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[met-uh-mawr-fiz-uh m] /ˌmɛt əˈmɔr fɪz əm/
Geology. a change in the structure or constitution of a rock due to natural agencies, as pressure and heat, especially when the rock becomes harder and more completely crystalline.
Archaic. metamorphosis.
Origin of metamorphism
First recorded in 1835-45; meta- + -morphism Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2018.
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Examples from the Web for metamorphism
Historical Examples
  • Nor is the metamorphism of the invaded rock limited to simple intrusion.

  • A common cause of the metamorphism of rocks is the intrusion into them of igneous rocks.

    Geology William J. Miller
  • This state of things is called general, or normal, metamorphism.

  • The birthplace of a large variety of ores and minerals is in the zone of metamorphism.

    North America Israel C. Russell
  • How is metamorphism on the large scale supposed to have been induced?

    Geology James Geikie
  • The metamorphism is more striking in the first change than in the second.

    A Journey in Other Worlds John Jacob Astor
  • metamorphism melts the silica into a glassy liquid cement; the particles are bound close together on cooling.

  • All of the chemical, mineralogical, and textural changes in rocks above described may be collectively referred to as metamorphism.

  • The subject, however, is a complex one, the full discussion of which belongs in treatises on metamorphism.

  • Certain kinds of metamorphism are suggestive of the nature of the mineral deposits with which they are associated.

British Dictionary definitions for metamorphism


the process by which metamorphic rocks are formed
a variant of metamorphosis
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
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Word Origin and History for metamorphism

1837, from metamorphic + -ism.

Online Etymology Dictionary, © 2010 Douglas Harper
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metamorphism in Science
The process by which rocks are changed in composition, texture, or structure by extreme heat and pressure. ◇ In prograde metamorphism metamorphic rocks that were formed under low pressure and temperature conditions undergo a second metamorphic event in which they are exposed to higher pressures and temperatures. ◇ In retrograde metamorphism metamorphic rocks that were formed under high pressure and temperature conditions undergo a second metamorphic event in which they are exposed to lower pressures and temperatures. See more at contact metamorphism, regional metamorphism.

The American Heritage® Science Dictionary
Copyright © 2002. Published by Houghton Mifflin. All rights reserved.
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