What are metamorphic Rocks??
Metamorphic rocks are created by changes induced at hightemperature (up to about 600°C) and/or high pressure(around 500 Mpa at 20 km depth). These changes(metamorphism) take place in the solid state.
The type of metamorphic rock produced depends on theoriginal rock material that was metamorphosed and thetemperature and pressure conditions which were imposed.
Agents of Metamorphism
The agents who bring about metamorphism of rocks are as follows:
Physical agents: Heat, uniform pressure, and directed pressure.
Chemical agents: Chemically active water and gases.