Variations in trace element (including rare earth element) concentrations with grain sizes in loess and their implications for tracing the provenance of eolian deposits
Variations in trace element (including rare earth element) concentrations with grain sizes in loess and their implications for tracing the provenance of eolian deposits
复制标题
黄土中微量元素（包括稀土元素）浓度随粒径的变化及其对风积物物源追踪的意义
DOI：
10.1016/j.quaint.2010.04.024
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发表时间：
2011-05-01
影响因子：
2.2
通讯作者：
Zhu, Li-Ping
中科院分区：
文献类型：
--
作者：
Feng, Jin-Liang;Hu, Zhao-Guo;Zhu, Li-Ping
对青藏高原、四川盆地和黄土高原的4个黄土样品的7个粒级中稀土元素和其它28种微量元素的含量进行了测定。结果表明，稀土元素的浓度，除了重稀土元素（HREE），几乎是粒度无关的。然而，稀土元素表现出明显的分馏与粒度。中稀土元素（MREE）亏损增加，而减少粒度的HREE富集增加。除稀土元素和钇外，大多数其他微量元素的浓度往往随着粒度的减小而增加。微量元素地球化学特征表明，四川盆地、黄土高原和青藏高原的风成沉积物可能的物源不同。这一对比研究证实了亚洲大陆风尘物质是北太平洋中部沉积物中陆源成分的来源，而中国黄土高原的黄土可以代表亚洲大陆风尘物质的平均组成。而四川盆地和青藏高原的风成沉积则主要是本地成因，具有短距离的风成搬运作用。(C)2010 Elsevier Ltd和INQUA。All rights reserved.
The concentrations of rare earth elements (REEs) and other 28 trace elements were determined in seven grain-size fractions from four loess samples collected from the Tibetan Plateau, the Sichuan Basin and the Chinese Loess Plateau. The results indicate that concentrations of REEs, except for heavy rare earth elements (HREEs), are almost grain-size independent. However, REEs show clear fractionation with grain size. Middle rare earth element (MREE) depletion increases with decreasing grain size, whereas HREE enrichment increases with decreasing grain size. Excluding REEs and Y, most of the other trace element concentrations tend to increase with decreasing grain sizes. The trace element geochemistry indicates that the potential sources of eolian deposits from the Sichuan Basin, the Chinese Loess Plateau and the Tibetan Plateau differ from one another. This comparative study confirmed that the eolian materials from the Asian continent are the source of the terrigenous component of the central North Pacific sediments, and the loess from the Chinese Loess Plateau could represent the average composition of eolian dust from the Asian continent. In contrast, the eolian deposits in the Sichuan Basin and in the Tibetan Plateau are mainly of local origin, with short-distance eolian transport. (C) 2010 Elsevier Ltd and INQUA. All rights reserved.