The Canadian Shield, which stretches north from the Great Lakes to the Arctic Ocean, is a region of exposed igneous and high-grade metamorphic rocks (geologic Shield) that forms the ancient geologic core of the North American continent.
It covers almost half of the country and is also one of the largest geological continental shields in the world. Most of Greenland and parts of the northern United States lie on this plateau.
It covers 8 million square km and has Hudson Bay at its center. Estimates place this Shield at 2 billion years old. It is mostly granite with a thin layer of soil.
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Canadian Shield Facts for Kids
- There are mountains and dike swarms in the Canadian Shield.
- It’s also known as the Precambrian Shield and the Laurentian Plateau.
- Baffin Island and northern Labrador have the highest points of this Shield.
- It also has the largest Boreal Forest in the world.
- It is composed mainly of igneous rocks and has a long history of volcanic eruptions.
- In the Shield are five physiographic provinces: Laurentian Upland, James, Kazan Region, Davis, and Hudson
- Formerly a mountain range with volcanic activity which has eroded to its current topographic appearance.
Why is the Canadian Shield important
Minerals, forests, and freshwater are abundant in the Canadian Shield. During Canada’s early years, mining was the region’s key economic driver. It has been mined for gold, silver, copper, zinc, nickel, iron, uranium, and diamonds, among others.
In the south, the Canadian Shield houses a variety of wildlife, and in the north, Arctic wildlife can be seen, including caribou, deer, wolves, lynx, moose, black bears, and beavers.
How Was the Canadian Shield Formed?
Canada’s Shield is one of the oldest on Earth, with areas dating from 2.5 to 4.2 billion years. It is full of rivers, lakes, and a dike swarm that is the largest dike swarm known to Earth.
The Canadian Shield is made up of deep-rooted mountains and spruce, lakes, bogs, and rock.
The Arctic Cordillera consists of Precambrian rock, which is dissected into many large mountain ranges in Canada’s far north.
The Canadian Shield was formed from the North American craton, which was split from Arctica 2.5 billion years ago.
The Canadian Shield is made up of different crustal blocks, called “provinces,” welded together over time by plate tectonics, erosion, and glaciation.
It was created by wind and rain and slowly eroded, creating the low-relief surface we see today.
Ice ages interrupted weathering processes and moved sediment, which became soil.
The Wisconsin glaciation, which began around 110,000 years ago, formed the Great Lakes and thousands of lakes throughout the Canadian Shield.
Geographical extent
The Canadian Shield is a physiographic division of a U-shaped area of the Laurentian craton that was once covered by jagged mountains but now is covered by rolling hills.
It’s a collage of Archean plates that were progressively amalgamated during the Trans-Hudson orogeny between 1.90 and 1.80 Ga. During the Pleistocene Epoch, the land surface was repressed, and ice sheets scooped out thousands of lake basins.
The Canadian Shield, which includes much of Greenland, all of Labrador, and most of Newfoundland, surrounds Greenland on the northeast, with Hudson Bay in the middle.
Ecology
The region consists of boreal forests, taiga, and tundra.
Many mammal species live in these areas, such as caribou, white-tailed deer, moose, wolves, wolverines, weasels, mink, otters, grizzly bears, polar bears, and black bears.
