南海北部深水区新生代热演化史

在构造沉降史恢复的基础上确定拉张期次，再采用非瞬时非均匀多期拉张纯剪切模型恢复南海北部深水区新生代热流史，结果表明：始新世以来，南海北部深水区存在多期热流升高的加热事件。裂谷阶段盆地基底热流幕式升高，裂后阶段也并非完全处于热衰减期。琼东南盆地新生代存在56.5～32 Ma、32～16 Ma和5.3 Ma以来3期加热事件，珠江口盆地存在56.5～32 Ma和32～23.3 Ma两期加热事件。琼东南盆地深水区基底热流始新世末为56～62 mW/m2; 早中新世末上升到60～64 mW/m2; 上新世末在深断陷区最高达75mW/m2。珠江口盆地深水区基底热流始新世末升高到60 mW/m2; 渐新世末升高到70 mW/m2。深水区新生代裂谷阶段多期拉张决定了基底热流幕式升高的多期加热事件，琼东南盆地晚期加热事件与红河走滑断裂在10～5 Ma时由左旋走滑转变为右旋走滑拉张有关。

Cenozoic thermal history of the deep water area of the northern margin of South China Sea

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.