The Arctic Lands is a physiographic region located in northern Canada. It is one of Canada's seven physiographic regions, which is divided into three divisions—the Innuitian Region , Arctic Coastal Plain, and Arctic Lowlands.
41-946: Each of the three divisions is distinguished by topography and geology. The other physiographic regions are the Canadian Shield , the Hudson Bay Lowlands , the Interior Plains , the Cordillera , the Great Lakes–St. Lawrence Lowlands , and the Appalachian Uplands . There are two mountain zones in the Innuitian Region . In between lies a vast terrain with plateaus, uplands and lowlands. The Arctic Coastal Plain includes its three divisions, Island Coastal Plain, Mackenzie Delta , and
82-603: A mineral. The kimberlite eruptions then bring the diamonds from over 150 kilometres (93 mi) depth to the surface. The Ekati and Diavik mines are actively mining kimberlite diamonds. Trans-Hudson orogeny The Trans-Hudson orogeny or Trans-Hudsonian orogeny was the major mountain building event ( orogeny ) that formed the Precambrian Canadian Shield and the North American Craton (also called Laurentia ), forging
123-405: A myriad population of other birds, including ravens and crows , predatory birds and many songbirds . The Canadian Shield is one of the world's richest areas in terms of mineral ores . It is filled with substantial deposits of nickel , gold , silver , and copper . There are many mining towns extracting these minerals. The largest, and one of the best known, is Sudbury , Ontario. Sudbury
164-560: Is a stub . You can help Misplaced Pages by expanding it . Canadian Shield The Canadian Shield ( French : Bouclier canadien [buklje kanadjɛ̃] ), also called the Laurentian Shield or the Laurentian Plateau , is a geologic shield , a large area of exposed Precambrian igneous and high-grade metamorphic rocks . It forms the North American Craton (or Laurentia) , the ancient geologic core of
205-648: Is a right-angled suture zone that extends eastward from Saskatchewan through collisional belts in the Churchill province , through northern Quebec , parts of Labrador and Baffin Island , and all the way to Greenland as the Rinkian belt and Nagssugtodidian Orogen. Westward it goes across Hudson Bay through Saskatchewan and then extends 90 degrees south through eastern Montana and the western Dakotas , downward through eastern Wyoming and western Nebraska , and
246-647: Is an exception to the normal process of forming minerals in the shield since the Sudbury Basin is an ancient meteorite impact crater . Ejecta from the meteorite impact was found in the Rove Formation in May 2007. The nearby but less-known Temagami Magnetic Anomaly has striking similarities to the Sudbury Basin. This suggests it could be a second metal-rich impact crater. In northeastern Quebec,
287-587: Is one of the world's best preserved mineralized Neoarchean caldera complexes, which is 2.7 Ga. The Canadian Shield also contains the Mackenzie dike swarm , which is the largest dike swarm known on 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. The Canadian Shield
328-726: Is part of an ancient continent called Arctica , which was formed about 2.5 Ga during the Neoarchean era. Mountains have deep roots and float on the denser mantle much like an iceberg at sea . 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. Although these mountains are now heavily eroded, many large mountains still exist in Canada's far north called
369-546: Is the Earth's greatest area of exposed Archean rock. The metamorphic base rocks are mostly from the Precambrian (between 4.5 Ga and 540 Ma) and have been repeatedly uplifted and eroded. Today it consists largely of an area of low relief 300–610 m (980–2,000 ft) above sea level with a few monadnocks and low mountain ranges (including the Laurentian Mountains ) probably eroded from the plateau during
410-974: Is then cut off by the Cheyenne belt - the northern edge of the Yavapai province (see Trans-Hudson Orogen map and the THOT Transect map. To the south, the orogen contributed to the subsurface Phanerozoic strata in Montana and the Dakotas that created the Great Plains . The Trans-Hudson orogeny was the culminating event of the Paleoproterozoic Laurentian assembly, which occurred after the Wopmay orogeny (West of Hudson Bay , ca. 2.1-1.9 Ga.). The Trans-Hudson orogeny resulted from
451-699: The Appalachian Plateau ). The Black Hills of South Dakota is one of the few remaining exposed portions of the Trans-Hudson orogenic belt. The peaks of the Black Hills are 3,000 to 4,000 feet above the surrounding plains, while Black Elk Peak - the highest point in South Dakota - has an altitude of 7,242 feet above sea level. These central spires and peaks all are carved from granite and other igneous and metamorphic rocks that form
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#1732772439080492-472: The Arctic Cordillera . 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. The current surface expression of the shield is one of very thin soil lying on top of
533-625: The Black Hills of South Dakota . The Trans-Hudson orogeny and the consequent upheaval of the continental crust in the middle Proterozoic eon caused the area around the Great Lakes to become a flattened plain, which in turn led to the creation of the intracontinental basin and the interior and central plains of the United States (the Great Plains are the westernmost portion of North America's Interior Plains , which extend east to
574-631: The Cenozoic Era. During the Pleistocene Epoch, continental ice sheets depressed the land surface (creating Hudson Bay ) but also tilted up its northeastern "rim" (the Torngat ), scooped out thousands of lake basins, and carried away much of the region's soil. The northeastern portion, however, became tilted up so that, in northern Labrador and Baffin Island , the land rises to more than 1,500 metres (5,000 feet) above sea level. When
615-646: The Greenland section is included, the Canadian Shield is approximately circular, bounded on the northeast by the northeast edge of Greenland, with Hudson Bay in the middle. It covers much of Greenland, all of Labrador and the Great Northern Peninsula of Newfoundland , most of Quebec north of the St. Lawrence River , much of Ontario including northern sections of the Ontario Peninsula ,
656-458: The Hearne - Rae , Superior , and Wyoming cratons to form the cratonic core of North America in a network of Paleoproterozoic orogenic belts. These orogenic belts include the margins of at least nine independent microcontinents that were themselves sections of at least three former major supercontinents, including Laurasia , Pangaea and Kenorland (ca. 2.7 Ga ), and contain parts of some of
697-558: The North American continent. Glaciation has left the area with only a thin layer of soil , through which exposures of igneous bedrock resulting from its long volcanic history are frequently visible. As a deep, common, joined bedrock region in eastern and central Canada , the shield stretches north from the Great Lakes to the Arctic Ocean , covering over half of Canada and most of Greenland ; it also extends south into
738-528: The Proterozoic Eon that were progressively amalgamated during the interval 2.45–1.24 Ga, with the most substantial growth period occurring during the Trans-Hudson orogeny , between c. 1.90–1.80 Ga. 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
779-707: The Adirondack Mountains of New York , the northernmost part of Lower Michigan and all of Upper Michigan , northern Wisconsin , northeastern Minnesota , the central and northern portions of Manitoba , northern Saskatchewan , a small portion of northeastern Alberta , mainland Northwest Territories to the east of a line extended north from the Saskatchewan-Alberta border, most of Nunavut's mainland and, of its Arctic Archipelago , Baffin Island and significant bands through Somerset , Southampton , Devon and Ellesmere islands. In total,
820-525: The Laurentia craton signifying the area of greatest glacial impact (scraping down to bare rock) creating the thin soils. The age of the Canadian Shield is estimated to be 4.28 Ga . The Canadian Shield once had jagged peaks, higher than any of today's mountains, but millions of years of erosion have changed these mountains to rolling hills. The Canadian Shield is a collage of Archean plates and accreted juvenile arc terranes and sedimentary basins of
861-830: The Superior Craton, south of the Kisseynew Domain, and east of the Glennie Domain. The Superior Boundary zone is a narrow, southeastern, ensialic foreland zone bordering Superior Craton, comprising the Thompson Belt, Split Lake Block, and Fox River Belt. The Flin Flon greenstone belt is one of the largest Proterozoic volcanic-hosted massive sulfide (VMS) districts in the world, containing 27 Cu-Zn- (Au) deposits from which more than 183 million tonnes of ore have been mined. Most of mined VMS deposits in
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#1732772439080902-863: The THO mountain building (orogeny). The Northwestern hinterland zone is a complex tectonically deformed region that includes the Peter Lake, Wollaston, and Seal River domains, and other parts of the Cree Lake Zone, now included in Hearne Province. The Reindeer zone to the north is a 500 km wide collage of Paleoproterozoic (1.92-1.83 Ga) arc volcanic rocks, plutons, volcanogenic sediments, and younger molasse , divisible into several lithostructural domains. Most of these rocks evolved in an oceanic to transitional, subduction-related arc setting, with increasing influence of Archean crustal components to
943-589: The Trans-Hudson orogeny, rifting at first separated the Superior craton from the rest of the continent. Then the Superior Craton reversed its direction and the ocean basin began to close. A subduction zone formed as the oceanic crust of the Superior Craton was subducted beneath the Hearne and Wyoming Craton with the Sask Craton in the middle. Volcanic arcs developed as the cratons collided, eventually resulting in
984-642: The Yukon Coastal Plain, each distinguished by physiographic characteristics. The Lancaster Plateau , Foxe Plain , Boothia Plain , Victoria Lowland , and Shaler Mountains comprise the Arctic Lowlands. This includes parts of Ellesmere Island , Devon Island , Somerset Island and the Brodeur Peninsula . This geology article is a stub . You can help Misplaced Pages by expanding it . This Nunavut location article
1025-426: The bedrock, with many bare outcrops . This arrangement was caused by severe glaciation during the ice ages that covered the shield and scraped the rock clean. The lowlands of the Canadian Shield have a very dense soil that is not suitable for forestation; it also contains many marshes and bogs ( muskegs ). The rest of the region has coarse soil that does not retain moisture well and is frozen with permafrost throughout
1066-592: The case of polar bears ( Ursus maritimus ), the shield area contains many of their denning locations, such as the Wapusk National Park . The many lakes and rivers on the shield contain a plentiful quantity of different sports fish species, including walleye , northern pike , lake trout , yellow perch , whitefish , brook trout , arctic grayling , and many types of baitfish. The water surfaces are also home to many waterfowl , most notably Canada geese , loons and gulls . The vast forests contain
1107-714: The collision of the Superior Craton of eastern Canada with the Hearne Craton in northern Saskatchewan and the Wyoming Craton of the western United States , with the Archean microcontinent Sask Craton trapped in the THO western interior. Similar to the Himalayas, the Trans-Hudson orogeny was also the result of continent-continent collision along a suture zone. Only the roots of this mountain chain remain, but these can be seen in northeastern Saskatchewan and in
1148-516: The continental shelves, and oceanic crust formed on the margins of the continental cratons as the divergence continued. Eventually the divergence stopped, then reversed direction, and collision occurred between continental land masses. During the Wopmay orogeny, subduction occurred as oceanic crust of the Slave Craton was subducted beneath an eastward moving continental plate. Likewise, during
1189-530: The core of the uplift. The nature and timing of this portion of the THO event in southern Laurentia is poorly understood, when compared to the exposed northern segments in Canada. The Black Hills offer the only surface exposure of the deformed and metamorphosed belt of Paleoproterozoic continental margin rocks in the collisional zone between the Archean Wyoming and Superior provinces. Based on geophysical evidence, this zone has been broadly interpreted to be
1230-617: The exposed area of the shield covers approximately 8,000,000 km (3,100,000 sq mi). The true extent of the shield is greater still and stretches from the Western Cordillera in the west to the Appalachians in the east and as far south as Texas , but these regions are overlaid with much younger rocks and sediment. The Canadian Shield is among the oldest geologic areas on Earth, with regions dating from 2.5 to 4.2 billion years. The multitude of rivers and lakes in
1271-460: The giant Manicouagan Reservoir is the site of an extensive hydroelectric project (Manic-cinq, or Manic-5). This is one of the largest-known meteorite impact craters on Earth , though not as large as the Sudbury crater. 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
Arctic Lands - Misplaced Pages Continue
1312-601: The initial North American continent . It gave rise to the Trans-Hudson orogen (THO), or Trans-Hudson Orogen Transect (THOT), (also referred to as the Trans-Hudsonian Suture Zone (THSZ) or Trans-Hudson suture ) which is the largest Paleoproterozoic orogenic belt in the world. It consists of a network of belts that were formed by Proterozoic crustal accretion and the collision of pre-existing Archean continents . The event occurred 2.0–1.8 billion years ago. The Trans-Hudson orogen sutured together
1353-413: The most northerly parts of Manitoba and Saskatchewan. Hydrologic drainage is generally poor, the soil compacting effects of glaciation being one of the many causes. Tundra typically prevails in the northern regions. Many mammals such as beaver , caribou , white-tailed deer , moose , wolves , wolverines , weasels , mink , otters , grizzly bear , polar bears and black bears are present. In
1394-727: The northern reaches of the continental United States . The Canadian Shield is a physiographic division comprising four smaller physiographic provinces: the Laurentian Upland , Kazan Region , Davis and James. The shield extends into the United States as the Adirondack Mountains (connected by the Frontenac Axis ) and the Superior Upland . The Canadian Shield is a U-shaped subsection of
1435-603: The northwest. The zone overlies Archean basement exposed in structural windows that are now recognized as the Sask craton. The Wathaman-Chipewyan batholith is an Andean-type continental-margin, magmatic arc emplaced 1.86-1.85 Ga. The Flin Flon domain is in the center of the Trans-Hudson Suture Zone and extends over the border of the Manitoba-Saskatchewan segment east and west. It is west of
1476-474: The oldest cratonic continental crust on Earth . These old cratonic blocks, along with accreted island arc terranes and intraoceanic deposits from earlier Proterozoic and Mesozoic oceans and seaways, were sutured together in the Trans-Hudson Orogen (THO) and resulted in extensive folding and thrust faulting along with metamorphism and hundreds of huge granitic intrusions . The THO
1517-446: The region is classical example of a deranged drainage system , caused by the watersheds of the area being disturbed by glaciation and the effect of post-glacial rebound . The shield was originally an area of very large, very tall mountains (about 12,000 m or 39,000 ft) with much volcanic activity, but the area was eroded to nearly its current topographic appearance of relatively low relief over 500 Ma. Erosion has exposed
1558-586: The roots of the mountains, which take the form of greenstone belts in which belts of volcanic rock that have been altered by metamorphism are surrounded by granitic rock. These belts range in age from 3.6 to 2.7 Ga. Much of the granitic rock belongs to the distinctive tonalite–trondhjemite–granodiorite family of rocks, which are characteristic of Archean continental crust . Many of Canada's major ore deposits are associated with greenstone belts. The Sturgeon Lake Caldera in Kenora District , Ontario,
1599-506: The southern extension of the THO that was later truncated by the ~1.680 Ga. Central Plains orogen . Marine evidence indicates that the area initially opened to form an ocean called the Manikewan Ocean . Faulting, sedimentary and igneous rocks all indicate that divergence formed a rift valley that continued to spread until it resulted in a passive margin in which there was no tectonic activity. Shallow marine deposits formed on
1640-481: The world, containing 27 copper - zinc -( gold ) deposits from which more than 183 million tonnes of sulfide have been mined." The portion in the Northwest Territories has recently been the site of several major diamond discoveries. 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
1681-523: The year. Forests are not as dense in the north. The shield is covered in parts by vast boreal forests in the south that support natural ecosystems as well as a major logging industry. The boreal forest area gives way to the Eastern Canadian Shield taiga that covers northern Quebec and most of Labrador. The Midwestern Canadian Shield forests that run westwards from Northwestern Ontario have boreal forests that give way to taiga in