Metamorphism

Abstract

Metamorphism may be defined as the response in solid rocks to pronounced changes of temperature, pressure, and chemical environment, which take place, in general, below the shells of weathering and cementation. In the great majority of cases metamorphism means the partial or complete recrystallisation of a rock, and the production of new structures; but the above definition does not exclude the effects of simple crushing and mylonisation with little or no recrystallisation.