The General Characteristics and Distribution of the Glaucophane‐Schist Belts of China

Abstract

Abstract On the basis of the temperature variation, the glaucophane‐schist facies can be classified into two facies groups, the glaucophane‐lawsonite facies group and the glaucophane‐greenschist facies group, and forms various facies series with other metamorphic facies. Glaucophane‐schist belts of China are of different types with regard to their average T‐ P gradients and tectonic environments. They are: (1) Proterozoic intracratonic glaucophane‐ schist belts, (2) Caledonian intracratonic glaucophane‐ schist belts, (3) Palaeozoic pericratonic glaucophane‐ schist belts along the northern margin of the Chinese Platform, and (4) Meso‐ Cenozoic glaucophane‐schist belts related to subduction.The initiation and evolution of glaucophane‐schist metamorphism are related to their tectonic environments. Most glaucophane‐schist belts of China were formed in sialic environments. First the crust began to break up and eventually oceanic crust was formed. It seems that a non‐uniformitarian mechanism may be involved as this evolution is related to the change of the configuration of the heat flow within the crust.