[1] The world's oldest rocks, dating to four billion years, are found in the Canadian Shield north of Great Slave Lake.

[2] The Taiga Shield ecozone covers almost all of the eastern area of the Northwest Territories, a tiny corner of northeastern Alberta, a narrow strip of all northern Saskatchewan and northwestern Manitoba, as well as all some parts of southern Nunavut.

[1] Terrain is typically flat or rolling hills[3] with thousands of depressions carved by glacial retreat now infilled, forming lakes, ponds, wetlands and other water features.

Mineral extraction is the most important economic activity, with iron being mined in Quebec and Labrador, uranium in Saskatchewan, and gold and more recently diamonds in the Northwest Territories.

[6] This subarctic zone experiences cool summers that are short, with at least 24 hours of full daylight a year in its most northern reaches, and winters that are extremely cold and long, with at least one 24-hour period of complete darkness.