印度洋热液区贻贝及栖息沉积物中金属元素的特征分析

Characteristics Analysis of Metal Elements in Sediments and Habitat Mussels from India Ocean Hydrothermal Area

本研究采集了印度洋热液区贻贝生物及其栖息沉积物样品,分析了生物体及沉积物中常见微量元素及稀土元素的含量与分布特征,研究了生物体与沉积物金属元素的相关性,以及稀土元素的生态化学特征等。结果表明:印度洋热液区沉积物中常见微量金属主要为Fe(96.62 mg/kg)、Mn(1.143 mg/kg)和Zn(322.6μg/kg),微量元素归一化计算得Fe含量比值高达98.15%,可获悉该热液区沉积物主要为铁矿类物质。深海贻贝中微量元素及稀土元素的分布趋势与深海沉积物中元素分布存在较好的相关性,相关性系数分别为0.991与0.996,近海贻贝中金属元素的含量及分布与深海贻贝存在差异性。深海沉积物与贻贝中轻重稀土元素均呈现分馏现象,且贻贝中富集轻稀土比较显著;从稀土配分模式可知,沉积物与贻贝中的Eu与Gd均呈现异常现象,深海沉积物和深海贻贝中Eu异常现象较为显著。深海沉积物、贻贝及近海贻贝中δEu分别为9.50、10.68和0.23,而δCe分别为2.21、2.71和4.38,表明近海贻贝中稀土元素富集来源与深海贻贝存在差异性,深海沉积物与深海贻贝稀土元素具有同源性。

The concentrations and distributions of trace metals and rare earth elements（ REE） in sediment and mussel samples collected from the India Ocean hydrothermal area were analyzed. The metal correlation between organisms and sediments was investigated,and the ecological and chemical characteristics of REE were also explored. The results showed that,the trace metals in sediments were mainly Fe（ 96. 6 mg/kg）,Mn（ 1. 14 mg/kg） and Zn（ 322. 6 μg/kg）,and Fe had high ratio of 98. 15% by normalized calculation,which indicated that the available sediments in this studying hydrothermal area mainly consisted of iron ore substances. Trace metals and REE distributions all had good correlation between deep-sea sediments and deep-sea mussels,and the correlation coefficients were 0. 991 for trace metals and 0. 996 for REE. The contents and distributions of metal elements in deep-sea mussels were different from those in offshore mussels.The REE distributions in sediments and mussels showed obvious fractionation phenomenon, and the enrichment of LREE in mussels was significant. Through the REE patterns,Eu and Gd in sediments and mussels all showed anomalies,and Eu had a significant abnormal phenomenon in deep-sea sediments and deep-sea mussels. Besides,δEuvalues were 9. 50,10. 68 and 0. 23 in deep-sea sediments,deep-sea mussels and offshore mussels,respectively,and δCewere 2. 21,2. 71 and 4. 38,which showed that the enrichment sources of REE in offshore mussels and deep-sea mussels were different,and the REE in sediments and mussels from the India Ocean were homologous.