Geological features of the Foping basal complex, Qinling orogenic belt

Systematic research shows that the primitive rock of the Foping basal complex consisted of volcanic-sedim entary rocks and mid-acid intrusive rocks, which suffered widespreadly multiple phase of intense deformation, metam orphism and migmatization. The forming age of the complex is 2.2～1.8Ga, and the reforming age is about 200Ma. The complex was subjected to three different evolution periods of tectonic deformation, that is, the period of complex formation, principal orog enesis and post orogenesis. During the period of principal orogenesis, the main deformation of the complex characterized by the super imposed deformation of the therm al doming on the basis of the thrustting-nappe structure.