schist

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Related to Schists: Mica schist, Gneisses

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.
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 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.
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 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.
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 (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 ?
These rocks are composed mainly of chlorite and actinolite to amphibole schists, the last of them with or without garnet, with minor amphibolites and garnet-bearing amphibolites and subordinate amounts of eclogites, serpentinized peridotites and metabasalts.
All selected soils are deep, basalt derived Bidar soil is moderately deep and the schist derived Hira and the limestone derived Shahabad soils are deep.
Inter-bedded schists, amphibolites and banded iron formations with thickness ranging between dozens of metres and 250m constitute the target zone of this deposit.
This is the only unit of platform in Romania which preserved to date the oldest structures and relief through the green schists, absolute age 470-540 million years (Ionesi, 1994).
Six plots of one hectare were selected in the two main geomorphologic domains, that is, three replicates per domain: plots CP3, CP2, and CP4 in the schist domain and plots CP1, CP7, and CP6 in the volcanic-plutonic domain.
The greenschists in their middle section are intercalated with layers of mica schists, such intercalations vary in thickness from millimeters to meters.
Seismic constructions suggest that the main rocks in the section are presented by mica schist and black shale.
Schists have been used globally for the manufacture of stone artefacts, including axes, adzes and cutting tools (Reedy 2008).
This area comprises a number of historical drill intersections as well as rock chip sampling of graphitic schists associated with the Mt Shannan Iron Formation.
Both the quartz-muscovite and talc schists are common lithologies in the schist melange unit.
Stare Mesto Belt (G5) is built by amphibolites, gneisses, mica schists and tonalites and in gravity field are indicated by high positive anomaly in the NNE-SSW zone.