黄河沉积物向渤海湾扩散的沉积地球化学示踪

The Sedimentary Geochemical Trace of the Yellow River Sediments Diffusion in the Bohai Bay

使用ICP-AES和ICP-MS对渤海中部118°54′E左右南北向断面的表层沉积物中53种常、微量及稀土元素进行了测试,研究了其含量变化和分布特征,并进行了物质组成分析。研究表明:该区沉积物以B94站为界,南北差异明显,南部区域沉积物以黏土质粉砂为主,富集Al2O3,CaO,Fe2O3,MgO,MnO,P2O5和TiO等常量元素以及绝大多数的微量元素和稀土元素等与细颗粒黏土矿物相关的元素;北部区域沉积物以粉砂-砂为主,富集SiO2,K2O和Na2O等常量元素以及Zr,Ba,Sr,Sb和Hf等微量元素,稀土元素相对亏损。物源对比表明南部沉积物具有黄河来源沉积物特点,北部沉积物具有滦河来源特点,两者的分界大致在38°42′N附近。河口动力过程、渤海环流是影响该区沉积物扩散的主要因素。

The 53 major, trace elements and REEs of the surface sediments collected near 118°54′ E in the central Bohai Bay were tested using ICP-AES and ICP-MS. Their contents, spatial distributions and the sediment compositions were analyzed. The results showed that the sediments in studied area were quite different between the north and south regions with B94 station as a boundary. In the southern region, sediments were mainly clayey silt enriched in Al2O3, CaO, Fe2 O3, MgO, MnO, P2O5, TiO and the vast majority of the trace elements and rare earth elements associated with the fine particles of clay minerals. Meanwhile, the northern region was mainly the silt-sand sediments enriched in the major elements of SiO2, K2O, Na2O and the trace elements of Zr, Ba, Sr, Sb, Hf etc. , and was relatively deficit in REEs. The comprehensive provenance analysis showed that, the southern region sediments were mainly affected by the Yellow River sediments, while the sediments in the north region were mainly come from the Luanhe River. The boundary was roughly near 380421 N. The estuarine dynamic process and the circulation in Bohai sea is the main factor affecting the sediment diffusion in this area.