Tectonic Subsidence of Qiongdongnan Basin and Its Main Control Factors

详细信息   

• 责任者：Yuan Yusong (Exploration and Production Research Institute ; SINOPEC ; Beijing 100083 ; China) ; Yang Shuchun
• 刊名：Chinese Journal of Geophysics
• 出版年：2008
• 卷期：51(2)
• 关键词：沉降 ; subsidence ; 南海 ; South China Sea
• 页码：p.376-383
• 图表：3 illus., 1 table, 49 refs.
• 分类号：0300
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

摘要

Based on the data from 28 boreholes and the latest data of 3 seismic lines, the estimation of tectonic subsidence shows that Qiongdongnan Basin (QDNB) experienced three episodes of rapid subsiding and one episode of weak subsiding in Cenozoic time. During Eocene and Oligocene to early Miocene time, both western and eastern QDNB underwent two episodes of rapid subsiding with different subsidence rates. There came a weak subsiding period from 16 Ma to 10.5 Ma in western QDNB and from 16 Ma to 5.3 Ma in mid-eastern QDNB. A rapid subsiding event occurred again at 10.5 Ma in the west and at 5.3 Ma in the mid-east areas of QDNB. The first rapid subsiding was a result of the combination of extension of Eastern Asia continental margin and the sinistral strike-slip of Red River Fault (RRF) in Eocene; the second one was related with the seafloor spreading of the South China Sea (SCS) and sinistral strike-slip of RRF in Oligocene to early Miocene; the third one is mainly controlled by the dextral strike-slip of RRF since 10 ~ 5 Ma; the weak subsiding process was coeval with the weakly strike-slipping period of RRF within mid-late Miocene time and a response to the cease of the seafloor spreading of SCS.