Metamorphic rock

Metamorphic rock is the result of the transformation of a pre-existing rock type, the protolith, in a process called metamorphism, which means "change in form" (from the Greek words meta, "change", and morphe, "form"). The protolith is subjected to extreme heat (greater than 150 degrees Celsius) and pressure causing profound physical and/or chemical change. The protolith may be sedimentary rock, igneous rock or another older metamorphic rock.

Related Topics:
Rock - Metamorphism - Greek - Sedimentary rock - Igneous rock

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Metamorphic rocks make up a large part of the Earth's crust and are classified by texture and by chemical and mineral assembly (metamorphic facies). They are formed deep beneath the Earth's surface by great stresses and high pressures and temperatures. They are also formed by the intrusion of molten rock, called magma, into solid rock and form particularly at the place of contact between the magma and solid rock where the temperatures are high.

Related Topics:
Earth - Crust - Mineral - Metamorphic facies - Intrusion - Magma

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The study of metamorphic rocks (now exposed at the Earth's surface following erosion and uplift) provides us with valuable information about the temperatures and pressures that occur at great depths within the Earth's crust.

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