schist


Also found in: Dictionary, Thesaurus, Wikipedia.
Related to schist: Mica schist, amphibolite

schist

(shĭst), metamorphic rockrock,
aggregation of solid matter composed of one or more of the minerals forming the earth's crust. The scientific study of rocks is called petrology. Rocks are commonly divided, according to their origin, into three major classes—igneous, sedimentary, and metamorphic.
..... Click the link for more information.
 having a foliated, or plated, structure called schistosity in which the component flaky minerals are visible to the naked eye. Schists are distinguished from the other foliated rocks, slates and gneisses, by the size of their mineral crystals; these are larger than those of slates, being visible to the naked eye, but smaller than those of gneisses, which are coarsely foliated rocks as opposed to finely foliated, or schistose, rocks. As contrasted with the folia of slates, the folia of schists are rough-surfaced and irregular. Schists split readily along their planes of schistosity, like slates along cleavage lines. Like other foliated rocks, schists owe their origin to the metamorphism of preexisting rocks. The commonest of the schists is mica schist, the essential minerals of which are quartzquartz,
one of the commonest of all rock-forming minerals and one of the most important constituents of the earth's crust. Chemically, it is silicon dioxide, SiO2.
..... Click the link for more information.
 and micamica
, general term for a large group of minerals, hydrous silicates of aluminum and potassium, often containing magnesium, ferrous iron, ferric iron, sodium, and lithium and more rarely containing barium, chromium, and fluorine.
..... Click the link for more information.
 (biotite or muscovite). Other schists are hornblende schist, talc schist, chlorite schist, and graphite schists. Schists are abundant in the Precambrian (Archean and Proterozoic) rocks.

schist

[shist]
(geology)
A large group of coarse-grained metamorphic rocks which readily split into thin plates or slabs as a result of the alignment of lamellar or prismatic minerals.

schist

A rock, the constituent minerals of which have assumed a position in more or less closely parallel layers or folia; due to metamorphic action; used principally for flagging.

schist

any metamorphic rock that can be split into thin layers because its micaceous minerals have become aligned in thin parallel bands
References in periodicals archive ?
It consists of metagabroic rocks, garnet amphibolites, amphibole schists, quartz-sericite schists and quartzites of medium- to low-pressure, as well as lawsonite and glaucophane schists and eclogites of high pressure and serpentinized ultramafic rocks (Maya and Gonzalez, 1995).
The main rock types along the axis of tunnel are granite, quartz mica schist, and calcareous quartzite.
33) than the limestone derived Shahabad soil and schist derived Hira soil.
Since the failures in quartz mica schist occurred in the weathered zones, the characteristics of these weathered earth materials were studied in order to interpret the features of the morphological zones.
The schists and quartz-schists (Esquistos Grises de Punta Claditas and Esquistos Grises de la Gruta, after Rebolledo and Charrier, 1994) consist of quartz, white-mica, chlorite, albite and garnet (Grt1 [+ or -] Grt2), with tourmaline, epidote, apatite, zircon, titanite, ilmenite and rutile as accessory minerals.
5[per thousand], Figure 2), with lower values on schist than on the volcanic-plutonic domain.
It consists of green schists parasitized by loess deposits where the rivers deepened and branched a lot, reaching to Proterozoic green schist, emphasizing the current geomorphological processes.
Geochemical trends in weathered profiles above granite gneiss and schists of Abeokuta area, Southwestern Nigeria.
CSDD12_006 was drilled in the south immediately west of outcropping graphite, intersected highly weathered graphitic schist to 21m.
The real section showed that the upper drill hole passed through mica schist with rare interbeds of biotite gneiss down to a depth of 1310 m (Kukkonen et al.
Researchers of University of New Mexico (USA), University of Arizona (USA), and University of Adelaide (Australia) presented results from a detailed geochronologic investigation of one of the oldest rock units of the Grand Canyon, the Vishnu Schist.