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Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, [1] is a surface mining technique that extracts rock or minerals from the earth. Open-pit mines are used when deposits of commercially useful ore or rocks are found near the surface where the overburden is relatively thin.
The Development of American Agriculture: A Historical Analysis (1998) Conkin, Paul. A Revolution Down on the Farm: The Transformation of American Agriculture since 1929 (2008) Gardner, Bruce L. (2002). American Agriculture in the Twentieth Century: How It Flourished and What It Cost. Harvard University Press. ISBN 0-674-00748-4. Hurt, R. Douglas.
The Siilinjärvi carbonatite complex, [1] an open-pit mine owned by Yara International, in Siilinjärvi, Finland Coal strip mine in Wyoming. Surface mining, including strip mining, open-pit mining and mountaintop removal mining, is a broad category of mining in which soil and rock overlying the mineral deposit (the overburden) are removed, in contrast to underground mining, in which the ...
Techniques of surface mining include: open-pit mining, which is the recovery of materials from an open pit in the ground; quarrying, identical to open-pit mining except that it refers to sand, stone and clay; strip mining, which consists of stripping surface layers off to reveal ore underneath; and mountaintop removal, commonly associated with ...
When coal seams are near the surface, it may be economical to extract the coal using open-cut, also referred to as open-cast, open-pit, mountaintop removal or strip, mining methods. Opencast coal mining recovers a greater proportion of the coal deposit than underground methods, as more of the coal seams in the strata may be exploited. This ...
The history of agriculture in the United States covers the period from the first English settlers to the present day. In Colonial America, agriculture was the primary livelihood for 90% of the population, and most towns were shipping points for the export of agricultural products. Most farms were geared toward subsistence production for family use.
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Intensive crop farming is a modern industrialized form of crop farming.Intensive crop farming's methods include innovation in agricultural machinery, farming methods, genetic engineering technology, techniques for achieving economies of scale in production, the creation of new markets for consumption, patent protection of genetic information, and global trade.