Transpressional Structures along the Eastern Flank of the Pamir Salient
Wang, Zhe; Wang, Xin
A growing body of geologic, seismic reflection data indicates that along the 300km boundary between the Pamir salient and the Tarim basin is a setting combining strike-slip and convergence. Regional structural map and balanced cross-sections of Damus segment document the geometry and kinematics of the boundary. The area is deformed by a series of northwest-striking dextral strike-slip faults, coupling relationship from the Aertashi fault in north, the Qipan fault in middle, and to the Momoke fault in south. The steeply dipping faults separate Paleozoic rocks of the Pamir salient to the west from Cenozoic rocks of the Tarim basin to the east. Mesozoic is sliced into pieces significantly along the faults. The seismic reflection sections show the strike-slip faults with positive flower structures and the fault flanks are deformed by en echelon folds with steeply plunging hinge lines and axes that trend more westerly or easterly than the adjacent faults. Structural measurements and asymmetric folds document right-slip shear sense along the faults. The dextral faults are commonly characterized by bends, marked by the NW 60° trending Qipan fault with an oblique orientation to the NW 10° trending Aertashi fault and the NW 25° trending Momoke fault at the northern and southern ends of the fault, respectively. A restraining bend form along the Qipan fault where a series of NW-SE trending Cenozoic anticlines and synclines have formed that indicates the shear results in a component of fault-parallel contraction. Several oil fields have been found along the eastern flank of the Pamir salient. These traps consist of anticlinal trends located along the boundary. It is hoped to understand the structure, trapping mechanisms and petroleum systems in this transpressional belt.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013