Differential tectonic deformation and dynamic processes in Caohu area, northeastern Tarim Basin

The Caohu area located in the northeastern Tarim Basin closed against the Kuluktag Lift. Paleozoic and Mesozoic strata were preserved very well, which recorded the tectonic evolution of the northeastern Tarim Basin. Based on the interpretation of the latest 2D seismic data and the theory of fault-related folding, this paper analyzed the geometrical and kinetic features of deformations in the Caohu area. Faulting deformations in the Caohu area have the characteristics of vertical stratification, S-N segmentation, and E-W zonation. Thrusts and thrust-strike slip faults were dominant. Tectonic deformation took place mainly in the late Hercynian, Indosinian and middle Yanshanian, and had the geometrical features of fault-related folds. Structural evolution history was recovered using an equilibrium profile technique. The late Caledonian to early Hercynian movements controlled the main upwarped and downwarped structural framework in the Caohu area, developing the Akekule Arch, Caohu Sag and Yuli Nose Arch. Thrust detachment faults developed during the late Hercynian, and experienced two phases of thrust-strike slip reform in the Indosinian and Yanshanian epochs, resulting in the present tectonic pattern of the study area.