Canadian Shield

Canadian Shield Landform.

The Canadian Shield — also called the Laurentian Plateau, or Bouclier Canadien (French) — is a large geological shield covered by a thin layer of soil that forms the nucleus of the North American or Laurentia craton. A shield is generally a large area of exposed Precambrian Crystalline igneous and high-grade metamorphic rocks that form tectonically Laurentia (also known as the North American craton) like all Craton land was created as continents moved about the surface of the Earth It has a deep, common, joined bedrock region in eastern and central Canada and stretches North from the Great Lakes to the Arctic Ocean, covering over half the country. Bedrock is the native consolidated rock underlying the surface of a terrestrial planet usually the Earth. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page The Laurentian Great Lakes are a chain of freshwater lakes located in eastern North America, on the Canada–United States border. The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region is the smallest and shallowest of the world's five major It also includes most of Greenland and extends into the United States as the Adirondack Mountains and the Northern Highland. Greenland (Kalaallit Nunaat meaning "Land of the Greenlanders" Grønland is a self-governing Danish Province located between the The Geology of North America, like most topics of scientific study is undergoing progressive investigation by numerous public- and private-sector The Adirondack Mountains are a Mountain range located in the northeastern part of New York, that runs through Clinton, Essex, Franklin In the US state of Wisconsin, the Northern Highland is a geographical region covering much of the state’s northern territory The Canadian Shield is U-shaped, but almost circular, which gives it an appearance of a warrior's shield or a giant horseshoe, and is a subsection of the Laurentia craton signifying the area of greatest glacial impact (scraping down to bare rock) creating the thin soils. A craton ( Greek kratos / κρἀτος ( neut. "strength" is an old and stable part of the Continental crust that has survived

The Canadian Shield is a collage of Archean plates and accreted juvenile arc terranes and sedimentary basins of Proterozoic age that were progressively amalgamated during the interval 2. 45 to 1. 24 Ga, with the most substantial growth period occurring during the Trans-Hudson orogeny, between ca. Annum is one form of the Latin noun meaning Year, not a form normally used for derivatives in modern languages the accusative singular The Trans-Hudson orogeny, Trans-Hudsonian orogeny, Trans-Hudson orogen (THO or Trans-Hudson Orogen Transect (THOT (also referred to as 1. 90 to 1. 80 Ga. ^[1] The Canadian Shield was the first part of North America to be permanently elevated above sea level and has remained almost wholly untouched by successive encroachments of the sea upon the continent. It is the earth's greatest area of exposed Archaean rock. The metamorphic base rocks are mostly from the Precambrian Era (between 4. Metamorphic rock is the result of the transformation of an existing rock type the protolith, in a process called Metamorphism, which means "change In Geology, rock is a naturally occurring aggregate of Minerals and/or Mineraloids The Earth's outer solid layer the ‘ Lithosphere The Precambrian ( Pre-Cambrian) is an informal name for the supereon comprising the eons of the Geologic timescale that came before the current 5 billion and 540 million years ago), and have been repeatedly uplifted and eroded. Today it consists largely of an area of low relief (1,000–2,000 ft/300–600 m above sea level) with a few monadnocks and low mountain ranges (including the Torngat and Laurentian Mountains) probably eroded from the plateau during the Cenozoic era. A monadnock or inselberg is an isolated hill knob ridge or small Mountain that rises abruptly from a gently sloping or virtually level surrounding Plain For the Montreal indie band see Torngat Torngat Mountains are a Mountain range located on the Labrador Peninsula at the northern tip The Laurentian Mountains (French Laurentides) are a Mountain range in southern Quebec, Canada, north of the St The Cenozoic (also Caenozoic or Cainozoic) Era (ˌsiːnəˈzoʊɪk/ /ˌsɛn- (meaning "new life" ( Greek ( kainos) "new" During the Pleistocene epoch, continental ice sheets depressed the land surface (see Hudson Bay), scooped out thousands of lake basins, and carried away much of the region's soil. The Pleistocene ('plaɪstəsin is the epoch from 18 million to 10000 years BP covering the world's recent period

Hydrographical drainage is generally poor, the effects of glaciation being one of the reasons. Hydrography focuses on the measurement of physical characteristics of Waters and marginal land "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. The Canadian shield is covered by boreal forests in the south, while tundra prevails in the northern regions. Taiga (ˈtaɪgə from Turkic or Mongolian) is a Biome characterized by Coniferous forests In physical Geography, tundra is an area where the Tree growth is hindered by low temperatures and short growing seasons Population is scarce, and industrial development is minimal^[2], however the region has a large water-power potential and is a source of ore and timber. An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining Lumber or timber is Wood in any of its stages from felling through readiness for use as structural Material for Construction, or Many mammals such as caribou, wolverines, weasels, mink, otters, grizzlies and black bears are also present in this area^[3]. Weasels are Mammals in the genus Mustela of the Mustelidae family. There are two living species of " mink," the American Mink and the European Mink. Otters are semi- aquatic (or in one case aquatic) fish-eating Mammals The otter subfamily Lutrinae forms part of the family The Grizzly Bear (Ursus arctos horribilis, also known as the Silvertip Bear, is a Subspecies of Brown bear (Ursus arctos that lives The American Black Bear ( Ursus americanus) is the most common Bear Species native to North America.

Regional extent

When the Greenland section is included, the Shield is approximately circular bounded on the northeast by the northeast edge of Greenland, with Hudson Bay in the middle. Greenland (Kalaallit Nunaat meaning "Land of the Greenlanders" Grønland is a self-governing Danish Province located between the It covers much of Greenland, Labrador, most of Quebec north of the St. Lawrence River, much of Ontario including northern sections of the southern peninsula between the Great Lakes, the Adirondack Mountains^[4] of northern New York, the northernmost part of Lower Michigan and all of Upper Michigan, northern Wisconsin, and northeastern Minnesota, the central/northern portions of Manitoba away from Hudson Bay and the Great Plains, northern Saskatchewan, a small portion of northeastern Alberta,^[5] and the mainland northern Canadian territories to the east of a line extended north from the Saskatchewan/Alberta border (Northwest Territories and Nunavut)^[6]. Modern Labrador Just like its island neighbour Newfoundland early settlement in Labrador was tied to the sea as demonstrated by the Montagnais, Innu and Quebec (kwɨˈbɛk Saint Lawrence River (in French: fleuve Saint-Laurent; Kahnawáˀkye in Tuscarora, Kaniatarowanenneh meaning big waterway Ontario (ɒnˈtɛrioʊ is a province located in the central part of Canada, the largest by population and second largest after Quebec The Laurentian Great Lakes are a chain of freshwater lakes located in eastern North America, on the Canada–United States border. The Adirondack Mountains are a Mountain range located in the northeastern part of New York, that runs through Clinton, Essex, Franklin New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous Michigan ( is a Midwestern state of the United States of America. The Upper Peninsula of Michigan is the northern of the two major land masses that comprise the U Wisconsin ( or wɪˈskɑnsɨn (French Ouisconsin) is one of the fifty United States of America, located in the north central part of the United States Minnesota ( Native Americans demonstrated the name to early settlers Manitoba (English ˌmænɨˈtoʊbə French /manitoba/ is a province of Canada, spanning 647797 square kilometres (250116  sq mi of North America The Great Plains are the broad expanse of Prairie and Steppe which lie east of the Rocky Mountains in the United States and Canada Saskatchewan (səˈskætʃəwən) is a prairie province in Canada, which has an area of 588276 Alberta (ælˈbɝtə is one of Canada's prairie provinces. It became a province on September 1 1905 The Northwest Territories (ˌnɔrθˌwɛstˈtɛrɨtɔriz ( NWT or NT; French, les Territoires du Nord-Ouest) is a territory Nunavut (ˈnuːnəvʊt ( Inuktitut syllabics: ᓄᓇᕗᑦ is the largest and newest territory of Canada; it was separated officially from the In total it covers approximately 8 million square kilometers. It covers even more area and stretches to the Western Cordillera in the west and Appalachians in the east but the formations are still underground. The Appalachian Mountains ( often called the Appalachians, are a vast system of mountains in eastern North America.

The underlying rock structure does include Hudson Bay and the submerged area between North America and Greenland.

The Canadian shield is so large the climate varies across it. In the southern parts the climate is seasonal; the average temperature in the winter is -18 degrees Celsius, and in the summer it is 25 degrees Celsius. The growing season of about 120 days coincides with summer daylight averaging about 15 hours, while winter daylight averages about 8. 5 hours. In the northern parts it is very cold. The average temperatures range from 15 degrees Celsius in the summer to -35 degrees Celsius in winter. The growing season is only 60 days. Winter daylight hours are about 5. 5 hours, and in the summer the daylight hours are about 18. 5 hours. The lowlands of the Canadian shield have soggy soil suitable for planting trees, but it contains many marshes and bogs. The rest of the region has coarse soil that doesn't hold moisture very well and is frozen all year round. Forests are less dense in the north.

Physiography

The Canadian shield is a physiographic division, consisting of 5 smaller physiographic provinces, the Laurentian Upland, Kazan, Davis, Hudson, and James. The physiographic regions of the world are a means of defining the Earth's landforms into distinct regions based upon Nevin Fenneman 's classic three-tiered approach of divisions The Laurentian Upland (or Laurentian Highlands) is a physiographic province which when referred to as the "Laurentian Region" is recognized by Natural ^[7]

Geology

Canadian Shield is exposed part of North American craton or Laurentia. Laurentia (also known as the North American craton) like all Craton land was created as continents moved about the surface of the Earth Laurentia (also known as the North American craton) like all Craton land was created as continents moved about the surface of the Earth

Such a large area of exposed old rock is unusual. The current surface expression of the Shield is one of very thin soil lying on top of the bedrock, with many bare outcrops. Geomorphology (from Greek: γη ge, "earth" μορφή morfé, "form" and λόγος Logos, "knowledge" Bedrock is the native consolidated rock underlying the surface of a terrestrial planet usually the Earth. This arrangement was caused by severe glaciation during the last ice age, which covered the Shield and scraped the rock clean. "Glacial" and "Glaciation" redirect here For the geological periods see Glacial period. An ice age is a period of long-term reduction in the Temperature of the Earth 's surface and atmosphere resulting in an expansion of continental Ice sheets 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. A drainage basin is an extent of Land where Water from Rain or Snow melt drains downhill into a body of water such as a River, Post-glacial rebound (sometimes called continental rebound, isostatic rebound, isostatic adjustment or post-ice-age isostatic recovery) The Shield was originally an area of very large mountains (about 12,000 meters)^[8] with much volcanic activity, but over the millennia the area was eroded to its current topographic appearance of relatively low relief. A mountain is a Landform that extends above the surrounding Terrain in a limited area with a peak Plate tectonics and hotspots Divergent plate boundaries At the Topography ( topo-, "place" and graphia, "writing" is the study of Earth 's Surface features or those of Planets It contains some of the most ancient volcanoes on Earth. It has over 150 volcanic belts (now deformed and eroded down to nearly flat plains) that range from 600 to 1200 million years old. A volcanic belt is a large volcanically active region Other terms are used for smaller areas of activity such as volcanic fields Volcanic belts are found above zones In Geography, a plain is an area of land with relatively low relief — meaning that it is flat Each belt probably grew by the coalescence of accumulations erupted from numerous vents, making the tally of volcanoes in the hundreds. Many of Canada's major ore deposits are associated with Precambrian volcanoes. The Sturgeon Lake Caldera in Kenora District, Ontario is one of the world's best preserved mineralized Neoarchean caldera complexes, which is some 2. Sturgeon Lake Caldera is a large extinct Caldera in Kenora District of Northwestern Ontario, Canada. Kenora District ( Canada 2006 Census population 64419 is a District and Census division in Northwestern Ontario in the Canadian For other uses see Mineralization In geology mineralization is the Hydrothermal deposition of economically important Metals The Neoarchean (ˌniːoʊɑrˈkiːən also spelled Neoarchaean) is a geologic era within the Archaean. A caldera is a cauldron-like volcanic feature formed by the collapse of land following a volcanic eruption 7 billion years old. ^[9] The Canadian Shield also contains the Mackenzie dike swarm, which is the largest dike swarm known on Earth. The Mackenzie dike swarm, also called the Mackenzie dikes, form a Large igneous province in the western Canadian Shield of Canada. A dike swarm or dyke swarm in Geology is a major group of parallel linear or radially oriented dikes intruded within Continental crust EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 ^[10]

Typical Canadian Shield: pines, lakes, bogs, and rock.

Mountains have deep roots and float on the denser mantle much like an iceberg at sea. The mantle is a part of an Astronomical object. The interior of the Earth, similar to the other Terrestrial planets, is Chemically divided An iceberg is a large piece of freshwater Ice that has broken off from a snow-formed Glacier or Ice shelf and is floating in open water This article is about the body of water For other uses see SEA and Seas. As mountains erode, their roots rise and are eroded in turn. The rocks that now form the surface of the Shield were once far below the earth's surface. The high pressures and temperatures at those depths provided ideal conditions for mineralization. For other uses see Mineralization In geology mineralization is the Hydrothermal deposition of economically important Metals Although these mountains are now heavily eroded, many large mountains still exist in Canada's far north called the Arctic Cordillera. The Arctic Cordillera, sometimes called the Arctic Rockies, are a vast deeply dissected mountain system running along the northeastern shore of North America This a vast deeply dissected mountain range, streching from northernmost Ellesmere Island to the northernmost tip of Labrador. A mountain range is a chain of Mountains bordered by highlands or separated from other mountains by passes or valleys Ellesmere Island is part of the Qikiqtaaluk Region of the Canadian territory of Nunavut. Modern Labrador Just like its island neighbour Newfoundland early settlement in Labrador was tied to the sea as demonstrated by the Montagnais, Innu and The range's highest peak is Nunavut's Barbeau Peak at 2,616 meters (8,583 feet) above sea level. Nunavut (ˈnuːnəvʊt ( Inuktitut syllabics: ᓄᓇᕗᑦ is the largest and newest territory of Canada; it was separated officially from the Barbeau Peak, on Ellesmere Island, is the highest Mountain in Nunavut. Mean sea level (MSL is the average (mean height of the Sea, with reference to a suitable reference surface ^[11] Precambrian rock is the major component of the bedrock. The Precambrian ( Pre-Cambrian) is an informal name for the supereon comprising the eons of the Geologic timescale that came before the current Bedrock is the native consolidated rock underlying the surface of a terrestrial planet usually the Earth.

The North American craton is the bedrock forming the heart of the North American continent and the Canadian Shield is the largest exposed part of the craton's bedrock. Laurentia (also known as the North American craton) like all Craton land was created as continents moved about the surface of the Earth

The Canadian Shield is part of an ancient continent called Arctica, which was formed about 2. Arctica was an ancient Continent which formed approximately 2 5 billion years ago, during the Neoarchean era. The Neoarchean (ˌniːoʊɑrˈkiːən also spelled Neoarchaean) is a geologic era within the Archaean. It was split into Greenland, Laurentia, Scotland, Siberia, East Antarctica and is now roughly situated in the Arctic around the current North Pole. Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain. Siberia (Сиби́рь Sibir) is the name given to the vast region constituting almost all of Northern Asia and for the most part currently serving East Antarctica, also called Greater Antarctica, is one of the two major regions of the Antarctic Continent, lying on the Indian Ocean side of The Arctic is the Region around the Earth 's North Pole, opposite the Antarctic region around the South Pole. The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is subject to the caveats explained below defined as the point in the northern

Mining and economics

The Shield is one of the world's richest area in terms of mineral ores. A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining It is filled with substantial deposits of nickel, gold, silver, and copper. Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 Silver (ˈsɪlvɚ is a Chemical element with the symbol " Ag " (argentum from the Ancient Greek: ἀργήντος - argēntos gen Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Throughout the Shield there are many mining towns extracting these minerals. The largest, and one of the best known, is Sudbury, Ontario. Greater Sudbury (2006 Census population 157857 is a city in Northern Ontario, Canada. Ontario (ɒnˈtɛrioʊ is a province located in the central part of Canada, the largest by population and second largest after Quebec Sudbury is an exception to the normal process of forming minerals in the Shield since there is significant evidence that the Sudbury Basin is an ancient meteorite impact crater. The Sudbury Basin, also known as Sudbury Structure or the Sudbury Nickel Irruptive, is the second largest known Impact crater or Astrobleme A meteorite is a natural object originating in Outer space that survives an impact with the Earth 's surface In the broadest sense the term impact crater can be applied to any depression natural or manmade resulting from the high velocity impact of a projectile with larger body The nearby, but less known Temagami Magnetic Anomaly has striking similarities to the Sudbury Basin. The Temagami Magnetic Anomaly, also called the Temagami Anomaly or the Wanapitei Anomaly, is a large buried geologic structure stretching from Lake Wanapitei Its magnetic anomalies are very similar to the Sudbury Basin and so it could be a second metal-rich impact crater. ^[12]

In northeastern Quebec, the giant Manicouagan Reservoir is the site of a massive hydroeletric project (Manic-cinq, or Manic-5). Manicouagan Reservoir (also Lake Manicouagan) is an annular lake in central Quebec, Canada. This is one of the largest-known meteor impact craters on Earth. In the broadest sense the term impact crater can be applied to any depression natural or manmade resulting from the high velocity impact of a projectile with larger body

The Flin Flon greenstone belt in central Manitoba and east-central Saskatchewan is one of the largest Paleoproterozoic volcanic-hosted massive sulfide (VMS) districts in the world, containing 27 copper-zinc-(gold) deposits from which more than 183 million tonnes of sulfide have been mined. The Flin Flon greenstone belt, also referred to as the Flin Flon-Snow Lake greenstone belt, is a Precambrian Greenstone belt located in the central area Manitoba (English ˌmænɨˈtoʊbə French /manitoba/ is a province of Canada, spanning 647797 square kilometres (250116  sq mi of North America Saskatchewan (səˈskætʃəwən) is a prairie province in Canada, which has an area of 588276 The Paleoproterozoic (ˌpeɪlɪoʊˌproʊtərəˈzoʊɪk also spelled Palaeoproterozoic) is the first of the three sub-divisions ( eras) of the The term sulfide ( sulphide in British English) refers to several types of Chemical compounds containing Sulfur in its lowest Oxidation Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 Gold (ˈɡoʊld is a Chemical element with the symbol Au (from its Latin name aurum) and Atomic number 79 ^[13]

The Shield, particularly the portion in the Northwest Territories, has recently been the site of several major diamond discoveries. The Northwest Territories (ˌnɔrθˌwɛstˈtɛrɨtɔriz ( NWT or NT; French, les Territoires du Nord-Ouest) is a territory In Mineralogy, diamond is the allotrope of carbon where the carbon atoms are arranged in The kimberlite pipes in which the diamonds are found are closely associated with cratons, which provide the deep lithospheric mantle required to stabilize diamond as a mineral. Kimberlite is a type of potassic Volcanic rock best known for sometimes containing Diamonds It is named after the town of Kimberley in South Africa The lithosphere (IPA, from the Greek λίθος for "rocky" + σφαίρα for "sphere" is the solid outermost shell of a rocky Planet. The mantle is a part of an Astronomical object. The interior of the Earth, similar to the other Terrestrial planets, is Chemically divided A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific The kimberlite eruptions then bring the diamonds from over 150 km depth to the surface. Currently the Ekati and Diavik mines are actively mining kimberlite diamonds. The Ekati Diamond Mine is Canada 's first Diamond mine. It is located near Lac de Gras north-east of Yellowknife, Northwest Territories The Diavik Diamond Mine is a Diamond mine in the North Slave Region of the Northwest Territories, Canada, about north of

The Shield is also covered by vast boreal forests that support an important logging industry. Taiga (ˈtaɪgə from Turkic or Mongolian) is a Biome characterized by Coniferous forests Logging is the process in which Trees are cut down for Forest management and Timber.

References

See also

• Glacial history of Minnesota
• Shield
• Craton
• Platform
• Oldest rock
• Basement
• Platform basement
• Volcanism in Canada