Mesozoic Structure and Its Impact on Cenozoic Deformation in Northern Piedmont of Tianshan Mountain

Ji Dongsheng; Gan Renzhong; Pang Zhichao; Li Jing; Wang Xinqiang; Li Quanhao

doi:10.3799/dqkx.2025.168

Abstract：The fold-thrust belt in the northern piedmont of the Tianshan Mountains underwent polyphase tectonic deformation,acquiring its present configuration during the Late Cenozoic contractional regime.Under multiphase superposition,the influence of basement architecture on subsequent compressive deformation remains constrained.This study investigates the Mesozoic structural characteristics and deformation mechanisms in the northern piedmont of the Tianshan Mountains based on seismic,drilling,and field observation data,aiming to reveal the influence and controlling factors of Mesozoic structures on Cenozoic deformation and hydrocarbon migration-accumulation.Strike-slip faults were developed in the Mesozoic in the northern piedmont of Tianshan Mountain,and were covered by the Cretaceous-Cenozoic strata.Under the Late Cenozoic compression environment,the Mesozoic strike-slip fault was reactivated,and the Cenozoic thrust fault and fold superimposed on the Mesozoic fault.The reactivation of Mesozoic structures played an important role in shaping the present structure of the northern piedmont of Tianshan Mountain.According to the deformation sequence,the sedimentary strata in the southern Junggar basin.are divided into three structural layers—shallow,intermediate,and deep.These tiers correspond to upper,middle,and lower hydrocarbon accumulation assemblages,respectively,with the intermediate and deep structural tiers demonstrating particularly significant exploration potential.In this paper it reveals the relationship between deep faults and late compressive structures in the northern piedmont of Tianshan Mountain,explains the influence of multi-stage tectonic evolution on oil and gas exploration,and has reference significance for the study of similar structures in the basins of western China.