| 引用本文: | 李金婵,陈秀玲,贾丽敏,李志忠.2014.新疆伊犁河谷沙漠沉积不同粒径组分的地球化学元素分布特征[J].地球环境学报,(2):102-110 |
| LI Jin-chan,CHEN Xiu-ling,JIA Li-min,LI Zhi-zhong.2014.The distribution of geochemical elements in different grain-size fractions of desert sediments in Ili Valley of Xinjiang, China[J].Journal of Earth Environment,(2):102-110 |
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| 摘要: |
| 本文通过对伊犁河谷西部塔克尔莫乎尔沙漠内的可克达拉（TKP）剖面典型层位样品
的不同粒级组分地球化学元素分析，探究西风环流控制的沙漠沉积区元素特征和化学风化指标
在不同粒级组分中的分布特征。研究结果表明TKP 剖面Na 和Sr 元素趋向于在粗粒级中富集；
Fe、Mg、Al、Rb 元素趋向于细粒级中富集，K 元素含量随粒径增大先升高再降低，16 ~ 32 μm 粒
级处出现谷值；Ti 元素含量与粒度关系不明确。CIA、Rb/Sr 随粒级增大逐渐降低，Na2O/Al2O3、
Na2O/K2O、K2O/Al2O3 随粒级增大逐渐升高。TKP 剖面地球化学元素和比值在<2 μm、2~16 μm、
16 ~32 μm 细粒级组分不同粒级间变化较为剧烈，32~ 63 μm、63~125 μm、>125 μm 粗粒级组分
变化则不明显，而且粗粒级组分在剖面中的变化也比较稳定。剖面整体风化程度较弱，因此这
种现象可能是物源不统一造成的，为塔克尔莫乎尔沙漠具有物源多样性特点的观点提供了地球
化学元素方面的证据。 |
| 关键词: 不同粒级 主量元素 Rb/Sr 比值 物质来源 塔克尔莫乎尔沙漠 |
| DOI：10.7515/JEE201402007 |
| CSTR： |
| 分类号:P595 |
基金项目:国家自然科学基金项目(41302149，41172166)；黄土与第四纪地质国家重点实验室开放基金(SKLLQG1103，
SKLLQG1113)；中科院科技创新交叉与合作团队资助项目；福建省科技计划项目公益类项目(K3-296)
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| The distribution of geochemical elements in different grain-size fractions of desert sediments in Ili Valley of Xinjiang, China |
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LI Jin-chan1, 2, CHEN Xiu-ling1, 2, JIA Li-min1, 2, LI Zhi-zhong1, 2
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1. Key Laboratory for Subtropical Mountain Ecology ( Ministry of Science and Technology and Fujian Province Funded ),
School of Geographical Sciences, Fujian Normal University, Fuzhou 350007, China; 2. State Key Laboratory of Loess and
Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an 710075, China
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| Abstract: |
| Previous studies have found that there is correlation between the distribution of minerals
in whole rock samples and grain size, which makes great influence on chemical weathering proxies.
Therefore the influence of grain size should be taken into consideration when using geochemical proxies.
In this study, we analyze geochemical elements of representative samples in Kekdala section (TKP) in
Takelmukul Desert, Ili valley, Xinjiang and explore the distribution character of geochemical elements
among different grain size fractions in westerly region. The results show that the concentrations of
Na and Sr increase as the enlargement of size fraction, while Fe, Mg, Al, and Rb concentrations show
the opposite phenomenon. K concentration decreases at first and then increases with the grain size
increasing, and the lowest value exists in size 16~32 μm. CIA, Na2O/Al2O3, Na2O/K2O, K2O/Al2O3 and
Rb/Sr vary regularly with grain-size changing. The distribution character indicates that the chemical
weathering proxies above considerably depend on grain size in westerly region and need carefully used.Most of the element concentration and ratios of TKP section change fiercely in fine size (<2 μm, 2~16 μm,
16~32 μm) and slightly in coarse size (32~63 μm, 63~125 μm, >125 μm). All of these afford new proof
to tell us that the TKP sand sediment has various source areas. |
| Key words: different grain size fractions major element Rb and Sr material source Takermohuer Desert |
