Canadian Shield

The Canadian Shield (French: Bouclier canadien), also called the Laurentian Shield or the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrianigneous and high-grade metamorphic rocks. It forms the North American Craton (or Laurentia), the ancient geologic core of the North American continent. Glaciation has left the area with only a thin layer of soil, through which exposures of igneous bedrock, resulting from its long volcanic history, are frequently visible. As a deep, common, joined bedrock region in eastern and central Canada, it also extends south into the northern reaches of the contiguous United States.