REE Geochemical Characteristics and Provenance Discrimination of Core LDC30 in the Southeastern  Part of Liaodong Bay

Key words: 
• Liaodong Bay /
• rare earth element /
• provenance

Abstract: In this study, rare earth elements (REEs) and grain size of Core LDC30 sediments taken from the southeastern Liaodong Bay have been analyzed to investigate the sediment elemental compositions, controlling factors and the provenance. The total content of rare earth elements of Core LDC30 is in average of 149.49 μg/g, slightly higher than the Yellow Sea and the East China Sea, but lower than the Bohai Sea, the South China Sea, and the average value of the global sediments. The REE patterns show significant enrichment in light REEs, with HREE relatively loss. The mean value of Eu is 0.71 which is in the scope of intermediate negative Eu abnormal, δCe is without anomalies. And the fractionation between light and heavy REEs is obvious. REEs concentrations of core sediments vary greatly in vertical profiles, LDC30 is divided into two sections by 51 cm. In the upper part (0~51 cm), REEs concentrations fluctuate more obvious than the underpart (51~99 cm),and the upper part REEs contents show an increasing trend with depth decreasing, while the underpart doesn't present a significant fluctuation in vertical. Besides that, the REE fractionation in the upperpart is more obvious than the underpart. δCe as a whole is relatively stable, but in the upper section shows a downward trend. δEu is being stable in vertical. The correlation between REE parameter and grain sizes is not obvious. But heavy minerals exert an important influence on REEs composition and distribution. The source of LDC30 sediments is relatively stable and shows strong terrigenous characteristics. Discrimination plots based on REE fractionation parameters suggest that the cored sediments originated mostly from the northern part rivers (Liaohe River, Xiaoling River, Shuangtaizi River) of the Liaodong Bay, and Luan river in the western part of Liaodong Bay has a certain contribution to the upper part of Core LDC30.