83 river; the beds are inclined slightly toward the west, and have a thickness ot about 200 feet. “The sandstones are coarse-grained and nodular, of yellowish or grey colour, grading into fine conglomerates, which are made up chiefly of black cherty argillite fragments.” -They are probably of Cretaceous age. Section on Peel and Wind Rivers In the section along Wind river, from Nash creek to the edge of the mountainous country, the following succession of rocks occurs in ascending order: ferruginous slates and argillites; limestones, and sandstones with some limestones; dark reddish conglomerate. At the mouth of Nash creek the rocks consist of closely-folded black slates with remnants of the overlying limestone occurring in the synclines. They strike east and west across the valley of the river and dip at high angles or are vertical. Northward the limestone becomes gradually more dominant and the underlying slate appears only when brought up by an anticline. Fifteen miles below Nash creek, a coarse-grained, white sandstone is met overlying the lime- stone and slate. The strata are horizontal or dip at a low angle to the north. At this place the limestone is not so thick as farther up stream and appears to rest unconformably on the slate. From Bear river to the point where Wind river Jeaves the mountains, sandstone and limestone appear in a succession of gentle anticlines and synclines. A small body of dark reddish conglomerate overlies these on the edge of the slope. On emerging from the mountains, Wind river enters a broad plateau. Yhe level of this plateau is broken in places by several short ranges of moun- tains, which are really the foothills of the main range. The foothills area extends northward some distance beyond the east and west stretch of Peel river and eastward to Snake river. Almost in the centre of this area lies a large basin of over 500 square miles, occupied by slightly disturbed Tertiary rocks. This basin, which is almost completely enclosed by foothills, lies between Wind and Bonnet Plume rivers and extends southward from the Peel some 50 miles. The geology of the foothills section is in marked contrast with that of the mountain section. Three miles from the base of the main range there are cliffs 150 feet high composed of slightly inclined beds of fine conglomerate holding fragments of fossil wood and ironstone nodules and merging into soft grey sandstone. The latter becomes feldspathic towards the top, and is overlain: by boulder clay. These sandstones, which are probably of Cretaceous age, form cliffs on both sides of the river down to within 2 miles of Little Wind river. The Illtyd range consists of massive, grey, dolomitic limestones having an anticlinal structure. ‘Mount Deslaurier is a west-facing fault scarp, rising abruptly from the water’s edge to a height of 850 feet. It is composed of about four hundred feet of dark reddish conglomerate, containing angular and water- worn fragments of limestone, quartzite, and other rocks; below this is a brecciated limestone, which, near the contact, also carries some foreign fragments. At the water’s edge is some sandstone.”! Mount Deception, standing at the junction of Hungry creek and Wind river, is composed of massive crystalline limestone. Below mount Deception the river enters the level country underlain by almost undisturbed Tertiary clays and sandstones. 1 Geol. Surv., Can., vol. XVI, pt. CC, p. 26. See Se gele ipa See a ee eos ag