| 摘要: |
| 通过对新疆伊犁昭苏黄土剖面微量元素和粒度的测定分析，并与黄土高原黄土进行
对比，揭示了西风区末次冰期以来黄土微量元素地球化学变化特征，探讨了其古气候意义。
分析结果表明，伊犁黄土除Sr 和Cr 元素出现富集外，其他微量元素含量与黄土高原总体具
有较好的相似性，可能表明末次冰期以来伊犁黄土形成环境较黄土高原干旱；伊犁黄土除
Sr、Zn、Co 和Ni 元素含量分布变化比黄土高原稍大外，其他微量元素变化均比黄土高原小
的多，可能意味着末次冰期以来伊犁地区环境变化幅度总体较黄土高原小的多。此外，研究
结果还表明，伊犁黄土Zr 元素主要赋存在粒径>20 μm 的粗颗粒中，暗示着黄土中锆石组分
主要赋存于这种粗颗粒组分中；该剖面微量元素在风化成壤过程中，其迁移性由强至弱依次
为Zr > Y > Sr > Cr > V > Ga > Rb > Ni > Cu > Ba > Th > Zn > Co > U，均出现不同程度的富集，富
集率均较低且变化幅度较小，可能指示末次冰期以来伊犁黄土沉积环境较为干旱且波动变化
较小。 |
| 关键词: 西风区 伊犁黄土 微量元素 地球化学 古环境 |
| DOI：10.7515/JEE201402002 |
| CSTR： |
| 分类号:P595；P532 |
基金项目:国家自然科学基金项目(41172166，41290250)；国家重点基础研究规划项目(2013CB955904)
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| The characteristics of distribution of trace elements and their paleoclimatic implications at the Zhaosu Loess Section in Westerly Area since the Last Glacial Period |
|
LI Chuan-xiang1, 2, 3, 4, SONG You-gui1
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1. Institute of Mountain Hazards and Environment, Chinese Academy of Sciences & Ministry of Water Conservancy,
Chengdu 610041, China; 2. State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment,
Chinese Academy of Sciences, Xi′an 710075, China; 3. Key Laboratory of Mountain Hazards and Surface Process, Chinese
Academy of Sciences, Chengdu 610041, China; 4. University of the Chinese Academy of Sciences, Beijing 100049, China
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| Abstract: |
| Based on trace elements and grain size analysis of Zhaosu loess from Yili basin in
Xinjiang, the authors reveal trace element variation characteristics in the westerly zone since the
last glacial period, and discuss its palaeoclimatic significance. The results show that the content of
other trace elements with the exception of the enrichment of Sr and Cr elements in the Ili loess have
a better consistency with the Chinese Loess Plateau, which may indicate that the environment of
the Ili loess formation was more arid than that of the Chinese Loess Plateau since the Last Glacial
Period. The changes in distribution of contents of Sr, Zn, Co and Ni elements are slightly larger
than that of the Chinese Loess Plateau, and the rest much smaller than it, which suggest that therange of environmental change in the Ili region since the Last Glacial Period was much smaller
than the Chinese Loess Plateau. In addition, the results also imply that the Zr element of the Ili
loess mainly contained in the coarse grain size >20 μm, which may indicate zircon components of
the Ili loess dominatedly enrich in this kind of coarse particle size. In the process of weathering and
pedogenesis, the trace elements migration intensity of Ili loess in the order from strong to weak was
Zr > Y > Sr > Cr > V > Ga > Rb > Ni > Cu > Ba > Th > Zn > Co > U, which there exist different degrees
of enrichment, and small changes in the lower level of enrichment, suggesting that the environment
was more arid and less fluctuating when the Ili loess deoposited . |
| Key words: Westerly area Ili loess trace elements geochemistry palaeoenvironment |
