metamorphism

[met-uh-mawr-fiz-uhm]

noun

1. 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.

2. Archaic.,  metamorphosis.

metamorphism

/ ˌmɛtəˈmɔːfɪzəm /

noun

1. the process by which metamorphic rocks are formed

2. a variant of metamorphosis

metamorphism

1. The process by which rocks are changed in composition, texture, or structure by extreme heat and pressure.

2. ◆ 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.

3. ◆ 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.

4. See more at contact metamorphism regional metamorphism

Word History and Origins

Origin of metamorphism¹

First recorded in 1835–45; meta- + -morphism

Example Sentences

As global stocks of these rocks build up they can then release their carbon during tectonic processes, including mountain building and metamorphism.

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Because seifertite and stishovite are easily disturbed by thermal metamorphism, they inferred the silica fragment likely originated from the collision that formed the Aristarchus crater.

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On Earth, metamorphism usually happens slowly and deep underground.

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In the Australian rocks with ancient stromatolites2, laminations are clearly visible; in the Greenland samples, however, the proposed laminations are less clear, and the degree of metamorphism is higher than that of the Australian rocks.

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Menzies, O. N., Bland, P. A., Berry, F. J. & Cressey, G. A Mössbauer spectroscopy and X-ray diffraction study of ordinary chondrites: quantification of modal mineralogy and implications for redox conditions during metamorphism.

Read more on Nature