SEA-COAST.—BITUMINOUS ALUM SHALE.
The main 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 from192
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199 clays 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 was200
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196 several 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 the201 surfaces 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.
SEA COAST.—LIMESTONE.
Parry's Peninsula, 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.
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204On 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 in highly 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.