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Metamorphic rocks are formed by subjecting any rock type—sedimentary rock, igneous rock or another older metamorphic rock—to different temperature and pressure conditions than those in which the original rock was formed. This process is called metamorphism, meaning to "change in form". The result is a profound change in physical properties ...
Metamorphic rocks once existed as igneous or sedimentary rocks, but have been subjected to varying degrees of pressure and heat within the Earth's crust. The processes involved will change the composition and fabric of the rock and their original nature is often hard to distinguish. Metamorphic rocks are typically found in areas of mountain ...
A rock formation is an isolated, scenic, or spectacular surface rock outcrop. Rock formations are usually the result of weathering and erosion sculpting the existing rock. The term rock formation can also refer to specific sedimentary strata or other rock unit in stratigraphic and petrologic studies.
Slate – Metamorphic rock - A low grade metamorphic rock formed from shale or silts; Suevite – Rock consisting partly of melted material formed during an impact event – A rock formed by partial melting during a meteorite impact; Talc carbonate – A metamorphosed ultramafic rock with talc as an essential constituent; similar to a serpentinite
Stage 3 began with a crust made of mafic (high in iron and magnesium) and ultramafic rocks such as basalt. These rocks were repeatedly recycled by fractional melting, fractional crystallization and separation of magmas that refuse to mix. An example of such a process is Bowen's reaction series. [1]
Uluru (Ayers Rock) is a large sandstone formation in Northern Territory, Australia.. Sedimentary rocks can be subdivided into four groups based on the processes responsible for their formation: clastic sedimentary rocks, biochemical (biogenic) sedimentary rocks, chemical sedimentary rocks, and a fourth category for "other" sedimentary rocks formed by impacts, volcanism, and other minor processes.
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A rock may consist of one type of mineral or may be an aggregate of two or more different types of minerals, spacially segregated into distinct phases. [3] Some natural solid substances without a definite crystalline structure, such as opal or obsidian, are more properly called mineraloids. [4]