The key structure in this area is a duplex that comprises of a shallow fault-bend fold of the Late Triassic and a deep blind stacking anticline imbricated by three thrust sheets of Cenozoic age.

The piedmont in the southwestern Tarim basin is the foreland thrust-fault belts formed by the nappe structure in the western Kunlun mountains and it is mainly composed of fault-related folding,duplex,imbricated structures and triangular zones.

Several problems exsisted in the theoretical model for the formation of duplex proposed by Boyer and Elliott have been pointed out on the basis of analysis of natural contractional duplexes.

It has three basic oil and gas accumulation patterns:oil accumulation of piedmont compressional fault anticline type,oil and gas accumulation of salt arch structure type and naturalgas accumulation of subsalt dual structure.

Based on the geophysics,geology and remote sensing image analysis,the western Qiulitagh structural belt developed strike-slip duplex on the surface and its form was affected by strike-slip faults in pre-Paleogene basement.

Yuantai reverse thrust nappe structure at Pulandian is a typical double reverse thrust structure with a overstep thrust propagation, which includes a series of fault nappes,lag faults,rip-up faults,recoil faults,klippes and windows,etc.