Mining and Economics
The 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. Throughout the Shield there are many mining towns extracting these minerals. The largest, and one of the best known, is Sudbury, Ontario. 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. 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, 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.
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 tons of sulfide have been mined.
The Shield, particularly 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 a mineral. The kimberlite eruptions then bring the diamonds from over 150 kilometres (93 mi) depth to the surface. Currently the Ekati and Diavik mines are actively mining kimberlite diamonds.
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Famous quotes containing the words mining and/or economics:
“In strict science, all persons underlie the same condition of an infinite remoteness. Shall we fear to cool our love by mining for the metaphysical foundation of this elysian temple? Shall I not be as real as the things I see? If I am, I shall not fear to know them for what they are.”
—Ralph Waldo Emerson (1803–1882)
“There is no such thing as a free lunch.”
—Anonymous.
An axiom from economics popular in the 1960s, the words have no known source, though have been dated to the 1840s, when they were used in saloons where snacks were offered to customers. Ascribed to an Italian immigrant outside Grand Central Station, New York, in Alistair Cooke’s America (epilogue, 1973)