biotite schist

biotite schist

[′bī·ə‚tīt ′shist]
(petrology)
A schist composed of biotite.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
domain-I dominantly comprises quartz mica schist and garnet bearing quartz mica schist (Class D), domain-II contains quartz biotite schist and garnet mica schist and marble (Class C), domain-III holds calcareous schist and marble (Class A and B), domain-IV covers Garnet mica schist (Class D), domain-V contains quartzite and quartz mica schist (Class E and F) and domain VI which dominantly have Garnet mica schist and calcareous schist (Class A and B).
These new thick zones of mineralization occur within a quartz, biotite schist within a zone of about 200 meters long, east-west dimension, and at least 120 meters wide, north-south, and to depths similar to the historic modeled deposit.
The host rock of this type of beryl occurrence is similar to beryl (emerald) deposits that are formed via syn- to post-tectonic reactions under low-grade regional metamorphism and within biotite schist tectonically overlain by ophiolite, such as in southern Egypt (Abdalla and Mohamed, 1999) and Habachtal, Austria, (Grundmann and Morteani, 1989) where the source of chromium is believed to be metasomatized ophiolitic rocks (Groat et al., 2008).
There are a variety of different types: clinozoisite-rich rock fragments, epidote-biotite quartz schist, amphibole-biotite-clinozoisite-quartz schist, biotite-clinozoisite-quartz schist, clinozoisite-biotite-opaques-quartz schist, biotite-rich rock fragments, amphibole-biotite-opaques-clinozoisite-quartz-titanite rock fragment, chlorite or anthophyllite-biotite schist (some possibly with accessory tourmaline?), chlorite biotite schist, clinozoisite feldspar rock fragment, altered feldspar-titanite-biotite replaced amphibole-clinozoisite rock fragment, amphibole-rich rock fragments, and garnet-banded biotite quartz rock fragment.
The acoustopolarigrams for sample ODB2297_85 of biotite schist are similar to the diagrams for schists from the upper section down to a depth of 1101.30 m (Kukkonen et al., 2009).
The rocks of the Karakoram block are mainly composed of meta-sediments and consist of garnet-muscovite-schist biotite schist graphitic-schist staurolite-schist calc- schist quratz-schist chlorite-schist and conglomerate with para-gneisses.
This rock unit contains appreciable amounts of biotite schist, migmatite, aplite, and quartz-orthoclase-muscovite-bearing pegmatite subordinate in volume to the granite gneisses.
The biotite sometimes forms euhedral crystals and rosettes up to 5 cm across in the country rock and in veins in biotite schist.
They are part of a late Proterozoid metasedimentary sequence with underlying paragneisses and overlying biotite schists intercalated in feldspathized (K-feldspar porphyroblasts) paragneisses.