What type of metamorphic facies are associated with subduction of oceanic crust?

For example, regions associated with subduction of oceanic material beneath either oceanic crust or continental crust are characterized by blueschist, greenschist, and eclogite facies rocks, whereas areas thought to reflect continent-continent collision are more typically distinguished by greenschist and amphibolite …

Which type of metamorphic rock is associated with subduction of oceanic crust?

Nearest to the trench is a zone of low temperature, high pressure metamorphic conditions characterized by blueschist to eclogite facies assemblages. This assemblage is associated with subduction along the trench and low heat flow.

Which metamorphic facies is common in subduction zones?

Blueschist-facies metamorphism is important in subduction zones, where high-pressure, relatively low-temperature mineral assemblages form. Glaucophane and lawsonite, both of which have a bluish color, are common minerals in this setting.

What metamorphic rocks form at subduction zones?

Subduction zone has distinct metamorphic rocks: formation of jadeite and glaucophane of blueschist faceis. Metamorphism in subduction zone is related to dewatering processes in magma generation. Dewatering and higher pressure and temperature induce prograde metamorphism.

Which type of metamorphism is most likely to occur at a mid ocean ridge?

Hydrothermal Metamorphism (Fig. 8.3): typically occurs along mid-ocean ridge spreading centers where heated seawater percolates through hot, fractured basalt.

Which metamorphic facies is associated with subduction zones quizlet?

Amphibolite and greenschist facies are most commonly associated with subduction zones.

What metamorphic facies would most commonly be associated with a subduction zone and why?

What metamorphic facies would most commonly be associated with a subduction zone and why? Subduction zone metamorphism is characterized by a low temperature, high-ultrahigh pressure metamorphic path through the zeolite, prehnite-pumpellyite, blueschist, and eclogite facies stability zones of subducted oceanic crust.

Is staurolite a metamorphic facies?

The chlorite and biotite zones represent greenschist facies metamorphism, and the garnet, staurolite, kyanite, and sillimanite zones represent amphibolite facies metamorphism.

What is the primary facies of rocks metamorphosed through subduction zone metamorphism?

The blueschist facies is at relatively low temperature but high pressure, such as occurs in rocks in a subduction zone. The facies is named after the schistose character of the rocks and the blue minerals glaucophane and lawsonite.

What is a metamorphic facies quizlet?

What is a metamorphic facies? Zones of contact metamorphism along an intrusive igneous rock. An assemblage of minerals that form in very similar metamorphic environments. A mineral that forms at specific metamorphic conditions and can be used to determine the metamorphic grade.

What is meant by metamorphic facies?

In current usage, a metamorphic facies is a set of metamorphic mineral assemblages, repeatedly associated in space and time, such that there is a constant and therefore predictable relation between mineral composition and chemical composition. The facies concept is more or less observation-based.

What distinguishes metamorphic grade of metamorphic facies?

Metamorphic grade is usually assessed on the basis of the mineral assemblage making up the metamorphic rock, as well as its foliation and other textural clues (such as grain size). Facies is a more precise term used for a restricted range of temperatures and pressures defined by the presence of key minerals.

What environment produces the Blueschist facies?

Blueschist, which contains the blue mineral glaucophane, forms in subduction zones under high pressures and low temperatures, and its rare occurrence in Precambrian rocks may indicate that temperatures in early subduction zones were too high for its formation.

What type of metamorphism makes blueschist?

Blueschist

Where does blueschist metamorphism occur?

subduction zones

Abstract. The blueschist metamorphic facies are characterized by the minerals jadeite, glaucophane, epidote, lawsonite, and garnet. They record metamorphism in the cool high-pressure/low-temperature thermal gradients at less than 7°C/km in subduction zones in the last 1 billion years.

What is blueschist metamorphic rock?

Blueschist ( /ˈbluːʃɪst/), also called glaucophane schist, is a metavolcanic rock that forms by the metamorphism of basalt and rocks with similar composition at high pressures and low temperatures (200–500 °C (392–932 °F)), approximately corresponding to a depth of 15–30 km (9.3–18.6 mi).

What is the difference between blueschist and greenschist facies?

As nouns the difference between blueschist and greenschist

is that blueschist is (geology) a metamorphic rock containing glaucophane while greenschist is a metamorphic rock formed at low temperature and pressure, often with an abundance of green minerals such as chlorite, serpentine, and epidote.

Which mineral is commonly present in amphibolite facies?

Amphibole, diopside, epidote, plagioclase, almandine and grossular garnet, and wollastonite are minerals typically found in rocks of the amphibolite facies. The disappearance of epidote and increase in calcium in plagioclase are characteristic chemical changes as metamorphic intensity increases through this facies.

Is blueschist a metamorphic rock?

Blueschist is a regional metamorphic rock formed under high-pressure (HP) low-temperature (LT) conditions.

Do Shields contain blueschist?

Blueschist is a common metamorphic rock of continental shields. Roofers use the rock schist to shingle roofs because its foliation, called schistosity, causes it to break in convenient size.

What type of rock is basalt?

Basalt is a hard, black volcanic rock. Basalt is the most common rock type in the Earth’s crust. Depending on how it is erupted, basalt can be hard and massive (Figure 1) or crumbly and full of bubbles (Figure 2).

Is greenschist foliated or Nonfoliated?

Such a rock is called greenschist if foliated, and greenstone if not. The protolith is either a mafic igneous rock or graywacke. Amphibolite: a metamorphic rock dominated by hornblende + plagioclase. Amphibolites may be foliated or non-foliated.

What is sub greenschist facies?

Oceanic basalts in the vicinity of mid-ocean ridges typically exhibit sub-greenschist alteration. The greenstone belts of the various archean cratons are commonly altered to the greenschist facies. These ancient rocks are noted as host rocks for a variety of ore deposits in Australia, Namibia and Canada.

Where does greenschist metamorphism occur?

1: Barrovian sequence in Scotland. The first of the Barrovian sequence has a mineral group that is commonly found in the metamorphic greenschist facies. Greenschist rocks form under relatively low pressure and temperatures and represent the fringes of regional metamorphism.

What are foliated and Nonfoliated metamorphic rocks?

​Foliated metamorphic rocks​ exhibit layers or stripes caused by the elongation and alignment of minerals in the rock as it undergoes metamorphism. In contrast, ​nonfoliated metamorphic rocks​ do not contain minerals that align during metamorphism and do not appear layered.

Which type of rock is non-foliated metamorphic rock Brainly?

Answer: Some examples of non-foliated metamorphic rocks are marble, quartzite, and hornfels. Marble is metamorphosed limestone.

What is a kind of non-foliated metamorphic rock?

Overview. Nonfoliated metamorphic rocks lack foliated texture because they often lack platy minerals such as micas. They commonly result from contact or regional metamorphism. Examples include marble, quartzite, greenstone, hornfel, and anthracite.