The Canadian Shield or canádico, also known as bulk of the farmer or Canadian Shield in English, is a region almost circular horseshoe that is composed of rock Precambrian exposed, and extending to the least 8 million square kilometers, or 3 million square miles.
It is the largest exposed Precambrian rock mass on earth, the surface of which is composed of very old crystalline rocks.
It has rocky hills, with a relief of 30 meters or 100 feet, irregular basins with lakes, swamps and mountain ranges.
Canadian Shield Location
The Canadian shield is located in North America, from Lake Superior located in the south, to the Arctic Islands in the north, and from the east in Greenland to western Canada.
It occupies small areas of the United States such as Wisconsin, New York, Michigan and Minnesota, and half of the total area of Canada.
Its underground rock structure also includes Hudson Bay and the underground area that lies between Greenland and North America. However, they are areas that are not considered within the shield because they are not on the surface.
Constitution
This shield is made up of some of the oldest rocks on Earth. It is the most exposed area of the North American Craton, a stable piece of the earth's crust that floats on a sea of magma or liquid rock and has the ability to support continents, sea beds and islands.
Unlike the rest of the Craton, which extends to Mexico and Greenland, the Canadic shield is mostly bare, only covered by a thin layer of earth and preventing activities such as agriculture, but at the same time being very useful for hydroelectric power generation and mining.
It is a very unusual ancient rock exhibit and its surface was scraped off in the last ice age, which is responsible for the fine soil and bare outcrops.
It also contains some of the oldest volcanoes on the planet. In fact there are more than 150 eroded and deformed volcanic belts today, which have left large mineral deposits in their wake.
Weather
Being such a large area, the climate varies in its areas. In general, the southern area has a seasonal climate, with an average temperature of -18 ° C in winter and 25 ° C in summer. Daylight also varies; in summer about 15 hours and in winter 8.
In the north, however, the climate is cold, with average temperatures of 15 ° C in summer and -35 ° C in winter. There are 18 daytime hours in summer and just 5.5 daylight hours in winter.
Ecology
The Canadian Shield is largely covered by boreal forests in the south. In the north, the tundra prevails.
In the transition between forests and tundras, located in Taiga in northern Canada, it has low shrubs due to the severe climate.
In this place the human population is very low due to climatic conditions. However, there are numerous species of other mammals. The most common in the area are weasels, otters, minks, caribou and black bears.
References
- New World Encyclopedia. (2008) Canadian Shield. Recovered from newworldencyclopedia.org
- Quizt, Michael. What is the Canadian Shield? - Definition, Location & Formation. Recovered from study.com
- The Editors of Encyclopedia Britannica. Canadian Shield. Recovered from britannica.com
- Eyles, Nick (2011) Canadian Shield: The Rocks that Made Canada. Fitzhenry & Whiteside, 2011. Recovered from books.google.com.