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Arkose – Type of sandstone containing at least 25% feldspar; Banded iron formation – Distinctive layered units of iron-rich sedimentary rock that are almost always of Precambrian age; Breccia – Rock composed of angular fragments; Calcarenite – Type of limestone that is composed predominantly of sand-size grains; Chalk – Soft carbonate ...
Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith ) is subjected to temperatures greater than 150 to 200 °C (300 to 400 °F) and, often, elevated pressure of 100 megapascals (1,000 bar ) or more, causing profound physical or chemical changes.
Arenite (from the Latin arena, "sand") [1] is a sedimentary clastic rock with sand grain size between 0.0625 mm (0.00245 in) and 2 mm (0.08 in) and containing less than 15% matrix. [2] The related adjective is arenaceous. The equivalent Greek-derived term is psammite, though this is more commonly used for metamorphosed sediments.
Psammite (Greek: psammitēs "(made) from sand", from psammos "sand") [1] is a general term for sandstone.It is equivalent to the Latin-derived term arenite [2] [3] and is commonly used in various publications to describe a metamorphosed sedimentary rock with a dominantly sandstone protolith. [4]
Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains, cemented together by another mineral. Sandstones comprise about 20–25% of all sedimentary rocks. [1] Most sandstone is composed of quartz or feldspar, because they are the most resistant minerals to the weathering processes at the Earth's ...
Quartzite can have a grainy, glassy, sandpaper-like surface. Quartzite is a hard, non-foliated metamorphic rock which was originally pure quartz sandstone. [1] [2] Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts.
In metamorphosed sandstone, recrystallization of the original quartz sand grains results in very compact quartzite, also known as metaquartzite, in which the often larger quartz crystals are interlocked. [14] Both high temperatures and pressures contribute to recrystallization.
Examples of lithologies in the second sense include sandstone, slate, basalt, or limestone. [ 4 ] Lithology is the basis of subdividing rock sequences into individual lithostratigraphic units for the purposes of mapping and correlation between areas.