长江口外海域表层沉积物微量元素地球化学特征

Geochemical Characteristics of Trace Elements in the Marine Surface Sediments Outer Yangtze River Estuary

对采自长江口外海域187个表层沉积物的25个微量元素含量进行了标准差系数、相关分析及R型因子分析,探讨了微量元素的来源和分布特征。长江口外海域沉积物微量元素Li、V、Cr、Co、Ni、Ga、Cu、Zn、Th和Rb分布基本相似;Sr分布与Li、Cu、Pb、Zn、Th和Rb相反;研究区东南部Sr分布与生物作用有明显关系;Cd和Mo分布与粒度之间的相关性较差,主要受氧化还原环境的控制;Zr分布反映了长江物源的影响。相关分析和R型因子分析结果表明,沉积作用、粒度控制效应、海洋生物作用、氧化还原环境和源区地质背景等对长江口外海域表层沉积物中微量元素分布起着主要控制作用。

This study analyzed the abundance of 25 trace elements in 187 pieces of marine surface sediments outer Yangtze River estuary using correlation analysis and R-mode factor analysis,and discussed the variation coefficient,and the source and distribution characteristics of trace elements in the sediments.Elements of Li,V,Cr,Co,Ni,Ga,Cu,Zn,Th and Rb have similar distributions,whereas Sr is negatively correlated with elements of Li,Cu,Pb,Zn,Th and Rb.The distribution of Sr in the southeast part of the study area reveals a clear link to source materials related to the biogenic process,whereas the distribution of Zr reflects the influence of materials from Yangtze River.The distributions of Cd and Mo are not obviously correlated with the type and granularity of sediments,but are mainly controlled by redox environment.The results of correlation analysis and R-mode factor analysis show that the sedimentation,grain size effect,marine biogenic process,redox environment and geological background of the source area play a dominant role in controlling the distribution of the contents of trace elements in marine surface sediments outer Yangtze River estuary.