Amphibolite


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Related to Amphibolite: Amphibolite Facies

amphibolite

[am′fib·ə‚līt]
(petrology)
A crystalloblastic metamorphic rock composed mainly of amphibole and plagioclase; quartz may be present in small quantities.

Amphibolite

 

a schistose metamorphic rock composed chiefly of alumina-bearing amphibole (hornblende) and plagiociase; sometimes contains granite. Amphibolite is formed from various matrices subjected to profound metamorphism sometimes accompanied by metasomatism and the introduction of silica, magnesium, and iron. Some black varieties of amphibolite are used as industrial gems and ashlars.

References in periodicals archive ?
The recent RC drill program undertaken by QMC in 2010 indicates the gold is controlled primarily by a near E-W trending shear zone developed along the contact between the amphibolite unit (marker bed) and underlying phyllite and schist sequence.
The graphical analysis of greenschist to amphibolite facies mineral assemblages in metabasites.
In the southern metamorphic belt, amphibolite and amphibolitic gneiss with lit-par-lit leucogranite sheets, similar to some components in the Arichat belt, outcrop on Green Island (Fig.
The Emily gold showing comprises gold mineralization in leucogabbro, associated with disseminated pyrrhotite and arsenopyrite in upper amphibolite facies, deformed gneisses of the Early Proterozoic Kisseynew gneiss belt.
Platt Creek Samples: June 2009 Drill area Sample Location Type Rock Unit Alteration % U(3)O(8) SB044 Platt Creek Boulder Amphibolite Hematite 1.
The pelitic unit may contain staurolite, garnet, and andalusite, whereas tourmaline and rare holmquistite (Hutchinson 1982) occur in the amphibolite adjacent to the pegmatite lenses.
The mineralization is located directly beneath Quaternary alluvial cover and is hosted along an iron oxide-rich, gently dipping zone within strongly weathered quartz-muscovite-feldspar gneiss and amphibolite.
The volcanic rocks of this unit commonly exhibit welded and flow-banded textures and are intruded by granite and amphibolite and felsic porphyry dykes (Barr and White 2001a).
Table 1 Mineralized Amphibolite from first drill target area.
The mafic component varies from rare examples of layered gabbro, to hornblenderich amphibolite to hornblende-plagioclasc rocks with minor quartz.
The orthogneiss has an igneous crystallization age of 605 [+ or -] 3 Ma, and was metamorphosed to amphibolite facies at 564 [+ or -] 6 Ma (Bevier et al.