RP 339(A) PRELIMINARY REPORT ON STE-FELICITE - GROSSES ROCHES AREA, MATANE ELECTORAL DISTRICT P. R. NO. 339
DEPARTMENT OF MINES
HON, W. M. COTTINGHAM. MINISTER A-O. DUFRESNE. DEPUTY MINISTER
GEOLOGICAL SURVEYS BRANCH E W. JONES, CHIEF
PRELIMINARY REPORT
ON
STE-FÉLICITÉ-GROSSES ROCHES AREA
MATANE ELECTORAL DISTRICT
BY
JACQUES BÉLAND
QUEBEC 1957
P- R. NO. 339 M-0-4298
PRELIMINARY REPORT
on the
Ste. Félicité-Grosses Roches Area
Matane Electoral District
by
Jacques Béland
INTRODUCTION
The Ste. Félicité-Grosses Roches Area, which was mapped by the writ- er during the summer of 1956, is in northwestern Gaspé Peninsula. It is bounded on the north by the St. Lawrence river, on the south by latitude 48945`, and on the east and west by longitudes 67°00" and 67°30`.. The west boundary passes one mile east of Matane. The area covers a surface of about 280 square miles and in- cludes parts of Dalibaire, Cherbourg, Leclercq, Cuoq, St, Denis and Tessier town- ships and part of Matane Seigniory.
It is fairly well settled except in the southeast, which is under forestry concessions to Hammermill Paper Company of Erie, Pennsylvania, and Price Brothers of Quebec. The principal settlements are, from west to east along the shore, Petite Matane, Ste. Félicité, and Grosses Roches; and, inland, St. Luc St. Adelme, St. Jean de Cherbourg, and St, Thomas. Access to practically any point in the region is provided by a network of good gravel roads which joins Provincial Route No. 6 at various points along the shore. A power line con- structed a few years ago crosses the northern part of the area,
Physiography
Physiographically, the area can be divided into three units, from south to north: a mountain range, a dissected plateau, and a coastal plain,. In the southeastern corner of the area is a small portion of the Shickshock range, here rising to 1,900 feet above sea level, Northwest of this range is a dis- sected plateau, about 15 miles wide, which crosses the whole area northeasterly, The plateau varies in elevation from 1,700 feet to 500 feet sloping northwest- erly toward the St. Lawrence and, in part, southwesterly toward Matane river
The coastal plain occupies a narrow band along the shore in the west- ern half of the area and is bounded southerly by an escarpment which marks the edge of the plateau above described, The escarpment bordering the coastal plain extends along the shore in the eastern part of the area Its summit more or less coincides with the maximum elevation reached by the Champlain Sea towards the end of the Wisconsin glacial episode as is indicated by fairly well preserved gravel terraces and wave-cut cliffs.. Wave-cut cliffs were noted up to an eleva- tion of about 550 feet.
Within the dissected plateau certain rock types have definite topo- graphic expressions. A belt of hummocky ground in the north-central part of the area is occupied by hard sandstones, Long ridges with even crests are generally made up of regularly dipping beds of limestone conglomerate or quartzite or boch. Gently rolling ground generally characterizes areas underlain by slates and siltstones. Drainage in the northern part of the area is effected by a series of short and steep streams flowing northerly into the St. Lawrence. The largest of these streams are, from west to east, Petite Matane, Cap de la Baleine, Jaco Hughes, Grosses Roches, Brouillé, Sem and Vapeur. Along most of their courses these streams cut across the structural trends of the area. In their lower parts they flow through deep, narrow gorges which point to fairly recent and rapid downcutting of the land by these streams.
Drainage in the southern part of the area is directed southwesterly to Matane river via a large tributary named Petite Matane river (1) whici. branches into several lesser streams in the southeastern part of the area, These lesser streams do not follow the general structural trend but Petite Matane river along most of its course is parallel to this trend, In its lower part, Petite Matane river flows through a deep narrow gorge with a moderately steep gradient, Rejuvenation is also indicated here, The upper part of the river is character- ized by gentle valley slopes pointing to a former more mature stage.
A few small lakes, less than 14 mile across, are scattered over the area. Most are formed by water impounded along stream courses or in shallow de- pressions at or near the heads of streams.
GENERAL GEOLOGY
The consolidated rocks in the area may be divided into five units as follows: metavolcanics and sandstones of the Shickshock group, impure sand- stones; slates, siltstones and limestones; limestone conglomerates and quartz- ites; basic volcanic rocks. The last four units probably are of Ordovician age.. The age of the Shickshock group is inferred here to be Ordovician, although it has previously been considered to be Cambrian or older.
The metavolcanics and sandstones of the Shickshock group occupy a very small portion in the southeastern corner of the area where they form a steep and high hill, part of the Shickshock range, The relations of the Shicks- hock group to the Ordovician belt to the northwest are not clear. The contact here appears to be transitional and conformable, but whether the Ordovician is above or below the Shickshock group is not apparent.
The impure sandstones which constitute one rock unit in the Ordovi- cian belt are found in the north-central part of the area over a length of about 10 miles and a width of 2 miles, They also occupy a small portion near the west- ern boundary„ Several structural features within the Ordovician belt tend to indicate that these sandstones in the northern part of the area are at the base of the exposed Ordovician section.
(1) There are in this area two rivers named Petite Matane., One, the larger, is a tributary of Matane river; the other empties directly into the St Lawrence at the village of Petite Matane, - 3 -
They are lithologically similar to the "Pillar sandstone" of the Tourelle area (1), considered on paleontological evidences to be Lower Ordovi- cian (Deepkill) .
The stratigraphie position of the sandstones near the western bound- ary is less clear. There are vague indications that they are above part of the series of slates, siltstones and limestones that extend between the sandstones in the northern part of the area and the Shickshock range,
Within these slates,siltstones and limestones are also zones of limestone conglomerate and quartzite and lenses of basic volcanic rocks, With the sandstones, all these rocks actually form one series. Areal extents as shown on the map are in many cases based on predominance of rock types, and boundaries are more or less arbitrary:, Slates and siltstones similar to those found over most of the area are interbedded with the sandstones and with the limestone conglomerates and quartzites. The southern contact of the sandstone belt in the northern part of the area, for instance, is one of transition, the slates and siltstones becoming more and more abundant as one proceeds southward
The slates, siltstones and limestones are much alike from the north- ern to the southern boundary of the area except that they show an increase in metamorphism southward toward the Shickshocks range,The slates become more phyllitic. The limestone conglomerate and quartzite similarly show a distinctive increase in degree of metamorphism. Near the Shickshocks the limestone pebbles are sheared, the matrix is phyllitic, and the quartzites are glassy. There is, therefore, no abrupt change in the metamorphism shown by the rocks of the Shickshock group and those considered to be of Ordovician age.
Lenses of basic volcanic rocks occur within the Ordovician assem- blage, The largest, located at about the centre of the area, is 2t miles long and y mile wide. Nearby is another lens about 1 mile long and !2 mile wide, Three other small occurrences, at respectively 1!%, 4 and 101 miles northeast, fall on a line which is the prolongation of the long axis of the largest lens. A fault might have controlled the emplacement of all these volcanic bodies.
Various types of glacial deposits including till, stratified gravel and sand, and a segment of an esker are found in the area, Glacial striae gen- erally trending northerly or northwesterly were noted on many outcrops Distri- bution of erratics points to successive movements of ice northward and southward
Deposits of possibly marine clay occur above sea-level at the mouths of some of the streams emptying into the St, Lawrence, Sand and gravel terraces and elevated beaches are found in the escarpment bordering the dissected plateau and on the narrow coastal plain., All these marine deposits are related to the Champlain Sea episode.
Recent deposits include sand and gravel accumulations along flat segments of streams, beach deposits on the shore, and weathered rock material and soil on hill slopes.
(1) McGerrigle, H.W.: The Tourelle and Courcelette Areas, Que. Dept. of Mines., Geol„ Rept., 62, 1954, The stratigraphie succession previously outlined is condensed in the following table of formations.
Table of Formations
Recent Stream and beach deposits
Pleistocene Marine (Champlain) Clay, sand and gravel; beach deposits.
Glacial Till, glacial outwash, esker
Basic volcanics.,
Limestone conglomerates and quartzites. Ordovician Slates, siltstones and limestones.
Impure sandstones.
Metavolcanics and impure OrdovicianShickshock group or older sandstones.
Shickshock Group
The Shickshock group in the area includes green metavolcanics or greenstones interlayered with green and grey arkosic sandstones. Also near the contact with the Ordovician assemblage are green—grey, fine—grained rocks that may be of volcanic or sedimentary origin. Metamorphic changes render identifi— cation difficult.
The metavolcanics were probably originally basalts or andesites. The sandstones contain abundant clastic grains of pink and grey feldspars. Their texture and mineralogic composition are not very different from those of the sandstones in the northern part of the area except that the latter probably are more quartzose and less feldspathic.
Ordovician
The Ordovician assemblage is made up mostly of slates and siltstones with subordinate amounts of limestones, impure sandstones, limestone conglom— erates, quartzites and basic volcanics. The slates and siltstones vary in colour, texture and composition, There are green, grey and red slates, also grey calcareous slates, all in al- ternate beds or zones. The siltstones, green or grey, shaly, sandy or calcare- ous, are generally in thin beds intercalated in the slates. In the southern part of the area, where an increase in metamorphism is noticeable, the cal- careous slates and siltstones are veined by calcite.
The limestones are grey, compact or crystalline, and commonly sandy. They are mostly within or near zones of limestone comglomerate and quartzite.
The impure sandstones represent a rather coarse clastic facies.. They contain abundant rock fragments and zones of quartz pebble comglomerate. Their main constituents are quartz and feldspar, Most sandstone beds are grey or green, 10 to 25 feet thick, uniform in texture and composition. Many beds also show a marked gradation, passing from a quartz pebble conglomerate to a clayey siltstone. Channelling and cross-bedding are common features in many medium- to coarse-grained beds„
Limestone conglomerates and quartzites are generally found together in zones varying in width from a few hundred feet to nearly two miles. The widest zone is near Grosses Roches. In general, the limestone conglomerates and quartzites alternate in beds 10 to 30 feet thick. They also interfinger or intergrade. Quite commonly thick and short lenses of either type of rock are found intercalated in slates. Wide lengthy zones made up exclusively of quartzites were encountered in the east-central part of the area. Thin beds of quartz pebble conglomerate are also associated with some of the quartzite beds:.
The limestone conglomerate varies considerably in texture and com- position from place to place„ The most common fa cies is grey and made up of limestone and sandy limestone pebbles set in a sandy calcareous matrix, Along the shore, east of Grosses Roches, several beds contain fossiliferous pebbles derived from Cambrian limestones (1). At this same locality the limestone con- glomerate also contains fragments of a basic dyke rock.
The quartzite associated with the limestone comglomerate is commonly calcareous and, at places, grades into a sandy limestone.
The basic volcanic rocks intercalated in the Ordovician assemblage are green or dark grey and of basaltic or andesitic composition. They are a- mygdular, schistose and much fractured. Lenses of agglomerate and flow brec- cias can be recognized at a few places. Some flow breccias are difficult to distinguish from disruption breccias. The latter are particularly noticeable at the margins of the volcanic bodies.
STRUCTURE
Structural trends within the area are northeasterly., The bedding and schistosity at most exposures are parallel, striking northeasterly and
(1) Rasetti, F.: Faunes Cambriennes des conglomérates de la "Formation de Sille- ry". Naturaliste Canadien, No. 72, pp. 61-63, 1945.. dipping southeasterly. This suggests a series of tight folds overturned to the northwest„ This interpretation is in part supported by top determinations along the shoreline in the belt of impure sandstones in the north-central part of the area Here two tight folds overturned to the northwest have been outlined. It is further substantiated by the presence, within thick sequences of slates and siltstones in the central and southern parts of the area, of minor folds that seem to be the remnants of larger folds which were sliced up along shear planes about parallel to the axial planes Sequences that involved zones of limestone conglomerate and quartzite and, therefore. were more resistant, have escaped this slicing in part, and here folds of larger amplitudes can be recognized The wide zone of limestone conglomerate and quartzite near Grosses Roches, for in- stance, is apparently the southeastern limb of an anticline overturned to the northwest and plunging northeasterly. A fault presumably has cut off the north- western limb,, Other folds involving zones of limestone conglomerate and quartzite can be recognized in the western part of the area, where they plunge southwesterly. Thus, it appears that the folds in the western part of the area plunge southwest- erly and in the eastern part, northeasterly This suggests that the impure sand- stones in the north-central part of the area are at the base of the Ordovician section as exposed
Several tear faults are indicated in the belt of impure sandstones in the north-central part of the area, and also within one zone of limestone con- glomerate and quartzite in the northeastern part. Similar faults also bound„ in part, the small area of impure sandstones near the west boundary.
ECONOMIC GEOLOGY
Copper
A Lots 1 to 5, range V, St, Denis township
Lots 36 to 40, range V, Tessier township
Scattered occurrences of copper minerals have been found within an elongate mass of basic volcanic rocks about 212 miles long and 12 mile wide and also within adjacent sedimentary rocks The principal showingscover an area of about 3,000 feet by 2,000 feet, including part of lot 40 range V, Tessier town- ship, and of lots 1 and 2, range V St. Denis township.
The discovery of the deposit dates back to 1893 when blocks of volcan- ic rocks carrying some native copper, found north of the deposit, were traced back to their source area. Mining operations were first undertaken in 1901, and up to 1916 several attempts at finding sizable amounts of ore were made. However, although some fairly good grade material was located, quantities were judged in- sufficient for profitable operations Assays, presumably of vein material, indi- cated tenors of 2 to 5 per cent copper and small amounts of gold
The workings consisted mainly of four vertical shafts, two at the "Saucier Mine" and two others at the "Tétreault Mine" The deepest shaft,; said to be 180 feet, is at the 'Saucier Mine" Two diamond drill holes were also put down in the vicinity of this shaft Work at the "Saucier Mine" was conducted in sedimentary rocks at the southeastern contact of the lens of volcanic rocks At the"Tétreault Mine" the shafts were sunk in volcanic rocks in the central part of the lens near the northwestern contact The two "mines" are about 1,;500 feet apart„ Other work, consisting mostly of test pits and trenches, was done in later years. Also, in 1951 an electromagnetic survey was conducted over lots 1 and 2, range V, St„ Denis township.
Mineralization in both the sedimentary and volcanic rocks consists of veins of calcite and quartz containing native copper with some chalcopyrite and bornite, At the surface is a marked alteration of the copper minerals to malachite and azurite.. Within the volcanic rocks where. it is said, the best mineralization was found, the veins are 1 to 2 inches thick and fill frac- tures and joints. The wall rock is practically barren, The veins are erratic in trend and widely spaced, They do not appear to form any particular zone or to be related to any major fault or sheared zone The copper mineralization is essentially the type commonly associated with basic volcanic rocks Here, the mineralization has spread into the nearby sedimentary rocks, largely slates with intercalated limestones, limestone conglomerates and quartzites
A noteworthy feature of the mineralization here is the presence of anthraxolite in the veins and the wall rock„ This mineral is a hard., coal-like material made up mostly of carbon. It also occurs in veins elsewhere in the region, in Ordovician sedimentary rocks.
B. Lot 17, range VII, St. Denis township
A little malachite and anthraxolite were noted in a road-cut hrough a small lens of basic volcanic rock at the northwest end of lot 17, range VII, St. Denis township, This is just south of the junction of the range VI-VII toad and the road crossing these two ranges east of St.. Adelme.,
Manganese Bog Ore
Manganese bog ore in the soil and manganese wad along fractures in the bedrock have been reported at several localities in Tessier,, St Denis and Charbourg townships. The localities lie within a belt 2 to 5 miles wide trending northeasterly. The belt approximately includes ranges V to IX of Tessier town- ship, ranges VII to IX of St., Denis township and ranges V to VII of Cherbourg township. It is underlain by green.:, grey, and some red slates interbedded with siltstones, limy siltstones and limestones. Part of the grey slate is also cal- careous .
One of the most extensive bog ore deposits within the belt occurs in the northeastern part of range VIII lots 45-48 of St: Denis township De- tailed investigation of this deposit was conducted during the summer of i956 by St. Maurice Minerals Corporation Work consisted of shallow drilling through the overburden to ascertain its thickness and the tenor of manganese Holes spaced 100 feet apart, in a grid pattern, were drilled over an area about 3,.000 feet long and 500 to 1,000 feet wide, This work was being continued at the end of September, 1956. The deposit is in gently rolling ground sloping southeast- erly. Marshes occupy part of the area Bedrock exposures are extremely rare.
The overburden, 5 to 10 feet thick, consists of soil over a clayey, sandy till containing abundant fragments of slates: Below the till is a tran- sitional zone of broken bedrock, here made up of green and grey slates., Within the marshy depressions the soil is thick and black Manganese ore is found in various forms. It occurs mostly in nodules disseminated in the soil below the vegetal cover. The nodules are generally 1/8 to 12 inch across, rather loosely packed, and mixed with soil and slate chips At places and particularly in the marshy areas they are aggregated in firm po- rous layers several inches thick. Very minute nodules disseminated in black soil are also common,. The nodules are rusty on the surface, but black and shiny when freshly broken. Wet, they are rather firm but, exposed to air, crumble easily to a fine dust Assays indicate that they contain from 20 to 50 per cent manganese, and from 8 to 10 per cent iron, Alumina amounts to about 9 per cent and silica/ 5 per cent.
The manganese ore also occurs as thin coatings on the slate in cracks and cleavages and on fragments within the till and more particularly in the transitional zone above the bedrock Assays indicate that these stained slates contain from 7 to 8 per cent manganese_ One assay of non-stained slate from the bedrock gave a tenor of 0,16 per cent manganese and 4,99 per cent iron This suggests that the manganese is derived from the slates rather than from veins or other sources
The greater abundance of nodules in the marshy areas and the nodular structure itself indicate that the deposition here, as at many other places where similar manganese deposits have been found, is controlled by the circulation of groundwater. Iron and manganese is dissolved from the bedrock or fragments thereof, carried in solution, and redeposited wherever evaporation takes place, In marshy depressions where water collects to evaporate during dry periods, thick- er deposits are formed,
Limestone
Limestone and limestone conglomerate suitable for extraction of lime are probably not very abundant in the region. Southeast of Petite Matane, however, is an area of about 8 square miles where exposures of rather pure limestone and limestone conglomerate are fairly abundant.. The area is crossed northwesterly by a road that ends at Petite Matane. Good exposures are found for about 2 miles on either side of that road in ranges II and III of Matane Seigniory
A previous report (1) mentions that several quarries were operated at various times in this area, An excellent limestone that does not seem to have been worked can be seen at and below a fall on Petite Matane river, '2 mile south of the junction of this river with the road separating ranges I and lI (Matane Seigniory) At this locality thick beds of crystalline limestone with some limestone conglomerates form a zone nearly 200 feet thick The gorge here would facilitate quarrying.
(13 Aubert de la Rue, E,,.:, .Matapedia Lake Area- Que. Dept of Mines Geol Rpt, No 9.. pp. 33-34, 1941,