The South Tianshan on the southern margin of the central Asian orogenic belt （CAOB） is a complicated accretionary-collisional orogenic belt. The final collision occured between the Tarim continent and Ili-central Tianshan volcanic arc. The initial time of the collision is a significant for the CAOB tectonics and remains debated. Almost all the previous studies on it were carried out within the South Tianshan Mountains, few within the related basins covered with think Cenozoic deposits. The northern Tarim Basin along the South Tianshan is the foreland of the South Tianshan orogenic belt. Both syn- and post-collision structures were discovered there after careful and systematic seismic interpretation. The syn-collision structures are the End Permian-Triassic thrusts. They are fairly seen as the syn-collision compressional structures of the South Tianshan collisional orogen. Timed with the Triassic/Permian and Jurassic/Triassic unconformities, there are two thrusting phases occurred at End Permian-beginning Triassic and End Triassic-beginning Jurassic, respectively. The post-collision structures are the Jurassic-Cretaceous normal faults. According to the growth indexes, the normal faulting began at beginning Jurassic, lasted to Middle Cretaceous and then ceased. On the basis of these observed syn- and post-collision structures, it can be fairly inferred that the collision between Tarim and Ili-central Tianshan initiated at End Permian, lasted in Triassic and ceased at End Triassic, and then evolved into the Jurassic-Middle Cretaceous extensional tectonic stage.
Li Honghui Li Yuejun Ma Debo Wen Lei Li Cheng Zhao Yan Liu Yalei Huang Tongfei Zhao Tianyu Gao Yanyan Shi Bin. Syn- and post-collision structures of the South Tianshan orogenic belt: Results of the seismic interpretation in the northern Tarim Basin along the South Tianshan[J]. Chinese Journal of Geology, 2020, 55(2): 322-338.