南海北部陆坡深水区新生代沉积演化东西部对比分析  

Contrastive Analysis on the Sedimentary Evolution in the Deep Water Areas from West to East,Northern South China Sea

作　　者：谢辉 区浩瑛[1] 石红才 孔德明 XIE Hui;OU Hao-ying;SHI Hong-cai;KONG De-ming(Guangdong Key Laboratory of Coastal Ocean Variation and Disaster Prediction//College of Ocean and Meteorology,Guangdong Ocean University,Zhanjiang 524088,China;Key Laboratory of Ocean and Marginal Sea Geology,CAS,Guangzhou 510301,China)

机构地区：[1]广东海洋大学海洋与气象学院//广东省近海海洋环境变化与灾害预警重点实验室,广东湛江524088 [2]中国科学院边缘海与大洋地质重点实验室,广东广州510301

出　　处：《广东海洋大学学报》2020年第4期41-50,共10页Journal of Guangdong Ocean University

基　　金：国家自然科学青年基金(41606065);广东省自然科学基金(2016A030310331);中国科学院边缘海地质重点实验室开放基金(MSGL15-02);广东海洋大学博士启动基金项目;广东海洋大学海洋科学科研团队项目(002026002004)。

摘　　要：【目的】研究南海北部陆坡深水区新生代沉积演化在陆缘东部和西部的异同。【方法】利用珠江口盆地深水区和琼东南盆地深水区钻井和地震勘探资料,通过回剥分析,重建两沉积盆地深水区的去压实沉积厚度和沉积速率变化并进行对比分析。【结果】两沉积盆地深水区的新生代都呈现幕式沉积演化的特征,大体可以划分为4幕。在29-23.03 Ma和19.8-11.9 Ma,珠江口盆地深水区的沉积速率明显大于琼东南盆地;而在8.2-0 Ma,尤其是3.2 Ma之后,情况相反。在23-19.8 Ma,两个盆地的深水区都表现出极低的沉积速率。【结论】南海北部陆缘深水区东西部的沉积演化在裂陷期基本近似,但是裂后期明显不同。珠江口盆地深水区裂后期沉积演化主要受到珠江流域变化、白云运动和亚洲季风强弱控制,而琼东南盆地深水区裂后期沉积演化主要受到红河物源、海南岛物源、红河断裂右旋走滑和亚洲季风强弱控制。【Objective】To study the discrepancy of the Cenozoic sedimentary evolution from west to east in the deep water areas,northern South China Sea.【Method】Based on drilling wells and seismic exploration data in the deep water area of the Pearl River Estuary Basin and the Qiongdongnan Basin,this work employed the method of backstripping to calculate the decompacted depositional thickness and sedimentary rate.【Result】Our results show that the sedimentary evolution of these two basins could be divided into four episodes in Cenozoic.However,the sedimentary rates were much higher in 29-23.03 Ma and 19.8-11.9 Ma in the deep water areas of the Pearl River Mouth Basin than in the Qiongdongnan Basin,the reverse was true in 8.2-0 Ma,especially after 3.2 Ma.In 23-19.8 Ma,both of them were characterized by low sedimentary rate.【Conclusion】The sedimentary evolution from west to east in the northern South China Sea may be similar in the rift stage,but the discrepancy is obvious in the post-rift stage.The post-rift sedimentary evolution in the deep water areas of the Pearl River Estuary Basin was mainly controlled by the Pearl River drainage system,Baiyun Movement and the Asia monsoon strength.But the post-rift sedimentary evolution in the Qiongdongnan Basin was controlled by the Red River drainage system,Hainan Island,Red River Fault dextral slip and the Asia monsoon strength.

关 键 词：南海北部 陆坡深水区 回剥分析 沉积演化 

分 类 号：P67[天文地球—海洋地质]