Contact metamorphism is directly related to the volcanic activity. When the hot molten magma comes to the surfaced of the Earth, it passes through joints and fissures in the rocks. The rocks coming in contact with the magma or lava get baked or burnt to form metamorphic rock. E.g. Marble from Limestone. Regional metamorphism is associated with Earth movements and processes of mountain building. In this the masses of Igneous and Sedimentary rocks are squeezed and buribd deep in the earth. E.g. Slate from Clay, Graphite from Coal.
