庙岛群岛西部海域表层沉积物常量和稀土元素的分布特征及其物源指示意义

通过对庙岛群岛西部海域表层沉积物常量、稀土元素的系统研究，探讨了表层沉积物元素地球化学特征、控制因素及其物质来源。结果表明，庙岛群岛西部海域表层沉积物常量元素以SiO₂和A1₂O₃为主，SiO₂含量随着沉积物粒径变粗逐渐增大，Al₂O₃含量随着沉积物粒径变细逐渐增大。稀土元素(Rare Earth Element,REE)呈现轻稀土元素(Light Rare Earth Element,LREE)富集、重稀土元素(Heavy Rare Earth Element,HREE)平坦以及中等程度的Eu负异常等特征，轻重稀土分异明显，稀土元素球粒陨石配分曲线与黄河沉积物类似。通过因子分析和相关性分析发现研究区沉积物的元素含量主要取决于陆源碎屑，海洋生物沉积和化学作用对沉积物元素含量有一定的影响，元素含量基本服从粒度控制规律。物源判别结果显示，庙岛群岛西部海域沉积物主要来源于黄河物质和辽河物质，并且从南到北辽河物质的混合比例逐渐升高，黄河物质的混合比例逐渐降低。

Distribution features of major elements and rare earth elements of the surface sediments in the western Miaodao Archipelago and their provenance implications

Based on the systematic study of major elements and rare earth elements (REEs) of the surface sediments in the western Miaodao Archipelago, we discussed the geochemical characteristics of REE and the controlling factors and provenance of the surface sediments in the study area. The results show that SiO2 and Al2O3 are the main major elements of the surface sediments in the western Miaodao Archipelago. The content of SiO2 gradually increases with the coarsening sediment grain siz. In contrast, the content of Al2O3 gradually increases with the decreasing sediment grain size. REEs are characterized by the enrichment of light rare earth elements (LREE), flatten heavy rare earth elements (HREE), and moderate negative Eu anomaly. The light and heavy rare earth elements are obviously differentiated. The chondrite-normalized REE distribution pattern is similar to that of the Yellow River sediments. Our factor analysis and correlation analysis indicated that the element contents of surface sediments in the study area are mainly determined by terrigenous detritus, and to some extent influenced by marine biological deposition and marine chemical action. In general, the element contents are basically controlled by the grain size of sediments. The results show that the sediments in the western Miaodao Archipelago are derived from the Yellow River sediments and Liaohe River sediments. And the mixing proportions of the Liahe River sediments gradually increase from south to north, while that of the Yellow River sediments gradually decrease.