A PRESSURE MODEL FOR ULTRAHIGH-PRESSURE METAMORPHISM

Based on the study on the ultrahigh-pressure metamorphism and the calculation of pressure pervading in the crust,the present paper shows that the pressure causing ultrahigh-pressure metamorphism should include in addition to the load of surrounding rocks also the pressure arising from phase change,and tectonism. A model for ultrahigh-pressure metamorphism to is thus proposed. In this model the pressure-depth relation is not linear.