High temperature and high pressure.
Two events that can result in cataclastic metamorphism are faulting, which involves the grinding and crushing of rocks along a fault zone, and impact cratering, where the intense pressure and heat generated by a meteorite impact cause rocks to be deformed and recrystallized.
Two processes that can cause metamorphism are heat (from deep burial or nearby magma) and pressure (from burial or tectonic forces). These processes can change the mineralogy, texture, and sometimes the chemical composition of rocks, leading to the formation of metamorphic rocks.
Transform boundary
Intense deformation and metamorphism are associated with convergent tectonic boundaries, where two plates move towards each other and one is forced beneath the other. This process, known as subduction, leads to intense compression and the formation of mountain ranges.
Regional metamorphism is associated with convergent plate boundaries where two tectonic plates are colliding. The intense pressure and heat generated during this collision cause the rocks to undergo metamorphism over a wide area, leading to the formation of regional metamorphic rocks.
Regional metamorphism would be the product of two plates colliding. The intense pressure and temperature generated during plate collision can create regional metamorphism, which affects a larger area and involves the recrystallization of rocks. Contact metamorphism, on the other hand, is caused by heat from a nearby magma intrusion and affects rocks in a localized area.
Metamorphism involves the combination of high temperature and pressure acting on the existing rock to change its mineral composition and texture. These conditions can alter the rock without completely melting it, leading to the formation of metamorphic rocks.
Foliated rocks form through regional metamorphism where intense heat and pressure create a banded or layered texture. They can also form through dynamic metamorphism, where deformation causes mineral alignment and banding in the rock.
Magmatic intrusionsBurial to great depth by sedimentary overburdenPlate tectonic collision
The short answer is that they don't! For metamorphism to occur rocks require either heat, pressure or a combination of the two. Both of these conditions occur together in the mantle, however they can occur in other places to. Such as in the rocks around igneous intrusions (high temperatures and low to moderate pressures) which cause contact metamorphism. It can also occur in zones of high tectonic stress (such as continental collision zones where mountains are being built where there is a relatively low temperature by mantle standards but very high pressure) which causes regional metamorphism. Finally in zones characterised by very high strains (e.g. the rocks in very close proximity to fault zones) metamorphism can occur. The type depends on the strain rate and the depth (which affects the pressure and temperature). This type of metamorphism is known as dynamic metamorphism). All the above conditions (and a number of others) can cause metamorphism to occur in sections of the earth outside the mantle. The differing types of metamorphism at differing temperatures and pressures create differing assemblages of minerals. These are known as metamorphic facies. Please see the related links for more information.
Two types of metamorphism occur in earth's crust. One is when small volumes of rock come in contact with magma. And the other is when large amounts of the earth's crust are effected by heat and pressure
Heat, Pressure, and Chemically active fluids.