GENERAL GEOLOGY

Detailed explanation-1: -Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors. Conditions like these are found deep within the Earth or where tectonic plates meet.

Detailed explanation-2: -Heat sources include magma, geothermal heat, and friction along faults. Pressure sources include the weight of overlying rocks deep in the earth. Shear pressure in fault zones can metamorphose rocks at shallower depths. Chemical activity is usually caused by water at higher temperatures and pressures.

Detailed explanation-3: -The pressure experienced by a rock during metamorphism is due primarily to the weight of the overlying rocks (i.e., lithostatic pressure) and is generally reported in units of bars or kilobars.

Detailed explanation-4: -Metamorphic rocks are rocks that have been changed from their original form by immense heat or pressure. Metamorphic rocks have two classes: foliated and nonfoliated. When a rock with flat or elongated minerals is put under immense pressure, the minerals line up in layers, creating foliation.

Detailed explanation-5: -Metamorphism therefore occurs at temperatures and pressures higher than 200oC and 300 MPa. Rocks can be subjected to these higher temperatures and pressures as they become buried deeper in the Earth.