塞舌尔群岛东北部海域现代沉积物黏土矿物特征及来源分析  

Sources and transport of clay mineral in surface sediments of the sea of northeastern Seychelles Islands

作　　者：武佳星 刘升发 曹鹏 张辉 黄牧 刘焱光 石学法 Wu Jiaxing;Liu Shengfa;Cao Peng;Zhang Hui;Huang Mu;Liu Yanguang;Shi Xuefa(Key Laboratory of Marine Geology and Metallogenesis,Ministry of Natural Resources,The First Institute of Oceanography,Ministry of Natural Resources,Qingdao 266061,China;Laboratory for Marine Geology,Pilot National Laboratory for Marine Science and Technology(Qingdao),Qingdao 266061,China)

机构地区：[1]自然资源部第一海洋研究所自然资源部海洋地质与成矿作用重点实验室,山东青岛266061 [2]青岛海洋科学与技术试点国家实验室海洋地质过程与环境功能实验室,山东青岛266061

出　　处：《海洋学报》2023年第6期160-170,共11页

基　　金：全球变化与海气相互作用专项(GASI-01-WIND-CJ01)。

摘　　要：本文基于塞舌尔群岛东北部海域34个表层沉积物样品的黏土矿物测试结果分析其组成特征、分布规律和物质来源。研究区表层沉积物中黏土矿物平均相对含量从高到低依次为伊利石(35%)、坡缕石(20%)、蒙皂石(20%)、高岭石(16%)、绿泥石(10%)。根据沉积物黏土矿物相对含量和空间分布规律,可将研究区分为2个亚区(I区、II区)。I区覆盖研究区北部大部区域,物质来源主要为阿拉伯半岛、印度半岛西南部以及索马里海岸沙漠的风尘物质;II区位于研究区南部的塞舌尔群岛以东,主要接收塞舌尔高原风化物质。综合分析研究区细颗粒物质来源、空间分布规律及区域动力环境特征,南亚夏季风搬运阿拉伯半岛、印度西部及索马里海岸沙漠风尘物质向南输运是影响I区黏土矿物组成的主要因素;南赤道逆流驱动塞舌尔高原富高岭石、绿泥石的细粒风化物质向东扩散,控制了II区黏土矿物组成特征和空间分布规律。The relative contents of clay minerals in 34 surface sediment samples were analyzed by X-ray diffraction.The results showed that the content of clay minerals in the surface sediments was illite(35%),palygorskite(20%),smectite(20%),kaolinite(16%)and chlorite(10%).Q-cluster analysis using SPSS software shows that clay minerals can be divided into two provinces(Province I and Province II).Province I covers most of the northern area,and the source is mainly the dust influx from the deserts of Arabian Peninsula,western India and Somali coast;Province II is located at the southwest of the study area,mainly receiving the weathering matters from the granite bedrock of Seychelles Plateau.A comprehensive analysis of the sources of fine particulate matter in the study area and the regional dynamical environment reveals that the southward transport of the aeolian dust from the Arabian Peninsula,western India and the Somali coastal deserts by the South Asian summer monsoon controls the composition of clay minerals in the Province I.The south equatorial low latitude ocean current system promotes the meridional diffusion of fine particles in the study area.The southern Equatorial Counter Current drives the eastward diffusion of kaolinite and chlorite-rich fine materials from Seychelles Plateau.

关 键 词：沉积物 黏土矿物 物源 季风 洋流 西印度洋 

分 类 号：P736.21[天文地球—海洋地质]