西北太平洋黑潮源区沉积特征及黑潮输入对东海沉积物的影响

Sedimentary characteristics of the Kuroshio origination area and the influence of the Kuroshio intrusion on sediments of the East China Sea

在对海流和地质背景分析的基础上将源区黑潮划分为3个区域,即北赤道流区、吕宋岛以东海区和台湾东部黑潮主干区,归纳总结了其沉积物矿物组成、元素组分特征和物源研究结论,探讨了黑潮输入对东海沉积物的影响。总体看来,黑潮源区沉积物的主要外来源是菲律宾群岛、菲律宾岛弧、台湾河流输入和亚洲大陆风尘的输入。黑潮源区沉积物矿物分布受菲律宾海沟的阻隔、北赤道流与黑潮的营力作用、海底火山热液活动和水深影响较大,常量元素组成主要与海底地形和水深有关,稀土元素组成表现出具有明显陆源输入的边缘海沉积特征,Sr、Nd同位素组成的研究在该区主要用于追踪亚洲风尘输入。由于黑潮入侵东海多分支的复杂性,东海黑潮对陆架沉积物的影响尚需深入研究。进一步研究应在台湾东部沉积物物源分析、黑潮输入对东海沉积物影响的历史变化、多指标整合的综合分析方法、有效物源识别端元的构建等方面展开。深入研究黑潮源区沉积特征及物源可有效揭示黑潮流域变化、构造活动和气候变化等,且探明黑潮输入对东海陆架沉积物分布的影响有利于揭示东海生态环境变化和海洋资源环境的可持续利用。

In this study, based on its ocean currents and geological background, the Kuroshio origination area are divided into three areas, which are the North Equatorial Current area, the eastern Luzon area and the eastern Taiwan Region. Besides, the mineralogical compositions, elemental compositions and provenance conclusions of sediments in the Kuroshio origination area are summarized, and while the influence of the Kuroshio intrusion on sediments of the East China Sea is discussed. Results suggest that the major exotic sources of sediments in the Kuroshio origination area are from the Philippine Islands, the Philippine Islands Arc, rivers in Taiwan and Asian continent. The sediment mineral distribution in the Kuroshio origination area is mainly influenced by barrier of the Philippine Trench, forces of the North Equatorial Current and the Kuroshio, submarine volcanism and hydrothermal activities and water depth.The major element composition is related to submarine topography and water depth. The rare element composition show marginal sea sedimentary characteristics with obvious terrigenous input. Sr and Nd isotope compositions are mainly used to trace Asian eolian input in this area. Due to the complexity of the multi-branches of the Kuroshio intrusion, the influence of the Kuroshio intrusion on the East China Sea continental shelf sediments need future study. Future researches should be implemented on the sediment origin analysis of eastern Taiwan, historical changes of the Kuroshio intrusion influence on the East China Sea continental shelf sediments, applications of multi-indicators, constructions of effective end members of source identification. It could effectively reveal the variations of the ocean currents, tectonic activities and climate changes in the origin basin of the Kuroshio to study the sedimentary characteristics and origins of the Kuroshio sediments. Meanwhile, to explore the influence of the Kuroshio intrusion on sediments of the East China Sea continental shelf is useful for revealing the ecological changes and sustainable utilization of marine resources and environment in the East China Sea.