胶州湾表层沉积物黏土矿物分布特征及物源分析

Clay mineral assemblages and provenance in the surface sediment of Jiaozhou Bay

利用X射线衍射(XRD)对胶州湾150个站位表层沉积物的黏土矿物组成及含量进行分析,研究了胶州湾表层沉积物黏土矿物的分布特征及其物质来源。结果表明,胶州湾表层沉积物中黏土矿物组成主要是伊利石(65.1%)和蒙脱石(17.1%),其次是绿泥石(9.0%)和高岭石(8.8%)。在空间分布上,伊利石含量表现为西侧高、东侧低,高值区主要分布在大沽河、洋河口外两侧;蒙脱石含量高值区分布于胶州湾东北部、大沽河口东侧和湾口附近;绿泥石含量表现为东侧高、西侧低,且高值区整体呈条带状分布;高岭石含量表现为斑状分布,规律性不明显。黏土矿物物源分析表明,大沽河、洋河等入海河流所携带的陆源物质是胶州湾的主要物质来源,其中,大沽河是胶州湾沉积物中伊利石、蒙脱石和高岭石的主要物源,绿泥石则是大沽河、李村河及胶州湾东侧沿岸物质侵蚀风化产物共同作用的结果。

The content and composition of clay minerals from 150 surface sediment samples obtained in 2019 from the Jiaozhou Bay,Qingdao,East China were analyzed using XRD.The distribution characteristics and sedi-ments resources were discussed.Results show that illite(65.1%)dominated in the surface sediments,smectite(17.1%)ranked the second,followed by chlorite(9.0%)and kaolinite(8.8%).On the spatial scale,the illite con-tents were higher in the west and lower in the east,and the higher value areas were mainly distributed near the mouths of Dagu River and Yanghe River.Smectite contents were higher in the northeast;chlorite contents were higher in the east and lower in the west area,and the higher area of chlorite showed a zonal distribution.The high-er distribution of kaolinite was patchy and the regularity was not obvious.Provenance analysis showed that ter-restrial materials carried by inflow rivers were the main material sources,including Dagu,Yanghe,and Nanjiaolai Rivers.Besides,the Dagu River was the main provenance of illite,smectite and kaolinite,while chlorite was jointly from the Dagu River borne materials and the erosion product of coastal materials.