regional metamorphism

American  

[ree-juh-nuhl met-uh-mawr-fiz-uhm] / ˈri dʒə nəl ˌmɛt əˈmɔr fɪz əm /

noun

1. Geology. metamorphism that affects rocks in a widespread region under conditions of high pressure and temperature, often resulting in the formation of such banded and crystalline rocks as gneiss and schist.

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regional metamorphism Scientific  

/ rē′jə-nəl /

1. A type of metamorphism in which the mineralogy and texture of rocks are changed over a wide area by deep burial and heating associated with the large-scale forces of plate tectonics. In regional metamorphism, rocks that form closer to the margin of the tectonic plates, where the heat and pressure are greatest, often differ in their minerals and texture from those that form farther away.

2. Compare contact metamorphism

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Example Sentences

In the late 1800s, British geologist George Barrow mapped zones of index minerals in different metamorphic zones of an area that underwent regional metamorphism.

From Textbooks • Jan. 1, 2017

Even if formed during regional metamorphism, quartzite does not tend to be foliated because quartz crystals don’t align with the directional pressure.

From Textbooks • Jan. 1, 2015

Most regional metamorphism takes place beneath mountain ranges because the crust becomes thickened and rocks are pushed down to great depths.

From Textbooks • Jan. 1, 2015

The quartz crystals show no alignment, but the micas are all aligned, indicating that there was directional pressure during regional metamorphism of this rock.

From Textbooks • Jan. 1, 2015

This regional metamorphism, as it is termed, has affected the rocks in certain instances throughout districts measuring many hundreds of square miles in surface extent, and with a vertical range of many thousands of feet.

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