地球化学方法示踪东亚大陆边缘源汇沉积过程与环境演变

Geochemical Approaches of Tracing Source-to-Sink Sediment Processes and Environmental Changes at the East Asian Continental Margin

东亚大陆边缘发育特征的河控型边缘海沉积,其源汇沉积过程的深入研究对于深入理解地球表生过程、物质循环和大陆边缘构造沉积演化特征,具有重要意义。东亚边缘海沉积地球化学研究主要集中于几方面:入海河流沉积物的地球化学组成示踪沉积物源区的风化剥蚀特征,河口陆架区沉积地球化学行为;通过大陆边缘的沉积地球化学记录,探讨不同时空尺度河流入海沉积物的通量、搬运扩散方式及其蕴含的季风气候和海区环境演化信息。目前相关研究与国际前沿水平依然存在较大差距,需要从海陆结合的地球系统科学角度,通过地球化学与其他学科方法交叉的研究手段,从整体上研究东亚大陆边缘的沉积过程,揭示从流域到河口、陆架至开阔海的沉积物源汇系统过程和环境演变规律,及东亚大陆边缘沉积和海陆相互作用的全球意义。

The east Asian continental margin is characterized by river-dominated marginal sedimentation,and understanding of its source-to-sink sediment process will significantly improve our recognition on earth surface processes,material cycling and tectonic-sedimentary evolution in continental margins. Thus,sedimentary geochemical studies of the east Asian marginal seas focus on：（ 1） geochemical compositions of river sediments and their indications to the provenance characters including weathering and erosion patterns;（ 2） sedimentary geochemical processes in estuarine and shelf seas;（ 3） sedimentary geochemical records of flux,transport and dispersal of river sediments into seas in continental margins,and monsoon climate and paleoenvironmental changes of marginal seas. A large knowledge gap exists between the international frontier and the present research progress of east Asian continental margin sedimentation,more research efforts could be put on the systematic and multidisciplinary work on the land-sea interaction and sedimentary process in the east Asian continental margin,with special emphases on the sediment source-to-sink transport system from catchments to estuaries and open seas,and on the relating environmental changes driven by natural and anthropogenic forcing. Thus,the global significance of east Asian continental margin sedimentation will be increasingly recognized by the international community.