Qinghai is geographically located in northeastern qinghai-tibet plateau and tectonically in the mid-western part of the pan-cathysian block group and the north part of eastern tethys .
青海位于青藏高原东北部、泛华夏陆块群的中西部，东特提斯的北部。
According to the fact that holcophylloceras caucasicum found in pk-2well belongs to the geographic subspecies of mediterranean coastal areas , it is suggested that there could be certain connection between east china and tethys sea during early cretaceous period .
Sanjiang area is located at the junction between two giant orogenic belts , the tethyan and the circum-pacific , and affected by the convergence of eurasian , indian and pacific three plates . It has a complicate history from the formation and evolution of the tethys to india-eurasia collision and uplift of the plateau .
