How do schists form?

How do schists form?

Schist is medium grade metamorphic rock, formed by the metamorphosis of mudstone / shale, or some types of igneous rock, to a higher degree than slate, i.e. it has been subjected to higher temperatures and pressures.

What schist means?

Definition of schist : a metamorphic crystalline rock that has a closely foliated structure and can be split along approximately parallel planes.

What is schistose texture?

Schistose Texture • Schistose rocks have visible grains. They are most commonly made up of platy minerals like mica. Schist (Photograph by Parvinder Sethi) Rocks with schistose texture, like this garnet schist, are more metamorphosed than those with phyllitic texture.

How do schists undergo metamorphism?

Schist – The size of the mineral grains tends to enlarge with increasing grade of metamorphism. Eventually the rock develops a near planar foliation caused by the preferred orientation of sheet silicates (mainly biotite and muscovite). Quartz and Feldspar grains, however show no preferred orientation.

What is shale and slate?

Shale-a fine grained rock or a clastic sedimentary rock, majorly composed of mud which is a mixture of clay mineral flakes as well as tiny fragments or silt sized particles of other minerals that include calcite, quartz etc., the ratio of clay to other minerals is very variable; Slate, which is also a fine grained rock …

What is schist used for?

Schist is not a very strong rock, so it is not often used as a building material. However it can be used for garden decoration, paving and sometimes sculpture.

How many types of schists are there?

The specific mineral composition of a schist is indicated by placing the name or names of significant subordinate minerals in front of the word schist; commonly occurring types include biotite schist, muscovite-chlorite schist, garnet-mica schist, staurolite kyanite schist, and hornblende schist.

What is schistose rock?

Definition. Geologists define schist as medium-grained metamorphic rock that shows well-developed schistosity. Schistosity is a thin layering of the rock produced by metamorphism (a foliation) that permits the rock to easily be split into flakes or slabs less than 5 to 10 millimeters (0.2 to 0.4 in) thick.