Mountains and marvels

When one sketches Canada, several large geographic units stand out. The first to emerge, because of both its venerable age and its central position around which everything else is arranged, is the Canadian Shield. From its throne in east-central Canada, it extends its hills and rocky plateaus over a good half of the country. All around this base extend shelves whose rocky layers, of more recent origin, were deposited by seas that no longer exist.

	Autumn leaves ©2003 ICN-RCI / Hemera

To the east is the narrow plain of the Great Lakes and the St. Lawrence; to the west, the rolling plains; to the centre, the Hudson Bay lowlands; and to the north, the Arctic lowlands. Together, these plains cover one quarter of the territory. Then, like sentinels posted at the three gates to Canada, mountain chains arise: the aging Appalachians to the east, the proud cordillera to the west and the little-known Innuitians to the north. The last geographic unit consists of the Atlantic, Pacific and Arctic continental shelves—the submerged part of the continent. Even though invisible to us, it is of great importance for Canada because of the immense resources that it contains.  

We could not draw the final line in this sketch of Canada without representing water, which is present everywhere and covers nearly 1 square kilometre in 11 of Canada's territory. The vast waters of the lakes and the swift waters of the rivers form intricate networks that are organized into the four great catchment basins of the Atlantic, the Pacific, the Arctic and Hudson Bay. A few errant rivers in southern Alberta and Saskatchewan take the southern route, toward the Gulf of Mexico basin. Two majestic river systems stand out: in the north, the Mackenzie, with a drainage area of 1,805,200 square kilometres, and in the east, the St. Lawrence, which has a drainage area of 839,200 square kilometres.