青藏高原上的高山作用(包括冰川研磨作用、山体剥蚀作用、山前冲洪积作用等)形成大量松散砂质物质就近分布于青藏高原及周边地区,这成为亚洲粉尘的源区之一,通过对青藏高原部分典型砂质表土样品的稀土元素特征的初步分析,结果表明:青藏高原砂质表土稀土元素特征主要受原岩性质的控制,同时在不同程度上受到风化作用的影响;其稀土含量变化较大,温暖湿润的藏南地区稀土含量较高,气候寒冷干燥地区则相对偏低;稀土元素的球粒陨石标准化分布模式与现代上地壳和中国黄土的稀土元素分布模式相似,均表现为轻稀土富集,Eu相对亏损的模式。
Mountain processes (including glacial grinding, hill-slope erosion, and fluvial deposition) on the Tibetan Plateau produced amounts of sand-and silt-like materials that was thought to be the main source for Asian dust. In this paper, the preliminary study results are presented on the rare earth elements (REE) from surface sand soils sampled on the Tibetan Plateau and adjacent regions and their patterns are compared with the loess and upper continental crustal (UCC). REE content,which is mainly caused by its parent rock and partly by weathering, varies largely in different sites, with the highest value in southern Tibetan Plateau where it is warm and humid. Chondrite-normalized REE distribution pattern, enrichment in LREE, and negative Eu anomaly closely resemble to those in loess regions and UCC showing that the Tibetan Plateau is a potential source area for Chinese loess deposition.