Some of Canada's most extensive forest grows on the Shield. During the Ice Ages of the Cenozoic Era, the glaciers removed enormous amounts of soil, clay, rock and gravel. Today, most of the Shield is covered by only a thin layer of soil. Due to a result of this no vegetation has grown. Coniferous trees which are better suited to thin sandy soil cover most of the areas.
There are thousands of lakes on the Canadian Shield because the igneous and metamorphic rock do not allow the water to pass through easily. As a result the water has formed depressions in the rock creating thousands of unsystematic lakes.