REEs fractionation and sedimentary implication in surface sediments from eastern South China Sea

To get features of rare earth elements （REEs） fractionation, 106 surface sediment samples from eastern South China Sea were determined for REEs combined with major and trace elements by ICP-MS. The distribution pattern of REEs, strong correlation between REEs and Al, North American shale composite （NASC） normalization all suggest a dominant crustal source for REEs in the research area. However distinct fractionation among REEs was observed in surface sediment from area with water depth over 2000 m, confirmed by the strong positive correlation among light rare earth elements （LREEs） and among heavy rare earth elements （HREEs） but weaker relationship between LREEs and HREEs. Eluviation by Cl- might be a key role on the fiactionation of REEs, comparing with factors such as grain size, co-precipitation with Fe and Mn hydroxide, calcareous and siliceous biogenic precipitation. The fractionation among REEs could be used as index to illustrate the sedimentary environment in reverse.

南海珠江口东部海底沉积物腐蚀性研究

总结了1994年在南海东部石油开发区及毗邻近岸海区开展的海底沉积物和海水共17个环境因子大面积调查研究的成果。文中探索性地提出一套适合于南海亚热带海区海底沉积物腐蚀性评价的方法，并根据调查和评价的结果评定出本海区各测站海底沉积物的腐蚀性等级。