amphibolite

amphibolite
amphibolitic /am fib'euh lit"ik/, adj.
/am fib"euh luyt'/, n. Petrog.
a metamorphic rock composed mainly of amphibole and plagioclase.
[1825-35; AMPHIBOLE + -ITE1]

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Igneous or metamorphic rock composed largely or dominantly of amphibole minerals.

For igneous rocks, the term hornblendite is usually used and is more restrictive; hornblende is the most common amphibole. Metamorphic amphibolites are more widespread and variable than igneous ones. Typically, they are medium-to coarse-grained and are composed of hornblende and plagioclase. Basic igneous rocks such as basalts and gabbros (see acid and basic rocks) can be the parent rocks of amphibolite.

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rock
      a rock composed largely or dominantly of minerals of the amphibole group. The term has been applied to rocks of either igneous or metamorphic origin. In igneous rocks, the term hornblendite is more common and restrictive; hornblende is the most common amphibole and is typical of such rocks. Hornblendite is an ultramafic rock (dominantly dark minerals). True hornblendites contain little other than amphibole and are probably derived from the alteration of pyroxene and olivine.

      Metamorphic amphibolites are a more widespread and variable group of rocks formed through metamorphism. Typically, they are medium- to coarse-grained and are composed of hornblende and plagioclase. These are the diagnostic rocks of the amphibolite facies of regional metamorphism and may be derived from premetamorphic rocks of various types. Mafic igneous rocks (e.g., basalts and gabbros) and sedimentary dolomite can be the parent rocks of amphibolite.

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Universalium. 2010.

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  • Amphibolite — (pronEng|æmˈfɪbəlaɪt) is the name given to a rock consisting mainly of hornblende amphibole, the use of the term being restricted, however, to metamorphic rocks. The modern terminology for a holocrystalline plutonic igneous rocks composed… …   Wikipedia

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  • amphibolite — n. 1. a metamorphic rock composed chiefly of amphibole and plagioclase. [WordNet 1.5] …   The Collaborative International Dictionary of English

  • amphibolite — [am fib′ə līt΄] n. [ AMPHIBOL(E) + ITE1] a metamorphic rock consisting largely of amphibole and plagioclase …   English World dictionary

  • Amphibolite — Une amphibolite est une roche métamorphique à amphiboles et plagioclases du métamorphisme général (mésozone à catazone), à clivages médiocres et texture assez massive, vert sombre. Elle est essentiellement constituée de cristaux d amphibole, plus …   Wikipédia en Français

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  • Amphibolite —    L amphibolite est une roche métamorphique à amphiboles et plagioclases du métamorphisme général, elle est constituée de cristaux d amphibole …   L'Abécédaire du Vin

  • amphibolite facies — One of the major divisions of the mineral facies classification of metamorphic rocks, encompassing rocks that formed under conditions of moderate to high temperatures (950°F, or 500°C, maximum) and pressures. Less intense temperatures and… …   Universalium

  • amphibolite — noun Date: 1826 a usually metamorphic rock consisting essentially of amphibole …   New Collegiate Dictionary

  • amphibolite — noun Any of a class of metamorphic rock composed mainly of amphibole with some quartz etc. See Also: amphibolitic …   Wiktionary

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