南海北部珠江口与琼东南盆地构造-热模拟研究  

Research on tectono-thermal modeling for Qiongdongnan Basin and Pearl River Mouth Basin in the northern South China Sea

作　　者：宋洋[1,2] 赵长煜[1,3] 张功成[4] 宋海斌[1] 单竞男[1,2] 陈林[1] 

机构地区：[1]中国科学院地质与地球物理研究所,油气资源研究重点实验室,北京100029 [2]中国科学院研究生院,北京100049 [3]中国地质大学(北京)地球物理与信息技术学院,北京100083 [4]中海石油(中国)有限公司北京研究中心,北京100027

出　　处：《地球物理学报》2011年第12期3057-3069,共13页Chinese Journal of Geophysics

基　　金：国家重点基础研究发展计划(973计划)(2007CB411 704,2009CB219400);国家科技重大专项课题(2008ZX05025-02-03)资助

摘　　要：珠江口盆地和琼东南盆地位于南海北部的大陆边缘,本文在此地区选取了13条典型剖面,进行了构造沉降史和热史的模拟,初步探讨了其新生代以来的构造-热演化历史.其研究结果表明:珠江口盆地存在两次热流升高过程,分别为始新世(56.5～32 Ma)和渐新世(32～23.3 Ma).琼东南盆地存在三期加热和两期冷却过程,始新世盆地热流缓慢升高,渐新世西部地区热流持续升高,而东部地区热流升高持续至16 Ma,并在5.4 Ma以来存在一期快速沉降,由西向东加热事件逐渐变弱.南海北部陆缘存在多期次裂谷作用、热流升高的特征;"热沉降"阶段也非完全处于热衰减期,晚期也存在热流升高的加热事件,这些都有别于典型的被动大陆边缘盆地的热演化模式.The 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 were 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 wereelevated 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.

关 键 词：琼东南盆地 珠江口盆地 构造-热演化 应变速率 古热流 

分 类 号：P314[天文地球—固体地球物理学]