Sir Alexander Mackenzie, who, on his return from the sea, walked over these hills, says, "Though the country is so elevated, it is one continued morass, except on the summits of some barren hills. As I carried my hanger in my hand, I frequently examined if any part of the ground was in a state of thaw, but could never force the blade into it beyond the depth of six or eight inches. The face of the high land towards the river is, in some places, rocky, and in others a mixture of sand and stone, veined with a kind of red earth, with which the natives bedaub themselves." It was on the 14th of July that he made these observations. On the 5th of the same month, in a milder year, we found that the thaw had penetrated nearly a foot into the beds of clay at the base of the hills.
Thespace between the Rocky Mountains and Rein-deer Hills, ninety miles in length from lat. 67° 40' to 69° 10', and from fifteen to forty miles in width, is occupied by flat alluvial islands, which separate the various branches of the river. Most of these islands are partially or entirely flooded in the spring, and have their centres depressed and marshy, or occupied by a lake; whilst their borders are higher and well clothed by white spruce trees. The spring floods find their way, through openings in these higher banks, into the hollow centres of the islands, carrying with them a vast quantity of drift timber, which, being left there, becomes water-soaked, and, finally, firmly impacted in the mud. The young willows, which spring up rapidly, contribute much towards raising the borders of the stream, by intercepting the drift sand which the wind sweeps from the margin of the shallow ponds as they dry up in summer. The banks, being firmly frozen in spring, are enabled to resist the weight of the temporary floods which occur in that season, and before they are thawed the river hasresumed its low summer level. The trees which grow on the islands terminate suddenly, in lat. 68° 40'.
I have already mentioned, that a large sheet of brackish water, named Esquimaux Lake, lies to the eastward of the Rein-deer Mountains, running to the southward, and approaching within sixty miles of the bend of Mackenzie's River at Fort Good Hope. This lake has a large outlet into Liverpool Bay, to the westward of Cape Bathurst, and there are many smaller openings betwixt that bay and Point Encounter, near the north end of the Rein-deer Hills, which are also supposed to form communications betwixt the lake and the sea. The whole coast-line from Cape Bathurst to the mouth of the Mackenzie, and the islands skirting it, as far as Garry and Sacred Islands, present a great similarity in outline and structure. They consist of extensive sandy flats, from which there arise, abruptly, hills of an obtuse conical form, from one to two hundred feet above the general level. Sandy shoals skirt the coast, and numerous inlets and basins of water divide the flat lands, and frequently produce escarpments of the hills, which show them to be composed of strata of sand of various colours, sometimes inclosing very large logs of drift timber. There is a coating of black vegetable earth, from six inches to a foot in thickness, covering these sandy hummocks, and some of the escarped sides appeared black, which was probably caused by soil washed from the summit.
It is possible that the whole of these eminences may, at some distant period, have been formed by the drifting of moveable sands. At present the highest floods reach only to their bases, their height being marked by a thick layer of drift timber. When the timber has been thrown up beyond the reach of ordinary floods, it is covered with sand, and, in process of time, with vegetable mould. TheElymus mollis, and some similar grasses with long fibrous roots, serve to prevent the sand-hills from drifting away again. Some of the islands, however, consist of mud or clay. Captain Franklin describes Garry's Island as presenting cliffs, two hundred feet high, of black mud, in which there were inclined beds of lignite.188Specimens of this lignite have the same appearance with the fibrous wood-coal occurring in the formation at the mouth of Bear Lake River, and, like it, contain resin.189190Imbedded in the same bank, there were large masses of a dark-brown calc-tuff, full of cavities containing some greenish earthy substance. Some boulders of lydian stone strew the beach. The cliffs of Nicholson's Island also consisted of sand and mud, which, at the time of our visit, (July 16th,) had thawed to the depth of three feet. This island rises four hundred feet above the level of the sea, and is covered with a thin sward of grasses and bents.
Themain land to the east of Nicholson's Island, as far as Cape Bathurst, presents gently swelling hills, which attain the height of two hundred feet at the distance of two miles from the beach, and the ground is covered with a sward of moss and grasses. At Point Sir Peregrine Maitland there are cliffs forty-feet high of sand and slaty clay, and the ravines are lined with fragments of whitish compact limestone, exactly resembling that which occurs in Lakes Huron and Winipeg, and which was afterwards seen forming the promontory of Cape Parry, bearing E.N.E. from this place. The beach, on the south side of Harrowby Bay, not far from Point Maitland, was thickly strewed with fragments of dark red and of white sandstone, together with some blocks of the above-mentioned limestone, and a few boulders of sienite.
From Cape Bathurst the coast line has a S.E. direction, and is formed by precipitous cliffs, which gradually rise in height from thirty feet to six hundred. The beds composing these cliffs appear to be analogous to those of the alum-shale banks at Whitby, and similar to those which skirt the Scented-grass Hill and Great Bear Mountain, in Great Bear Lake. The Scented-grass Hill is distant from Cape Bathurst about three hundred miles, on a S.E. bearing, which corresponds, within a point, with the direction of the principal mountain chains in the country.191There is evidently a striking similarity in the form of the ground plan of these two promontories. At the extremity of Cape Bathurst the cliffs consist of slaty-clay, which, when dry, has a light bluish-gray colour, a slightly greasy feel, and falls down in flakes. The rain-water had penetrated the cliff to the depth of three yards from the summit; and this portion was frozen, on the 17th July, into an icy wall, which crumbled down as it thawed. On proceeding a little further along the coast, some beds were observed that possessed, when newly exposed to the air, tenacity enough to be denominated stone, but which, under the action of water, speedily softened into a tenacious bluish-clay.
At Point Traill we were attracted by the variegated colours of the cliff, and on landing found that they proceeded from192193197198199clays baked by the heat of a bed of bituminous-alum-shale which had been on fire. Some parts of the earth were still warm. The shale is of a brown colour and thin slaty structure, with an earthy fracture. It contains many interspersed crystals of selenite; between its lamina there is much powdery alum, mixed with sulphur, and it is traversed by veins of brown selenite, in slender prismatic crystals. The bed was much broken down, and hid by the debris of the bank, but parts in it was200194195196several yards thick, and contained layers of the wax-coloured variety of alum, named Rock-butter. The shale is covered by a bed of stone, chiefly composed of oval distinct concretions of a poor calcareous clay-iron stone. These concretions have a straight cleavage in the direction of their short axis, and are often coated by fibrous calc-sinter and calcedony. The upper part of the cliff is clay and sand passing into a loosely cohering sandstone. The strata are horizontal, except in the neighbourhood of ravines, or of consumed shale, when they are often highly inclined, apparently from partial subsidence. The debris of the cliff form declivities, having an inclination of from fifty to eighty degrees, and the burnt clays variously coloured, yellow, white, and deep red, give it much the appearance of the rubbish of a brick-field. The view of the interior, from the summit of the cliff, presents a surface slightly varied by eminences, which swell gently to the height of fifty or sixty feet above the general level. The soil is clayey, with a very scanty vegetation, and there are many small lakes in the country.
Ten miles further on, the alum-shale forms a cliff two hundred feet high, and presents layers of the Rock-butter about two inches thick, with many crystals of selenite on the201surfaces of the slates. The summit of the cliff consists of a bed of marly gravel two yards thick, which is composed of pebbles of granite, sienite, quartz, lydian-stone, and compact limestone, all coated by a white powdery marl. The dip of the strata at this place is slightly to the northward.
A few miles to the south-east of Wilmot Horton River the cliffs are six hundred feet high, and present acclivities having an inclination of from thirty to sixty degrees, formed of weathered slate-clay. Some beds of alum-shale are visible at the foot of these cliffs, containing much sulphate of alumina and masses of baked clay.
Two miles further along the coast the shaly strata were on fire, giving out smoke, and beyond this the cliffs become much broken but less precipitous, having fallen down in consequence of the consumption of the combustible strata. These ruined cliffs gradually terminated in green and sloping banks, whose summit was from one to two miles inland, and about six hundred feet above the sea level. Considerable tracts of level ground occurred occasionally betwixt these banks and the beach. Wherever the ground was cut by ravines, beds of slate-clay were exposed. On reaching the bottom of Franklin Bay, we observed the higher grounds keeping an E.S.E. direction until lost to the view, becoming, however, somewhat peaked in the outline.
Parry'sPeninsula, where it joins the mainland, is very low, consisting mostly of gravel and sand, and is there greatly indented by shallow bays, but it gradually increases in height towards Cape Parry. The bays and inlets are separated from the sea by beaches composed of rolled pieces of compact limestone; and which, although they are in places only a few yards across, are several miles in length. The northern part of Parry's Peninsula belongs entirely to a formation which appears from the mineralogical characters of the stone composing the great mass of the strata, and the organic remains observed in it, to be identical with the limestone formations of Lakes Winipeg and Huron.
202204On the north side of Sellwood Bay, in lat. 69° 42', cliffs about twenty feet high are composed of a fine-grained[43]brownish dolomite, in angular distinct concretions, and containing corallines and veins of calc-spar.203In the same neighbourhood there is a bed of grayish-black compact luculite with drusses of calc-spar, very similar to the limestone which occurs inhighly inclined strata at the "Rock by the River Side," on the Mackenzie, and in horizontal strata in an island near that rock, where it forms angular concretions.
After passing Sellwood Bay, the north and east shores of Cape Parry, and the islands skirting them, present magnificent cliffs of limestone, which, from the weathering action of the waves of the sea, assume curious architectural forms. Many of the insulated rocks are perforated. Between the bold projecting cliffs of limestone there are narrow shelving beaches, formed of its debris, that afford access to the interior. The strata have generally a slight dip to the northward, and the most common Rock is a yellowish-gray dolomite which has a very compact structure, but presents some shining facets of disseminated calc-spar. This stone, which is not to be distinguished by its mineralogical characters from the prevailing limestone of Lake Winipeg, and at the passage ofLa clochein Lake Huron, forms beds six or eight feet thick, and is frequently interstratified with a cellular limestone, approaching to chert in hardness, and exhibiting the characters of rauchwacke. In some parts, the rauchwacke is the predominating rock, and has its cells beautifully powdered with crystals of quartz or of calc-spar, and contains layers of chert of a milky colour. The chert has sometimes the appearance of calcedony, and is finely striped.
208, 209The extremity of Cape Parry is a hill about seven hundred feet high, in which beds of brownish dolomite, impregnated with silica, are interstratified with a thin-slaty, gray limestone, having a compact structure.[44]The vegetation is very scanty, and there are some spots covered with fragments of dolomite, on which there is not the vestige even of a lichen. Many large boulders of greenstone were thrown upon the N.W. point of Cape Parry. The islands in Darnley Bay, between Capes Parry and Lyon, are composed of limestone.
FromCape Lyon to Point Tinney, the rocks forming the coast-line are slate-clay, limestone, greenstone, sandstone, and calcareous puddingstone.
214Near the extremity of Cape Lyon theslate-claypredominates, occurring in straight, thin, bluish-gray layers, which are interspersed with detached scales of mica.215It sometimes forms thicker slates, that are impregnated with iron, and occurs alone, or interstratified in thin beds with a reddish, small-grained limestone. The strata, in general, dip slightly to the N.E., and form gently-swelling grounds, which at the distance of about fifteen miles to the southward terminate in hills, named the Melville Range. These hills are apparently connected with those which skirt the coast to the westward of Parry's Peninsula, have rather a soft outline, and do not appear to attain an altitude of more than seven or eight hundred feet above the sea. Ridges of naked trap-rocks, which traverse the lower country betwixt the Melville hills and the extremity of the Cape, rise abruptly to the height of one hundred or one hundred and fifty feet, and have, in general, an E.N.E. direction. When these trap ridges reach the coast, they form precipices which frequently have a columnar structure, and the nearly horizontal strata of slate-clay are generally seen underlying the precipices. In many places the softer clay strata are worn considerably away, and the columns of greenstone hang over the beach. Columns of this description occur at the north-eastern extremity of the Cape, and the slate-clay is not altered at its point of contact with the greenstone. The soil in this neighbourhood is clayey, and some small streams have pretty lofty and steep clayey banks; the shaly strata appearing only at their base. A better sward of grasses and carices exists at Cape Lyon, than is usual on those shores. Many boulders of greenstone and large fragments of red sandstone strew the beach.
At Point Pearce, four or five miles to the eastward of Cape Lyon, a reddish, small-grained limestone forms perpendicular cliffs two hundred feet high, in which a remarkable cavern occurs. Near these cliffs the slate-clay and reddish limestone are interstratified, and form a bold rocky point, in which the strata dip to the N.E. at an angle of 20°. The coast line becomes lower to the eastward, and at Point Keats a fine-grained, flesh-coloured sandstone occurs. This sandstone is quartzose, does not possess much tenacity, and is without any apparent basis.
At Point Deas Thompson the limestone re-appears, having reddish-brown and flesh-red colours, and a splintery fracture. There are some beautiful Gothic arches formed in the cliffs there by the weathering of the strata.
Five miles farther along the coast, near Roscoe River, the same kind of limestone forms cliffs twenty-five feet high, and is covered by thin layers of soft slate-clay. On the top of these cliffs we observed a considerable quantity of drift-timber and some hummocks of gravel. The spring tides do not rise above two feet. The Melville Range approaches within three miles of the coast there, and presents a few short conical summits, although the hills composing it are mostly round-backed.
At Point De Witt Clinton, a compact blackish-blue limestone, traversed by veins of calc-spar, forms a bed thirty feet thick,217218219which reposes on thin layers of a soft, compact, light, bluish-gray limestone or marl. The cliffs at this place are altogether about seventy feet high, but their bases were concealed by accumulations of ice. Veins filled with compact and fibrous gypsum traverse the upper limestone. Naked and barren ridges of greenstone, much iron-shot, cross the country here, in the same manner as at Cape Lyon. The soil consists of gravel and clay; the former mostly composed of whitish magnesian limestone; and the vegetation is very scanty.
At Point Tinney, in lat. 69° 20', cliffs of a calcareous puddingstone, about forty feet high, extend for a mile along the coast. The basis, in most of the beds, is calc-spar; but in some small layers it is calcareous sand. The imbedded pebbles are smooth, vary in magnitude, from the size of a pea to that of a man's hand, and are mostly or entirely of chert, which approaches to calcedony, and, when striped, to agate in its characters. Perhaps, much of the gravel which covers the country is derived from the destruction of this conglomerate rock.
FromPoint Clifton to Cape Hearne, the whole coast consists of a formation of limestone precisely similar to that which occurs on Lake Winipeg and Parry's Peninsula.
Dolomite, the prevailing rock in this formation, is generally in thin layers, and has a light smoke-gray colour, varying occasionally to yellowish gray, and buff. Its structure is compact, with little lustre, except from facets of disseminated calc-spar. It sometimes passes into milk-white chert, which forms beds. In some places the dolomite alternates with cellular limestone, which is generally much impregnated with quartz, and has its cavities powdered with crystals of that mineral. No organic remains were observed in the strata, but fragments, evidently derived from some beds of the formation, contained orthoceratites, like those of Lake Huron. The strata, though nearly horizontal, appear to crop out towards the north and east, forming precipices about ten feet high, facing in that direction, and running like a wall across the country. In many places, however, and particularly at Cape Krusenstern, the strata terminate in magnificent cliffs upwards of two hundred feet high, the country in the interior remaining level. Mount Barrow is a small hill of limestone, of a remarkable form, being a natural fortification surrounded by a moat. The coast line is indented by shallow bays, and skirted by rocks and islands.
In the whole country occupied by this formation, the ground is covered with slaty fragments, sometimes to the depth of three feet or more. These slates appear to have been detached from the strata they cover, by the freezing of the water, which insinuates itself betwixt their layers. At Cape Bexley, the fragments of dolomite cover the ground to the exclusion of all other soil; and in a walk of several miles, I did not see the vestige of a vegetable, except a small green scum upon some stones that formed the lining of a pond which had dried up. In this neighbourhood there are a number of straight furrows a foot deep, as if a plough had been drawn through the loose fragments. After many conjectures as to the cause of this phenomenon, I ascertained that the furrows had their origin in fissures of the strata lying underneath.
At the commencement of this formation between Point Tinney and Point Clifton, the coast is low, and a stream of considerable magnitude, named Croker River, together with many rivulets, flow into the sea. Its termination to the southward of Cape Hearne is also marked by a low coast line, which is bounded by the bold rocky hills of Cape Kendall.
Thebeach between Cape Hearne and Cape Kendall is in some places composed of slate-clay, and of a clay resembling wacke. Many large boulders of greenstone occur there. Cape Kendall is a projecting rocky point, about five or six hundred feet high, and nearly precipitous on three sides, which are washed by the sea. On the north, its rocks consist entirely of greenstone, but on the south side of the Cape the greenstone in lofty columns reposes on thin-slaty beds of fine-grained, bluish-gray limestone. Back's Inlet presents on each side a succession of lofty precipitous headlands, which have the shape termed, by seamen, "the gunner's quoin." Most of the islands and points near the mouth of the Coppermine have this form, and are composed of trap rocks.220One of Cowper's islands on which we landed consists of beds of greenstone cropping out like the steps of a stair.
A low ridge of greenstone exists at the mouth of the Coppermine river, and from thence to Bloody-fall, a distance of ten miles, the country is nearly level, with the exception of some low ridges of trap which run through it. The channel of the river is sunk about one hundred and fifty feet below the surrounding country, and is bounded by cliffs of yellowish white sand, and sometimes of clay, from beneath which, beds of greenstone occasionally crop out.
At Bloody-fall, a round-backed ridge of land, seven or eight hundred feet high, crosses the country. It has a gentle ascent on the north, but is steep towards the south. The river at the fall makes its way through a narrow gap, whose nearly precipitous sides consist of tenacious clay, the bed and immediate borders of the stream being formed of greenstone.[45]From thence to the Copper Mountains, gently undulated plains occur, intersected in various parts by precipitous ridges of trap rocks, and the river flows in a narrow chasm, sunk about one hundred feet below their level. A few miles above Bloody-fall, strata of light gray clay-slate, dipping to the north-east, at an angle of 20°, support some greenstone cliffs on the banksof the river.222223224From this place to the Copper Mountains the rocks observed in the ravines were a dark reddish-brown, felspathose sandstone, and gray slate-clay, in horizontal strata, with greenstone rising in ridges. The soil is sandy, and in many places clayey, with a pretty close grassy sward. Straggling spruce trees begin to skirt the banks of the river about eighteen or twenty miles from the sea.
TheCopper Mountains rise perhaps eight or nine hundred feet above the bed of the river, and at a distance, present a somewhat soft outline, but on a nearer view they appear to be composed of ridges which have a direction from W.N.W. to E.S.E. Many of the ridges have precipitous sides, and their summits, which are uneven and stony, do not rise more than two hundred, or two hundred and fifty feet above the vallies, which are generally swampy and full of small lakes. The only rocks noticed when we crossed these hills on the late journey, were clay-slate, greenstone, and dark red sandstone, sometimes containing white calcareous concretions, resembling an amygdaloidal rock. On our first journey down the Coppermine River, we visited a valley where the Indians had been accustomed to look for native copper, and we found there many loose fragments of a trap rock, containing native copper, green malachite, copper glance, and iron-shot copper green; also trap containing greenish-gray prehnite with disseminated native copper, which, in some specimens was crystallized in rhomboidal dodecahedrons. Tabular fragments of prehnite, associated with calc-spar and native copper, were also picked up, evidently portions of a vein, but we did not discover the vein in its original repository. The trap-rock, whose fragments strewed the valley, consists of felspar, deeply coloured by hornblende. A few clumps of white spruce trees occur in the vallies of the Copper Mountains, but the country is in general naked. The Coppermine River makes a remarkable bend round the end of these hills.
After quitting the Copper Mountains, and passing a valley occupied by a chain of small lakes in lat. 67° 10', long. 116° 45', we travelled over a formation whose prevailing rocks are spotted sandstone and conglomerate, and which forms theheight of landbetwixt Bear Lake and the Coppermine River. Theascent to this height from the eastward is gradual, but the descent towards Bear Lake is more rapid. The country is broken and hilly, though the height of the hills above the sea is perhaps inferior to that of the Copper Mountains. The vallies through which the small streams that water the country flow, are narrow and deep, resembling ravines, and their sides are clayey. The ground is strewed with gravel.
Thesandstonehas very generally a purplish colour, with gray spots of various magnitudes. It is fine grained, hard, has a somewhat vitreous lustre and contains little or no disseminated mica.
Theconglomerateconsists of oval pebbles of white quartz, sometimes of very considerable magnitude, imbedded in an iron-shot cement. Many of the pebbles appear as if they had been broken and firmly re-united again. The conglomerate passes into a coarse sandstone.
Porphyry and granite form hills amongst the sandstone strata.
Theporphyryhas a compact basis, like hornstone, of a dull brown colour, which contains imbedded crystals of felspar and quartz, and occasionally of augite. It forms some dome-shaped and short conical hills.
Thegraniteis disposed in oblong ridges, with small mural precipices. It has, generally, a flesh-red colour, and contains some specks of augite, but little or no mica. The granite and porphyry were observed only on the east side of the height of land, the brow of which, and its whole western declivity, is formed of sandstone. Boulders of granite and porphyry, precisely similar to the varieties which occurin situon the height of land, are common on the beach at Fort Franklin, and on the banks of the Mackenzie above Bear Lake.
To the westward of the height of land, the country on the banks of Dease River is more level, and few rocksin situwere seen, until within five or six miles of Bear Lake, where the stream flows through a chasm, whose sides are composed of a soft, fine-grained red sandstone, like that which occurs in the vale of Dumfries, in Scotland. Several ravines here have their sides composed of fine sand, inclosing fragments of soft sandstone.
About three miles from the mouth of Dease River we came to a limestone formation, which has been already noticed in the account of the geological structure of the shores of Great Bear Lake.
Thepreceding part of the paper describing the rock formations which were noticed on the route of the expedition from Great Slave Lake down the Mackenzie along the shores of the Arctic Sea, the Coppermine, Great Bear Lake, and Great Bear River, being a distance of three thousand miles, I shall, by way of supplement, mention very briefly some of the more southern deposits.
The first I have to speak of is the chain of primitive rocks to which I have alluded in page 289, as extending for a very great distance in a north-west direction, and inclining in the northern parts slightly towards the Rocky Mountain Chain. Dr. Bigsby, in his account of the geology of Lake Huron says, that "The primitive rocks on the northern shores of that lake are part of a vast chain, of which the southern portion, extending probably uninterruptedly from the north and east of Lake Winipeg, passes thence along the northern shores of Lakes Superior, Huron, and Simcoe, and after forming the granitic barrier of the Thousand Isles, at the outlet of Lake Ontario, spreads itself largely throughout the state of New York, and there joins with the Alleghanies, and their southern continuations." It is not my intention to say any thing further of the rocks in the districts of which Dr. Bigsby speaks, although in travelling from the United States to Lake Winipeg the expedition passed over them. That zealous geologist has already given, in various publications, many interesting and accurate details of the formations on the borders of the great lakes; an account of those which lie some degrees farther to the north is inserted in the second volume of the Geological Transactions,—and there are some notices of them in the Appendix to the narrative of Captain Franklin's First Journey. My object at present is, merely to trace the western boundary of the primitive rocks in their course through the more northerly parts of the American continent.
I have already quoted Sir Alexander Mackenzie's original and important remark, of the principal lakes in those quarters being interposed betwixt the primitive rocks and the secondary strata, lying to the westward of them—Lake Winipeg is an instance in point. It is a long, narrow lake, and is bounded throughout on its east side by primitive rocks, mostly granitic, whilst its more indented western shore is formed of horizontal limestone strata. The western boundary of the primitive rocks, extending on this lake about two hundred and eighty miles, has nearly a north-north-west direction. From Norway Point, at the north end of the lake, to Isle à la Crosse, a distance of four hundred and twenty miles in a straight line, the boundary has a west-north-west direction. For two hundred and forty miles from Isle à la Crosse to Athabasca Lake, the course of the primitive rocks is unknown to me; but from Athabasca Lake to M'Tavish's Bay, in Great Bear Lake, a distance of five hundred miles, their western edge runs about north-west-by-west, and is marked by the Slave River, a deep inlet on the north side of Great Slave Lake, and a chain of rivers and lakes, (including great Marten Lake,) which discharge themselves into that inlet.
Captain Franklin on his voyage crossed this primitive chain nearly at right angles to its line of direction, in proceeding from Hudson's Bay to Lake Winipeg—it was there two hundred and twenty miles wide.
The hills composing the chain are of small elevation, none of them rising much above the surrounding country. They have mostly rounded summits, and they do not form continuous ridges; but are detached from each other, by vallies of various breadth, though generally narrow, and very seldom level. The sides of the hills are steep, often precipitous. When the vallies are of considerable extent, they are almost invariably occupied by a lake, the proportion of water in this primitive district being very great; from the top of the highest hill on the Hill River, which has not a greater altitude than six hundred feet, thirty-six lakes are said to be visible. The small elevation of the chain may be inferred from an examination of the map, which shows that it is crossed by several rivers, that rise in the Rocky Mountains, the most considerable of which are the Churchill and the Saskatchewan, or Nelson River. These great streams have, for many hundred miles from their origin, the ordinary appearance of rivers, in being bounded by continuous parallel banks; but on entering the primitive district, they present chains of lake-like dilatations, which are full of islands, and have a very irregular outline. Many of the numerous arms of these expansions wind for miles through the neighbouring country, and the whole district bears a striking resemblance, in the manner in which it is intersected by water, to the coast of Norway and the adjoining part of Sweden. The successive dilatations of the rivers have scarcely any current, but are connected to each other by one or morestraits, in which the water-course is more or less obstructed by rocks, and the stream is very turbulent and rapid. The most prevalent rock in the chain is gneiss; but there is also granite and mica-slate, together with numerous beds of amphibolic rocks.
Tothe westward of the chain of primitive rocks, through a great part, if not through the whole of its course, lies an extensive horizontal deposit of limestone.
Dr. Bigsby, in the Geological Transactions, has described, in detail, the limestone of Lake Huron, and is disposed to refer "the cavernous and brecciated limestone of Michilimackinac to the magnesian breccia, which is in England connected with the red marl;" whilst the limestones of St. Joseph, and the northern isles, he considers as more resembling the well-known formation of Dudley, in Staffordshire. The limestone of Thessalon Isle, in which there occurs the remarkable species of orthoceratite which he has figured, he describes as decidedly magnesian. I observed this orthoceratite in the limestone strata of one of the isles forming the passage of La Cloche in Lake Huron. The limestone deposits of Lake Winipeg and Cape Parry exactly resemble that of La Cloche in mineralogical characters, and in containing the same orthoceratite which was also found by Captains Parry and Lyon at Igloolik.
The colour of the limestone of Lake Winipeg is very generally yellowish-white, passing into buff, on the one hand, and into ash-gray on the other. A reddish tinge is also occasionally observed. Much of it has a flat fracture, with little or no lustre, and a fine-grained arenacious structure. A great portion of it, however, is compact, and has a flat conchoidal and slightly splintery fracture. This variety passes into a beautiful china-like chert.1001, 1014Many of the beds are full of long, narrow vesicular cavities, which are lined sometimes with calc-spar, but more frequently with minute crystals of quartz. The beds of this formation seldom exceed a foot in thickness, and are often very thin and slaty. The arenacious and cherty varieties frequently occur in the same bed; sometimes they form distinct beds. The softer kinds weather readily into a white marl, which is used by the residents to whitewash their houses. Wherever extensive surfaces of the strata were exposed, as in the channels of rivers, they were observed to be traversed by rents crossing each other at various angles. The larger rents, which were sometimes two yards or more in width, were however, generally parallel to each other for a considerable distance.
Professor Jameson enumeratesterebratulæ,orthoceratites,encrinites,caryophyllitæ, andlingulæ, as the organic remains in the specimens brought home by Captain Franklin on his first expedition. Mr. Stokes and Mr. James De Carle Sowerby have examined those which we procured on the last expedition, and found amongst themterebratulites,spirifers,maclurites, andcorallines. The maclurites belonging to the same species, with specimens from Lakes Erie and Huron, and also from Igloolik, are perhaps referrible to theMaclurea magnaof Le Sueur.10151019Sowerby determined a shell, occurring in great abundance in the strata at Cumberland-house, about one hundred and twenty miles to the westward of Lake Winipeg, to be thePentamerus Aylesfordii.
The extent to the westward of the limestone deposit of Lake Winipeg is not well known to me; but I have traced it as far up the Saskatchewan as Carlton House, and its breadth there is at least two hundred and eighty miles. For about one hundred miles below Carlton House, the river Saskatchewan flows betwixt banks from one to two hundred feet in height, consisting of clay or sand, and the beds of limestone are exposed in very few places. The plains in the neighbourhood of Carlton abound in small lakes, some of which are salt. The country which the Saskatchewan waters for one hundred and ninety miles before it enters Lake Winipeg, is of a different kind. It is still more flat than that about Carlton, and is so little raised above the level of the river, that in the spring-floods the whole is inundated, and in several places the river sends off branches which reunite with it after a course of many miles. In this quarter the soil is generally thin, and the limestone strata are almost every where extensively exposed. To the southward of Cumberland House, the Basquiau Hill has considerable elevation. I had not an opportunity of visiting it; but in the flat limestone strata, near its foot, there are salt springs, from which the Indians sometimes procure a considerable quantity of salt by boiling; and there are several sulphureous springs within the formation.
I observed no beds of conglomerate in it, and no sandstone associated with it; but the extensive plains which lie betwixtCarlton House and the Rocky Mountains are sandy, and beds of sandstone are said to be visible in some of the ravines.
The line of contact of the limestone with the primitive rocks of Lake Winipeg, is covered with water; but at the Dog's-Head, and near the north end of Beaver Lake, they are exposed within less than a mile of each other. To the southward of the Dog's-Head in Lake Winipeg, and in a few other quarters, some schistose rocks, belonging to the transition series, are interposed between the two formations.
Before quitting the formations of Lake Winipeg, I may remark, that the height of that lake above the sea is perhaps equal to that of Lake Superior, which is eight hundred feet.
Thenext formation I have to mention is one which appears to possess most of the characters ascribed by German geologists to the zechstein. It extends from the north side of the Methy carrying-place down the Clearwater, Elk, and Slave Rivers, and along the south shore of Great Slave Lake to the efflux of the Mackenzie. The line I have traced was the route of the expedition, and is also very nearly that of the eastern boundary of the limestone. Primitive rocks occur in Lake Mammawee, Athabasca Lake, and on the Stony River; and on several parts of the Slave River they are separated from the limestone only by the breadth of the stream. On Great Slave Lake, the Stony Island, on the north-east side of the mouth of Slave River, is composed of granite, whilst the limestone strata are exposed at Fort Resolution on the south-west side.
The limestone in this extensive tract is commonly in thin and nearly horizontal beds, and much of it exactly resembles in mineralogical characters the dolomite and chert of Lake1027, 1028Winipeg. It is interstratified with thin beds of soft white marl; and in a few places with a marly sandstone. Extensive beds of stinkstone also occur, and many beds of limestone containing fluid bitumen in cavities. The bitumen is in such quantity, in some quarters, as to flow in streams from fissures in the rock; and in an extensive district, around Pierre au Calumet on the Elk River, slaggy mineral pitch fills the crevices in the soil, and may be collected in large quantities by digging a well.
A calcareous breccia also exists in various places, particularly on the Slave River. Springs depositing from their waters sulphur, and sulphate of lime, slightly mixed with sulphate of magnesia, muriate of soda, and iron, are common and copious. A few miles to the westward of the Slave River, there is a ridge of hills several miles long, and about two hundred feet high, having several beds of compact, grayish gypsum exposed on its sides. From the base of this hill there issue seven or eight very copious, and many smaller springs, whose waters deposit a great quantity of very fine muriate of soda by spontaneous evaporation. The collected rivulets from these springs form a stream which is, at its junction with the Slave River, sixty yards wide and eight or ten feet deep.
1020 to 1026The organic remains, in this deposit, according a list kindly furnished by Mr. Sowerby, consist ofspirifers,1029 to 1032one of which is thespirifer acuta; several newterebratulæ, of which one resembles theT. resupinata, acirrus, some crinoidal remains, and corals.
At the union of Clearwater and Elk Rivers, the limestone beds are covered to the depth of one hundred and fifty feet with bituminous shale.
I have stated, that on Slave River this limestone formation succeeds immediately to primitive rocks, but I am not acquainted with the rocks that lie to the eastward of it on the Elk River. The traders report that there are extensive deposits of sandstone on the eastern arm of the Athabasca Lake, and, perhaps, these sandstones extend nearly to Clearwater River. Sand covers the limestone on that river to the depth of eight or nine hundred feet, and the fragments of sandstone in it are large, numerous, and not worn.
The quantity of gypsum in immediate connection with extremely copious and rich salt springs, and the great abundance of petroleum in this formation, together with the arenacious, soft, marly, and brecciated beds interstratified with the dolomite, and above all, the circumstance of the latter being by far the most common and extensive rock in the deposit, led me to think that the limestone of the Elk and Slave Rivers was equivalent to the zechstein of the continental geologists. My opinion, however, on this subject is, from a total want of practical acquaintance with the European rock formations, of little weight; and several eminent geologists are, after an examination of the organic remains and mineralogical characters of the specimens brought home, inclined to consider the formationas analogous to the carboniferous or mountain-limestone of England.
As to the limestone formation of Lake Winipeg, I have no doubt of its identity with that occurring in the islands at the passage of La Cloche, in Lake Huron, and also with that at Cape Parry and at Cape Krusenstern, on the coast of the Arctic Sea. It is probable, also, that these four deposits belong to the same epoch with the limestone of Elk and Slave Rivers, although they differ in containing little or no petroleum. It is proper to mention, however adverse it may be to the opinion I have ventured to hint at above, of these extensive horizontal deposits of limestone being referable to the zechstein, that the limestone of Lake Huron is generally considered as belonging to the mountain-limestone; and Professor Jameson, from a review of the organic remains occurring in the Lake Winipeg deposit, considered that it also belonged to that formation. The formation of Cape Lyon may be, with less danger of a mistake, referred to the transition or mountain-limestone.
Map of North America
FOOTNOTES:[20]This was estimated by allowing one foot descent per mile for Bear Lake River, whose length is seventy miles; and three inches per mile for the descent of Mackenzie River, from the junction of the former river to the sea, being a distance of five hundred miles.[21]In our former journey, we sounded near the Rein-Deer Islands in Slave Lake, with sixty-five fathoms line, without reaching the bottom.[22]Section of the cliffs at Limestone Point—strata dipping to the N.N.W.In the section the strata are represented much more inclined than they really are.231 Fine-grained, nearly compact, yellowish-gray dolomite, forming the summit of the hill, but the first, or lowest stratum, in the language of geologists.232 Compact, splintery dolomite, with a conchoidal fracture, and wax-yellow colour—second stratum.233 A cherty dolomite; containing calc-spar—third stratum.234 Bluish-gray dolomite, traversed by calc-spar—is nearly compact, and has an uneven, splintery fracture—forms the uppermost portion of the fourth stratum.235 Talcose? limestone, having a curved slaty structure, and containing cherty portions—from the lower part of the fourth stratum.236, 237 Earthy greenstone? forms the fifth stratum.238 Brownish-red dolomite, with an uneven fracture; scarcely splintery. It has a compact structure, and is intersected by veins of calc-spar—from the sixth stratum.239 Light yellowish gray dolomite, passing into chert—seventh stratum.240, 241 Thin slaty beds of brownish-red dolomite, like 238—eighth stratum.242 Bluish-white porcelain chert, sometimes mixed with red dolomite—243—ninth stratum.[23]List of boulders gathered on the beach at Fort Franklin.261 Coarse crystalline granite; felspar flesh-red in large crystals; quartz gray; mica black.262 Granite; felspar paler, and less distinctly crystallized; quartz in small quantity, gray; mica blackish, and rather abundant.263 Granite; felspar partly reddish, partly yellowish-white, quartz in small grains; mica equalling the quartz in quantity, black.264 Granite, fine-grained: quartz and felspar, white, the former nearly transparent, black; mica in small specks, garnets.265, 268 Granite; quartz in regular crystals; mica blackish, in small quantity.266 Granite? red felspar in large crystals; quartz gray; mica replaced by chlorite?267 Granite; felspar gray; chlorite? in small quantity.269 Granite, small grained, passing into gneiss; reddish-brown felspar and gray quartz, intimately mixed, and having in the aggregate, a vitreous lustre; mica in layers.270 Granite coarser grained than the preceding, containing more quartz; the mica disseminated.271, 273 Granite with little mica, some portions of the felspar tinged green.272, 274, 275, 277, 278, 279, 280, Granite grayish and small grained mica black.276 Granite; brick-red felspar; quartz; and augite?—no mica.The mica is mostly black in all the granite boulders that occur here, the felspar most frequently reddish.281 Porphyritic granite? felspar imperfectly crystallized, containing large, imbedded crystals; quartz; and chlorite?282 Granite? composed of felspar, of quartz, with, perhaps, a few minute grains of chlorite?283 Granite? contains little quartz, and a few scales of mica, with some chlorite?284 Sienite; felspar somewhat granular, a little quartz and chlorite?285 Porphyritic sienite? having a basis of slightly granular felspar, with light-coloured crystals of felspar, some quartz and disseminated grains of chlorite?286 Reddish-brown hornstone porphyry.287 Crystalline greenstone.288 Fine-grained greenstone.289 Porphyritic greenstone.290 Pitchstone porphyry.291 Greenstone slate with pyrites.292 Amygdaloidal claystone porphyry.293 Compact grayish-blue dolomite.294 Splintery dolomite.295 Cellular dolomite.296 Swinestone.297 Limestone with corallines.298 Chert.299 White quartz.300 Quartz-rock.301 Coarse sandstone.302 Fine-grained white sandstone.303 Fine-grained red sandstone.304 Fine-grained striped sandstone.305 Fine-grained spotted sandstone.306 Slaty sandstone verging towards slate-clay.307 Dark-red claystone.308 Light-coloured claystone.[24]List of Specimens from Diluvial Gravel, Fort Franklin.1 Amphibolic granite, rather coarse crystalline, felspar flesh-red.2 Ditto, approaching to gneiss.3 Gneiss approaching to mica-slate, felspar white, and in small quantity.4 Greenstone with much felspar and minute disseminated pyrites.5 Quartz rock? having brownish and imperfect crystals, and a reddish disintegrated mineral disseminated.6 Brownish-red and fine granular quartz-rock, with a somewhat splintery fracture. It has the aspect of compact felspar.7 Quartz rock, reddish crystalline texture, and vitreous lustre, but with small rounded grains imbedded in it, bringing it near to sandstone.8 Coarse sandstone; rounded grains of quartz united by a clayey basis.9 Fine-grained purplish sandstone, with grayish spots. This sandstone occursin situnear the Copper Mountains, between Dease Bay and the Coppermine River.10 Fine-grained yellowish-white sandstone.11 Yellowish-gray sandstone, composed of small rounded grains of quartz united by a powdery white basis.12 Yellowish-gray sandstone, composed of fine grains of vitreous quartz.13 Sandstone, having different shades of brownish-red colour, in layers.14 Lydian stone.[25]Mr. Sowerby, who inspected all the specimens containing organic remains, says of this species of ammonite, "it is, as far as I can discover, new. It contains sulphate of barytes, and is probably referrible to some of the Oolites near the Oxford clay." Although it was found lying on the beach, I have no doubt of its having fallen from some of the beds of clayey sandstone, which form the walls of the rapid.[26]33 This limestone appears as if composed of an aggregate of small crystals, and presents many drusy cavities.34 Is an adjoining bed of a similar colour, of a fine crystalline texture, but without the drusy cavities. It appears to be a dolomite. These two beds dip to the northward.35, 36 Calcareous breccia. The two preceding beds (33 and 34) were from the summit of the portion of the hill which forms the cliff, but taken a little farther to the N.W. In the cliff the beds dip, as has been stated, to the S.W. The following beds occur in going to the north-westward, towards the summit of the highest peak, commencing near its base, in a valley behind the cliff.37 A fine-grained blackish-gray dolomite, having interspersed many nodules of chert, or grayish-white quartz, not crystallized.38 A very compact, opaque limestone, of a smoke-gray colour, having a flat and slightly splintery fracture. Effervesces briskly.39 Blackish-gray rather compact limestone, having a flat and dull fracture, and intersected by small veins of calc-spar. This is a prevalent stone in the hill, and also occurs in quantity in other limestone ridges in the neighbourhood.40 An ash-gray, fine-granular dolomite.41 A conglomerate, forming the summit of the highest peak.[27]57 This breccia has a white calcareous basis, which incloses angular fragments of compact, yellowish-gray limestone, with smooth dull surfaces.58 Grayish-white limestone, having a fine crystalline texture, with drusy cavities, incrusted with bitumen.59 Limestone, apparently composed of crystalline fragments, highly charged with bitumen, cemented by a whitish carbonate of lime in minute crystals. I could not satisfy myself whether this variety of colour proceeded from partial impregnations of bitumen, or from a brecciated structure. Specimens 58 and 59 were from beds near the western part of the hill.60 A fine-grained dolomite, approaching to compact, having a flat and somewhat splintery fracture, and a brownish-gray colour.61, 62 Limestone in the body of the hill, resembling No. 39 in the hill at the rapid in Bear Lake River, but with larger veins of calc-spar.63, 64 Dark blackish-brown bituminous shale, veined with calc-spar, and passing into bituminous marl-slate. It contains nodules of iron pyrites.65 Thin bed of indurated shale, approaching to flinty-slate, lying at the foot of some beds of bituminous limestone. Their connection not clearly made out.66, 67, 68 Bluish-gray, fine-grained sandstone, some of them passing into slate-clay, and scarcely to be distinguished from those at the rapid in Bear Lake River. Capt. Franklin took these specimens from horizontal beds at the foot of the hill facing Bear Lake River.[28]Sir Alexander Mackenzie, in p. 95 of his Voyage to the Arctic Sea, states, that he saw several small mineral springs running from the foot of this mountain, and found lumps of iron ore on the beach.[29]Travels in the Arkansa, p. 52-54.[30]Section I.The section of the bank at the mouth of the Bear Lake River is as follows, beginning with the lowest bed:—81Gravel, with thin layers of sand rising from the water's edge in a perpendicular cliff, to the height of30feetLignite (70 to 80 and 84)183Potter's clay of a bluish gray colour, alternating with layers of sand40A sloping uneven brow, covered with soil, extends to the summit of the bank2091Lydian stone is the most abundant, and whitish quartz the least so of the pebbles mentioned in the text as entering into the composition of the gravel.82A little farther up the Mackenzie, this bed of gravel passes into sand, which, in some spots, has sufficient coherence to merit for it the name of sandstone. During a great part even of the summer season, all the beds of sand are frozen into a hard sandstone; but a piece having been broken off and put into the pocket, speedily thawed into sand.83Specimens of the clay, which I have denominated potter's clay, taken from near the beds of lignite, have a colour intermediate between yellowish-gray and clove-brown, a dull earthy fracture, and a slightly greasy feel. It is not gritty under the knife, and acquires a slightly shining smooth surface, adheres slightly to the tongue, and, when moistened with water, assumes a darker colour, and becomes plastic.Section II.About five miles above Bear Lake River, the cliff consists of Slaty sandstone evidently composed of the same materials with the friable kinds described in the text, but having tenacity enough to form a building stone. It incloses someseams of lignite10feetLignite14½Clay and Sand50Irregular slope from top of cliff to summit of bank90154½Section III.A little farther up the river than the preceding:—85Pipe-clay on a level with the water1foot86Lignite190Potter's clay14feet87Pipe-clay1foot89Lignite191Potter's clay10feetLignite1footSandstone8feetLignite2½Potter's clay1094Friable sandstone and clay20Sandstone a little more durable12Sloping Summit40121½The pipe-clay, when taken newly from the bed, is soft and plastic, has little grittiness, and when chewed for a little time, a somewhat unctuous but not unpleasant taste. When dried in the air it acquires the hardness of chalk, adheres to the tongue, and has the appearance of the whiter kinds of English pipe-clay, but is more meagre.Section IV.A little above the preceding:—A precipitous bank of gravel12feetLignite and clay, the beds concealed by debris40Friable sandstone30Height of the cliff82Section V.Ten miles above Bear Lake River, at the junction of a small torrent with the Mackenzie, there is a cliff about forty feet high, in which the strata have a dip of sixty degrees to the southward.98Bed, No. 1 Porcelain clay2yards992 Potter's clay slightly bituminous100, 1012½3 Thin-slaty lignite, with two seams of clay-iron stone, an inch thick1041054 Pipe clay, (nine inches)¼1065 Porcelain clay36 Bituminous clay31077 Lignite, with a conchoidal fracture28 Pipe clay¼1109 Porcelain clay310 Bituminous clay311 Lignite, earthy paste, enclosing fibrous fragments212 Porcelain earth913 Bituminous clay14 Porcelain earth31yardsThe three last beds it is probable, once inclosed seams of coal which have been consumed, but the quantity of debris prevented this from being ascertained satisfactorily during the hurried visit I paid to them.108Over these inclined beds there is a shelving and crumbling cliff of sand and clay covered by a sloping bank of vegetable earth. A layer of peat at the summit has a thin slaty structure, and presents altogether, except in colour and lustre, a striking resemblance to the shaly lignite, forming bed No. 3 in the preceding Section.104, 98. The substance composing beds Nos. 1 and 5, which I have denominated Porcelain clay, has a fine, granular texture, and the appearance of some varieties of chalk. It adheres slightly to the tongue, yields readily to the nail, is meagre, and soils the fingers slightly. There are many specks of coaly matter disseminated through it, and some minute scales of mica, and perhaps of quartz. When moistened with water, it becomes more friable, and is not plastic. It does not effervesce with acids.Bed No. 9 is the same mineral that forms beds 1 and 5; but it has a grayer colour from the greater quantity of coaly particles, and its structure is slightly slaty.The bituminous clay of bed No. 6, has a thick-slaty structure, a grayish-black colour, and a shining resinous streak. It is sectile, but does not yield to the nail. Pieces of lignite occur imbedded in it, and it is traversed by fibrous ramifications of carbonaceous matter.Specimens 115, 116, 117, 118, 119, are of substances altered by contact with beds of burning coal.[31]See Page50of the Narrative.[32]Noticed in page267.[33]List of specimens, collected by Captain Franklin, on the sea-coast, to the westward of the Mackenzie.From Mount Fitton in the Richardson Chain.344 Grauwacke-slate in columnar concretions, detached from the rocky strata by an Esquimaux.348 Grauwacke-slate, resembling the preceding, from the same place. Used by the Esquimaux as a whetstone.345, 346 Globular balls of dark, blackish-gray, splintery limestone, and of flinty-slate, traversed by minute veins of calc-spar. Picked up at the base of the mountain.347 Worn pebbles of quartz, lydian stone, splintery limestone, and grauwacke, from the same spot.349 Fine-grained, mountain-green clay-slate, approaching to potstone; quarried by the Esquimaux in the Cupola Mountain of the same chain, and used to form utensils.350 Rock-crystal from the same chain of mountains.From the beach between Point Sabine and Point King.351 Brown-coal, woody structure scarcely perceptible. There are beds of this coal in the earthy cliffs where the party was encamped on the 13th and 14th July near Point King.352 Clay-iron stone, forming boulders in the channels of the rills, which cut the earthy banks containing coal.353, 354 Pitch-coal, having a fibrous structure and a very beautiful fracture, presenting a congeries of circles. (This coal was recognised by Professor Buckland to be a tertiary pitch-coal, and is precisely similar to specimens brought from the upper branches of the Saskatchewan, by Mr. Drummond: see page284.) The specimen was picked up from the gravelly beach at the mouth of the Babbage River.355 Greenish-gray limestone, with a somewhat earthy granular aspect; containing shells which Mr. Sowerby considers to be very like thecyclas mediusof the Sussex weald-clay. Picked up at the same place with the preceding specimen.Captain Franklin remarks, that "the Babbage flows between the mountains of the Richardson Chain, and that there were no solid strata nor any large boulders near its mouth. The gravel consisted of pebbles of red and white sandstone, slaty limestone, greenstone, and porphyry, much worn by attrition."From Mount Conybeare, in the Buckland Chain.356 Greenish-gray grauwacke slate, (resembling No. 348,) with specks of effervescent carbonate of lime. The surfaces of the slates exhibit interspersed scales of mica. The specimens were broken from the summit of Mount Conybeare, at the western extreme of the Buckland Chain: latitude 69° 27', longitude 139° 53' west.358 Fine-grained grauwacke-slate in columnar concretions, from the same place with specimen 356.357 Grauwacke-slate, in thick slaty columnar concretions, besprinkled with scales of mica. Taken from a bed about the middle of Mount Conybeare. The resemblance of this stone to that of Mount Fitton (No. 344) is very remarkable.360 Similar rock to 358, with an adhering portion of a vein of crystallized quartz, and on one side a bit of bluish-gray slate. From the middle of Mount Conybeare.359 Columnar concretion of a slaty rock, like 356, but more quartzose, breaking into rhomboidal fragments. From the middle of Mount Conybeare.361, 362 Grauwacke-slate, with a thin adhering vein of carbonate of lime and numerous particles of disseminated mica. From the middle of Mount Conybeare.363 Bluish-gray grauwacke-slate, resembling Nos. 348 and 344. From the Upper Terrace, at the base of Mount Conybeare.364 Dark-bluish gray and very fine-grained grauwacke-slate, with a glimmering lustre, traversed by a vein of quartz. From the same place.365 A thick-slaty angular concretion of a very quartzose grauwacke-slate, (similar to Nos. 348 and 358,) decomposed on the surface and breaking into rhomboidal fragments. From the middle Terrace at the base of Mount Conybeare.366 A somewhat rhomboidal portion of flinty-slate, apparently part of a bed. From the Lower Terrace of Mount Conybeare, which is composed of this rock. The terrace is ten miles distant from the sea-coast, and the intervening ground is swampy.The whole series of specimens from Mount Conybeare, (Nos. 356 to 366,) appear to belong to transition rocks; and the continuity of the formation with that of Mount Fitton is rendered probable, both by the resemblance of the specimens and the geographical situation of the mountains.Captain Franklin saw no rocks,in situ, on the coast to the westward of the Richardson Chain; but he gathered boulders of the following rocks from the bed of the Net-setting Rivulet, which flows from the British Chain of the Rocky Mountains, and falls into the Arctic Sea, between Sir P. Malcolm River and Backhouse River.367 Greenstone; 368, yellowish-gray sandstone; 369, dark-coloured splintery-limestone; 370, 371, 372, dolomite; 373, quartzose sandstone, like the old red sandstone; 374, grauwacke-slate; 375, quartz and iron pyrites.Boulders of the under-mentioned rocks were gathered on Flaxman Island.378 Fine-grained, greenish clay-slate, obviously of primitive rock, abundant in the neighbourhood, and supposed to have been brought down by the rivulets which flow from the Romanzoff Chain. 379, quartz.376 and 377 were from Foggy Island, and are rolled specimens of flinty-slate; one of them containing corallines.[34]Page268.[35]134. These specimens have a wood-brown colour internally, and appear to be composed of minute grains of quartz, variously coloured, white, yellowish-brown and black, cemented together by an earthy basis. It is a hard and apparently durable stone, occurring in layers an inch thick, and having its seam-surfaces of a grayish-black colour, with little lustre, as if from a thin coating of bituminous clay.135, are specimens of a more compact, harder, and finer-grained quartzose sandstone, with less cement, and of a deeper bluish-gray colour.[36]Mackenzie attempted to ascend this hill, but was compelled to desist by clouds of musquitoes, (July 6th, 1789.Voyage to the Arctic Sea, p. 40.)136 This limestone effervesces strongly with acids, breaks into irregular fragments, but with an imperfect slaty structure, and has a brown colour, with considerable lustre in the cross fracture.The specimens collected by Captain Franklin were as follows:—144a Sandstone of an ash-gray colour, composed of rounded grains of semi-transparent quartz of various sizes, imbedded in a considerable proportion of a powdery basis which effervesces with acids. This bed weathers readily.145 Thick-slaty sandstone passing into slate-clay, having a very fine-grained earthy fracture, and a light bluish-gray colour. It is very similar to some of the softer sandstones that occur in the coal field at Edinburgh, particularly in the Calton Hill.146 Sectile ash-gray slate-clay which forms the partings of the beds.144b Bluish-gray marl, impregnated with quartz, forming a moderately hard stone, and containing corallines (amplexus.)[37]Upper part of the ramparts.148 A fine-granular, foliated limestone, of a white colour, having large patches stained yellowish-brown, apparently by bitumen.149 A yellowish-gray slightly granular limestone, with disseminated calc-spar.150 Compact, white limestone, which, when examined with a lens, appears to be entirely composed of madrepores.151 Specimens of limestone, having a crystalline texture, a brownish colour and slaty structure.152 The seams are dark, as if from the carbonaceous matter—portions of this bed have the appearance of old mortar; but contain obscure madrepores.From the middle of the ramparts.153 Fine-granular limestone, having a pale, wood-brown colour, and a splintery fracture. It resembles the limestone of the hill at the mouth of Bear Lake River.154 Pale yellowish-brown limestone, with a dull fracture, but interspersed with small, shining, sparry plates, and traversed by concretions of calc-spar, that appear to have originated in corallines.155 Yellowish-gray limestone, passing into a soft marl slate.156 Some beds contain a shell, which Mr. Sowerby refers, though with doubt, to the species named terebratula sphæroidalis, a fossil of the cornbrash. The substance of the shells is preserved.Some of the specimens containproducti, and fragments of the coral namedamplexus.Lower end of the ramparts.157 Fine-grained limestone, of a dark-brown colour, containing some small, round, smooth balls of dark limestone—occurs in horizontal strata.158 Brownish-black flinty-slate, which forms a layer an inch thick, and covers the horizontal beds of limestone last mentioned. (157.)[38]Specimens from the cliffs in lat. 66¾°.159 Very fine-grained sandstone, with much clayey basis—portions of the bed iron-shot.160 Sandstone fine-grained, and appearing, when examined with a lens, to be composed of minute grains of whitish translucent quartz, black Lydian stone, and ochre-coloured grains, probably of disintegrated felspar.161 Rounded grains of nearly transparent quartz united without cement—this stone is friable.162 Sandstone composed of grains like the preceding, united by a basis, and forming a firmer stone.163 Hard, thin, slaty, bluish-gray sandstone, much iron-shot.164 Fine-grained, bluish-gray sandstone, not to be distinguished in hand-specimens from some of the sandstones which occur at the rapid in Bear Lake River.[39]Horizontal limestone beds lying under the sandstone.166 Fine-grained limestone, with an earthy fracture, coloured brown and grayish-white in patches.167, 168 Similar stone to preceding, containing many shells. Some beds contain only broken shells.169 Bed of imperfectly crystalline limestone, of a brownish-gray colour, traversed by veins of calc-spar.170 Fragments containing madrepores and chain coral—occur amongst the debris of the limestone cliffs.[40]Sandstone cliffs twenty miles below Fort Good Hope.173 Friable sandstone, composed of grayish-white quartz, in smooth, rounded grains, cemented by a brownish basis. Some carbonaceous matter is interspersed through the stone, and it contains small fragments of bituminous shale.174 Calcareous sandstone passing into slate-clay—bluish-gray colour.175 Black, flinty-slate, with a flat conchoidal cross fracture. Some of the pieces appear to be rhomboidal distinct concretions.176 Dull, flinty-slate, with an even fracture.178 Thin-slaty blackish-gray sandstone, much indurated, containing scales of mica.179, 180 Bluish-gray sandstone, containing many minute specks of carbonaceous matter; also, in patches, grains of chert, and flinty-slate, and imbedded pieces of iron-shot clay, which has obscure casts of shells. Scales of mica are interspersed through this stone.181, 182 Sandstone containing specks of bituminous? coal, and casts of some vegetable? substance.183 Gray limestone, much impregnated with quartz, and having an imperfect crystalline structure.[41]Mackenzie notices the precipices of "gray stone," which bound the river here, p. 71.[42]See page288.[43]Specimens from Sellwood Bay.202 Fine-grained dark brownish-gray dolomite, with corallines filled with white calc-spar.203 Lucullite grayish-black, compact, and without lustre.204 Gray dolomite.205 A rolled piece, evidently of the same rock with the preceding, containing the impression of acardium.206[44]Specimens from the Promontory of Cape Parry, which rises into a hill, seven hundred feet high. Strata dipping lightly to the northward.207 Yellowish-gray dolomite, imperfectly crystalline, being similar to the limestone of Lake Winipeg.208 Brownish dolomite impregnated with silica.209 Thin-slaty, gray limestone. Very common also in Lake Winipeg.210, 211 Boulders of dolomite.212213 Brown dolomite, with drusy cavities and veins, lined by calc-spar.[45]In the geological notices appended to the narrative of Captain Franklin's Journey to the Coppermine, I have termed this rock a dark purplish-red felspar rock. On examining it again on this journey, I perceived it to be a greenstone, whose surfaces weather of a rusty brown colour.
[20]This was estimated by allowing one foot descent per mile for Bear Lake River, whose length is seventy miles; and three inches per mile for the descent of Mackenzie River, from the junction of the former river to the sea, being a distance of five hundred miles.
[20]This was estimated by allowing one foot descent per mile for Bear Lake River, whose length is seventy miles; and three inches per mile for the descent of Mackenzie River, from the junction of the former river to the sea, being a distance of five hundred miles.
[21]In our former journey, we sounded near the Rein-Deer Islands in Slave Lake, with sixty-five fathoms line, without reaching the bottom.
[21]In our former journey, we sounded near the Rein-Deer Islands in Slave Lake, with sixty-five fathoms line, without reaching the bottom.
[22]Section of the cliffs at Limestone Point—strata dipping to the N.N.W.In the section the strata are represented much more inclined than they really are.231 Fine-grained, nearly compact, yellowish-gray dolomite, forming the summit of the hill, but the first, or lowest stratum, in the language of geologists.232 Compact, splintery dolomite, with a conchoidal fracture, and wax-yellow colour—second stratum.233 A cherty dolomite; containing calc-spar—third stratum.234 Bluish-gray dolomite, traversed by calc-spar—is nearly compact, and has an uneven, splintery fracture—forms the uppermost portion of the fourth stratum.235 Talcose? limestone, having a curved slaty structure, and containing cherty portions—from the lower part of the fourth stratum.236, 237 Earthy greenstone? forms the fifth stratum.238 Brownish-red dolomite, with an uneven fracture; scarcely splintery. It has a compact structure, and is intersected by veins of calc-spar—from the sixth stratum.239 Light yellowish gray dolomite, passing into chert—seventh stratum.240, 241 Thin slaty beds of brownish-red dolomite, like 238—eighth stratum.242 Bluish-white porcelain chert, sometimes mixed with red dolomite—243—ninth stratum.
[22]Section of the cliffs at Limestone Point—strata dipping to the N.N.W.
In the section the strata are represented much more inclined than they really are.
231 Fine-grained, nearly compact, yellowish-gray dolomite, forming the summit of the hill, but the first, or lowest stratum, in the language of geologists.
232 Compact, splintery dolomite, with a conchoidal fracture, and wax-yellow colour—second stratum.
233 A cherty dolomite; containing calc-spar—third stratum.
234 Bluish-gray dolomite, traversed by calc-spar—is nearly compact, and has an uneven, splintery fracture—forms the uppermost portion of the fourth stratum.
235 Talcose? limestone, having a curved slaty structure, and containing cherty portions—from the lower part of the fourth stratum.
236, 237 Earthy greenstone? forms the fifth stratum.
238 Brownish-red dolomite, with an uneven fracture; scarcely splintery. It has a compact structure, and is intersected by veins of calc-spar—from the sixth stratum.
239 Light yellowish gray dolomite, passing into chert—seventh stratum.
240, 241 Thin slaty beds of brownish-red dolomite, like 238—eighth stratum.
242 Bluish-white porcelain chert, sometimes mixed with red dolomite—243—ninth stratum.
[23]List of boulders gathered on the beach at Fort Franklin.261 Coarse crystalline granite; felspar flesh-red in large crystals; quartz gray; mica black.262 Granite; felspar paler, and less distinctly crystallized; quartz in small quantity, gray; mica blackish, and rather abundant.263 Granite; felspar partly reddish, partly yellowish-white, quartz in small grains; mica equalling the quartz in quantity, black.264 Granite, fine-grained: quartz and felspar, white, the former nearly transparent, black; mica in small specks, garnets.265, 268 Granite; quartz in regular crystals; mica blackish, in small quantity.266 Granite? red felspar in large crystals; quartz gray; mica replaced by chlorite?267 Granite; felspar gray; chlorite? in small quantity.269 Granite, small grained, passing into gneiss; reddish-brown felspar and gray quartz, intimately mixed, and having in the aggregate, a vitreous lustre; mica in layers.270 Granite coarser grained than the preceding, containing more quartz; the mica disseminated.271, 273 Granite with little mica, some portions of the felspar tinged green.272, 274, 275, 277, 278, 279, 280, Granite grayish and small grained mica black.276 Granite; brick-red felspar; quartz; and augite?—no mica.The mica is mostly black in all the granite boulders that occur here, the felspar most frequently reddish.281 Porphyritic granite? felspar imperfectly crystallized, containing large, imbedded crystals; quartz; and chlorite?282 Granite? composed of felspar, of quartz, with, perhaps, a few minute grains of chlorite?283 Granite? contains little quartz, and a few scales of mica, with some chlorite?284 Sienite; felspar somewhat granular, a little quartz and chlorite?285 Porphyritic sienite? having a basis of slightly granular felspar, with light-coloured crystals of felspar, some quartz and disseminated grains of chlorite?286 Reddish-brown hornstone porphyry.287 Crystalline greenstone.288 Fine-grained greenstone.289 Porphyritic greenstone.290 Pitchstone porphyry.291 Greenstone slate with pyrites.292 Amygdaloidal claystone porphyry.293 Compact grayish-blue dolomite.294 Splintery dolomite.295 Cellular dolomite.296 Swinestone.297 Limestone with corallines.298 Chert.299 White quartz.300 Quartz-rock.301 Coarse sandstone.302 Fine-grained white sandstone.303 Fine-grained red sandstone.304 Fine-grained striped sandstone.305 Fine-grained spotted sandstone.306 Slaty sandstone verging towards slate-clay.307 Dark-red claystone.308 Light-coloured claystone.
[23]List of boulders gathered on the beach at Fort Franklin.
261 Coarse crystalline granite; felspar flesh-red in large crystals; quartz gray; mica black.
262 Granite; felspar paler, and less distinctly crystallized; quartz in small quantity, gray; mica blackish, and rather abundant.
263 Granite; felspar partly reddish, partly yellowish-white, quartz in small grains; mica equalling the quartz in quantity, black.
264 Granite, fine-grained: quartz and felspar, white, the former nearly transparent, black; mica in small specks, garnets.
265, 268 Granite; quartz in regular crystals; mica blackish, in small quantity.
266 Granite? red felspar in large crystals; quartz gray; mica replaced by chlorite?
267 Granite; felspar gray; chlorite? in small quantity.
269 Granite, small grained, passing into gneiss; reddish-brown felspar and gray quartz, intimately mixed, and having in the aggregate, a vitreous lustre; mica in layers.
270 Granite coarser grained than the preceding, containing more quartz; the mica disseminated.
271, 273 Granite with little mica, some portions of the felspar tinged green.
272, 274, 275, 277, 278, 279, 280, Granite grayish and small grained mica black.
276 Granite; brick-red felspar; quartz; and augite?—no mica.
The mica is mostly black in all the granite boulders that occur here, the felspar most frequently reddish.
281 Porphyritic granite? felspar imperfectly crystallized, containing large, imbedded crystals; quartz; and chlorite?
282 Granite? composed of felspar, of quartz, with, perhaps, a few minute grains of chlorite?
283 Granite? contains little quartz, and a few scales of mica, with some chlorite?
284 Sienite; felspar somewhat granular, a little quartz and chlorite?
285 Porphyritic sienite? having a basis of slightly granular felspar, with light-coloured crystals of felspar, some quartz and disseminated grains of chlorite?
286 Reddish-brown hornstone porphyry.
287 Crystalline greenstone.
288 Fine-grained greenstone.
289 Porphyritic greenstone.
290 Pitchstone porphyry.
291 Greenstone slate with pyrites.
292 Amygdaloidal claystone porphyry.
293 Compact grayish-blue dolomite.
294 Splintery dolomite.
295 Cellular dolomite.
296 Swinestone.
297 Limestone with corallines.
298 Chert.
299 White quartz.
300 Quartz-rock.
301 Coarse sandstone.
302 Fine-grained white sandstone.
303 Fine-grained red sandstone.
304 Fine-grained striped sandstone.
305 Fine-grained spotted sandstone.
306 Slaty sandstone verging towards slate-clay.
307 Dark-red claystone.
308 Light-coloured claystone.
[24]List of Specimens from Diluvial Gravel, Fort Franklin.1 Amphibolic granite, rather coarse crystalline, felspar flesh-red.2 Ditto, approaching to gneiss.3 Gneiss approaching to mica-slate, felspar white, and in small quantity.4 Greenstone with much felspar and minute disseminated pyrites.5 Quartz rock? having brownish and imperfect crystals, and a reddish disintegrated mineral disseminated.6 Brownish-red and fine granular quartz-rock, with a somewhat splintery fracture. It has the aspect of compact felspar.7 Quartz rock, reddish crystalline texture, and vitreous lustre, but with small rounded grains imbedded in it, bringing it near to sandstone.8 Coarse sandstone; rounded grains of quartz united by a clayey basis.9 Fine-grained purplish sandstone, with grayish spots. This sandstone occursin situnear the Copper Mountains, between Dease Bay and the Coppermine River.10 Fine-grained yellowish-white sandstone.11 Yellowish-gray sandstone, composed of small rounded grains of quartz united by a powdery white basis.12 Yellowish-gray sandstone, composed of fine grains of vitreous quartz.13 Sandstone, having different shades of brownish-red colour, in layers.14 Lydian stone.
[24]List of Specimens from Diluvial Gravel, Fort Franklin.
1 Amphibolic granite, rather coarse crystalline, felspar flesh-red.
2 Ditto, approaching to gneiss.
3 Gneiss approaching to mica-slate, felspar white, and in small quantity.
4 Greenstone with much felspar and minute disseminated pyrites.
5 Quartz rock? having brownish and imperfect crystals, and a reddish disintegrated mineral disseminated.
6 Brownish-red and fine granular quartz-rock, with a somewhat splintery fracture. It has the aspect of compact felspar.
7 Quartz rock, reddish crystalline texture, and vitreous lustre, but with small rounded grains imbedded in it, bringing it near to sandstone.
8 Coarse sandstone; rounded grains of quartz united by a clayey basis.
9 Fine-grained purplish sandstone, with grayish spots. This sandstone occursin situnear the Copper Mountains, between Dease Bay and the Coppermine River.
10 Fine-grained yellowish-white sandstone.
11 Yellowish-gray sandstone, composed of small rounded grains of quartz united by a powdery white basis.
12 Yellowish-gray sandstone, composed of fine grains of vitreous quartz.
13 Sandstone, having different shades of brownish-red colour, in layers.
14 Lydian stone.
[25]Mr. Sowerby, who inspected all the specimens containing organic remains, says of this species of ammonite, "it is, as far as I can discover, new. It contains sulphate of barytes, and is probably referrible to some of the Oolites near the Oxford clay." Although it was found lying on the beach, I have no doubt of its having fallen from some of the beds of clayey sandstone, which form the walls of the rapid.
[25]Mr. Sowerby, who inspected all the specimens containing organic remains, says of this species of ammonite, "it is, as far as I can discover, new. It contains sulphate of barytes, and is probably referrible to some of the Oolites near the Oxford clay." Although it was found lying on the beach, I have no doubt of its having fallen from some of the beds of clayey sandstone, which form the walls of the rapid.
[26]33 This limestone appears as if composed of an aggregate of small crystals, and presents many drusy cavities.34 Is an adjoining bed of a similar colour, of a fine crystalline texture, but without the drusy cavities. It appears to be a dolomite. These two beds dip to the northward.35, 36 Calcareous breccia. The two preceding beds (33 and 34) were from the summit of the portion of the hill which forms the cliff, but taken a little farther to the N.W. In the cliff the beds dip, as has been stated, to the S.W. The following beds occur in going to the north-westward, towards the summit of the highest peak, commencing near its base, in a valley behind the cliff.37 A fine-grained blackish-gray dolomite, having interspersed many nodules of chert, or grayish-white quartz, not crystallized.38 A very compact, opaque limestone, of a smoke-gray colour, having a flat and slightly splintery fracture. Effervesces briskly.39 Blackish-gray rather compact limestone, having a flat and dull fracture, and intersected by small veins of calc-spar. This is a prevalent stone in the hill, and also occurs in quantity in other limestone ridges in the neighbourhood.40 An ash-gray, fine-granular dolomite.41 A conglomerate, forming the summit of the highest peak.
[26]33 This limestone appears as if composed of an aggregate of small crystals, and presents many drusy cavities.
34 Is an adjoining bed of a similar colour, of a fine crystalline texture, but without the drusy cavities. It appears to be a dolomite. These two beds dip to the northward.
35, 36 Calcareous breccia. The two preceding beds (33 and 34) were from the summit of the portion of the hill which forms the cliff, but taken a little farther to the N.W. In the cliff the beds dip, as has been stated, to the S.W. The following beds occur in going to the north-westward, towards the summit of the highest peak, commencing near its base, in a valley behind the cliff.
37 A fine-grained blackish-gray dolomite, having interspersed many nodules of chert, or grayish-white quartz, not crystallized.
38 A very compact, opaque limestone, of a smoke-gray colour, having a flat and slightly splintery fracture. Effervesces briskly.
39 Blackish-gray rather compact limestone, having a flat and dull fracture, and intersected by small veins of calc-spar. This is a prevalent stone in the hill, and also occurs in quantity in other limestone ridges in the neighbourhood.
40 An ash-gray, fine-granular dolomite.
41 A conglomerate, forming the summit of the highest peak.
[27]57 This breccia has a white calcareous basis, which incloses angular fragments of compact, yellowish-gray limestone, with smooth dull surfaces.58 Grayish-white limestone, having a fine crystalline texture, with drusy cavities, incrusted with bitumen.59 Limestone, apparently composed of crystalline fragments, highly charged with bitumen, cemented by a whitish carbonate of lime in minute crystals. I could not satisfy myself whether this variety of colour proceeded from partial impregnations of bitumen, or from a brecciated structure. Specimens 58 and 59 were from beds near the western part of the hill.60 A fine-grained dolomite, approaching to compact, having a flat and somewhat splintery fracture, and a brownish-gray colour.61, 62 Limestone in the body of the hill, resembling No. 39 in the hill at the rapid in Bear Lake River, but with larger veins of calc-spar.63, 64 Dark blackish-brown bituminous shale, veined with calc-spar, and passing into bituminous marl-slate. It contains nodules of iron pyrites.65 Thin bed of indurated shale, approaching to flinty-slate, lying at the foot of some beds of bituminous limestone. Their connection not clearly made out.66, 67, 68 Bluish-gray, fine-grained sandstone, some of them passing into slate-clay, and scarcely to be distinguished from those at the rapid in Bear Lake River. Capt. Franklin took these specimens from horizontal beds at the foot of the hill facing Bear Lake River.
[27]57 This breccia has a white calcareous basis, which incloses angular fragments of compact, yellowish-gray limestone, with smooth dull surfaces.
58 Grayish-white limestone, having a fine crystalline texture, with drusy cavities, incrusted with bitumen.
59 Limestone, apparently composed of crystalline fragments, highly charged with bitumen, cemented by a whitish carbonate of lime in minute crystals. I could not satisfy myself whether this variety of colour proceeded from partial impregnations of bitumen, or from a brecciated structure. Specimens 58 and 59 were from beds near the western part of the hill.
60 A fine-grained dolomite, approaching to compact, having a flat and somewhat splintery fracture, and a brownish-gray colour.
61, 62 Limestone in the body of the hill, resembling No. 39 in the hill at the rapid in Bear Lake River, but with larger veins of calc-spar.
63, 64 Dark blackish-brown bituminous shale, veined with calc-spar, and passing into bituminous marl-slate. It contains nodules of iron pyrites.
65 Thin bed of indurated shale, approaching to flinty-slate, lying at the foot of some beds of bituminous limestone. Their connection not clearly made out.
66, 67, 68 Bluish-gray, fine-grained sandstone, some of them passing into slate-clay, and scarcely to be distinguished from those at the rapid in Bear Lake River. Capt. Franklin took these specimens from horizontal beds at the foot of the hill facing Bear Lake River.
[28]Sir Alexander Mackenzie, in p. 95 of his Voyage to the Arctic Sea, states, that he saw several small mineral springs running from the foot of this mountain, and found lumps of iron ore on the beach.
[28]Sir Alexander Mackenzie, in p. 95 of his Voyage to the Arctic Sea, states, that he saw several small mineral springs running from the foot of this mountain, and found lumps of iron ore on the beach.
[29]Travels in the Arkansa, p. 52-54.
[29]Travels in the Arkansa, p. 52-54.
[30]Section I.The section of the bank at the mouth of the Bear Lake River is as follows, beginning with the lowest bed:—81Gravel, with thin layers of sand rising from the water's edge in a perpendicular cliff, to the height of30feetLignite (70 to 80 and 84)183Potter's clay of a bluish gray colour, alternating with layers of sand40A sloping uneven brow, covered with soil, extends to the summit of the bank2091Lydian stone is the most abundant, and whitish quartz the least so of the pebbles mentioned in the text as entering into the composition of the gravel.82A little farther up the Mackenzie, this bed of gravel passes into sand, which, in some spots, has sufficient coherence to merit for it the name of sandstone. During a great part even of the summer season, all the beds of sand are frozen into a hard sandstone; but a piece having been broken off and put into the pocket, speedily thawed into sand.83Specimens of the clay, which I have denominated potter's clay, taken from near the beds of lignite, have a colour intermediate between yellowish-gray and clove-brown, a dull earthy fracture, and a slightly greasy feel. It is not gritty under the knife, and acquires a slightly shining smooth surface, adheres slightly to the tongue, and, when moistened with water, assumes a darker colour, and becomes plastic.Section II.About five miles above Bear Lake River, the cliff consists of Slaty sandstone evidently composed of the same materials with the friable kinds described in the text, but having tenacity enough to form a building stone. It incloses someseams of lignite10feetLignite14½Clay and Sand50Irregular slope from top of cliff to summit of bank90154½Section III.A little farther up the river than the preceding:—85Pipe-clay on a level with the water1foot86Lignite190Potter's clay14feet87Pipe-clay1foot89Lignite191Potter's clay10feetLignite1footSandstone8feetLignite2½Potter's clay1094Friable sandstone and clay20Sandstone a little more durable12Sloping Summit40121½The pipe-clay, when taken newly from the bed, is soft and plastic, has little grittiness, and when chewed for a little time, a somewhat unctuous but not unpleasant taste. When dried in the air it acquires the hardness of chalk, adheres to the tongue, and has the appearance of the whiter kinds of English pipe-clay, but is more meagre.Section IV.A little above the preceding:—A precipitous bank of gravel12feetLignite and clay, the beds concealed by debris40Friable sandstone30Height of the cliff82Section V.Ten miles above Bear Lake River, at the junction of a small torrent with the Mackenzie, there is a cliff about forty feet high, in which the strata have a dip of sixty degrees to the southward.98Bed, No. 1 Porcelain clay2yards992 Potter's clay slightly bituminous100, 1012½3 Thin-slaty lignite, with two seams of clay-iron stone, an inch thick1041054 Pipe clay, (nine inches)¼1065 Porcelain clay36 Bituminous clay31077 Lignite, with a conchoidal fracture28 Pipe clay¼1109 Porcelain clay310 Bituminous clay311 Lignite, earthy paste, enclosing fibrous fragments212 Porcelain earth913 Bituminous clay14 Porcelain earth31yardsThe three last beds it is probable, once inclosed seams of coal which have been consumed, but the quantity of debris prevented this from being ascertained satisfactorily during the hurried visit I paid to them.108Over these inclined beds there is a shelving and crumbling cliff of sand and clay covered by a sloping bank of vegetable earth. A layer of peat at the summit has a thin slaty structure, and presents altogether, except in colour and lustre, a striking resemblance to the shaly lignite, forming bed No. 3 in the preceding Section.104, 98. The substance composing beds Nos. 1 and 5, which I have denominated Porcelain clay, has a fine, granular texture, and the appearance of some varieties of chalk. It adheres slightly to the tongue, yields readily to the nail, is meagre, and soils the fingers slightly. There are many specks of coaly matter disseminated through it, and some minute scales of mica, and perhaps of quartz. When moistened with water, it becomes more friable, and is not plastic. It does not effervesce with acids.Bed No. 9 is the same mineral that forms beds 1 and 5; but it has a grayer colour from the greater quantity of coaly particles, and its structure is slightly slaty.The bituminous clay of bed No. 6, has a thick-slaty structure, a grayish-black colour, and a shining resinous streak. It is sectile, but does not yield to the nail. Pieces of lignite occur imbedded in it, and it is traversed by fibrous ramifications of carbonaceous matter.Specimens 115, 116, 117, 118, 119, are of substances altered by contact with beds of burning coal.
[30]Section I.
The section of the bank at the mouth of the Bear Lake River is as follows, beginning with the lowest bed:—
Lydian stone is the most abundant, and whitish quartz the least so of the pebbles mentioned in the text as entering into the composition of the gravel.
82A little farther up the Mackenzie, this bed of gravel passes into sand, which, in some spots, has sufficient coherence to merit for it the name of sandstone. During a great part even of the summer season, all the beds of sand are frozen into a hard sandstone; but a piece having been broken off and put into the pocket, speedily thawed into sand.
83Specimens of the clay, which I have denominated potter's clay, taken from near the beds of lignite, have a colour intermediate between yellowish-gray and clove-brown, a dull earthy fracture, and a slightly greasy feel. It is not gritty under the knife, and acquires a slightly shining smooth surface, adheres slightly to the tongue, and, when moistened with water, assumes a darker colour, and becomes plastic.
Section II.
About five miles above Bear Lake River, the cliff consists of Slaty sandstone evidently composed of the same materials with the friable kinds described in the text, but having tenacity enough to form a building stone. It incloses some
Section III.
A little farther up the river than the preceding:—
The pipe-clay, when taken newly from the bed, is soft and plastic, has little grittiness, and when chewed for a little time, a somewhat unctuous but not unpleasant taste. When dried in the air it acquires the hardness of chalk, adheres to the tongue, and has the appearance of the whiter kinds of English pipe-clay, but is more meagre.
Section IV.
A little above the preceding:—
Section V.
Ten miles above Bear Lake River, at the junction of a small torrent with the Mackenzie, there is a cliff about forty feet high, in which the strata have a dip of sixty degrees to the southward.
The three last beds it is probable, once inclosed seams of coal which have been consumed, but the quantity of debris prevented this from being ascertained satisfactorily during the hurried visit I paid to them.
108Over these inclined beds there is a shelving and crumbling cliff of sand and clay covered by a sloping bank of vegetable earth. A layer of peat at the summit has a thin slaty structure, and presents altogether, except in colour and lustre, a striking resemblance to the shaly lignite, forming bed No. 3 in the preceding Section.
104, 98. The substance composing beds Nos. 1 and 5, which I have denominated Porcelain clay, has a fine, granular texture, and the appearance of some varieties of chalk. It adheres slightly to the tongue, yields readily to the nail, is meagre, and soils the fingers slightly. There are many specks of coaly matter disseminated through it, and some minute scales of mica, and perhaps of quartz. When moistened with water, it becomes more friable, and is not plastic. It does not effervesce with acids.
Bed No. 9 is the same mineral that forms beds 1 and 5; but it has a grayer colour from the greater quantity of coaly particles, and its structure is slightly slaty.
The bituminous clay of bed No. 6, has a thick-slaty structure, a grayish-black colour, and a shining resinous streak. It is sectile, but does not yield to the nail. Pieces of lignite occur imbedded in it, and it is traversed by fibrous ramifications of carbonaceous matter.
Specimens 115, 116, 117, 118, 119, are of substances altered by contact with beds of burning coal.
[31]See Page50of the Narrative.
[31]See Page50of the Narrative.
[32]Noticed in page267.
[32]Noticed in page267.
[33]List of specimens, collected by Captain Franklin, on the sea-coast, to the westward of the Mackenzie.From Mount Fitton in the Richardson Chain.344 Grauwacke-slate in columnar concretions, detached from the rocky strata by an Esquimaux.348 Grauwacke-slate, resembling the preceding, from the same place. Used by the Esquimaux as a whetstone.345, 346 Globular balls of dark, blackish-gray, splintery limestone, and of flinty-slate, traversed by minute veins of calc-spar. Picked up at the base of the mountain.347 Worn pebbles of quartz, lydian stone, splintery limestone, and grauwacke, from the same spot.349 Fine-grained, mountain-green clay-slate, approaching to potstone; quarried by the Esquimaux in the Cupola Mountain of the same chain, and used to form utensils.350 Rock-crystal from the same chain of mountains.From the beach between Point Sabine and Point King.351 Brown-coal, woody structure scarcely perceptible. There are beds of this coal in the earthy cliffs where the party was encamped on the 13th and 14th July near Point King.352 Clay-iron stone, forming boulders in the channels of the rills, which cut the earthy banks containing coal.353, 354 Pitch-coal, having a fibrous structure and a very beautiful fracture, presenting a congeries of circles. (This coal was recognised by Professor Buckland to be a tertiary pitch-coal, and is precisely similar to specimens brought from the upper branches of the Saskatchewan, by Mr. Drummond: see page284.) The specimen was picked up from the gravelly beach at the mouth of the Babbage River.355 Greenish-gray limestone, with a somewhat earthy granular aspect; containing shells which Mr. Sowerby considers to be very like thecyclas mediusof the Sussex weald-clay. Picked up at the same place with the preceding specimen.Captain Franklin remarks, that "the Babbage flows between the mountains of the Richardson Chain, and that there were no solid strata nor any large boulders near its mouth. The gravel consisted of pebbles of red and white sandstone, slaty limestone, greenstone, and porphyry, much worn by attrition."From Mount Conybeare, in the Buckland Chain.356 Greenish-gray grauwacke slate, (resembling No. 348,) with specks of effervescent carbonate of lime. The surfaces of the slates exhibit interspersed scales of mica. The specimens were broken from the summit of Mount Conybeare, at the western extreme of the Buckland Chain: latitude 69° 27', longitude 139° 53' west.358 Fine-grained grauwacke-slate in columnar concretions, from the same place with specimen 356.357 Grauwacke-slate, in thick slaty columnar concretions, besprinkled with scales of mica. Taken from a bed about the middle of Mount Conybeare. The resemblance of this stone to that of Mount Fitton (No. 344) is very remarkable.360 Similar rock to 358, with an adhering portion of a vein of crystallized quartz, and on one side a bit of bluish-gray slate. From the middle of Mount Conybeare.359 Columnar concretion of a slaty rock, like 356, but more quartzose, breaking into rhomboidal fragments. From the middle of Mount Conybeare.361, 362 Grauwacke-slate, with a thin adhering vein of carbonate of lime and numerous particles of disseminated mica. From the middle of Mount Conybeare.363 Bluish-gray grauwacke-slate, resembling Nos. 348 and 344. From the Upper Terrace, at the base of Mount Conybeare.364 Dark-bluish gray and very fine-grained grauwacke-slate, with a glimmering lustre, traversed by a vein of quartz. From the same place.365 A thick-slaty angular concretion of a very quartzose grauwacke-slate, (similar to Nos. 348 and 358,) decomposed on the surface and breaking into rhomboidal fragments. From the middle Terrace at the base of Mount Conybeare.366 A somewhat rhomboidal portion of flinty-slate, apparently part of a bed. From the Lower Terrace of Mount Conybeare, which is composed of this rock. The terrace is ten miles distant from the sea-coast, and the intervening ground is swampy.The whole series of specimens from Mount Conybeare, (Nos. 356 to 366,) appear to belong to transition rocks; and the continuity of the formation with that of Mount Fitton is rendered probable, both by the resemblance of the specimens and the geographical situation of the mountains.Captain Franklin saw no rocks,in situ, on the coast to the westward of the Richardson Chain; but he gathered boulders of the following rocks from the bed of the Net-setting Rivulet, which flows from the British Chain of the Rocky Mountains, and falls into the Arctic Sea, between Sir P. Malcolm River and Backhouse River.367 Greenstone; 368, yellowish-gray sandstone; 369, dark-coloured splintery-limestone; 370, 371, 372, dolomite; 373, quartzose sandstone, like the old red sandstone; 374, grauwacke-slate; 375, quartz and iron pyrites.Boulders of the under-mentioned rocks were gathered on Flaxman Island.378 Fine-grained, greenish clay-slate, obviously of primitive rock, abundant in the neighbourhood, and supposed to have been brought down by the rivulets which flow from the Romanzoff Chain. 379, quartz.376 and 377 were from Foggy Island, and are rolled specimens of flinty-slate; one of them containing corallines.
[33]List of specimens, collected by Captain Franklin, on the sea-coast, to the westward of the Mackenzie.
From Mount Fitton in the Richardson Chain.
344 Grauwacke-slate in columnar concretions, detached from the rocky strata by an Esquimaux.
348 Grauwacke-slate, resembling the preceding, from the same place. Used by the Esquimaux as a whetstone.
345, 346 Globular balls of dark, blackish-gray, splintery limestone, and of flinty-slate, traversed by minute veins of calc-spar. Picked up at the base of the mountain.
347 Worn pebbles of quartz, lydian stone, splintery limestone, and grauwacke, from the same spot.
349 Fine-grained, mountain-green clay-slate, approaching to potstone; quarried by the Esquimaux in the Cupola Mountain of the same chain, and used to form utensils.
350 Rock-crystal from the same chain of mountains.
From the beach between Point Sabine and Point King.
351 Brown-coal, woody structure scarcely perceptible. There are beds of this coal in the earthy cliffs where the party was encamped on the 13th and 14th July near Point King.
352 Clay-iron stone, forming boulders in the channels of the rills, which cut the earthy banks containing coal.
353, 354 Pitch-coal, having a fibrous structure and a very beautiful fracture, presenting a congeries of circles. (This coal was recognised by Professor Buckland to be a tertiary pitch-coal, and is precisely similar to specimens brought from the upper branches of the Saskatchewan, by Mr. Drummond: see page284.) The specimen was picked up from the gravelly beach at the mouth of the Babbage River.
355 Greenish-gray limestone, with a somewhat earthy granular aspect; containing shells which Mr. Sowerby considers to be very like thecyclas mediusof the Sussex weald-clay. Picked up at the same place with the preceding specimen.
Captain Franklin remarks, that "the Babbage flows between the mountains of the Richardson Chain, and that there were no solid strata nor any large boulders near its mouth. The gravel consisted of pebbles of red and white sandstone, slaty limestone, greenstone, and porphyry, much worn by attrition."
From Mount Conybeare, in the Buckland Chain.
356 Greenish-gray grauwacke slate, (resembling No. 348,) with specks of effervescent carbonate of lime. The surfaces of the slates exhibit interspersed scales of mica. The specimens were broken from the summit of Mount Conybeare, at the western extreme of the Buckland Chain: latitude 69° 27', longitude 139° 53' west.
358 Fine-grained grauwacke-slate in columnar concretions, from the same place with specimen 356.
357 Grauwacke-slate, in thick slaty columnar concretions, besprinkled with scales of mica. Taken from a bed about the middle of Mount Conybeare. The resemblance of this stone to that of Mount Fitton (No. 344) is very remarkable.
360 Similar rock to 358, with an adhering portion of a vein of crystallized quartz, and on one side a bit of bluish-gray slate. From the middle of Mount Conybeare.
359 Columnar concretion of a slaty rock, like 356, but more quartzose, breaking into rhomboidal fragments. From the middle of Mount Conybeare.
361, 362 Grauwacke-slate, with a thin adhering vein of carbonate of lime and numerous particles of disseminated mica. From the middle of Mount Conybeare.
363 Bluish-gray grauwacke-slate, resembling Nos. 348 and 344. From the Upper Terrace, at the base of Mount Conybeare.
364 Dark-bluish gray and very fine-grained grauwacke-slate, with a glimmering lustre, traversed by a vein of quartz. From the same place.
365 A thick-slaty angular concretion of a very quartzose grauwacke-slate, (similar to Nos. 348 and 358,) decomposed on the surface and breaking into rhomboidal fragments. From the middle Terrace at the base of Mount Conybeare.
366 A somewhat rhomboidal portion of flinty-slate, apparently part of a bed. From the Lower Terrace of Mount Conybeare, which is composed of this rock. The terrace is ten miles distant from the sea-coast, and the intervening ground is swampy.
The whole series of specimens from Mount Conybeare, (Nos. 356 to 366,) appear to belong to transition rocks; and the continuity of the formation with that of Mount Fitton is rendered probable, both by the resemblance of the specimens and the geographical situation of the mountains.
Captain Franklin saw no rocks,in situ, on the coast to the westward of the Richardson Chain; but he gathered boulders of the following rocks from the bed of the Net-setting Rivulet, which flows from the British Chain of the Rocky Mountains, and falls into the Arctic Sea, between Sir P. Malcolm River and Backhouse River.
367 Greenstone; 368, yellowish-gray sandstone; 369, dark-coloured splintery-limestone; 370, 371, 372, dolomite; 373, quartzose sandstone, like the old red sandstone; 374, grauwacke-slate; 375, quartz and iron pyrites.
Boulders of the under-mentioned rocks were gathered on Flaxman Island.
378 Fine-grained, greenish clay-slate, obviously of primitive rock, abundant in the neighbourhood, and supposed to have been brought down by the rivulets which flow from the Romanzoff Chain. 379, quartz.
376 and 377 were from Foggy Island, and are rolled specimens of flinty-slate; one of them containing corallines.
[34]Page268.
[34]Page268.
[35]134. These specimens have a wood-brown colour internally, and appear to be composed of minute grains of quartz, variously coloured, white, yellowish-brown and black, cemented together by an earthy basis. It is a hard and apparently durable stone, occurring in layers an inch thick, and having its seam-surfaces of a grayish-black colour, with little lustre, as if from a thin coating of bituminous clay.135, are specimens of a more compact, harder, and finer-grained quartzose sandstone, with less cement, and of a deeper bluish-gray colour.
[35]134. These specimens have a wood-brown colour internally, and appear to be composed of minute grains of quartz, variously coloured, white, yellowish-brown and black, cemented together by an earthy basis. It is a hard and apparently durable stone, occurring in layers an inch thick, and having its seam-surfaces of a grayish-black colour, with little lustre, as if from a thin coating of bituminous clay.
135, are specimens of a more compact, harder, and finer-grained quartzose sandstone, with less cement, and of a deeper bluish-gray colour.
[36]Mackenzie attempted to ascend this hill, but was compelled to desist by clouds of musquitoes, (July 6th, 1789.Voyage to the Arctic Sea, p. 40.)136 This limestone effervesces strongly with acids, breaks into irregular fragments, but with an imperfect slaty structure, and has a brown colour, with considerable lustre in the cross fracture.The specimens collected by Captain Franklin were as follows:—144a Sandstone of an ash-gray colour, composed of rounded grains of semi-transparent quartz of various sizes, imbedded in a considerable proportion of a powdery basis which effervesces with acids. This bed weathers readily.145 Thick-slaty sandstone passing into slate-clay, having a very fine-grained earthy fracture, and a light bluish-gray colour. It is very similar to some of the softer sandstones that occur in the coal field at Edinburgh, particularly in the Calton Hill.146 Sectile ash-gray slate-clay which forms the partings of the beds.144b Bluish-gray marl, impregnated with quartz, forming a moderately hard stone, and containing corallines (amplexus.)
[36]Mackenzie attempted to ascend this hill, but was compelled to desist by clouds of musquitoes, (July 6th, 1789.Voyage to the Arctic Sea, p. 40.)
136 This limestone effervesces strongly with acids, breaks into irregular fragments, but with an imperfect slaty structure, and has a brown colour, with considerable lustre in the cross fracture.
The specimens collected by Captain Franklin were as follows:—
144a Sandstone of an ash-gray colour, composed of rounded grains of semi-transparent quartz of various sizes, imbedded in a considerable proportion of a powdery basis which effervesces with acids. This bed weathers readily.
145 Thick-slaty sandstone passing into slate-clay, having a very fine-grained earthy fracture, and a light bluish-gray colour. It is very similar to some of the softer sandstones that occur in the coal field at Edinburgh, particularly in the Calton Hill.
146 Sectile ash-gray slate-clay which forms the partings of the beds.
144b Bluish-gray marl, impregnated with quartz, forming a moderately hard stone, and containing corallines (amplexus.)
[37]Upper part of the ramparts.148 A fine-granular, foliated limestone, of a white colour, having large patches stained yellowish-brown, apparently by bitumen.149 A yellowish-gray slightly granular limestone, with disseminated calc-spar.150 Compact, white limestone, which, when examined with a lens, appears to be entirely composed of madrepores.151 Specimens of limestone, having a crystalline texture, a brownish colour and slaty structure.152 The seams are dark, as if from the carbonaceous matter—portions of this bed have the appearance of old mortar; but contain obscure madrepores.From the middle of the ramparts.153 Fine-granular limestone, having a pale, wood-brown colour, and a splintery fracture. It resembles the limestone of the hill at the mouth of Bear Lake River.154 Pale yellowish-brown limestone, with a dull fracture, but interspersed with small, shining, sparry plates, and traversed by concretions of calc-spar, that appear to have originated in corallines.155 Yellowish-gray limestone, passing into a soft marl slate.156 Some beds contain a shell, which Mr. Sowerby refers, though with doubt, to the species named terebratula sphæroidalis, a fossil of the cornbrash. The substance of the shells is preserved.Some of the specimens containproducti, and fragments of the coral namedamplexus.Lower end of the ramparts.157 Fine-grained limestone, of a dark-brown colour, containing some small, round, smooth balls of dark limestone—occurs in horizontal strata.158 Brownish-black flinty-slate, which forms a layer an inch thick, and covers the horizontal beds of limestone last mentioned. (157.)
[37]Upper part of the ramparts.
148 A fine-granular, foliated limestone, of a white colour, having large patches stained yellowish-brown, apparently by bitumen.
149 A yellowish-gray slightly granular limestone, with disseminated calc-spar.
150 Compact, white limestone, which, when examined with a lens, appears to be entirely composed of madrepores.
151 Specimens of limestone, having a crystalline texture, a brownish colour and slaty structure.
152 The seams are dark, as if from the carbonaceous matter—portions of this bed have the appearance of old mortar; but contain obscure madrepores.
From the middle of the ramparts.
153 Fine-granular limestone, having a pale, wood-brown colour, and a splintery fracture. It resembles the limestone of the hill at the mouth of Bear Lake River.
154 Pale yellowish-brown limestone, with a dull fracture, but interspersed with small, shining, sparry plates, and traversed by concretions of calc-spar, that appear to have originated in corallines.
155 Yellowish-gray limestone, passing into a soft marl slate.
156 Some beds contain a shell, which Mr. Sowerby refers, though with doubt, to the species named terebratula sphæroidalis, a fossil of the cornbrash. The substance of the shells is preserved.
Some of the specimens containproducti, and fragments of the coral namedamplexus.
Lower end of the ramparts.
157 Fine-grained limestone, of a dark-brown colour, containing some small, round, smooth balls of dark limestone—occurs in horizontal strata.
158 Brownish-black flinty-slate, which forms a layer an inch thick, and covers the horizontal beds of limestone last mentioned. (157.)
[38]Specimens from the cliffs in lat. 66¾°.159 Very fine-grained sandstone, with much clayey basis—portions of the bed iron-shot.160 Sandstone fine-grained, and appearing, when examined with a lens, to be composed of minute grains of whitish translucent quartz, black Lydian stone, and ochre-coloured grains, probably of disintegrated felspar.161 Rounded grains of nearly transparent quartz united without cement—this stone is friable.162 Sandstone composed of grains like the preceding, united by a basis, and forming a firmer stone.163 Hard, thin, slaty, bluish-gray sandstone, much iron-shot.164 Fine-grained, bluish-gray sandstone, not to be distinguished in hand-specimens from some of the sandstones which occur at the rapid in Bear Lake River.
[38]Specimens from the cliffs in lat. 66¾°.
159 Very fine-grained sandstone, with much clayey basis—portions of the bed iron-shot.
160 Sandstone fine-grained, and appearing, when examined with a lens, to be composed of minute grains of whitish translucent quartz, black Lydian stone, and ochre-coloured grains, probably of disintegrated felspar.
161 Rounded grains of nearly transparent quartz united without cement—this stone is friable.
162 Sandstone composed of grains like the preceding, united by a basis, and forming a firmer stone.
163 Hard, thin, slaty, bluish-gray sandstone, much iron-shot.
164 Fine-grained, bluish-gray sandstone, not to be distinguished in hand-specimens from some of the sandstones which occur at the rapid in Bear Lake River.
[39]Horizontal limestone beds lying under the sandstone.166 Fine-grained limestone, with an earthy fracture, coloured brown and grayish-white in patches.167, 168 Similar stone to preceding, containing many shells. Some beds contain only broken shells.169 Bed of imperfectly crystalline limestone, of a brownish-gray colour, traversed by veins of calc-spar.170 Fragments containing madrepores and chain coral—occur amongst the debris of the limestone cliffs.
[39]Horizontal limestone beds lying under the sandstone.
166 Fine-grained limestone, with an earthy fracture, coloured brown and grayish-white in patches.
167, 168 Similar stone to preceding, containing many shells. Some beds contain only broken shells.
169 Bed of imperfectly crystalline limestone, of a brownish-gray colour, traversed by veins of calc-spar.
170 Fragments containing madrepores and chain coral—occur amongst the debris of the limestone cliffs.
[40]Sandstone cliffs twenty miles below Fort Good Hope.173 Friable sandstone, composed of grayish-white quartz, in smooth, rounded grains, cemented by a brownish basis. Some carbonaceous matter is interspersed through the stone, and it contains small fragments of bituminous shale.174 Calcareous sandstone passing into slate-clay—bluish-gray colour.175 Black, flinty-slate, with a flat conchoidal cross fracture. Some of the pieces appear to be rhomboidal distinct concretions.176 Dull, flinty-slate, with an even fracture.178 Thin-slaty blackish-gray sandstone, much indurated, containing scales of mica.179, 180 Bluish-gray sandstone, containing many minute specks of carbonaceous matter; also, in patches, grains of chert, and flinty-slate, and imbedded pieces of iron-shot clay, which has obscure casts of shells. Scales of mica are interspersed through this stone.181, 182 Sandstone containing specks of bituminous? coal, and casts of some vegetable? substance.183 Gray limestone, much impregnated with quartz, and having an imperfect crystalline structure.
[40]Sandstone cliffs twenty miles below Fort Good Hope.
173 Friable sandstone, composed of grayish-white quartz, in smooth, rounded grains, cemented by a brownish basis. Some carbonaceous matter is interspersed through the stone, and it contains small fragments of bituminous shale.
174 Calcareous sandstone passing into slate-clay—bluish-gray colour.
175 Black, flinty-slate, with a flat conchoidal cross fracture. Some of the pieces appear to be rhomboidal distinct concretions.
176 Dull, flinty-slate, with an even fracture.
178 Thin-slaty blackish-gray sandstone, much indurated, containing scales of mica.
179, 180 Bluish-gray sandstone, containing many minute specks of carbonaceous matter; also, in patches, grains of chert, and flinty-slate, and imbedded pieces of iron-shot clay, which has obscure casts of shells. Scales of mica are interspersed through this stone.
181, 182 Sandstone containing specks of bituminous? coal, and casts of some vegetable? substance.
183 Gray limestone, much impregnated with quartz, and having an imperfect crystalline structure.
[41]Mackenzie notices the precipices of "gray stone," which bound the river here, p. 71.
[41]Mackenzie notices the precipices of "gray stone," which bound the river here, p. 71.
[42]See page288.
[42]See page288.
[43]Specimens from Sellwood Bay.202 Fine-grained dark brownish-gray dolomite, with corallines filled with white calc-spar.203 Lucullite grayish-black, compact, and without lustre.204 Gray dolomite.205 A rolled piece, evidently of the same rock with the preceding, containing the impression of acardium.206
[43]Specimens from Sellwood Bay.
202 Fine-grained dark brownish-gray dolomite, with corallines filled with white calc-spar.
203 Lucullite grayish-black, compact, and without lustre.
204 Gray dolomite.
205 A rolled piece, evidently of the same rock with the preceding, containing the impression of acardium.
206
[44]Specimens from the Promontory of Cape Parry, which rises into a hill, seven hundred feet high. Strata dipping lightly to the northward.207 Yellowish-gray dolomite, imperfectly crystalline, being similar to the limestone of Lake Winipeg.208 Brownish dolomite impregnated with silica.209 Thin-slaty, gray limestone. Very common also in Lake Winipeg.210, 211 Boulders of dolomite.212213 Brown dolomite, with drusy cavities and veins, lined by calc-spar.
[44]Specimens from the Promontory of Cape Parry, which rises into a hill, seven hundred feet high. Strata dipping lightly to the northward.
207 Yellowish-gray dolomite, imperfectly crystalline, being similar to the limestone of Lake Winipeg.
208 Brownish dolomite impregnated with silica.
209 Thin-slaty, gray limestone. Very common also in Lake Winipeg.
210, 211 Boulders of dolomite.
212
213 Brown dolomite, with drusy cavities and veins, lined by calc-spar.
[45]In the geological notices appended to the narrative of Captain Franklin's Journey to the Coppermine, I have termed this rock a dark purplish-red felspar rock. On examining it again on this journey, I perceived it to be a greenstone, whose surfaces weather of a rusty brown colour.
[45]In the geological notices appended to the narrative of Captain Franklin's Journey to the Coppermine, I have termed this rock a dark purplish-red felspar rock. On examining it again on this journey, I perceived it to be a greenstone, whose surfaces weather of a rusty brown colour.