Abstract:

Hetian fault belt is one of the major fault belts along the southwest margin of Tarim Basin extending more than 300km and dipping south with dip angles of 20-60?.It cuts through the Upper Proterozoic to Pliocene strata and lay consealed under the Pliocene.It was initialed in Early Permian and has undergone several stages of evolution.High-dipping anticlines such as Piaman,Duwa,Sangzhu,Yuliqun and Pusalocate on the upthrown wall of this faul belt,whereas low dipping anticlinesas Keliyang and Kokyar on its downthrown side.Among them,the long-axial Keliyang anticline,screened by the north walls of Sangzhu and Yuliqun antic-linal structures,contains the favourable Middle Jurassic source rock and thepossible Eogene source rock.It is obvious that when the source material is matured in Late Miocene,the fault belt could be a fine passage for hydrocarbon migration,while synchronous Keliyang anticline provides a favourable space for hydrocarbon accumulation during Late Miocene-Pliocene.In accordance with the fact that secondary oil and gas pools are discover-ed in Miocene Series of Kokyar structure,and oil shows corp out on the north walls of Sangzhu and Yuliqun structures,the author points out that Keliyang subtle structure could be inferred to have good petroleum potential.