Chlorite schist, a type of greenschistGreenschist (prasinite) at Cap Corse in Corsica, FranceGreenschist (epidote) from Itogon, Benguet, Philippines
Greenschists are metamorphic rocks that formed under the lowest temperatures and pressures usually produced by regional metamorphism, typically 300–450 °C (570–840 °F) and 2–10 kilobars (29,000–145,000 psi).[1] Greenschists commonly have an abundance of green minerals such as chlorite, serpentine, and epidote, and platy minerals such as muscovite and platy serpentine.[1] The platiness gives the rock schistosity (a tendency to split into layers). Other common minerals include quartz, orthoclase, talc, carbonate minerals and amphibole (actinolite).[1]
Greenschist is a general field petrologic term for metamorphic or altered mafic volcanic rock. In Europe, the term prasinite is sometimes used. A greenstone is sometimes a greenschist but can also be rock types without any schistosity, especially metabasalt (spilite). However, basalts may remain quite black if primary pyroxene does not revert to chlorite or actinolite. To qualify for the name a rock must also exhibit schistosity or some foliation or layering. The rock is derived from basalt, gabbro or similar rocks containing sodium-rich plagioclase feldspar, chlorite, epidote and quartz.[2]
^ abc"Encyclopædia Britannica, Metamorphic Rock, Greenschist Facies". Retrieved 9 April 2013.
^"America's volcanic past: Vermont". Archived from the original on 2006-09-23. Retrieved 2006-11-25.
Greenschists are metamorphic rocks that formed under the lowest temperatures and pressures usually produced by regional metamorphism, typically 300–450 °C...
mode or origin. Special names still in wide use include amphibolite, greenschist, phyllite, marble, serpentinite, eclogite, migmatite, skarn, granulite...
+ quartz In metapelites: muscovite + chlorite + albite + quartz The greenschist facies is at low pressure and temperature. The facies is named for the...
a common product of retrograde metamorphism of metabasalt at (upper) greenschist facies conditions. Often, this will take on the crystal form and habit...
Slickensides on a fault plane in Corona Heights Park, San Francisco Greenschist with slickensides in Itogon, Benguet, Philippines. Tjia, H. D. (1964)...
within orogenic belts as terranes of lithology in faulted contact with greenschist or rarely eclogite facies rocks. Blueschist, as a rock type, is defined...
component of chromium rich phyllitic or schistose metamorphic rocks of the greenschist facies. Verdite is a type of metamorphic rock made mostly of an impure...
example, anthracite of the Narragansett Basin in Rhode Island is of greenschist metamorphic facies (muscovite-chlorite sub-facies). "Coal explained"...
common in low-grade metamorphic rocks and in altered igneous rocks. Greenschist, formed by metamorphism of basalt or other low-silica volcanic rock,...
Depending on the temperature and pressure of metamorphism, these may include greenschist, amphibolite, or eclogite. Basalts are important rocks within metamorphic...
Granulite – Class of high-grade medium to coarse grained metamorphic rocks Greenschist – Metamorphic rock – A mafic metamorphic rock dominated by green amphiboles...
seen: the lower part is sedimentary rock (brown); the middle part is greenschist from the oceanic crust. The peak itself is gneiss from the African continent...
metamorphism of calcium and magnesium rich siliceous sedimentary rocks and in greenschist facies metamorphic rocks derived from ultramafic or magnesium carbonate...
26 people camping in the area. Blueschist – Type of metavolcanic rock Greenschist – Metamorphic rock List of rock textures – List of rock textural and...
others roughly-hewn, megalithic blocks. In north-central Crete blue-greenschist was used to pave floors of streets and courtyards between 1650 and 1600 BC...
in deep-seated igneous rocks like syenite as well as serpentines and greenschists. Demantoid is one of the most prized of garnet varieties. Grossular is...
during that period. These more magnesium-rich rocks metamorphose into greenschist at conditions when modern oceanic crust rocks metamorphose into blueschist...
Green Head is an ancient Egyptian statue head (AeMP 12500) made from greenschist and housed in the Egyptian Museum of Berlin, one floor down from the...
in metamorphosed dolomitic limestones, and actinolite in metamorphic greenschists/glaucophane schists. Jadeite is a sodium- and aluminium-rich pyroxene...
three-sided peak known as Summit Pyramid. The mountain is composed of Shuksan greenschist, oceanic basalt that was metamorphosed when the Easton terrane collided...
Alpine, Otago and Chatham schist. The metamorphic grade progresses from greenschist, biotite, garnet and finally orthoclase. Myrmekitic textures occur within...
Stratigraphic range: Statherian Pha. Proterozoic Archean Had. Tijeras Greenschist along Old Highway 66 in Tijeras Canyon, New Mexico, US Type Formation...
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