A

David

Darling

Canadian Shield

The Canadian Shield, also called the Laurentian Shield, is an area of North America (including the eastern half of Canada and small portions of the United States) which has remained more or less stable since Precambrian times. Its surface rocks, which are igneous and metamorphic, are among the oldest in the world, younger structures having disappeared through erosion, in some areas by glaciers of the Pleistocene.