metamorphism

American  

[met-uh-mawr-fiz-uhm] / ˌmɛt əˈmɔr fɪz əm /

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.

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metamorphism British  

/ ˌmɛtəˈmɔːfɪzəm /

noun

1. the process by which metamorphic rocks are formed

2. a variant of metamorphosis

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metamorphism Scientific  

/ mĕt′ə-môr′fĭz′əm /

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

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Etymology

Origin of metamorphism

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

Example Sentences

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.

From Science Daily • Feb. 6, 2024

Shock metamorphism has happened often on Mars, but there’s also evidence for metamorphism that’s a bit like a cooler, gentler version of what can happen on Earth.

From National Geographic • Oct. 12, 2023

On Earth, metamorphism usually happens slowly and deep underground.

From National Geographic • Oct. 12, 2023

"For the first time, we propose that shock metamorphism in quartz grains exposed to an atomic detonation is essentially the same as during a low-altitude, lower-pressure cosmic airburst," Kennett said.

From Science Daily • Oct. 3, 2023

In the case of the foliated rocks motion within the mass seems to have been the predominating factor, and dynamical metamorphism is considered as important as heat metamorphism.

From North America by Russell, Israel C. (Cook)