摘要
The Red River Fault,which originated from the southeastern margin of the Tibetan Plateau,has a great significance for obtaining a further understanding of the regional tectonics,topography and river catchment evolution,as well as the petroliferous sedimentary basin formation.The junction of the Yinggehai and Qiongdongnan Basins(YQB Junction)is the key to understanding when and how the strike-slip deformation on the South China Sea resulted from the collision between the Indian and Eurasian plates.In this study,we show regional seismic profiles,3D seismic and drilling core data to analyze the tectonostratigraphy in the YQB Junction,aiming to identify its tectonic framework and the associated faults system.A transitional domain from the strike-slip zone to the extensional deformation zone was mapped,which consisted of the No.1 Fault and the Zhongjian Uplift.The strike-slip faulting in the YQB Junction was active during the Oligocene-Early Miocene,with a period of strong faulting in the Early Oligocene.Integrated with the regional tectonic evolution,a coevolution model of strike-slip and extensional deformation in the YQB Junction and the adjacent area was built.In the Eocene,the YQB Junction was controlled by the NW-SE extension and formed a series of distributed rifts bounded by the NE-striking faults and filled up with proximal sediment.In the earliest Oligocene,a NW-trending strike-slip fault began to develop in the YQB Junction and crosscut the NEstriking normal faults.Since the occurrence of the strike-slip faults,the NE-striking faults,to the west of the No.1 Fault and the Zhongjian Uplift,failed to grow.However,to the east of the No.1 Fault and the Zhongjian Uplift,the faulting continued to develop until the latest Late Oligocene.The faulting of the NW-trending faults was observed to be active until the earliest Middle Miocene.Since then,with the exception of some diapiric structures and associated small-scale faulting in the Yinggehai Basin,we did not observe any basement-involved faulting.Our results will improve our understanding of the tectonics in the southeastern margin of the Tibetan Plateau and the South China Sea.
基金
This work was supported by the National Natural Science Foundation of China(Grant Nos.41772093,41830537)
the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(Grant No.GML2019ZD0208)
the National Science and Technology Major Project of the Ministry of Science and Technology of China(Grant No.2017ZX05008001).
