南海深海盆的非均一沉积充填：基于高分辨率反射地震和IODP349资料的地震地层学分析

As the largest marginal sea basin between the Eurasia and the Pacific, the South China Sea oceanic basin not only reflects the seafloor spreading and evolution of the South China Sea by basin-filling, but also records neotectonics in East Asia and West Pacific. The IODP349, for the first time, got the complete sedimentary records in the South China Sea oceanic basin. Cores show that the East and Southwest Sub-basins display notable differences in sediment rates and processes. Aiming to investigate the uneven basin-filling features, this project will investigate sedimentary filling characteristics of the South China Sea oceanic basin and their tectonic implications, based on high-resolution seismic reflection profiles and calibration to drilling data of IODP349. In detail, the project will: (1) document spatial and temporal sedimentary distribution, (2) identify deep-water depositional types of the oceanic basin, (3) describe basin-filling patterns, (4) explore the sedimentary filling history, and discuss the seafloor spreading processes of the South China Sea and late Cenozoic tectonics of the East Asia and West Pacific revealed by sedimentary filling characteristics of the South China Sea oceanic basin. The findings will enhance our standing of sedimentary-tectonic evolution of the South China Sea, and provide seismic reflection evidences of seafloor spreading of the South China Sea and surrounding late Cenozoic tectonic events.

作为欧亚大陆与太平洋之间最大的边缘海盆，南海深海盆的沉积充填，不仅反映了南海的扩张和演变，还记录了东亚和西太平洋的新构造活动。2014年IODP349航次U1431和U1433站位首次获得南海深海盆的完整沉积记录。钻探结果显示，南海东部和西南次海盆在沉积速率和岩性方面均存在明显差异。为了调查整个深海盆沉积充填的非均一性，本项目拟在IODP349航次岩芯和测井资料标定下，根据高分辨率反射地震剖面，详细揭示南海深海盆百万年、五十千米时空尺度沉积充填特征及其构造意义。具体内容包括：（1）查明南海深海盆沉积厚度空间分布和百万年尺度时间变化；（2）识别深海盆沉积类型；（3）建立深海盆充填模式，重建深海盆百万年尺度的充填历史；（4）探讨深海盆沉积充填演变所记录的南海扩张和晚新生代东亚与西太平洋构造活动。研究成果可望加深对南海海盆沉积-构造演变的认识，并为南海扩张和周边新构造事件提供反射地震的证据。

作为欧亚大陆与太平洋之间最大的边缘海盆，南海深海盆的沉积充填，不仅反映了南海的扩张和演变，还记录了东亚和西太平洋的新构造活动。IODP349航次U1431和U1433站位首次获得了南海深海盆的完整沉积记录。钻探结果显示，南海东部和西南次海盆在沉积速率和岩性方面均存在明显差异。为了调查整个深海盆沉积充填的非均一性，本项目在IODP349航次岩芯和测井资料标定下，根据高分辨率反射地震剖面，详细揭示南海深海盆百万年、五十千米时空尺度沉积充填特征及其构造意义。具体内容包括：（1）查明南海深海盆沉积厚度空间分布和百万年尺度时间变化；（2）识别深海盆沉积类型；（3）重建南海深海盆百万年尺度的充填历史；（4）探讨深海盆沉积充填演变所记录的南海扩张和晚新生代东亚与西太平洋构造活动。研究成果加深对南海海盆及临域深水沉积-构造演变的认识，并为南海扩张和周边新构造事件提供了反射地震的证据。