Cenozoic thermal history of the deep water area of the northern margin of South China Sea
Yuan Yusong1,2 Zheng Herong1 Zhang Gongcheng3 Zhong Kai3 He Lijuan4
1.Exploration and Production Research Institute|Sinopec|Beijing 10083|2.China University of Geosciences, Beijing 100083|3.Beijing Research Center of CNOOC China Ltd.|Beijing 100027|4.Institute of Geology and Geophysics|Chinese Academy of Sciences|Beijing 100029
The Cenozoic heat flow history of the deep water area of the northern margin of South China Sea(SCS)is estimated through non?instantaneous，non?homogeneous，multi?episode and pure shear model. It shows that the deep water area of the northern margin of SCS has experienced multi?episodes of heating event since Eocene time. The base heat flow elevated episodically in rifting phase and it did not always keep attenuating in post?rifting phase. Qiongdongnan Basin(QDNB)experienced three episodes of heating event in 56.5～32 Ma, 32～16 Ma and 5.3 Ma～，respectively. The Pearl River Mouth Basin(PRMB)experienced two in 56.5～32 Ma and 32～23.3 Ma. The heat flow of QDNB was 56～62 mW/m2 at the end of the Eocene time. It elevated to 60～64 mW/m2 at the end of early Miocene time and reached as high as～75 mW/m2 at the end of the Oligocene. The heat flow elevated to 60 mW/m2 in the Baiyun sag of PRMB at the end of Eocene time and it ascended to～70 mW/m2 at the end of Oligocene time. In the deep water area of the northern margin of SCS，the multi?episodic stretching in the rifting phase resulted in the multi?episodic heat events. The latest heating event in the QDNB is related to the shifting of the strike?slip of the Red River Fault from sinistral to dextral in 10～5 Ma.