Canadian shield

Big image

Location

The Canadian shield underlies most of canada and parts of the united states More than 4800000 sq.km. of Canada is covered by it

Geology

The Canadian Shield is amongst the oldest on earth, with regions dating 2.5 - 3.5 billion years.The multitude of rivers and lakes in the entire region is caused by the watersheds of the area being so young and in a state of sorting themselves out with the added effect of post-glacial rebound.The Canadian Shield was originally an area of very large mountains(about 12000 Metres)with much volcanic activity, but over hundreds of millions of years, the area has been eroded to its current topographic appearance of relatively low relief. It has some of the oldest (extinct) volcanoes on the planet.It has over 150 volcanic belts (now deformed and eroded down to nearly flat plains) whose bedrock ranges from 600 to 1200 million years old.Massive volcanic eruptions raised mountains from the sea to form the core of a new continent.Rich veins of metallic minerals,such as gold,silver, and nickel,squeezed into these igneous rocks(rocks created from molten magma).Then, billions of years of erosion levelled the mountains,putting the minerals within reach of miners.During the ice ages, moving glaciers scraped much of the soil from the Shield. As they moved,the glaciers marked the land with hollows and depressions.

Land

The shield underlies most of Canada and parts of the UNITED STATES More than 4800000 sq.km.of Canada is covered by it. It contains some of the world's oldest rocks (about 3.96 billion years old).This region covers almost half of Canada. it's shaped like a doughnut ,with Hudson Bay as the hole.

Land Uses

The Shield is one of the world's richest areas in terms of mineral ores,two types of rock,igneous and metamorphic form most of the Shield. These rocks contain minerals such as,lead,gold,nickel,coper,and,zinc in great quantites.Because of this, the Canadian Shield is often called the storehouse of canada's METALLIC MINERALS. Minerals were deposited the shield as magma slowly intruded and cooled.

Canadian Shield also provide jobs.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 Shield is ill-suited for farming due to its thin soils,but is ideal for RECREATION. The plentiful water flow has made the region an excellent source of WATER-GENERATED energy.Since the outer portion of the Shield is lower than the centre, most rivers flow towards its centre and into Hudson Bay.Canadian Shield also provide many flash water.

Tourism

Family Adventure at Georgian Bay Islands National Park
The Evolution of the Canadian Shield