长江每年输送大量的泥沙进入东海，其中细颗粒沉积物具有搬运距离远、扩散范围大的特点，成为示踪河口及近海沉积物源汇过程的良好载体。本文基于采自长江口及邻近海域的44个表层沉积物样品，分析了细颗粒组分中重金属的空间分布和沉积通量，探讨了重金属来源和搬运沉积过程。研究表明：长江口及邻近海域细颗粒沉积物中 Cu、Cr、Ni、V 和 Zn 含量、沉积通量的空间分布具有高度的相似性，总体表现为长江口及浙闽沿岸高，向外急剧降低；该区细颗粒沉积物中的重金属主要来自长江，入海后向两个方向扩散，其一为向西南方向扩散，沉积于内陆架泥质区；其二是向东的跨陆架输送，沉积于长江冲淡水影响的海域。从长江口向西南方向的输送和沉积是长江入海重金属最重要的汇。%The Changjiang River discharges large amounts of fine-grained sediments into the East China Sea (ECS) each year.Fine-grained sediment transports far distance and spreads widely when it enter the continental shelf, which makes it an excellent archive to explore the source to sink of sediment from river to continental shelf.In this paper,the ICP-AES method was used to determine the concentration of heavy metals of fine-grained surface sedi-ments of 44 samples collected in the Changjiang Estuary and its adjacent areas.The spatial distribution patterns, sedimentary fluxes,and source to sink of these elements were discussed.The results show:(1)the spatial distri-bution patterns and sedimentary fluxes of heavy metals in the area are similar,which have high values in the Changjiang Estuary and the inner mud shelf,decreasing dramatically in southeastern direction;(2)The heavy met-als in the fine-grained sediments in the study areas mainly originate from the Changjiang River;then they disperse in two ways,one along the inner shelf outside the Zhe-Min coast,the other along the Changjiang River diluted wa-ter spreading area and into the outer continental shelf.Our results suggest that the sub-aquatic Changjiang River delta and the inner shelf of ECS are dominant sinks for the heavy metals from the Changjiang River.
展开▼
