The Granitoid and Its Tectonic Evolution in Tianshui Area

The granitoids can be devided into three tectonics magma belts according to the petrochemistry and geochemistry study of Tianshui area located in the junction region between the Qinling orogenic belt and Qilian orogenic belt.The two belts are subordinate to two orogenic belt before Neopaleozoic.According to the research results of the tectonic environment,they are evidently different with regard to magma events,tectonic background and evolvement pattern.But in Neopaleozoic,Qinling orogenic belt and Qilian orogenic belt united and began continent evolvement together.The study of granitoids in this area provided evidence of its tectonic evolvement.