Rocks formed during metamorphism depend on what?
Rocks formed during metamorphism depends majorly on Temperature and Pressure. Other factors affecting metamorphism are Stresses and effects of Fluids.
Why are metamorphic rocks formed by contact metamorphism usually not as dense as those formed by regional metamorphism?
These rocks get their name from the Greek words 'meta' and 'morph', meaning 'change of form'. Metamorphic rocks are produced by the alteration of pre-formed rocks by pressure, temperature and migrating fluids, often in environments deep in the Earth's crust. Because of the severe conditions which rocks undergo during metamorphism, the original minerals may become unstable and change to maintain equilibrium with the new environment. This can involve changes in mineralogy (recrystallization of existing minerals…
Only an intrusive igneous rock forms underground, but you can argue that all metamorphism occurs underground. The issue here is that when the metamorphism is thermal, often the ground it is under has only just been formed (i.e. a lava flow). To avoid confusion, only regional metamorphism can take place underground. The rocks formed by regional metamorphism and intrusive magma cooling are rocks with crystalline texture.
There is only one similarity: regional metamorphism and the formation of sedimentary rock both require high pressure. The differences are: All metamorphism requires heat, whereas if heat is too excessive, a sedimentary rock is not formed, but an igneous or metamorphic one. Sedimentary rocks are made of fragments, whereas metamorphic rocks are from existing rocks Metamorphism requires the partial recrystallisation of the old rock, but in a sedimentary rock there are no crystals, so no…
Magma erupts from volcanic eruptions and on reaching earths crust it is called lava and solidifies by cooling. So they are referred to as primary rocks Igneous rocks are the rocks which are the original/initial rocks, as they were formed first. eg. sedimentary rocks are formed by denudation of a preexisting rock. and metamorphic rocks are also formed by metamorphism of preexisting rocks. Igneous rocks are also known as parent rocks because all other rocksare…
Cataclastic meta rocks are formed from rocks grinding past each other in fault zones. Burial metamorphism creates altered rock simply from overburden pressure. Contact metamorphism occurs from exposure to heat from an intrusive magma body. Regional metamorphism occurs from pressure and heat caused by tectonic forces.
The difference of metamorphic rocks from igneous and sedimentary rocks is on the way these rocks are formed. Igneous rocks form when magma cools down and becomes solid while sedimentary rocks form due to erosion and weathering of the Earthâ??s material, whereas, metamorphic rocks are formed as a result of rock transformation called metamorphism.
Contact metamorphism occurs typically around intrusive igneous rocks as a result of the temperature increase caused by the intrusion of magma into cooler country rock. The area surrounding the intrusion where the contact metamorphism effects are present is called the metamorphic aureole. Contact metamorphic rocks are usually known ashornfels. Rocks formed by contact metamorphism may not present signs of strong deformation and are often fine-grained.
During a mountain building phase, the sedimentary rocks may be buried deeply and subjected to heat and pressure causing certain minerals to form which were not present in the original rock. Also, an igneous intrusion may cause adjoining sediments to be altered in a contact metamorphism leading minerals such as garnets to form.
No matter what kinds of rocks they are they can be changed into any other kind of rock. Sedimentary rocks and igneous rocks can become metamorphic rocks with either contact or regional metamorphism. This means that either the rocks have been in contact with or close to high heat and high pressure that changes the rock.