Plate tectonic control on the formation and tectonic migration of Cenozoic basins in northern margin of the South China Sea

• Published in: Di xue qian yuan. Vol. 11; no. 4; pp. 1231 - 1251
• Main Authors: Wang, Pengcheng, Li, Sanzhong, Suo, Yanhui, Guo, Lingli, Wang, Guangzeng, Hui, Gege, Santosh, M., Somerville, Ian D., Cao, Xianzhi, Li, Yang
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.07.2020; Elsevier Science Ltd; School of Earth Sciences and Resources, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing 100083, China; Key Lab of Submarine Geosciences and Prospecting Techniques, MOE and College of Marine Geosciences, Ocean University of China, Qingdao 266100, China b Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, China; School of Earth Sciences and Resources, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing 100083, China%Department of Earth Sciences, University of Adelaide, Adelaide, SA, 5005, Australia; Key Lab of Submarine Geosciences and Prospecting Techniques, MOE and College of Marine Geosciences, Ocean University of China, Qingdao 266100, China b Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, China%Key Lab of Submarine Geosciences and Prospecting Techniques, MOE and College of Marine Geosciences, Ocean University of China, Qingdao 266100, China b Laboratory for Marine Geology, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266235, China; UCD School of Earth Sciences, University College Dublin, Belfield, Dublin 4, Ireland
• Subjects: Basins; Cenozoic; Domains; Fault lines; Geodynamics; Geological faults; Magma; Magnetic anomalies; NE-Striking fault; Nonuniformity; Northern Cenozoic basin group; Pacific Plate; Plate tectonics; Plates (tectonics); Seismic analysis; South China Sea; Subduction (geology); Tectonic migration; Tethyan tectonic domain; Red River; South China Sea; Pacific Plate; Tectonic migration; South China Sea; Tethyan tectonic domain; NE-Striking fault; Northern Cenozoic basin group
• ISSN: 1674-9871; 2588-9192
• DOI: 10.1016/j.gsf.2019.10.009

The tectonic evolution history of the South China Sea (SCS) is important for understanding the interaction between the Pacific Tectonic Domain and the Tethyan Tectonic Domain, as well as the regional tectonics and geodynamics during the multi-plate convergence in the Cenozoic. Several Cenozoic basins formed in the northern margin of the SCS, which preserve the sedimentary tectonic records of the opening of the SCS. Due to the spatial non-uniformity among different basins, a systematic study on the various basins in the northern margin of the SCS constituting the Northern Cenozoic Basin Group (NCBG) is essential. Here we present results from a detailed evaluation of the spatial-temporal migration of the boundary faults and primary unconformities to unravel the mechanism of formation of the NCBG. The NCBG is composed of the Beibu Gulf Basin (BBGB), Qiongdongnan Basin (QDNB), Pearl River Mouth Basin (PRMB) and Taixinan Basin (TXNB). Based on seismic profiles and gravity-magnetic anomalies, we confirm that the NE-striking onshore boundary faults propagated into the northern margin of the SCS. Combining the fault slip rate, fault combination and a comparison of the unconformities in different basins, we identify NE-striking rift composed of two-stage rifting events in the NCBG: an early-stage rifting (from the Paleocene to the Early Oligocene) and a late-stage rifting (from the Late Eocene to the beginning of the Miocene). Spatially only the late-stage faults occurs in the western part of the NCBG (the BBGB, the QDNB and the western PRMB), but the early-stage rifting is distributed in the whole NCBG. Temporally, the early-stage rifting can be subdivided into three phases which show an eastward migration, resulting in the same trend of the primary unconformities and peak faulting within the NCBG. The late-stage rifting is subdivided into two phases, which took place simultaneously in different basins. The first and second phase of the early-stage rifting is related to back-arc extension of the Pacific subduction retreat system. The third phase of the early-stage rifting resulted from the joint effect of slab-pull force due to southward subduction of the proto-SCS and the back-arc extension of the Pacific subduction retreat system. In addition, the first phase of the late-stage faulting corresponds with the combined effect of the post-collision extension along the Red River Fault and slab-pull force of the proto-SCS subduction. The second phase of the late-stage faulting fits well with the sinistral faulting of the Red River Fault in response to the Indochina Block escape tectonics and the slab-pull force of the proto-SCS. •NE-striking faults propagated from the South China Block into the NCBG.•Rifting is divided into three phases of early-stage and two phases of late-stage.•Early-stage rifting was younger eastward with diachronic features.•Late-stage rifting is synchronous with the slab-pull and activation of Red River Fault.