辽东湾东南部海域柱状沉积物稀土元素地球化学特征与物源识别
摘要: 对辽东湾东南部海域LDC30孔沉积物稀土元素（REE）、粒度等指标进行了分析，研究了其沉积物中稀土元素组成特征及其控制因素，并对其物质来源进行了探讨。结果表明，LDC30孔沉积物ΣREE平均值为149.49 μg/g，略高于黄海和东海，但是低于渤海和南海，并且低于全球沉积物ΣREE的平均值。研究区沉积物REE配分模式表现为明显的轻稀土富集、重稀土相对亏损；δEu的平均值为0.71，为中度亏损，δCe无异常；轻稀土与重稀土之间的分异作用较强，且轻重稀土内部分异明显。根据沉积物REE垂向变化特征，可将LDC30岩芯以51cm为界划分为两段，上段（0~51 cm）ΣREE含量随着深度的减小而呈增加的趋势，下段（51~99 cm）ΣREE含量在垂向上没有明显的波动变化，并且上段较下段稀土分异明显。δCe整体上比较稳定，但是在上段（0~51 cm）呈现下降的趋势。δEu垂向上也相对稳定的趋势。该孔沉积物REE参数与粒度之间无明显的相关性，REE组成不受粒度的控制，但重矿物对REE的组成和分布状况有重要的影响。LDC30孔沉积物物质来源比较稳定，并且具有强烈的陆源特征，其沉积物主要来源于辽东湾北部河流（大辽河、小凌河、双台子河等），同时辽东湾西部河流滦河可能对LDC30孔上段沉积物有一定贡献。
REE Geochemical Characteristics and Provenance Discrimination of Core LDC30 in the Southeastern Part of Liaodong Bay
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.
辽东湾东南部海域柱状沉积物稀土元素地球化学特征与物源识别[J]. 沉积学报, 2014, 32(4): 684-691.
| 引用本文: |
辽东湾东南部海域柱状沉积物稀土元素地球化学特征与物源识别[J]. 沉积学报, 2014, 32(4): 684-691.
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REE Geochemical Characteristics and Provenance Discrimination of Core LDC30 in the Southeastern Part of Liaodong Bay[J]. Acta Sedimentologica Sinica, 2014, 32(4): 684-691.
| Citation: |
REE Geochemical Characteristics and Provenance Discrimination of Core LDC30 in the Southeastern Part of Liaodong Bay[J]. Acta Sedimentologica Sinica, 2014, 32(4): 684-691.
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