The Canadian Shield (French: Bouclier canadien [buklje kanadjɛ̃]), also called the Laurentian Plateau, is a large area of exposed Precambrian igneous and high-grade metamorphic rocks (geologic shield) that forms the ancient geologic core of the North American continent (the North American Craton or Laurentia). Glaciation has left the area with only a thin layer of soil, through which the composition of igneous rock resulting from long volcanic history is frequently visible. As a deep, common, joined bedrock region in eastern and central Canada, the Shield stretches north from the Great Lakes to the Arctic Ocean, covering over half of Canada and most of Greenland; it also extends south into the northern reaches of the United States. Human population is sparse and industrial development is minimal, but mining is prevalent.