Canadian shield

The Canadian Shield, also called the Laurentian Plateau, or Bouclier Canadien (French), is a large area of exposed Precambrian igneous and high-grade metamorphic rocks that forms the ancient geological core of the North American continent, covered by a thin layer of soil. It is an area mostly composed of igneous rock which relates to its long volcanic history. It has a deep, common, joined bedrock region in Eastern and central Canada and stretches North from the Great Lakes to the Arctic Ocean, covering over half of Canada; it also extends South into the Northern reaches of the United States. Human population is sparse, and industrial development is minimal, while mining is very prevalent.

Source: wikipedia.org