l i gh t ly i ron-3tained and weathers reddish-brown. This doiomitic limestone occurs in the normal sequence of S i lu r i an rocks. Moreover, some layers of th in ly banded sandy limestone interbedded with the doiomitic limestone have yielded poorly preserved fragments of grap-t o l i t e s . These fragments are believed to be Monograptus clintonensis, which also occurs in the south in the Si lur ian rocks. The doiomitic limestone, because of lack of exposures, was not seen to grade Into the typical dolomite. However, the structure which is one of gentle, undulatory warping, suggests that the doiomitic limestone and the dolomite belong to the same dequence of rocks. Consequently the dolomite Is placed in the S i lu r i an . Another group of rocks of uncertain age has been included i n the S i lu r ian on the two maps accompanying this thesis. They consist mainly of a course to medium-grained, schistose, s e r i c i t i c quartzite. The rock is very poorly exposed at four places along the eastern part of -38-Seventeen-Mile brook (South branch). It may belong to the Shickshock series or i t may represent a contact phase of the S i lu r ian rocks In the v i c i n i t y of the Mount Albert intrusive. L i t t l e can be said about i t u n t i l more exposures are found. PALEONTOLOGY Fragments of foss i l s are re la t ive ly abundant in this belt of rocks. As mentioned previously, sorffe beds are almost entirely made of comminuted she l l fragments. Well preserved speciments however are scarce. A small fauna was collected along the Faribeault-Richard township l i ne , 700 feet west of the Salmon branch of the Cascapedia r ive r . Fossi ls were found i n a conglomeratic zone interbedded with thin bands of pure, l ight grey limestone. This faunule was seen to contain the following forms: Atrypa re t i cu la r ic (Linnaeus) Camarotoechia sp. Conchidium ef laqueatum (Courad) Cyrt ia exporrecta (Wahlenberg) Favosites ef niagarensis (Hall) Favosites sp. Leptaena rhomboidalis (Wilckens) Meris te l la sp. Proctus ef turgidus. Northrop. Proetus sp. Rhynchotreta ef curreata americana (Hall) -39-Sowerbyella sp. Bryozoa Several criraoid columuals Fragmentary gastropods Fragment of glabella referred to Dalmanltes sp. Several unidentifiable t r i l o b i t e fragments. Several other forma are present but they are so poorly preserved that even a generic determination would be questionable. Deacription of the Six Beat Preserved Species. Conchidium of laqueatum (Conrad) Conchidium laqueatum, H a l l and Clarke, Pa l . New York. V l l l , Pt. 11, 1883, p.232, f i g . I68j p. 234, p l . 65, f igs . 3 - 9 . Large, stout, elongate, aubtrigonal to aub-pentagonal biconvex s h e l l . Approximate length: 65 cm: width: 50 mm. Apparently strongly inequivabre. Very fa in t , almost non-oxisting, dorsal, median f o l d . Surface ornamented e with numerous rounded, strong costal', extending from beak to anterior margin; becoming angular near anterior margin. Widely and i r regular ly spaced, growth wrinklea. Cardinal slopea f l a t , amooth, broad, leaving the ventral surface abruptly, at r igh angle. Ventral beak curved and acute but arching very s l igh t ly over dorsal valve. Pedicle opening present, very small re la t ively to the size of the specimen"^. Delthyrium large. Deltidium not preaent on -40-the actual specimen. Strong median septum composed of two contiguous converging plates or lamellae. Other structures, not pressrved. Age: Middle S i lur ian (Niagara) Note: A few specimens related to the same gerrus were collected. They exhibit a more rounded, subcircular outline than Conchidlum lagueatum. They have, however, s imilar plications and a long median septum extending half the length of the valve. They seem cogeneric with Gonchidium sp. i l lus t ra ted on plate LXVl, f i g . 23 of Ha l l aod Clarke, Pa l . New York, Part 11. Cyrt ia exporrecta (WaHeysberg) Cyrt ia exporrecta. Ha l l aid Clarke. Pa l . New York, V l l l , Pt 11, 1893, p. 42 p. 28 Pigs. 1, 48, 49, 51. Shimer and Shrock. Index-fossil of North America p. 321, p i . 121, f i g s . 38 - 40. This form is represented by a dorsal valve showing the characteristic shallow sinus originating at beak and extending the whole length of the specimen. Shel l gently convex, triangular in shape with area on the two sides of the sulcus f la t and s l igh t ly striated by concen-t r i c , delicate l ines . Radiating, fine str iat ions i n the sulcus in te rva l . Internal structures not v i s i b l e . Age: Middle S i lu r i an . Favosites ef niagarensis (Hall) Favosites niagarensis, H a l l , 18 52. Palcon, New York, -41-v o l . 11, p. 125. p i . 34 A b i s . f i ga . $a - 1. Lambe, 1899, Contr. Can. Pa l . C.G.S. V o l . IV Part 1, p. 7. Broadly expanding, hemiapherical corallum: amall ba3al attachment. Coral l i tea varying in size from 1.5 to 1.8 mm., a few reaching 2 mm. Poorly preaerved tabulae spaced 0.5 mm apart. Lateral faces of cora l l i tea pierced by one row of small rounded pores: 13 pores in 8 mm. Other internal structurea not preaerved. Age: Middle S i lur ian to Lower Devonian. Leptaena rhomboldalis (Wilckens) Leptaena termistr iata . H a l l . f a l . New York, 1. 1847, p. 108. p i . 31A, f ig 4. Hal l and Clarke, P a l . New York, V l l l , Pt 1, 1892 p i . 8, f i g s . 12 - 16. Leptaena depressa. H a l l , Pa l , New York, 11, 1852, p. 62 p i . 21. f i g . 8j p.257, p l . 53, f i g . 6. Strophomena rugosa. H a l l , Pa l . New York 111, 1859* P» 195, p l . 19, f i g 1. Strophomena rhomboidalis. B i l l i n g s - Geol. Canada. I863. p. 311 f i g 314; p. 367, f i g 373. Pa l . Pos., 11, 1874, P . 27. Lepaena rhomboidalis. Ha l l and Clarke. Pa l . New York, V l l l Part 1, 1892, p. 279, p l . 8, figs 17 0 31. Medium sized, transversely subrectangular, -42-s l igh t ly concavo-convex she l l . Strong geniculation near anterior margin. Hinge l ine represents greatest width: 32 mm; straight but rais ing s l i gh t ly i n the beak area. Cardinal extremities subauriculate. Angle between hinge l ine and l a t e ra l margin, less than 4 5 ° . Suggestion of small conical delthyrium. Surface ornamented by prominent, con-centric growth wrinkles extending to the geniculation; also f ine, concentric growth l ines between the wrinkles. Paint, radiating, widely spaced costae crossing the concentric corrugations, intervals between costae, provided with four, f ine, radiating l ines . Range: Ordovician to Lower Carboniferous. Proetus cf turgldus. Northrop Proetus turgidus. Northrop. G.S.A. sp. paper No. 2 1 p. 233 p i . 26 figs 8 - 9 - 1 0 . This form Is represented by a well-preserved pygidium to which four thorax segments are attached. Pygidium semi-circular bounded by a narrow f la t margin. Marginal furrow s l igh t ly concave. Pleural lobes r i s ing steeply from the gsarginal border and flattening gently near a well-marked dorsal furrow. A x i a l lobe r i s ing rapidly above pleural lobes, giving to the whole py/gidium a charact-e r i s t i c inf lated, swollen appearance. At anterior margin, width of pygidium: 7 . 5 m m ; width of ax ia l lobe: 3 . 5 mm. Axia l lobe tapering gently f i r s t , then rapidly towards the end and terminating 1 mm in front of marginal border. -43-Segraentation poorly developed on the a x i a l lobe: segments, 8 to 9 in number. Segments very s l igh t ly grooved on the pleural lobes. Age: Middle S i l u r i an . West Point formation of the Chaleur series. Note: Another fragmentary pygidium can be referred undoubt-edly to the genus Proetus. I t differs from the specimen described above by a wider marginal border, a apidly tapering axia l lobe and a more flattened pleural area. Rhynchotreta cf cuneata americana (Hall) Rhynchotreta cuneata americana. H a l l and Clarke, New York, V l l l , Pt 11, 1893, p. 187, p l . 56 f igs . 31 - 38. Rhynchotreta cuneata americana. Northrop. G.S.A. Sp. paper No. 21, p. 183. Small, triangular, biconvex she l l indent i f l e d by comparison with an american form coming from Waldron, Ind. Beak pa r t i a l l y broken but shows an erect, acuminate outline. Cardinal slopes broad and f l a t . Deep neutral sulcus consist-ing of three strong pl icat ions: three plications also on the sides. The present specimen i s s l i gh t ly deformed but shows dorsal fo ld consisting of four plications with two plications elevated In the center of the fo ld . Doral p l icat ions: three In number on the wldes. Northrop notes that the form from the Chaleur series i s neither so robust nor so large as the typ ica l american forms and that, possibly, It should be -44-regarded as intermediate between the European R. cuneata 8 1 1 ^ R* cuneata americana. This can easily be applied to the present specimen which i s s l i gh t ly different in outline from the typ ica l american form. Age: Middle Si lur ian (Niagara). Correlation. On a purely l i t ho log ica l basis, the present group of rocks appears to belong to the northernmost Si lur ian belt of Gaspe. This belt was mapped by Alcock (1926) and by Jones (1931; 1932; 1933; 1935). It forms a narrow band varying in width from a few hundred feet to a l i t t l e more than a mile. It f i r s t appears in the Dart-mouth r iver area and extends westward and southwestward apparently to Lake Matapedia. The following table gives a composite l i s t of foss i l s recorded from this belt by Alcock, Jones and Logan (1863) : Loca l i t i e s . Dart-mouth r iver area. Bonne camp area. Table top area. Mount Albert area. Head waters of Cap Chat River. Atrypa re t icu la r i s ( l i n i Atrypina cf disparalis (Hall) Bryozoa Cafymene blumenbachll Camarotoechia cf neglecta C. nr . v ic ina (Bil l ings] C. sp. Chonetes jerseysensis (Weller) taeus) X X X X X X X X X -45-Loca l i t i e s . Dart- Bonne Table Mount Head mouth camp top Albert waters r iver area. area. area. of area. Cap Chat River. C. sp. X Cladopora sp. X cf Clorlnda sp. X Coelocaulus cp. X cf. Conchldium sp. X Crimoidal columnals X X Crispe l la elegans X Crotalocrimus columnals X Cyathophyllum sp. X cf . Dalmanites angelini Barande X Delthyris cf elevata (Dalman) X D. aff . sulcatus submarsus (Grab an) X D. eriensis (Graban) X D. corall ineusis (Graban) X Encrinurus sp. X Eophacops orestes X Eospirifer radiatus >s) X Favosites favosus ?(Goldfuj X F. sps. X X Fenestella cf parvulipora X Gypidula sp. X Halysites §atenulatus (Limiaeus) X Nr. H. compactus. Bominger X Hel io l i t es subtubuletus McC oy X H in del l a congregata pus i l i t I Swartz? X Leptaena rhomboidalls (?filckens) X X X Leptostrophia b ipar t i t a (Hall) X Meristella? n.sp. X Nuclospira? sp. X X Orthis davidsoni X 0. sp. X Parmorthis cf elegantula (Dalman) X X Pentamerus cf oblongus. Sowerby X cf Pentamerus pesovis Withfield. X Pholipods sp. X 46-Loca l i t i ea . Dart- Bonne Table Mount Head mouth camp top Albert watera r iver area. area. area. of area. Cap Chat River. Platyoatoma? sp X Proetus sp. X Retlcularia bicostata (Hall) X Rhipidomella hydrlda (Sowerby) X X Rhynchospira cf globosa Ha l l X Schuchertella pecten X S. sp. X ? Sieverella sp. X Streptelasma cf latusculum B i l l i n g s X Stricklandia brevis X S. ap. X S. lens (? S. davidsoni) X Stromatopora damilensis Parks X S. sp X S ? aporita Parks X Strophomena antiquata X Strophonella sp/ X X Strophoatylus sp. X Whitf ieldel la cf n i t ida X cf. Wilsonia sp. X Zaphrentis sp. X It can be aeen that most of the foss i l s found in the present area are included i n this table. Cyr t la cf exporrecta and Sowerbyella ap. occur in the St. Leon formation (Middle Silurian) of the Matapedia Valley (Crickmay 1932). Proetua turgidus and Rhyncotreta cuneata americana are both found in the West Point formation of the chaleur series (Northrop 1939). P. turgldua ia reatr icted to the Weat Point formation while R. cuneata americana i s also found in the La V i e i l l e and Bouleaux formationa. -47-Mori ogr apt us clintoneusis was collected at various loca l i t i e s In the present area. The presence of this species indicates def ini te ly a Si lur ian age. The faunule described above may'not be sa t i s fac tor i ly diagnostic by i t s e l f . With the aid of the l i thology, however, i t gives enough information to correlate the beds with the northernmost belt of S i lur ian rocks. No lower Si lur ian i s known to occur in Gaspe. The upper S i lur ian may be present at the eastern end of the Si lur ian belt in Dartmouth r iver area but this i s not known def in i te ly . On the other hand, a great thickness of Middle S i l u r i a n strata occurs in Fart-Daniel and Black-Cape areas on the Bay of Chaleur. U n t i l further evidence, therefore, the present group of rocks i s belfared to bei*Middle S i lur ian age. DEVONIAN. The Devonian rocks in the present area cover the southern half of the map-sheet. Exposures are f a i r l y abundant near the center of the area but are very scarce in the southern part. As usual i n the areas underlain by sedi-mentary rocks in Gaspe, outcrops are to be found along the courses of the streams. A few c l i f f exposures occur in the limestone series. Gaspe Limestone series. An attempt has been made in the f i e l d to -48-correlate the Lower Devonian rocks of the present area with the type section e&po3ed at the P l o r i l l o n Peninsula, at the eastern end of Gaspe. In the coastal section, the so-called Gaspe limestone series has been divided by Clarke (1Q08) into three formations, namely: the St. Alban, Cape Bon Ami and Grande Greve formations. Recently, Russel (1946) has been doing very detailed work along the same section i n order to f a c i l i t a t e the correlation in the in ter ior be l t . Russel favours the early Logan's subdivisions into eight members but retains Clarke's terminology since i t is well established in the l i te ra ture . The lower St. Alban formation could not be conclusively recognised in the present area. Aa described in the coastal section, i t contains some aoft, argillaceoua, grey and greenish' grey limestonea somwwhat airoilar to some of the Si lur ian beds described above. The formation aeems to pinch out (Mc" Garrigte 1946) west of Dartmouth r iver area. It i s probable that i t does not occur i n the present area except, possibly, for a small lena which w i l l be diacuased la ter . The Bon Ami formation occurs in the present area as a diarupted belt of i r regular ly jointed, gently dipping beds overlying the Si lur ian rocka apparently conformably. It consists of dark grey to almost black, aoft, shaly to f inely sandy limestone weathering pale chocolate-brown. Some beds are magnesian. A rough colour banding was found in some of the arenaceoua limeatones. The beds range -49-in thickness from 2 inches to 2 ffiet. The formation differs from the overlying Grande Greve by i t s colour and i t s characteristic softness. Some beds contain poor plant fragments much comminuted and carbonized. Poorly preserved corals, bracirfrspods, pelecypods and cephalopods are found in this formation. Conularla sp. and Atrypa re t icu la r i s were identif ied in the f i e l d . One species was available for description: Leptocoella f l abe l l i t e s (Conrad) Leptocoelia f l a b e l l i t e s . B i l l i n g s . Geol. Canada. 1863. P. 369. f i g . 382; Pa l . Fossils 11, 1874, p. 42. p i . 3, f i g s . 5, 6. Ha l l and Clarke, Pa l . New York, V l l l , Pt 11, 1893, p. 137, p l 53, f i g s . 40 - 46, 53. Small, subcircular to squarish, plano-convex she l l . Exterior coarsely costate, Two or three prominent, concentric growth lines i n the older stages of the organism. Faint, shallow, poorly developed, dorsal sinus. The sinus vanishes before the anterior margin is reached. Structure at the cardinal margin and in ter ior of the valv© are not preserved. Loo a l i t y ; lef t bank of Bridge brook, 500 feet upstream from the Salmon Branch of the Grand Cascapedia r ive r . Age; Lower Devonian. -50-The overlying Grande Greve formation consists of grey to brownish-grey, hard, sil iceous limestones and s i l t -stones weathering pale brown. These limestones and siltstones are usually f a i r l y well bedded but parts of them show poor bedding, the rock breaking in f la t irregular slabs. A common feature of the formation i s the occurrence of f la t "warm t r a i l s " . Similar "worm t r a i l s " , however, occur near the top of the Bon Ami formation. Unfortunately, not enough information i s presently available to give the thickness of the Grande Greve formation i n the area. McGerrigle (1946) found the thickness of the formation to range from 3000 to 4000 feet for the region between the Salmon Brancfe of the Cascapedia r iver and the Matapedia r ive r . The Bon Ami formation appears to be thick approximately 2000 feet''for the section along the Salmon Branch. Gaspe sandstone series. The term 'Gaspe sandstone' Is a descriptive term given by Logan for the section along the shore of the Bay of Gaspe. These Middle Devonian sandstones have been further subdivided into the Malbr'ale, Battery Point, York River and York Lake formations. In the area, only the York River and Battery Point formations are present. Both are very poorly exposed, especially the Battery Point. The York River formation overlies the Lower Devonian Grande Greve limestone. It consists of greenish to brownish grey, medium to fine-grained, sometimes argillaceous sandstones, containing a small amount of grey feldspars. Some fine-grained variet ies -51-grade rapidly to thinly bedded greenish-grey shale. In the Battery Point formation, on the other hand, the sandstones are generally finer-grained but some medium-grained beds are present. The formation is composed of chocolate-brown to brownish red sandstones and shales. Near the southern boundary of the area, on the Lake Branch of the Cascapedia r ive r , some deep red beds can also be found. As a general rule, these red variet ies are more abundant in the southern part of the bel t . Ripple-marks and cross bedding are common features. In the area immediately to the east, Jones (1929) observed ^ut icular structures, mud-crracks, worm borings and rain imprints in these rocks. Jones notes that these features are probably the resuHtts of freshwater and subaerial deposition. In both formations, plant fragments can be found. The same series of sandstones and shales continues sexk south of the present area. The whole sequence of rocks form "a major fo ld , somewhat basin-shaped, and referred to as the Berry Mountain synclive" (McGerrigle, 1946, p.50). Only the northern flank of this fold underlies the present area. Not enough information i s available to give an accurate idea of the thickness of the series in Richard town-ship. The formations, however, have certainly a much larger surface extent than in the area along the Bay of Gaspe. There i s no reason to believe that r ep i t i t i on of strata due to folding occurs. On the east, Jones (1929) suggested a thickness of 7,700 feet. -52-Aside from the limestone and sandstone series, a group of Lower Devonian rocks was found at an unexpected loca l i t y , along the South Branch of Seventeen-Mile brook. The rocks are squeezed between the Shickshock series on the north and the S i lur ian beds on the south. Psilophyton princeps. Dawson ( 1 ) was collected in these beds. In Gaspe, this plant is known to occur in the Lower Devonian. The beds were seen to consist of the following variet ies of rocks: 1 . Greenish grey, medium-grained sandstone with abundant Interbeds of very soft, unaltered, greenish shale. 2. Interbedded greenish shaly g r i t s , greenish drab and brownish shales. 3. Lensy bands of reddish shales. 4. Well-bedded, dark, arenaceous limestone weathering brown. 5. Dark grey, soft, slaty shale. 6. Lenses of Basal (?) conglomerate. The conglomerate, just mentioned, i s made of subrounded pebbles, generally under half an inch in diameter, embedded in a greenish g r i t ty shale. The pebbles consist of the following rock types or minerals: quartz very common; s e r i c l t i c , schisted quartzite common; in smaller amount; dark, calcareous sandstone, quartzite, greenstone and diabase. Except for Psilophyton princeps, no fossi ls were found i n these rocks. However, carbonaceous material occurs commonly in various layers of the greenish, soft, ( 1 ) This plant was ident i f ied as such by Dr. J .H. Clark, McGil l Universi ty. -53-unaltered shale. These rocks are located along a fault zone. Consequently they are much disturbed and sheared. Slickensided surfaces occur frequently (Plate IX) . However, no definite fault plane could be seen. The general character of these sedimentary rocks and the pebbles of the conglomerate suggest that the group is basal on the old erosion surface of the Shickshock series. As to the stratigraphic position of these rocks In the standard section of the P l o r i l l o n peninsula, no statement can be made. The rocks do not occur In the proper s t r a t i -lenses graphic sequence. However, red and green shaly ba-s-e-s occur commonly i n the typ ica l St. Alban formation. Nevertheless, a correlation based on such l i t h o l o g i c a l characteristics over such a distance is certainly subject to much uncertainty. Basic volcanics and basic dykes. A band of basic volcanics runs acrossthe southern part of the area. These volcanice rocks are inter-bedded with the Gaspe limest-one series. Occasional flows occur in the Grand Greve formation but none were observed in the Cape Bon Ami limestone. Owing to i t s hardness and res is t -ance to erosion, this volcanic complex i s r e l a t ive ly we l l -exposed along the stream courses and in mountain c l i f f s . However, outcrops are scarce in the south-western part of the bel t . Alcock (1926) and Mailhot (1918) have made a very detailed study of these rocks which cover an extensive -54-area, south of Mount Albert . When freshly broken, the rock is dense, fine-grained, steel grey to black coloured. Some phases are medium grained. A porphyritic texture occurs in some flows; the phenocrysts consist of grey feldspar. Amygdulfcs can be found but do not constitute a common feature In the present area. The amygdules are f i l l e d with ca lc i te or less commonly quartz. Alcock(1926) and Jones (1929) observed a l ight green f i lm of dele^ite surrounding the ca lc i te f i l l i n g s in the volcanics of Mount Albert area. A s imilar coating was observed in the amygdules, in the present area. Occasional small cubes of pyrite occur i n the ca lc i te f i l l i n g s . Crystals and globular aggregates of the sane mineral are sparingly scattered throughout the rock. A similar faint mineralization was observed in the volcanics south of the Federal Mine, i n the Mount Albert area (Jones 1929). At the Federal Mine deposit, however, the ore-bearing solutions were not associated with basic volcanics, but with the granit ic intrusive of the Tabletop mountains. The occurrence of pi l low lavas (Jones 1929) and amygdules i n Berry Mountain area, shows that, in the main at least, these rocks represent lava flowa Some parts of this complex, however, may be of an intrusive type since dykes of similar material were seen cutting the Devonian and S i lu r i an rocks in the area. These dykes consist of a dark-grey, fine to medium grained diabasic rock. Some phases are porphyritic; the phenocrysts are lath-shaped, grey feldspar. Some dykes even contain amygdules f i l l e d with calci te and l ined with a f i lm of delessite. Occasional cubes of pyrite can also be -55-found. Some of these Intrusives may be s i l l s but the majority of them are dykes. Several of the dykes have a trend of north 45° west. As a general rule , the dykes invade the country rock without producing much al terat ion. In places, a narrow zone of s l i gh t ly baked and s i l i c i f i e d limy material Is developed at the contact; when this occurs calc i te venllets are abundant both i n the country rock and i n the border of the dyke. Acid Volcanics. An acid, l ight-grey to light-brown, rhyo l i t i c rock outcrops along the brooks and valley sides, located south of squaw Cap Mountain. Similar rock was observed by Alcock (1926) "northwest of Indian brook". This may correspond to the present l o c a l i t y . Alcock noted the presence of a banded variety which, in thin-section, he saw to be "evidently a result of f luxion" . This variety was not observed In place. However, about one mile westward from the l o c a i l i t y mentioned above, a breccia was found with fragments consisting of f ine ly banded rhyol i te . These l i gh brown, angular fragments stand out from the greyiwh brown to dark green weathered surface of the basic matrix. The relations of the acid rocks to the basic volcanics or to the granite Intrusive of Squaw Cap are not f u l l y understood. The breccia, however, shows that at least in part the acid volcanics antfdate the basic flows. INTRUSIVE ROCKS. Serpentine. Two small, elongated, Intrusive bodies of -56-serpentine are exposed In the central part of the area, approximately three miles north of the Bathurst road. The summit part of the eastern mass - South Mountain - forms a continuous outcrop extending for two miles, roughly east and weat(oPlate 1). The unnaed western body Is not so wel l exposed, but good outcrops can be found along the neighbouring streams. These two masses are undoubtedly connected In depth with the serpentine intrusive of Mount Albert , exposed four miles to the east. The rock was very f u l l y described by Alcock (1926) in his report on Mount Albert area. Hence no attempt has been made to give a new petrographic description. Only one thin-aection was examined. It was seen t6 consist of the following minerals: 1. Olivine: 45 percent. Anhedral cry3tals i r regular ly fractured. Stain of magnetite f i l l i n g the fracture. The magnetite ataining aid the opt ical character of the mineral (negative) indicate an i ron-r ich o l iv ine . 2. Baatite: 35 percent. Occur as large, fibrous, lamellar aggregatea leaving l i t t l e of the original enatatite. Cleavage at 90° a t l l l preaerved in places. Carbonates accompany the tranaformation of enatatite into baatite. Theae fibrous aggregates are aheared and twiated. 3. Antigori te: 5 percent. Beside i t a occurrence aa a product of alteration, of the enatatite, fibers of thia mineral f i l l the fractures in the o l iv ine . -57-4. Chrysotile: 3 percent. Short fibers growing perpendicular to the fractures and crystal boundaries In the o l iv ine . 5. Chlori te; 5 percent. Distributed as large, i r regular i crystals throughout the section. b 6. Caronates; 5 percent. Seems to enter in the process of alteration of enstatlte. Distributed also sparingly throughout the section. 7. Magnetite: 3 percent. The processes of weathering gave a character-i s t i c pit ted appearance to the surface of the rock. Two sets of joints is developed in the rock, at the eastern end of South Mountain (Plate V ) . These sets of joints , however, have no prevalent direction and cannot be worked out system-a t i c a l l y . A coarse-grained, greenish-black amphibolite was found associated with the serpentine. I t i s made wholly, of large, dark, shining crystals of hornblende. It i s exposed at the south-east end of South Mountain and along Barren Brook. Alcock(1926) records the presence of a hornblendic fringe, bordering the serpentine mass of Mount Alber t . In the present area, the amphibolite does not seem to be continuous so as to form a ring around South Mountain. However, the lack of exposures renders this conclusion uncertain. Age of the serpentine. In the Mount Albert area, the serpentine -58-\h intrude,,Into the volcanic complex of the Shickshock series. It was not seen by Alcock (1926) to cut any rock younger than Ordovician. In order to find more data on the age of the serpentine, Alcock (1924c) v is i ted Mount Serpentine, located near Dartmouth r ive r , about 65 miles east of Mount ATlbert. The serpentine was found to intrude a volcanic complex similar to that surrounding Mount Albert . I t was not aeen to cut the Gaape limeatone which overliea unconformably the igneous complex in the south-east. And the contact, notes Alcock, i s not a fault contact. On the north east aide of Mount Serpentine, the Gaape aandstone ia brought in contact with the achistose volcanics by a thrust faul t . Since the serpentine was not seen to Intrude the Gaape limestone, Alcock concluded quite reasonably that the intruaive body waa pre-Dsvonian, probably Ordovician, aa the Taconic diaturbance took place i n Gaape at the end of the Ordovician Period. In the Saatern townahips, where aimilar ultrabaaic rocks occur, Cooke(1937) found evidence that "aeema to place the peridotite Injection at or near the very end of the Post-Ordovician folding movement". He states: "Aa the peridotites were injected after one folding movement, and are themaelvea folded, i t i s evident that they must have been introduced during or ahortly after the f i r s t folding" (Cooke 1937 p. 71) In the composite volume on the Geology of Quebec (1944 p.426), Dresser notes for the same belt of rocks -59-that " nowhere have any of the rock types been observed cutt'ing Devonian or younger strata". After a review of the different reports concerning the serpentine, he concluded: "It Is known that, in the northern Appalachian region, the Devonian was a period of folding, deformation, and igneous ac t i v i t y , and i t appears most probable that, i n the main at least, the rocks of the serpentine belt were intruded at that time". In the Lake Matapedia region, Aubert de l a Rue (1941) found a small body of peridoti te, serpentine and gabbro intruding Si lur ian rocks. In the Mount Serpentine region, Jones (1935) saw " tongues of serpentine" cutting through Lower Devonian limestone. In the present area, dykes or tongues of serpen-tine were seen intruding rocks believed to be S i l u r i an . The relationship between ttee S i lur ian dolomite aid the serpentine have been mentioned previously. It must be confessed that the sedimentary rocks invaded by the serpentine, were f i r s t thought to be Ordovlcian. It was shown why they are placed in the S i lu r i an . Moreover, the serpentine intrusive of South Moun-tain appears to be injected between the Shickshock series and the Si lur ian rocks. Exposures are scarce on the south side of South Mountain, but there is no reason to believe that Ordovlcian rocks occur along this contact. East and west of the present area, no definite Ordovician rocks have ever been found overlying the Shickshock series. On the contrary, i t appears that basal Devonian overlies the Shickshock series along the south branch of Seventeen-Mile brook. - 6 0 -The result of this discussion is that, in the present area, the evidence is i n favour of a Post-Silurian age for the serpentine. This would agree with the age relationships found by Jones (1935) and de l a Rue (1941) but does not conform to the opinion expressed by Alcock (1926) and Cooke ( 1 9 3 7 ) , and conversely adds support to Dresser's suggestion, namely that these rocks were .probably intruded in Devonian time. Granite. In the eastern central part of the area, a granit ic body intrudes the Lower Devonian Gaspe limestone series. This body i s the western extension of a granite belt which forms a continuous series of ridges in the central part of Mount Albert area.(l) In the present area, such topographical features as Barren, Squaw Cap and Barn-shaped mountains are due to the more resistant character of the granite. (Plate 1) The rock i s a l ight grey to greyish pink, coarse to medium-grained granite. The phenocrysts of feldspar and quartz are lying in a fine to medium-grained, dense matrix. A phase exposed on the ridge east of Barren Mountain was seen to consist of a grey, s l i gh t ly porphyritic syenite. Dykes of porphyritic granite cut the Devonian limestone on the north-west slope of Barren Mountain. (1) A petrographic study of this Intrusive can be found in the report on Mount Albert area. Alcock (1926) pp. 4 7 - 4 8 . -61-Dlor l t e . A r e l a t i v e l y small s i l l of d ior i te i s injected into the Gape Bon Ami formation, near the mouth of Seventeen-Mile hrook on the Salmon Branch of the Cascapedia r i ve r . The d ior i te i s well-exposed along the Salmon Branch but outcrops which could be used to mark the la te ra l extent of the s i l l are lacking. The rock i s course-grained to medium-grained and contains about 50 percent of grey feldspar. Near the contact with the Cape Bon Ami formation, debris of s i l i c i f i e d , baked, hard, l ight-yellow rock were found. This zone of metamorphism, however, does not appear to extend far from the contact with the d io r i t e . STRUCTURE. Structure north of the Shickshock series. The structure in the sedimentary rocks lying north of the Shickshock series i s complex. The limestone and slate beds were involved in at least two periods of orogeny, the Taconic disturbance at the end of the Ordovlcian and the Acadian revolution in Middle Devonian time. The beds are highly contorted, drag-folded, and in places, fractured. The bedding, where i t could be detected, runs generally east-west and dips steeply to the south. No definite faults could be observed. The present map area is too small to suggest any type of major structure. Since some beds were found to be overturned, north of the St. Anne -62-r iver , high-angle, repeated, overthrust ^©ieVfcfig may occur. In the Marsohl map area, Jones (1933 p. 46) found the structure "to he one of repeated folds which apparently form a major anticlinorium whose easterly-trending axis i s about twelve miles from the St . Lawrence shore". In the Marsonl area, however, no repeated folds were observed on the south limb of the anticlinorium. To the south, the Shickshock series apparently overlies the sedimentary rocks. The writer v i s i t ed the section along du Gros Volume brook. Along this stream, there i s no observable strat igraphical break between the Ordovician limestones and slates and the Shickshock series. The contact there is not exposed but there Is no evidence of faulting either in the volcanics or the sedimentary rocks on either side of the contact. I t i s unknown whether the beds are overturned or not. The fact that the volcanics appear to l i e s trat igraphical ly above the sedimentary series, has led Alcock (1924c) to place the volcanic complex In the Ordovician. On the other hand, i f metamorphism is to be considered alone, the Shickshock Series appears to be older than the sedimentary complex. Some basic volcanics are interbedded with the typ ica l Ordovician beds of the north coast, i n the region between the Matapedia Valley and Cap Chat. According to HcGerrigle,(1) these volcanics are not as altered as the Shickshock volcanics. Aubert de l a Rue (1941) records the presence of basic volcanics Interbedded with the S i l l e r y (1) Personal communication. - 6 3 -(Lower Ordovician) and the Pohenegamook (Middle Ordosxician) formations, in the Lake Matapedia region. According to the description given, these rocks seem to he as altered as the Shickshock series: the pyroxenes have undergone u ra l i t i sa t ion and secondary epidote and chlori te are developed. In the Marsoni and Tabletop mountain areas, Jones ( 1 9 3 3 , 1 9 3 4 ) found some basic volcanics interbedded with the Ordovician limestone and s la te . These, volcanics are not described as being as metamorphosed as the Shickshock volcanics. I f the degree of metamorphism Is considered, therefore, the Shickshock series may antedate the Ordovician sedimentary complex. In such a case, they would most l i k e l y be precambrian. However, a structural d i f f i cu l t y s t i l l remains: the volcanics appear to overlie the limestone and s la te . Structure in the Shickshock series. The Shickshock series covers a belt approx-imately eight miles wide in the present area. The sbhistosity planes, developed i n this series, strike south-west and dip steeply south. The succession of flows was not seen to be different from the schistosi ty. The series has probably not the thickness suggested by i t s width. Folding and e faul t ing, therefore, are probably responsible for repetition of the flows. Unfortunately, the rocks are too much metam-orphosed to give information as to the exact nature of the se folds and faul ts . -64-Structure south of the Shickshock series. Th© Si lur ian beds south of the Shickshock series are not as intensely folded as the Ordovician rocks of the North coast. Drag-folding occurs but i t is not common. Fault zones trending east-west were observed in various l oca l i t i e s in the belt of rocks exposed along Seventeen-Mile brook. The rocks appear to be thrown in a succession of small an t i c l i na l and synclinal folds, running to the. roughly east-west and, in places, s l i gh t l y overturned vnorth. Lack of exposures makes i t impossible to trace the axis of these folds . The pressure apparently came from the south-east. The fault zone exposed along Seventeen-Mile brook appears to be developed near the crest of an an t ic l ine . Some beds are probably overturned In this region. The faults are probably high-angle reverse faults arranged somewhat in echelon. The throw along these faults could not be determined because of the lack of horizon markers. It does not have to be large to explain the present succession of rocks. This type of fault ing and folding decreases in intensity in the western part of the present area. A fault running east-west, had to be inferred to account for the missing Cape Bon Ami formation north-west of Barren moun-ta in . A system of ve r t i ca l faults trending north-south i s also developed throughout the area. I t follows from these different systems of faults that the Si lur ian complex of Seventeen-Mile brook was l i f t e d as a block between the G-rande -65-Greve formation on the south and the basal Devonian on the north. The Cape Bon Ami formation yielded differently under the stresses. I t forms a belt of gentle warping with beds dipping in every possible d i rect ion. The dior i te intrusive may also have caused a local structure to develop. The Cape Bon Ami formation appears to overly the Si lur ian series conformably. Identical strikes were found within 1000 feet between the two groups of rocks. The same relations were recorded between the Cape Bon Ami and the Grande Greve formations. Lack of information makes i t impossible to form an adequate idea of the structure in the Grande Greve limestone. As mentioned previously, the Gaspe sandstone beds form the northern flank of a major, basin-l ike fold which extends south of the present area. -66-BIBLIOG-RAPHY. Alcock, P.V. (1921) Geology of Lemieux Township, Baspe County, Quebec. C.G.S. Sum. Rapt. pp. 71 - 96. (1924) Across Gaspe. Geo. Rev. 14, 2, pp. 197 - 214. (1924) Shickshock Mountains, Central Gaspe. C.G.S. Sum. Rept. pp. 127 - 133. (I924) Geology of Mount Serpentine, Gaspe, Quebec. C.G. S. Sum. Rept. pp. 134 - 141. (1926) Mount Albert Map-area, Quebec. C.G.S. Mem. 144. 75 pp. (1928) Rivers of Gaspe. Geol. Soc. Am. B u l l . , 39, 2, 403 - 420. (1931) Relationships of the Devonian and the Si lur ian in the Gaspe Peninsula and Northern New Brunswick. Roy. Soc. Can. Trans. 3rd ser. 25, IV, 113 - 117. (1931b) Geology, New Brunswick - Gaspe sheet (map: scale equals 1 inch to 8 miles) C.G.S. Map 259A, P u l l . No. 2254. (1932) The Geology of New Brunswick and Gaspe. Can. Min. Journ., 53, 3, 120 - 122. (1935) Geology of Chaleur Bay Region. C.G.S. Mem. 103, 246 pp. (1942) Further information on Glaciation In Gaspe. Trans. Roy. Soc. Can., 3rd ser. , 38, IV, pp. 1 5 - 2 2 . Alcock, F . J . (1932) Plumb-line deflections and Gravity and Anomalies in Gaspe Peninsula and the i r s ignif-M i l i s r , A .H . icance. Trans. Roy. Soc. Can., 3rd ser., 26, IV, pp. 321 -333. Ashley, G.H. (1930) Age of the Appalachians Peneplains. Geol. Soc. Am. B e l l . , 41, 4, 695 - 700. (1933) Studies in Appalachian Mountain Structure. Geol. Soc. Am. P r o c , 6 1 - 6 2 . -67-Aubert de l a Rue, E, B i l l i n g s , E . Brown, R.A. Chalmefrs, R. Clark, T.H, Clarke, J .M. _G.o l e m a n , A . P (1941) Region du Sac Matapedia. Serv. des Min . , Quebec. Rap. Geol. 9 . (1862) Palaeozvic Foss i l s . V o l . 1. Can. Geol. Surv. (1874) Palaeozvic Foss i l s . V o l . 11. Can Geol. Surv. (1938) North Shore of Gaspe Bay. Adv. Rept. Que. Bur. Min. No. 125. (1894) Report on the Surface Geology of Eastern New Brunswick, North Western Scotia and Prince-Edward Island. C.G.S. An. Dept. V o l . V l l , Pt M. (1897) Surface Geology and Auriferous Deposits of South-Eastern Quebec. C.G.S. An. Rept. Vol X, Pt J , pp. 25 - 54. (1904) An. Rept. Pt A Vo l . XVI pp. 250-263. (1924) Review of the evidence for the Taconic Revolution. Boston Soc. Nat. H i s t . P r o c , 36, 135 - 163. (1908) Early Devonic History of New York and Eastern North-America. N.Y. State Mus., Mem. 9 Pt 1. (1909) Ibid, pt 2. (1912) A remarkable S i l u r i c Section on the Bay of Chaleurs, in Notes on the Geology of the Gulf of St. Lawrence. N.Y. Mus., B u l l . 158, pp. 120 - 126. (1913) The Heart of Gaspe - Sketches of the Gulf of St. Lawrence. New York. (1923) The Gaspe. New Haven, Yale University Press. (1920) Extent and Thickness of the Labrador Tee-sheet. Geol. Soc Am. B u l l . 31, 326 - 327. (1922) Physiography and Glac ia l Geology of the Gaspe Peninsula. C.G.S. Mus. B u l l . No. 34. 52 pp. -68-Cooke, H.C. Crickmay, G.W, Dresser J .A. and Denis T.C. (1937) Thetford, Dis rae l i s , and eastern half of Warwick map-area. Quebec. C.G.S. Mem 211, p. 71. (1948) Age of the Bolton Lavas, Memphremagog D i s t r i c t , Quebec. Trans. Roc. Soc. Can., 3rd ser. , V o l . XL11, IV, pp. 17 - 29. (1930) Structure and Stratigtaphy of the Matapedia Valley, Gaspe, Que. (Abst) Geol. Soc. Am. B a l l , 41, 1, 116 - 117. (1932) Evidence of Taconic Orogeny in Matapedia Val ley. Am. Jour. S c i . , 5th ser. 24, 368 - 386. (1944) Geology of Quebec. Vol 11, Geol Rep. No. 20. Que. Bur. Min. E l l s , R.W. Paessler, C. F l i n t , R.F. F l i n t , R .F . Desmorest, M. Washburn, A. 'L. (1883) Report on Explorations and Surveys in the Interior of the Gaspe Peninsula. Rept. of Prog., 1882 - 83 - 84, Pt E . (1940) North Shore of the Saint-Lawrence from des Rapids to Matamec r ive r , Saguenay county. Que. Bur. Min. P.R. 144. (1947) Glac ia l Geology and the Pleisocene Epoch. John Wiley, p. 82. (1942) Glaciation of the Shickshock Mountains, Gaspe Peninsula. Geol. Soc. Am. B u l l . , 53, 1211 - 1230. Goldthwait,J.W.( 1915) The Occurrence of the Glac ia l Drif t on the Magdalen Islands. C.G.S. Mus. B e l l . 14. H a l l , James and Clark, J .M. Jones, I.W. (1892) An Introduction to the study of the genera of Palaeozoic Brachlopoda. Paleout. N.Y. Vo l . 8, pt 1. (1893) Ib id , pt 2. (1929) The Berry Mountain Map area. Que. Bur. Min. An. Rept. pt D. (1930) The Lesseps Area. Ib id . (1931) The Borinecamp Map area. Que. Bur. Min. An. Rept. pt C. - 6 9 -( 1 9 3 2 ) The Tabletop Map area. Que. Bur. Min. An. Rept. pt D. ( 1 9 3 3 ) Marsoni Map area, Gaspe Peninsula. Ib id . ( 1 9 3 3 ) Summary report of North Central Gaspe. Ib id . ( 1 9 3 4 ) Dartmouth r iver Map area, Gaspe Peninsula. Ib id . ( 1 9 3 5 ) Geology of North Central Gaspe. (Ab3t) Geol. Soc. Am. Proc. 4 4 7 - 4 4 8 . ( 1 9 3 5 ) Upper York River Map area, Gaspe Peninsula. Que. Bur. Min. An. Rept. Pt D. ( 1 9 3 6 ) Mount Alexander Map area, Gaspe Peninsula. Ib id . ( 1 9 3 9 ) Rapport geologique sur une partie de 1 ! Est de Gasped Que. Eur. Min. R.P. No. 1 3 0 . (1923) Outlines of Appalachian Structure. Geol. Soc. Am. B u l l . 34, 2, 309 - 380. (1936) Reconnaissance of the Appalachians i n Quebec. (Abst) Geol. Soc.4Am. Proc. 85. (1938) The correlation of Certain Devonian Faunas of Eastern and Western Gaspe. B u l l . Am. Paleout. Vo l . 24, 82. (1899h) A revision of the genera and species of Canadian Palaeozvis coralsj the Madreporaria Perforata and the Alcyonaria. C.G.S. Contr. Can. Palcont., V o l . 4, Pt. 1. ( I 8 4 4 ) On the Geology of the Chat and Cascapedia r ivers , Gaspe, and the Chaleur Bay. C.G.S. Rept. Prog. 5 - 66. (1863) Geology of Canada. C • G. S . 1911) Geological Reconnaissance in the Gaspe D i s t r i c t , Que. Que. Dept. C o l . Min. F i s h . , Rept. Min. Oper; -70-Mailhot, A. McGerrigle, H.W. Northrop, S.A. Odell, N .E . Parka, W.AS (1918) Geology of a portion of the projected township of Lemleux, County of Gaape, Que. Ib id . (1919) Geology of Mount Albert , County of Gaape, Que. Ib id . (1938) Joncas -Portin area, Gaspe County, Que. Que. Bur. Min. P.R. No. 12 5. (1940) The Power-Joncas area, Gaspe County, Que. Ib id . P.R. No. 153. (1946) A reviaion of the Gaspe Devonian. Trans. Roy. Soc. Can. 3rd ser. , IV, E o l . XL pp. 41 - 54. (1932) Chaleur Series of Port Daniel, Que. (Abst.) Geol. Soc. Am. B u l l . , 43, 1, 270 - 271. (1939) Paleontology and Stratigraphy of the Si lur ian rocks of the Port Daniel-Black Cape Region, Gaspe. Geol. Soc. Am. Sp Papers, 21. (1938) Northernmoat Labrador mapped from the a i r . Am. Geog. S o c , Spec Publ . , No. 22, pp. 204-215. (1931) Geology of the Gaspe Peninsula, Que. Geol. Soc. Am. B e l l . 39, 785-799. Quebec, MInistere des Terres et For§ts (1930) Peninsula de Gaspe, Bonawenture, Matane, (map:scale equala 1 inch to 3 milea) Leve aerien, Fejsillet No. 1 Rosett i , F, Richardson,J. Russel, L . S . (1945) Paunes cambrienn^ia des conglomerate, de la "Formation de S i l l e ry" • Le Nat. Can. V o l . 72 pp. 53 - 67. (1946) Early Upper Cambrian Tr ibo l i t e from Weatern Gaspe. Journ. of Pale on. V o l . 20, No. 5. (1946) Canadian and Early Ordovician Stratigraphy of the Lower St. Lawrence Val ley. Geol. Soc. Am. B u l l . , 57, 687-706. (1857) Report for the Year 1857, Gaape Peninsula. C.G.S. Rept. Prog. 105-169. (1946) On the Stratigraphy of the Gaspe Limestone -71-Schuchert, C. Schuchert, C. and Dart, J .D. Swans on, C O . T e r r i e r , P. Twenhof e l , W.H. Williams. ^ . Y . Series, P l o r i l l o n Peninsula, Gap des Rosiers township, County of Gaspe-South. Que. Bur. Min. P.R. No. 195. (1897) A synopsis of American f o s s i l Brachiopoda including Bibliography and Synonymy. U.C.G.S. B u l l . 87. (1925) Significance of Taconic Orogeny. Geol. Soc. Am. B u l l . 36, 341, 350. (1930) Orogenic Times of the Northern Appalachians. Geol. Soc. Am. B u l l . , 41, 4, 701-724. (1926) Stratigraphy of the Port-Daniel-Gascons area of Southeastern Quebec. C.G.S. B u l l . 44, 35-58. (1928) Isostasy and Mountain Building. Jour. Geol. V o l . 36. 411-433. p.415 (1914) La re'gion appalachianne du Canada. N.Y. State Mus. B u l l . , 173, 75-79. (Translation). (1914) The Ant icost i Island faunas. C.G.S. Mus. B u l l . 3 . (1928) Geology of Ant icost i Island. C.G.S. Mem. 154. (1919) The Si lur ian Geology and faunas of Ontario Peninsula, and Manitoulin and adjacent Islands. C.G.S. Mem. 111. PLATE 1 View looking southeast from a high point i n the Shickshock mountains. Foreground: South Mountain. Center: Squaw Cap and Barn-shaped mountains. Background: level-crested surface of the lower plateau. PLATS 11 A view from the Shickshock to the northern plateau Background: St. Lawrence r i v e r . PLATE 111 Ground moraine a l o n g the B a t h u r s t r o a d i n t h e e a s t e r n p a r t of the a r e a . PLATE IV On t o p of Mount A l b e r t , angular d e b r i s or felaenmeer PLATE V J o i n t i n g i n tne serpentine or South Mountiaini PLATS VI Interior of a g l ac i a l cirque on the south flank of Mount Alber t . PIAT3 V l l An exposure of competent, S i lu r ian limestone beds dipping nortn. seventeen-mile tirook (Soutn orancn)* PLATE V l l l North-dipping bods of S i lur ian dolomite exposed along the Salmon Branch of the Cascapedia r i ve r . PLATS IX Slickensides in Devonian rocks exposed along Seventeen-Mile brook (South branch). C A R B O N I F E R O U S S ILURIAN o o o o o O O o E A R L Y - P A L E O Z OIC O R - O L D E R D E V O N I A N [77771 E s r - u m m a c //// S c r i e s I G N E O U S R O C K S 1/ 1' 1 •' 1/ 1/ 1/ 1/ 1/ "V&lcemics * a ^ « s o f Granitic mtrusiyes A A A ti A A A A A Perpepiine , etc ; Orc iDvic icHi ; F o r i i of * bot» T t> j-i<ss /viHritj. D e v o n i a n L E G E N D M I D D L E DEVONIAN G R A N I T E PORPHYRY DIORITE L O W E R DEVONIAN G R A N D E GRLVE FORMAT iOM C A P E BON AMf FORMATION MIDDLE SILURIAN UND/Vf DEO ORDOVICIAN (?) | T E R P E N T I N E a) 3 HICK5HOCK -SE RlE.5 5tr^e ana J*f b.^mc*/ Gco/ojicaI boun dary assumed Normal fault showma do*/nthro */ Side Reverse fault sho^/cna uplifted side Fosuls Loca/ic y Scale o* M\.\es C R O S S - S E C T I O N S 2500' 6 6 ° 15 G E O L O G I C A L M A P A P R I L \<\4<\ OP THE A R E A IN T H E V IC IN ITY OP THE B A T H U R S T ROAD * 3 C. C A R B O N N EAU ( . 6 * 3 0 ' GEOLOGICAL S K E T C H - M A P OF A PORTION OP THE SHICKSHOCK MOUNTAINS GASPE PENINSULA QUE. L E G E N D M I D D L E D E V O N I A N G R A N I T E PCRPH>Ry. & A 5 I C V O L C A N I C S G A S P E 5 A (M D-STO M E 6 E R I E S L O W E R D E V O N I A N G A S P E L I M E S T O N E - S E R I E S 3 I L U R I A N LIMESTONE, SHALE , CONGLOMERATE OROOVIClAN SER PEN T/N£ SHICKSHOCK VOLCANfCS J SLATE, SHALE, LIME ST ON E Geolotji < a / b o u n d a r y a s s u m e . c l To wn & h i/> fine. fee0 ©4* St L a w r« r\ C « •49 6m" L o c u t i o n a r e * 66/3 A P R \ L sSca / e of A/Wej C . C A R B O M ^ E A U
Thesis/Dissertation
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Geological Engineering
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Graduate
Stratigraphy and structure of a portion of the Shickshock Mountains, Gaspe Peninsula
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