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 coa.r.s.e crystalline, felspar flesh-red.
2 Ditto, approaching to gneiss.
3 Gneiss approaching to mica-slate, felspar white, and in small quant.i.ty.
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 l.u.s.tre, but with small rounded grains imbedded in it, bringing it near to sandstone.
8 Coa.r.s.e sandstone; rounded grains of quartz united by a clayey basis.
9 Fine-grained purplish sandstone, with grayish spots. This sandstone occurs _in situ_ near 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 quant.i.ty 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 pa.s.sing 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 pa.s.sing 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:--
81 Gravel, with thin layers of sand rising from the water"s edge in a perpendicular cliff, to the height of 30 feet Lignite (70 to 80 and 84) 1 83 Potter"s clay of a bluish gray colour, alternating with layers of sand 40 A sloping uneven brow, covered with soil, extends to the summit of the bank 20 ---- 91
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.
[Sidenote: 82] A little farther up the Mackenzie, this bed of gravel pa.s.ses 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.
[Sidenote: 83] Specimens 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, a.s.sumes 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 seams of lignite 10 feet Lignite 4-1/2 Clay and Sand 50 Irregular slope from top of cliff to summit of bank 90 --------- 154-1/2
Section III.
A little farther up the river than the preceding:--
85 Pipe-clay on a level with the water 1 foot 86 Lignite 1 90 Potter"s clay 14 feet 87 Pipe-clay 1 foot 89 Lignite 1 91 Potter"s clay 10 feet Lignite 1 foot Sandstone 8 feet Lignite 2-1/2 Potter"s clay 10 94 Friable sandstone and clay 20 Sandstone a little more durable 12 Sloping Summit 40 --------- 121-1/2