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Over half of the Canadian land existing today is comprised of the Canadian Shield. Some of the oldest rock is found here, ageing from over 4 000 000 000 years. The two major rock types, igneous and metamorphic, make up most of the shield. These rocks make up a platform on which the rest of Canada is built. Igneous and metamorphic rocks contain a great quantities of lead, gold, nickel, copper, zinc and other such valuable minerals, and therefore making the shield rich in such natural resources. These rocks were originally mixed in the Earth's interior rocks. This molten intruded it's way through cracks and cavities in the Shield rock. As the molten rock cooled, it separated in groups according to their mineral composition and weight.
STRUCTURE
Cutway of Canadaian Landforms
The structure of the Shield is more or less like a saucer, much lower in the centre than the outer portions. This lowest are of the Canadian Shield is comprised of the Hudson Bay and the Hudson Bay Lowlands. Most rivers on the Shield flow down towards the centre and into the Hudson Bay.
CHARACTERISTICS
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.
Over the centuries many lakes have been filled by silt and decomposing vegetation, creating swamps. These swamps has provided breeding grounds for hated insects such as mosquitoes and black flies.
Pictures: Bottom Left- A typical Canadian Characteristic
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