胡刚,杜学鑫,祝文君,等. 孟加拉深海扇大洋钻探研究:科学问题与钻探前景[J]. 海洋地质与第四纪地质,2022,42(5): 1-15. doi: 10.16562/j.cnki.0256-1492.2022061402
引用本文: 胡刚,杜学鑫,祝文君,等. 孟加拉深海扇大洋钻探研究:科学问题与钻探前景[J]. 海洋地质与第四纪地质,2022,42(5): 1-15. doi: 10.16562/j.cnki.0256-1492.2022061402
HU Gang,DU Xuexin,ZHU Wenjun,et al. Progresses of ocean drilling in Bengal Fan: Scientific issues and drilling prospect[J]. Marine Geology & Quaternary Geology,2022,42(5):1-15. doi: 10.16562/j.cnki.0256-1492.2022061402
Citation: HU Gang,DU Xuexin,ZHU Wenjun,et al. Progresses of ocean drilling in Bengal Fan: Scientific issues and drilling prospect[J]. Marine Geology & Quaternary Geology,2022,42(5):1-15. doi: 10.16562/j.cnki.0256-1492.2022061402

孟加拉深海扇大洋钻探研究:科学问题与钻探前景

Progresses of ocean drilling in Bengal Fan: Scientific issues and drilling prospect

  • 摘要: 孟加拉深海扇是连接高原与深海“源-汇”过程的转换带,不仅是板块漂移与碰撞过程的重要产物,而且其巨厚的沉积层是研究构造隆升与沉积演化等相关核心科学问题的天然“档案室”。前人基于钻探样品及地球物理资料,获取了孟加拉扇早渐新世以来沉积演化过程、90°E海岭性质与演化、南亚季风形成与变化等科学问题的重要认识。但埋藏于海底的大型线性基底性质的争议和扇体对隆升过程全时序沉积揭示的不足,直接制约了南亚季风形成时限、板块碰撞过程的构造特征和扇体物源时空转换等关键科学问题的揭示。因此,在存在构造隆升过程完整沉积记录并同时兼顾特殊构造地区开展大洋钻探,有利于上述科学问题的揭示。依据在扇体下游合理位置新近获取的高质量多道地震数据,查明了孟加拉深海扇下游地区的基底起伏、完整沉积层结构和构造发育特征,并在此基础上针对孟加拉深海扇全时序地层层序揭露不完整、玄武岩洋壳年龄和特殊构造性质等钻探科学目标,选取了该地区未来3个科学钻探井位,并分别对其开展了井位标定与岩性预测,钻探实施不仅对解决以青藏高原为核心的地球系统科学前沿具有重要科学意义,而且对服务我国自有大洋钻探船钻探井位储备具有现实意义。

     

    Abstract: The Bengal Fan is not only a source-sink transition zone connecting the plateau and the deep sea, but also an important product of plates drift and collision. Its deep sedimentary records are the natural archives of the India-Eurasia plate collision, the uplift and erosion process of the Qinghai Tibet Plateau and the evolution of climate and environment. We summarized the drilling expeditions and the latest research progress focusing on the sedimentary process and climate evolution since the late Miocene, the nature and evolution of the 90°E Ridge, and the formation of the South Asian monsoon in the Bengal Fan. However, constrained by drilling capacity and scientific targets, the full time sedimentary strata, the age and structural characteristics of the underlying oceanic crust in the Bengal Fan have not been effectively revealed which hinders the research on the long-time scale source to sink transition, the South Asia Mosoon formation and plate reconstruction. Based on the recently acquired high-quality multi-channel seismic data, the basement fluctuation, sedimentary structure and tectonic development characteristics of the Bengal Fan downstream are interpreted. Furthermore, we proposed three future scientific drilling locations which aim at the scientific drilling objectives including the complete sedimentary strata, age of oceanic crust basalt, and special structure characteristics. Well calibration and lithology prediction are carried out for these proposed drillings respectively. These proposed drillings are not only contributed to the reserve of scientific drilling for Chinese Ocean Drilling Vessel, but also significant for solving the frontier scientific issues of the Qinghai Tibet Plateau.

     

/

返回文章
返回