Metamorphic rocks are derived from the transformation of igneous or sedimentary rocks under the effect of temperature and / or high pressures. Two main types of metamorphism produce the majority of metamorphic rocks: Contact metamorphism and regional metamorphism.
Contact metamorphism is the one that occurs in the host rock in a aureole in contact with intrusive magma. When the introduced magma is still hot in a sequence of cold rocks, there is heat transfer (arrows) and cooking of the host rock on the contact limit. The width of the aureole is a function of the size of the intrusive mass varying from a few millimeters to several hundred meters, even going a few kilometers in the case of a very large intrusive mass.
Regional metamorphism is the one that affects large areas. It is controlled by the significant increases in both pressure and temperature. The following table shows the most common metamorphic rocks according to the degree of metamorphism.
