Answer: prograde
The transformation of low-grade metamorphic rocks into high-grade metamorphic rocks is termed ________ metamorphism.
Metamorphic rocks arise from the transformation of existing rock types in a process called metamorphism which means "change in form". The original rock (protolith) is subjected to heat (temperatures greater than 150 to 200 °C) and pressure (100 megapascals (1 000 bar) or more) causing profound physical or chemical change. The protolith may be a sedimentary igneous or existing metamorphic rock. Metamorphic rocks make up a large part of the Earth's crustand form 12% of the Earth's land surface. T…
Gneiss - Wikipedia
Metamorphic rock - Wikipedia
Metamorphic rock - Wikipedia
Metamorphism is the change of minerals or geologic texture in pre-existing rocks without the protolith melting into liquid magma. The change occurs primarily due to heat pressure and the introduction of chemically active fluids. The chemical components and crystal structures of the minerals making up the rock may change even though the rock remains a solid. Changes at or just beneath Earth's surface due to weathering or diagenesis are not classified as metamorphism . Metamorphism …
Migmatite is a composite rock found in medium and high-grade metamorphic environments. It consists of two or more constituents often layered repetitively; one layer was formerly paleosome a metamorphic rock that was reconstituted subsequently by partial melting; the alternate layer has a pegmatitic aplitic granitic or generally plutonic appearance. Commonly migmatites occur below deformed metamorphic rocks …
Gneiss is a common and widely distributed type of metamorphic rock . Gneiss is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks . Orthogneiss is gneiss derived from igneous rock . Paragneiss is gneiss derived from sedimentary rock …
Thu Jan 27 2005 13:30:0...
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