南极罗斯海R11柱样晚更新世晚期以来稀土元素地球化学特征

南极大陆边缘沉积物记录着南极及周缘地区海洋沉积与气候变化的重要信息。利用ICP—MS分析技术对取自南极罗斯海的R11柱状样沉积物进行了稀土元素地球化学特征分析。在R11柱样沉积物中，∑REE介于132.33~200.75 μg/g之间，在纵向上呈现波动式变化，体现出了沉积环境的不稳定性；REE含量变化与沉积物细粒组分(粉砂+黏土)和硅质生物碎屑不具有显著相关性；经球粒陨石标准化的REE配分特征表现为轻稀土富集、重稀土相对均一和Eu明显负异常的右倾型，与上陆壳(UCC)和澳大利亚后太古代页岩(PAAS)的配分模式较为接近，揭示R11柱样沉积物来源自晚更新世晚期以来相对稳定，物源区具有大陆性质。综合REE配分模式、富集因子和典型参数等特征分析表明，R11柱样沉积物主要来自于周缘的维多利亚地、横断山脉和玛丽伯德地古老沉积岩石或地层提供的长英质碎屑，新生代火山岩物源贡献相对较低。

REE GEOCHEMICAL CHARACTERISTICS OF CORE R11 IN THE ROSS SEA,ANTARCTIC

The information of marine deposition and climate change is adequately recorded in the continental margin sediments of the Antarctic and adjacent areas. By determining the REE contents in the sediments from Core R11 of the Ross Sea of the Antarctic, the analysis of REE geochemical characteristics are conducted by the authors. The REE fluctuate vertically within a range from 132.33 μg/g to 200.75 μg/g, indicating an unstable depositional environment. The contents of REE are properly correlated neither with fine-grained deposits (silt and clay) nor siliceous bioclastics. The chondrite-normalized REE distribution patterns of the core sediments are characterized by enriched LREE, stable HREE and negative Eu anomaly, which is consistent with the patterns of UCC and PAAS, suggesting a relatively stable continental provenance since Late Pleistocene. It is believed that the sediments is from a kind of felsic rock or/and the strata in Victoria Land, Marie Byrd Land and Transantarctic Mountains around the Ross Sea, and the contribution of the Cenozoic volcanic rocks is relatively low.