Geological interpretation of the seismic profile in Tarim Basin and tectonic evolution of this area

Abstract：Seismic Profile shows that the Tarim Basin has experienced a violin-style evolutionary process, which has led to the formation of the three-layer (fault subsidence－depression“ structure: (1) Sinian “fault subsidence” and Paleozoic－Triassic “depression”；(2) Jurassic “fault subsidence” and Cretaceous “depression”; (3) Paleogene “fault subsidence” and Neogene "depression”. The fault subsidence and the depression resulted respectively from the pull-apart and the squeezing stress field, and the variation of such a stress field was caused by the subduction dip angle variation of the neighboring ocean crust plate from small to large. The polycyclic movement of the earth's crust led to the repeated tectonic-sedimentary evolution and produced quite a few oil-generating－oil-bearing－covering assemblages which formed oil-gas accumulations characterized by varied fields and varieties of trap styles. From Sinian through Paleozoic, Mesozoic to Cenozoic, basins with the fault subsidence－depression" structure were all likely to have geological conditions favorable for the formation of oil-gas accumulations.