Origin of the anomalies in light and middle REE in sediments of an estuary affected by phosphogypsum wastes (south-western Spain).
Origin of the anomalies in light and middle REE in sediments of an estuary affected by phosphogypsum wastes (south-western Spain).
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DOI：
10.1016/j.marpolbul.2004.07.009
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发表时间：
2004-12
影响因子：
5.8
通讯作者：
J. Borrego;Nieves López-González;B. Carro;O. Lozano-Soria
中科院分区：
文献类型：
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作者：
J. Borrego;Nieves López-González;B. Carro;O. Lozano-Soria
用ICP-MS分析了14个表层沉积物样品和2个重力岩心样品中Sc、Y、Th、Cu和稀土元素的含量，结果表明，表层沉积物中Sc、Y和Th的平均含量分别为6.23、4.76和16.30ppm，低于上陆壳中的含量。这些沉积物中的铜浓度非常高，为1466 ppm，是由Odiel河和Tinto河的输入造成的，受到酸性矿山排水的影响。ΣREE平均浓度为106.8 ppm，低于其他河流和河口的观测值。在核心，Sc，Y和Th浓度显示出显着增加的中间水平，10和40厘米之间的深度。Cu也存在相同的模式，其浓度可达到4440 ppm。Sc、Y、Cu和重稀土元素的垂向演化规律与Th、轻稀土元素和中稀土元素的垂向演化规律相反，而与重稀土元素的垂向演化规律相似。北美页岩复合（NASC）的稀土元素归一化数据的表层沉积物的情节显示稀土元素浓度略有减少。相对于轻稀土和重稀土，大多数样品表现为中等稀土富集。相反，样品的中间水平的核心表现出显着的富集稀土元素相对于NASC和高值的（La/Gd）NASC和（La/Yb）NASC比值。轻、重稀土元素富集引起的分馏模式异常与高浓度Th有关。它们是由1968年至1998年期间使用磷矿石作为原料的化肥厂的废水产生的。
Sc, Y, Th, Cu and rare earth elements (REE) concentrations have been analyzed in 14 samples of surface sediments and in two gravity cores by means of ICP-MS. Mean concentrations of Sc, Y and Th in surface sediments are 6.23, 4.76 and 16.30 ppm, respectively, lower than those present in the Upper Continental Crust (UCC). Cu concentration in these sediments is very high, 1466 ppm, and is caused by inputs from the Odiel and Tinto rivers, affected by acid mine drainage. ΣREE mean concentration is 106.8 ppm, lower than that observed in other rivers and estuaries. In the cores, Sc, Y and Th concentrations show a significant increase in the intermediate levels, between 10 and 40 cm depth. The same pattern exists with Cu, where concentrations of 4440 ppm can be reached. Vertical evolution patterns for Sc, Y, Cu and heavy REE (HREE) are similar, and contrary to those shown by Th, light REE (LREE) and middle REE (MREE). Plots of North American Shale Composite (NASC)-normalized REE data of surface sediments show a slight depletion in REE concentrations. Most samples present with middle REE enrichment relative to light REE and heavy REE. Conversely, samples of the intermediate levels of the cores show significant enrichment of REE relative to NASC and high values in the (La/Gd)NASCand (La/Yb)NASCratios. These anomalies in the fractionation patterns caused by enrichments in LREE and MREE concentrations is related to the presence of high concentrations of Th. They were generated by effluents from fertilizer factories between 1968 and 1998 which used phosphorite as source material.