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43-533: The basin is located on the Canadian Shield in the city of Greater Sudbury , Ontario . The former municipalities of Rayside-Balfour , Valley East and Capreol lie within the Sudbury Basin, which is referred to locally as "The Valley". The urban core of the former city of Sudbury lies on the southern outskirts of the basin. An Ontario Historical Plaque was erected by the province to commemorate

86-485: A suevite and sedimentary package composed of the Onaping (fallback breccias ), Onwatin, and Chelmsford Formations in stratigraphic succession. Footwall rocks, associated with the impact event, consist of Sudbury Breccia ( pseudotachylite ), footwall breccia, radial and concentric quartz dioritic breccia dikes (polymict impact melt breccias), and the discontinuous sub layer. Because considerable erosion has occurred since

129-499: A 19th-century prospector and early mine owner. As a result of these metal deposits, the Sudbury area is one of the world's major mining communities, and has fathered Vale Inco and Falconbridge Xstrata . The Basin is one of the world's largest suppliers of nickel and copper ores. Most of these mineral deposits are found on its outer rim. Most soils in the Sudbury Basin are acidic and sandy; where well drained they usually belong to

172-651: 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 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

215-433: A meteorite was the cause of the Sudbury geological structures. A further difficulty in proving that the Sudbury complex was formed by meteorite impact rather than by ordinary igneous processes was that the region was volcanically active at around the same time as the impact, and some weathered volcanic structures can look like meteorite collision structures. Since its discovery, a layer of breccia has been found associated with

258-538: 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. Temagami Magnetic Anomaly The Temagami Magnetic Anomaly , also called the Temagami Anomaly or the Wanapitei Anomaly , is a magnetic anomaly resulting from a large buried geologic structure in

301-405: 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

344-595: Is a collage of Archean plates and accreted juvenile arc terranes and sedimentary basins of 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

387-584: 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,

430-468: Is long and narrow. With an areal extent of 50 x 15 km, it reaches a magnitude of approximately 10,000 nanoteslas , making it one of the largest positive anomalies in North America. The eastern section coincides with a small positive gravity anomaly, indicating the presence of dense rocks at depth. The anomaly was discovered by a magnetic survey and a gravity survey. In 2014, a 2200m borehole

473-587: 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

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516-726: 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

559-530: Is the third-largest crater on Earth, after the 300 km (190 mi) Vredefort impact structure in South Africa , and the 180 km (110 mi) Chicxulub crater under Yucatán , Mexico . Geochemical evidence suggests that the impactor was likely a chondrite asteroid or a comet with a chondritic component. The full extent of the Sudbury Basin is 62 km (39 mi) long, 30 km (19 mi) wide and 15 km (9.3 mi) deep although

602-472: 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

645-707: The Canadian Shield near Temagami, Ontario , Canada . It stretches from Lake Wanapitei in the west to Bear Island in Lake Temagami . The Aboriginal community of Teme-Augama Anishnabai lies partly within the Temagami Magnetic Anomaly, including the Temagami First Nation on Bear Island. Located nearby are a number of other geological structures, including the Sudbury Basin , the Lake Wanapitei impact crater , and

688-646: 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 ,

731-723: 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 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

774-563: The Podzol great soil group. Poor drainage results in gleysols and peats . Regardless of drainage or classification, the Basin has deeper soils than the surrounding terrain, much of which is mapped as Rockland (a combination of frequent bedrock outcrops and shallow soil). Consequently, considerable areas in the Basin have been cleared for agriculture. The best soils, mapped as Azilda series and Bradley series, occur around Chelmsford . NASA used

817-482: The Temagami Greenstone Belt . The Temagami Magnetic Anomaly is egg-shaped, 58 km (36 mi) long and 19 km (12 mi) wide. The central section has the greatest amplitude and an east–west strike. The Temagami Magnetic Anomaly was first found in the late 1940s during a magnetic survey by Norman Bell Keevil. The western portion appears smoother in character while the eastern section

860-760: 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,

903-538: The Canadian Copper Company) made the first identification in 1889 of the arsenide of platinum which bears his name . As a result of the 1917 Royal Ontario Nickel Commission , which was chaired by Englishman George Thomas Holloway , the legislative structure of the prospecting trade was significantly altered. Some of the Holloway recommendations were in line with the advocacy of Aeneas McCharles ,

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946-468: The Sudbury event, an estimated 6 km (3.7 mi) in the North Range, it is difficult to directly constrain the actual size of the diameter of the original transient cavity, or the final rim diameter. The deformation of the Sudbury structure occurred in five main deformation events (by age in millions of years): Some 1.8 billion years of weathering and deformation made it difficult to prove that

989-847: 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 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

1032-634: The area that were strongly suggestive of mineral deposits, especially near what later became the Creighton Mine . The area was examined by Alexander Murray of the Geological Survey of Canada , who confirmed "the presence of an immense mass of magnetic trap". Due to the then-remoteness of the Sudbury area, Salter's discovery did not have much immediate effect. The construction of the Canadian Pacific Railway through

1075-483: The area, however, made mineral exploration more feasible. The development of a mining settlement occurred in 1883 after blasting at the railway construction site revealed a large concentration of nickel and copper ore at what is now the Murray Mine site, named by owners William and Thomas Murray. The Vermillion Mine , which was the first in the Basin to be exploited, was the site at which Frank Sperry (a chemist of

1118-426: 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

1161-592: 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

1204-574: The discovery of the Sudbury Basin. The Sudbury basin formed as a result of an impact into the Nuna supercontinent from a large impactor body approximately 10–15 km (6.2–9.3 mi) in diameter that occurred 1.849 billion years ago in the Paleoproterozoic era. Debris from the impact was scattered over an area of 1,600,000 km (620,000 sq mi) thrown more than 800 km (500 mi); and ejecta —rock fragments ejected by

1247-617: 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

1290-456: 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

1333-469: The impact event and stressed rock formations have been fully mapped. Reports published in the late 1960s described geological features that were said to be distinctive of meteorite impact, including shatter cones and shock-deformed quartz crystals in the underlying rock. Geologists reached consensus by about 1970 that the Sudbury basin was formed by a meteorite impact. In 2014, analysis of the concentration and distribution of siderophile elements as well as

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1376-413: The impact—have been found as far away as Minnesota . Models suggest that for such a large impact, debris was most likely scattered globally, but has since been eroded. Its present size is believed to be a smaller portion of a 130 km (81 mi) round crater that the meteor originally created. Subsequent geological processes have deformed the crater into the current smaller oval shape. Sudbury Basin

1419-737: The modern ground surface is much shallower. The main units characterizing the Sudbury Structure can be subdivided into three groups: the Sudbury Igneous Complex (SIC), the Whitewater Group, and footwall brecciated country rocks that include offset dikes and the Sub layer. The SIC is believed to be a stratified impact melt sheet composed from the base up of sub layer norite, mafic norite, felsic norite, quartz gabbro, and granophyre. The Whitewater Group consists of

1462-413: 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

1505-650: The plateau during 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

1548-446: 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

1591-586: 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,

1634-558: The sea upon the continent. It 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

1677-619: The site to train the Apollo astronauts in recognizing rocks formed as the result of a very large impact, such as breccias . Those who used this training on the Moon include Apollo 15 's David Scott and James Irwin , Apollo 16 's John Young and Charlie Duke , and Apollo 17 's Gene Cernan and Jack Schmitt . Notable geologist instructors included William R. Muehlberger . Canadian Shield The Canadian Shield ( French : Bouclier canadien [buklje kanadjɛ̃] ), also called

1720-749: The size of the area where the impact melted the rock indicated that a comet rather than an asteroid most likely caused the crater. The Sudbury Basin is located near a number of other geological structures, including the Temagami Magnetic Anomaly , the Lake Wanapitei impact crater, the western end of the Ottawa-Bonnechere Graben , the Grenville Front Tectonic Zone and the eastern end of the Great Lakes Tectonic Zone , but

1763-517: The structures are not directly related to one another in the sense of resulting from the same geological processes. The large impact crater filled with magma containing nickel , copper , palladium , gold , the platinum group and other metals . This magma formed into pyrrhotite , chalcopyrite and pentlandite rocks, as well as cubanite and magnetite . In 1856 while surveying a baseline westward from Lake Nipissing , provincial land surveyor Albert Salter located magnetic abnormalities in

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1806-481: 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

1849-523: 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

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