鸭绿江河口及近岸地区稀土元素的物源指示意义

通过对鸭绿江河口及近岸地区所采集的沉积物样品,分析研究了该地区沉积物REE的组成特征及分异模式,确立其地球化学参数,探讨了它的物源指示意义。结果显示,鸭绿江沉积物的REE总量较高,其REE组成分异特征与世界其他大河相类似,LREE富集,而HREE相对亏损;源岩是控制该区沉积物REE组成特征的主要因素,风化作用、粒度与重矿物等因素对其影响相对较弱;鸭绿江沉积物REE组成相对上陆壳分异很弱,表明沉积物来源于上游源岩的风化产物;此外,其REE组成/分布模式及分异参数与长江、黄河较为接近,而与韩国一些河流相差较大,因此,可作为鸭绿江入海物质组成代表,指示黄海海洋陆源沉积物物质组成。

IMPLICATIONS OF REE FOR PROVENANCE IN THE YALU ESTUARY AND ITS ADJACENT SEA AREA

In this paper, rare earth elements (REE) composition and their differentiation patterns are stu-died,geochemical parameters established, and the significance of its provenance implications discussed for the sediments in the Yalu River Estuary and coastal waters. Results show that the total REE of the sediments is high, and the REE composition and differentiation patterns are similar to those of other rivers in the world. LREE are enriched and HREE deficient;the distribution patterns of REE are mainly controlled by source rocks, and factors,such as weathering, grain size and heavy minerals are subordinate;the differentiation of REE composition in the sediments of Yalu River is much weaker than that in the continental crust,so it can be used to represent the average composition of the continental crust. In addition, the REE composition of the sediments in the Yalu Estuary is consistent with the figure from Changjiang and Yellow rivers and different with those from the rivers of Korea. Its differential parameter is similar to the rivers in China,but different with the rivers in Korea. Therefore,the REE composition of the sediments from the Yalu Estuary,may indicate the materials from the hinterland,and be used as a repsesentative of the chemical composition of the terrigenous sediments doposited offshore.