home :: North America :: USA :: Geography :: Regions of the United States :: Regional Breakdowns :: The Northern Forests :: Natural Features
The Northern Forests, Natural Features
broad lowland, rounded hills, Pleistocene Epoch, Canadian Shield, ice sheets
The Canadian Shield, a vast, gently rolling surface made up of granitic rocks, underlies the eastern two-thirds of the region. During the Pleistocene Epoch, ice sheets scoured the land, remolding the surface and removing most of the existing soil to expose bare rock and rounded hills almost devoid of soil. To the west of the shield is a large, broad lowland that is underlain by softer sedimentary materials, deposited by rivers flowing across the Rocky Mountains and the Canadian Shield.
Article key phrases: