What Is The Precambrian Shield

The Canadian Shield constitutes the largest mass of exposed Precambrian rock on the face of Earth. The region, as a whole, is composed of ancient crystalline rocks whose complex structure attests to a long history of uplift and depression, mountain building (orogeny), and erosion.

What is Precambrian Shield in geology?

A shield is a large area of exposed Precambrian crystalline igneous and high-grade metamorphic rocks that form tectonically stable areas. These rocks are older than 570 million years and sometimes date back to around 2 to 3.5 billion years.

Where is the Precambrian Shield?

Comprising over half the area of present-day Canada, the eight million square kilometres of pre-Cambrian “shield” is the exposed portion of the ancient geological core of North America.

Why is the Precambrian Shield important?

While at times a barrier to settlement, the Shield has also yielded great resources, including minerals, coniferous forests and the capacity for hydroelectric developments. (This is the full-length entry about the Canadian Shield.

Why is the Canadian Shield also referred to as the Precambrian Shield?

The Canadian Shield is sometimes called the Precambrian Shield because it contains some of the most famous rocks from this era in world.

What is a land shield?

continental shield, any of the large stable areas of low relief in the Earth’s crust that are composed of Precambrian crystalline rocks. See all related content →.

How many shields are there in the world?

The Six Geological Provinces and Continental Shield. The entire Earth has been divided into several Geological Provinces on the basis of their origin.

Where can we find Shields in the North American plate?

The craton region of North America includes the region between the Rocky Mountains (to the west) and the Appalachian Mountains (to the east) and include the Canadian Shield. A shield is a large area of exposed Precambrian-age crystalline igneous and high-grade metamorphic rocks that form tectonically stable areas.

How stable is the Canadian Shield?

It contains some of the oldest rocks on the Earth, its interior has been stable for the longest period of time, and it was the first continent to achieve approximately its present size and shape. Although its known geologic history spans almost 4 billion years, two ages stand out as turning points.

Why is the Canadian Shield uninhabited?

This region has dry, barren, and mostly uninhabited areas. This is largely because it has long, cold winters with heavy snow and perpetually frozen soil.

Why is the Canadian Shield not good for farming?

The shield contains many natural resources, including many minerals. Not many people live directly on the Canadian Shield. It is too rocky and the land is not good for farming.

Is Ottawa on the Canadian Shield?

Major cities that are located in the Canadian Shield are Sudbury, Ottawa, Montreal, Quebec, Iqaluit, Thunder Bay, and Winnipeg. The Canadian shield was formed throughout 3 billion years through the process of plate tectonics, glaciation and erosion’s. Sudbury, Ontario, is the largest and most well known.

What are the characteristics of the Canadian Shield?

The physical features of the Canadian Shield includes rocks , bares and plateaus . The Canadian Shield has uplands which are high or hilly areas, and there are also a lot of rivers , lakes , streams and wetlands. Wetlands help clean water by trapping harmful chemicals.

What is meant by Canadian Shield?

Canadian Shield. noun. Also called: Laurentian Shield, Laurentian Plateau (in Canada) the wide area of Precambrian rock extending west from the Labrador coast to the basin of the Mackenzie and north from the Great Lakes to Hudson Bay and the Arctic: rich in mineralsSee shield (def. 7).

Is the Canadian Shield a mountain range?

This is a vast, deeply dissected mountain range, stretching from northernmost Ellesmere Island to the northernmost tip of Labrador. The range’s highest peak is Nunavut’s Barbeau Peak at 2,616 metres (8,583 ft) above sea level. Precambrian rock is the major component of the bedrock.

Why is the Canadian Shield region full of lakes name any three lakes other than the five Great Lakes?

When Ice Age ended these depressions were filled by meltwater from glaciers and ice-sheets. Apart from the Great Lakes Lake Winnipeg Great Bear Lake Great Slave Lake and Lake Athabasca are important lakes present in this region.

What is the difference between shields and stable platform?

Cratons can be described as shields, in which the basement rock crops out at the surface, and platforms, in which the basement is overlaid by sediments and sedimentary rock. The ancient, stable, interior layer of continents composed of primarily Precambrian igneous or metamorphic rocks.

What is shield and craton?

craton, the stable interior portion of a continent characteristically composed of ancient crystalline basement rock. A shield is that part of a craton in which (usually) Precambrian basement rocks crop out extensively at the surface.

What is the shield of a continent?

continental shield, any of the large stable areas of low relief in the Earth’s crust that are composed of Precambrian crystalline rocks.

What is the shield of the ocean called?

The Shield of the Ocean is a craftable Pre-Hardmode accessory that grants +2 defense, and an additional 5 defense when submerged in a liquid.Shield of the Ocean. Type Accessory – Crafting material Tooltip Increased defense by 5 when submerged in liquid Increases movement speed and life regen while wearing the Victide armor.

What is shield in Brazil?

The Brazilian Shield extends over much of South America to the east of the Andean Chain, and is partly covered by Phanerozoic sedimentary rocks. The Neoproterozoic Brasiliano Cycle belts contain 5% of juvenile crust in central and southern Brazil, but are dominantly derived from reworking of older crust.

What are shields of the Earth?

Earth is surrounded by invisible gases that form a thin protective blanket that we call the atmosphere. It contains the oxygen that we breath as well as other important gases such as nitrogen, carbon dioxide, water vapor, and ozone.