Abstract:

The two stages of regional metamorphism are developed in  the Altai area of Xinjiang, of which the first is characterized by the regional low-temperature dynamic metamorphic type, and the second is represented by the regional dynamic heat flow metamorphic type.The progressive metamorphic belt of   the Chonghuer area belongs to a part of the second stage of metamorphism.The staurolite-kyanite belt, biotite-garnet belt, chlorite-biotite belt and sericite-chlorite belt developed respectively from the center of volcanic sedimentary basin to margin, representing progressively decreasing in metamorphic grade.The metamorphic process is divided into three stages of early episode, peak episode and late episode according to the feature and evolution of metamorphism and deformation.The both of early episode and peak episode are a continued metamorphic process, forming a typical mid-pressure type progressive metamorphic belt.The late episode is a regressive metamorphic process.The geodynamic process of metamorphic evolution shown a clockwise p-t path,  representing a specific tectonic condition and the earth crustal evolution regime of Hercynian orogenic belt in the Altai area of Xinjiang.

Key words: orogenic belt, metamorphic type, progressive metamorphic belt, metamorphic evolution, Altai area, Xinjiang