The authors have made the comprehensive study on the petrology, lithogeochemistry and tectonic feature of basalts, silicalites, mudstones and sandstones in different tectonic block of Bai quanmen area of Sunan county, Gansu province and thought that they form separately in the environment of ocean ridge, oceanic island, continetal island arc, continental margin and intraplate. The blocks in the various environments mixed together and mixed and accumulated with a lot of ultrabasic rock blocks and formed the ophiolitic melange, which is the important unit of subduction complex body of the Northern Qilian Caledonides.