Swamps, lakes, hills, basins and mountain ranges create the suite of physical features in the Canadian Shield. The Canadian Shield covers a vast stretch of land, ranging from the Hudson Bay into eastern, central and northern parts of Canada. The Canadian Shield also includes the Great Lakes, extends north of the Arctic Circle and stretches into Greenland.
The Canadian Shield formed from glacial activity during the Pleistocene Epoch and gradual accretion and deposition of Precambrian rocks. The Canadian Shield contains the largest concentration of Precambrian rocks of all natural features on the planet. These rocks shaped the Canadian Shield by alternatively depositing in river basins and eroding. Some areas contain more rocky deposits than others. These areas include ancient mountain ranges and hills. While Precambrian rocks gave the Canadian Shield some structure, glaciers generated a more substantial impact. Glaciers descended over the region during the Pleistocene Epoch after moving southward from northern Canada. They sculpted the landscape by removing layers of rock deposits and giving round shapes to jagged rocky hills. Glaciers left some sedimentary deposit in the Canadian Shield but carried most organic material farther south. Glaciers formed troughs and basins in the process and filled lakes and swamps with water. The Canadian Shield varies in altitude and topography; some spots rise just 100 feet above sea level, while others exceed 5,000 feet.