Which rock is the result of metamorphosis?
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Which rock is the result of metamorphosis?
Metamorphic rock is the result of the transformation of an existing rock type, the protolith, in a process called metamorphism. The protolith is subjected to heat and pressure causing profound physical and chemical change. The protolith may be sedimentary rock, igneous rock, or another (older) metamorphic rock.
Can metamorphic rocks be fine grained?
Low-grade metamorphic rocks tend to be fine-grained (the newly formed metamorphic mineral grains that is). High-grade metamorphic rocks tend to be coarse-grained. But grain size is also dependent on the grain size of the protolith.
What is the metamorphosed form of granite?
When granite is subjected to intense heat and pressure, it changes into a metamorphic rock called gneiss.
What is the example of metamorphic rocks?
Types of metamorphic rocks include gneiss, quartzite, marble, schist, soapstone, and phyllite.
How are metamorphic rocks with fine grains formed?
Hornfels is a fine-grained metamorphic rock formed by the action of heat on clay rocks, known as contact metamorphism. It has a non-foliated metamorphic rock that has no specific composition. Hornfels are heated when near a heat source such as a sill, dike, or magma chamber.
Which is an example of a fine-grained foliated metamorphic rock?
Slate is a fine-grained metamorphic rock that exhibits a foliation called slaty cleavage that is the flat orientation of the small platy crystals of mica and chlorite forming perpendicular to the direction of stress. The minerals in slate are too small to see with the unaided eye.
What are the two types of metamorphism?
There are two major kinds of metamorphism: regional and contact. Regional metamorphism. Most metamorphic rocks are the result of regional metamorphism (also called dynamothermal metamorphism). These rocks were typically exposed to tectonic forces and associated high pressures and temperatures.
What rocks contain sillimanite?
Introduction: sillimanite is a metamorphic mineral found in high-grade rocks (upper amphibolite/lower granulite facies) most typically in aluminium-rich pelites. Sillimanite has two polymorphs, kyanite and andalusite, which develop under conditions of lower temperature and different pressure to sillimanite.
What grade of metamorphism is sillimanite?
high-grade
Sillimanite from a variety of high-grade metamorphic rocks contains from 0-13 to 1-82 weight per cent Fe2O3 and less than 0-1 weight per cent TiO2. The iron is trivalent and substitutes for Al only.
Which is an example of a fine grained foliated metamorphic rock?
What type of metamorphism is marble?
Marble
| Type | Metamorphic Rock |
|---|---|
| Metamorphic Type | Regional or Contact |
| Metamorphic Grade | Variable |
| Parent Rock | Limestone or Dolostone |
| Metamorphic Environment | Variable grade regional or contact metamorphism along a convergent plate boundary |
Can any rock be metamorphosed?
Metamorphic rocks started out as some other type of rock, but have been substantially changed from their original igneous, sedimentary, or earlier metamorphic form. Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors.
Where is sillimanite found?
Sillimanite is found at many points in France, Madagascar, and the eastern United States; a pale sapphire-blue gem variety occurs in the gravels of Sri Lanka. For detailed physical properties, see silicate mineral (table).
Where does sillimanite occur?
It is sometimes used as a gem, as brown chatoyant crystals and aggregates are known from several localities, among them southern India and Sri Lanka. The finest light blue, transparent crystals are found in the gem sands of Sri Lanka and Burma.
How is sillimanite formed?
Metamorphic rocks Disten or sillimanite, cordierite, and staurolite schists occur in conditions of high-degree metamorphism from pelite sediment, that is, shale, mudstone, and marl.
