Metamorphic Form Of Granite

When granite is subjected to intense heat and pressure it changes into a metamorphic rock called gneiss.

Metamorphic form of granite. The type of rock that a metamorphic rock used to be prior to metamorphism is called the protolith. What rock does granite form from heat and pressure. The only rock that granite forms is the metamorphic. Granulite facies one of the major divisions of the mineral facies classification of metamorphic rocks the rocks of which formed under the most intense temperature pressure conditions usually found in regional metamorphism at the upper limit of the facies migmatite formation may occur.

The word metamorphism comes from ancient greek words for change meta and form morph. Consider how granite changes form. Granite ˈ ɡ r æ n ɪ t is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Originally granite was thought to form mainly from magmatic differentiation of basaltic magma but geologists now believe there is simply too much of it for it to have formed this way except locally.

Granites can be predominantly white pink or gray in color depending on their mineralogy the word granite comes from the latin granum a grain in reference to the coarse grained structure of such a completely crystalline rock. Granite can be metamorphosed into a rock called gneiss pronounced like nice. Metamorphic rocks form when rocks are subjected to high heat high pressure hot mineral rich fluids or more commonly some combination of these factors. Granite is an igneous rock that forms when magma cools relatively slowly underground.

A metamorphic rock used to be some other type of rock but it was changed inside the earth to become a new type of rock. Granite is a light colored rock made of quartz feldspars mica and small amounts of hornblende. It is usually composed primarily of the minerals quartz feldspar and mica. Gneissgranite gneiss is a metamorphic rock formed from granite gneiss schist quartzite.

Most granite seems to have formed either by melting partial. The preexisting rocks may be igneous sedimentary or other metamorphic rocks. The production of granite by metamorphic heat is difficult but is observed to occur in certain amphibolite and granulite terrains. Slate is another common metamorphic rock.

Debate has long centered on whether granite is igneous or metamorphic in origin. Metamorphic rock any rock that results from the alteration of preexisting rocks in response to changing conditions such as variations in temperature pressure and mechanical stress and the addition or subtraction of chemical components. Gneiss has about the same mineral composition as granite but the pressure of metamorphism causes the. In situ granitisation or melting by metamorphism is difficult to recognise except where leucosome and melanosome textures are present in migmatites.

Temperatures of 650 1 100 c 1 200 2 000 f and pressures of 3 to 10 kilobars 1 kilobar equals.