Intra-continental deformation and metamorphism are related to crustal thickening,crustal thinning,exhumation of highgrade metamorphic rocks,and basin formation during the terminal stages of continental collision(Davis et al.,1986;McDonough and Simony,1988;Yin,2004;Lee et al.,2004;Faure et al.,2005).Most of these evolutions are associated with extensive ductile deformation,such as large–scale ductile shear zones in the crystalline basement,which would weaken crust.Gneiss and granite domes are classic structures of exposed continental middle crust in the thickened crust of orogenic belts(e.g.,Brun,1980;Burg,1987Teyssier and Whiney,2002;Whitney et al.,2004).The cores of the gneiss domes have been differentially exhumed relatively to the surrounding host rocks.