DEFORMATION OF ARCHAEAN WULASHAN GROUP IN GUYANG REGION OF INNER MONGOLIA

There have existed different views on the metamophism-deformation of the Wulashan Group. It is pointed in this paper that the late Archaean Wulashan Group has experienced two major deformation events on the basis of recent results obtained from 3 sheets of 1:50000 geological mapping and other regional studies since 90's. The first deformation event is characterized by solid flow fold and high temperature ductile shear zone resulting from nearly horizontal shearing by extension. The metamorphism is of high amphibolite granulite facies. The deformation took place at the end of Archaean. The second deformation even is characterized by shallow tight homoclinal similar fold-main fold and low temperature ductile shear zone arising from post-crustal uplifting compression. The event occurred in the early Proterozoic.