Landform Regions Landform Regions of Canadaof CanadaCanadian Geography 11Canadian Geography 11 PowerPoint Presentation PowerPoint Presentation Canada is a land of great physical diversity. Perhaps this is not surprising since Canada is the worlds second largest country, and has the worlds longest coastline. We can look at Canadas topography by focusing on landforms. Topography is the study of the earths surface features, including vegetation, soils, and those features shaped by people. The Canadian ShieldThe Canadian Shield The Canadian Shield has two major landforms, a rocky surface of mainly igneous rock and many coniferous forests. The reason that this region has rocky surfaces is because millions of years ago there were mountains in the sub-region, through water, freeze thaw and the mountains have eroded into hard even land. The southern section of the Canadian Shield is mainly boreal, meaning that it is mostly coniferous forests - concentrations of evergreen trees normally found on slopes and mountains. In the northern part it is had rocky frozen tundra. Vegetation in the Canadian Shield is mainly coniferous forests. In the south the trees are larger and closer together. As you go north, trees are smaller and not as dense. There is eventually a spot up north in the Shield that doesnt have any forest; this is again in the tundra. Shown above is a coniferous forest located in the middle of the Canadian Shield. The Canadian Shield is the geographic foundation of Canada. The Shield underlies not only much of Canada but also parts of the United States. The Shield covers more than half of Canada, about 4,800,000 km. Some of the worlds oldest rocks (3.96 billion years old) are located in the Shield near Great Slave Lake. Today, most of the Shield is relatively flat with rounded hills of rock that are actually the roots of ancient mountains. Two types of rock, igneous and metamorphic, form most of the Shield. They contain valuable minerals in great quantities. Through the vast deposits of lead, gold, nickel, copper, zinc, and other important metals, the Canadian Shield is often called the storehouse of Canadas metallic minerals. In addition, diamonds have recently been found where ancient volcanoes once existed. How were mineral deposits formed in the rock of the Shield? How were mineral deposits formed in the rock of the Shield? Minerals were present in magma (molten rock) beneath the Minerals were present in magma (molten rock) beneath the earths crust. earths crust. As magma rose toward the surface, it forced its way into As magma rose toward the surface, it forced its way into cracks and cavities in the shield rock. This process of magma cracks and cavities in the shield rock. This process of magma slowly rising toward the surface took thousands or millions of slowly rising toward the surface took thousands or millions of years. As it cooled, some minerals were deposited in the years. As it cooled, some minerals were deposited in the magma itself. magma itself. Other deposits were formed when minerals, dissolved in very hot water, were forced deep into cracks in the surrounding rock. This process allowed minerals to be deposited in high concentrations which makes mining worthwhile. As the minerals slowly cooled, they separated into layers according to their density. The lighter ones floated on top of the heavier ones. Those that had similar density floated to the same level. Nickel and copper are often found together because they have similar densities. Mining companies are attracted to the Shield because of the presence of metallic minerals. Many cities and towns, such as Sudbury in Ontario, Thompson in Manitoba, and Yellowknife in the Northwest Territories, rely on the mining industry for jobs. The mineral ores are smelted to remove waste materials. The concentrated minerals are shipped to factories in Canada and other parts of the world where they are used to manufacture products we use every day. While the Shield is well-suited to mining, it is ill- suited to farming because it has very thin soils. However, it is ideal for recreation because of it scenic rivers, waterfalls, lakes, rock outcrops, and vast forests. Glaciers removed enormous amounts of soil, clay, rock, and gravel from the Shield. Today, a thin layer of soil covers most of the Shield, and the bedrock is visible in many places. The action of the glaciers affected the drainage (process whereby water is removed from an area by flowing out of depressions in the land such as lakes and rivers.) of the Shield. The scraping and gouging action of the ice created depressions in the bedrock (solid rock beneath the soil). These depressions filled with water to form the hundreds of thousands of lakes that now 0dot the Shield. Because the bedrock is impervious (quality of a substance that does not allow water to pass through it), water d