Structural characteristics and genetic mechanism of the Meso-Cenozoic Yingjisu piggyback foreland basin

Abstract：The Meso-Cenozoic Yingjisu depression is a piggyback foreland basin developed in the setting of the Paleozoic thrust nappe structure. The sedimentation and deformation of the basin is strictly controlled by thrusts. From north to south the Meso-Cenozoic structure may be divided into seven belts: the northern slope belt, Qongkol-Xinkaiping anticlinal belt, northern Yingjisu synclinal belt, Alagan anticlinal belt, southern Yingjisu synclinal belt, Guchengxu slope belt and Luobuzhuang fault rise. The imbricate thrusts, upthrust structure, structural triangle zones, fault-propagating folds and drape structure are the main deformation styles of the Yingjisu depression. Since the Triassic, the depocenters in different epochs migrated from the orogenic belt to the foreland. The Meso-Cenozoic deformation dynamics and kinematics are related to the amalgamation of plates on the active continental margin of the southern Tarim plate margin and intracrustal detachment-shortening.