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Article: Shock Metamorphism
- Article from:
- World of Earth Science
CopyrightCOPYRIGHT 2003 The Gale Group, Inc. This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
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Shock metamorphism
Except for certain laboratory experiments and outdoor detonations of high explosives (including nuclear weapons), evidence of shock metamorphic conditions of extreme pressure and heat on Earth exist only within and around impact craters. Only hypervelocity impact between objects of substantial size moving at cosmic velocity (at least several kilometers per second) can produce these conditions. Meteorites larger than approximately 246 ft (75 m) in diameter,
asteroids
, and
comets
can pass through Earth's atmosphere and yet retain a very high percentage of their original velocity. In such events, this energy of motion is converted into seismic and heat energy almost ...
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