长江口南支沉积物元素地球化学分区与环境指示意义  

Study on Geochemical Province of Bottom Sediment Elements From South Branch of the Changjiang River Estuary

作　　者：王国庆[1] 石学法[1] 刘焱光[1] 窦衍光[1] 

机构地区：[1]国家海洋局第一海洋研究所

出　　处：《海洋科学进展》2007年第4期408-418,共11页Advances in Marine Science

基　　金：国家自然科学基金项目--末次冰期以来西北太平洋中高纬度边缘海关键断面古环境演化记录(40431002);我国近海海洋综合调查与评价专项课题--重要三角洲演变规律及重大事件的沉积记录与可持续发展研究专题(908-02-02-05);青岛市科技将才专项计划项目--西北太平洋中;高纬度边缘海古环境演化及其对青岛近海黄海海域矿产资源的影响(05-2-JC-79)

摘　　要：对采自长江口南支的130个表层底质沉积物样品采用X射线荧光光谱法进行了20种常、微量元素的地球化学分析。在此基础上,应用系统聚类法对该区域进行了元素地球化学分区。研究结果表明,研究区主要可以分为两大地球化学分区:Ⅰ区以相对富集SiO2,Sr,Zr元素为典型特征,主要涵盖5 m等深线以浅的长江三角洲前缘区;Ⅱ区以相对富集Al2O3,TFe2O3(全铁),MgO,Pb元素为典型特征,涵盖了前三角洲的广大区域。从地球化学分区的空间分布来分析,这两个分区元素之间的差异反映的是沉积水动力条件与沉积介质物化性质这两个环境要素空间分布的差异性,即在研究区内,表层沉积物元素地球化学空间分布的差异性实质上反映了沉积环境空间分布的差异性。The X-ray fluorescence spectrometry was used to make a geochemical analysis of 2 macroelements and microelements in 130 surface sediment samples from the south branch of the Changjiang River estuary, and the system cluster analysis was then used to make an element geochemical province for the sea area. It is shown from the study results that the study area can be classified into two geochemical provinces, province Ⅰ is characterized by comparatively concentrated SiO2 ,Sr and Zr elements in the surface sediments, and covers mainly the Changjiang River delta front in 5 m of water or less; province Ⅱ is characterized by comparatively concentrated Al2O3, TFe2O3 ,MgO and Pb elements in the surface sediments, and covers an extensive area of the Changjiang River prodelta. As viewed from the spatial distributions of geochemical provinces, the difference in element contents in the two geochemical provinces reflects the difference in spatial distributions of environmental factors including sedimentary hydrodynamics and physicochemical properties of sedimentary media, that is,the difference in the spatial geochemical distributions of surface sediment elements substantially reflects the difference in spatial distributions of sedimentary environments.

关 键 词：长江口 元素地球化学 沉积环境 系统聚类分析法 

分 类 号：P736.21[天文地球—海洋地质]