Tectonic‐Thermal Modeling for Qiongdongnan Basin and Pearl River Mouth Basin in the Northern South China Sea

Abstract

AbstractThe Qiongdongnan Basin (QDNB) and Pearl River Mouth Basin (PRMB) are located in the northern continental margin of South China Sea. Based on the data from 13 seismic lines, tectonic and thermal modeling was performed in order to study the tectonic and thermal history in the northern South China Sea during the Cenozoic era. The results show that the PRMB experienced two episodes of heat flow rising processes. The first episode occurred from 56.5 Ma to 32 Ma, and the second one occurred from 32 Ma to 23.3 Ma. The QDNB experienced three episodes of heat flow rising processes and two episodes of cooling processes. The heat flows were elevated from 56.5 Ma to 32 Ma within the whole basin, and a heating period followed from 32 Ma to 23.3 Ma in the western QDNB and from 32 Ma to 16 Ma in the eastern QDNB. In the QDNB there was a rapid subsidence and rise of heat flow event around 5.4 Ma, and the effects of heating event gradually weaken from west to east. In the northern SCS margin, multi‐episode rifting and heat flow rising occurred. There is a late heating event and it is not completely a heat flow decreasing process in the thermal cooling stage. All of these features are different from the thermal evolution of a typical passive margin.