gions which have been covered with ice in pleistocene times. The situation of the Barren Grounds as the northwest corner of the Canadian shield therefore at the same time characterises this region as a low, once ice-covered land principally built up of pre-Cambrian rock.
In particular J. B. Tyrrell's work has given us detailed information as to the geology and physiography of this region, and the few observations that are due to other travellers, or which I have myself had an opportunity of making at places off Tyrrell's routes, closely agree with his investigations and show extraordinarily great uniformity. The foundations of the country consist of grey or lightred gneiss, granite-gneiss, or granite, which are classified as Laurentian. At the coast between Rankin and Dawson Inlet there are dark, crystalline schists and plutonic rocks as well as light quartzite of Huronian age, while similar rocks are also to be found at several places in the interior. However, the determination of age is everywhere very uncertain.[1] Soapstone, which the Eskimos make into lamps and cooking pots, is to be found a little to the north of the Caribou Eskimo territory between Wager Inlet and Boothia Peninsula,[2] by Lake Thaolintoa in the interior,[3] and at Qiqertarjuaq and Rankin Inlet. J. B. Tyrrell discovered copper ore at several places among the Huronian rocks, but as it is chalcopyrite and not free metal, it is of course of no importance to the natives. The south side of Baker Lake is formed of a coarse, red sandstone, the southern boundary of which I found a few kilometres above the lake at Kazan River. Similar sandstone and conglomerates, which presumably date from Keweenawan,[4] are also known from the east side of Dubawnt Lake and Thelon River and are assumed to form a connected area. The Eskimos use the sandstone for skin scrapers, which also are traded among the neighbouring tribes to a rather wide extent.
In our day the land forms a slightly elevated peneplane, which in pleistocene times was the centre of the Keewatin inland ice and by this was turned into a rolling country with low relief, where rounded hills stretch up over flat, till-covered areas. Terminal moraines, eskers and drumlins provide further evidence of the glaciation. We can, however, differentiate between an inner plateau and a coastal
- ↑ Cf. van Hise and Leith 1909; 546.
- ↑ Hall 1879; 161.
- ↑ Lofthouse 1922; 160.
- ↑ These layers being described as Cambrian by J. B. Tyrrell (1898; 199) and later — for instance on the Atlas of Canada 1915 — it must be remembered that Canadian geologists give this name to all layers between the Huronian and the Cambro-Silurian formations. As a rule however the upper limit of pre-Cambrian is defined by the first appearance of Olenellus, a genus of Brachiopoda, or corresponding fossils.
