中国东部海域泥质沉积区现代沉积速率及其物源控制效应初探  

Modern Sedimentation Rate,Budget and Supply of the Muddy Deposits in the East China Seas

作　　者：李军[1,2] 胡邦琦[1,2] 窦衍光[1,2] 赵京涛[1,2] 李国刚[3] 

机构地区：[1]国土资源部海洋油气资源与环境地质重点实验室,山东青岛266071 [2]青岛海洋地质研究所,山东青岛266071 [3]国家海洋局北海海洋工程勘察研究院,山东青岛266033

出　　处：《地质论评》2012年第4期745-756,共12页Geological Review

基　　金：国家自然科学基金资助项目(编号40976036、40506013、40906033)的成果

摘　　要：中国东部陆架(渤、黄、东海)是欧亚大陆和太平洋之间的一个重要物质交换通道,其周边的河流每年向海输入了大量的细颗粒沉积物。这些物质在海洋动力(潮流、波浪、环流等)的作用下形成了多个泥质沉积区(带)。过去的数十年间,国内外学者对东部陆架海沉积物扩散和沉积动力机制进行了深入的研究,但是,目前对陆架泥质沉积的形成机制以及沉积物收支情况还存在争议。本文利用整理的现代沉积速率资料,从物源控制的角度出发,研究了各泥质沉积区10～100a尺度的沉积速率和沉积通量的分布规律,并与全新世泥质沉积记录进行对比,指出物源是控制这些泥质沉积形成的主要因素。河流携带入海物质是这些泥质沉积的主要"源",而这些泥质区是典型的"汇"。小型河流河口沉积过程和物质贡献需引起重视。定量化物源分析需结合物源供应等方面的资料,在遵守沉积物收支平衡的前提下进行。The East China Seas （Bohai, Yellow, and East China seas） （ECSs）, an important linkage between the global largest continent （Eurasia） and the ocean （ Pacific ）, annually received more than 1.7 billion tons of sediment from the adjacent rivers. These huge amounts of fine-grained material, combined with the effects of tide, wave/storm and current, contributed to several muddy depositional areas in the broad and shallow shelf of ECSs. During the last several decades, many papers have been released and focused on sediment dispersal and sediment dynamics in the ECSs shelf. However,little is known relevant to the modern sedimentation flux （SF） and budgets in this large continental marginal sea system. In this study, on the basis of a number of 137Cs and 21~Pb-derived sediment accumulation rate （SR） data,we firstly evaluated the modern SR and SF over the entire muddy areas of the ECSs shelf, and then calculated a sediment budget for the muddy areas of ECSs shelf to assess whether the sediment mass （input from rivers vs. accumulation flux） is balance or not. We also compared the Modern and Holocene sediment accumulation rates （millennial - scale ） in different muddy areas. The results show that sediment source is a dominant factor controlling the formation of these muddy areas of the ECSs shelf. The sediment delivered by adjacent rivers is the major sediment source, whereas the muddy areas of the ECSs shelf are typical sediment sink. We emphasized the role of small rivers in the sedimentary process of the local river estuaries and its contribution to the muddy areas. A quantitative sediment provenance study should be conducted by considering constrains of sediment source and sediment mass balance.

关 键 词：泥质沉积 现代沉积速率 物源供应 沉积物收支平衡 中国东部海域 

分 类 号：P736.21[天文地球—海洋地质]