| 喜马拉雅河流Sr同位素异常源岩研究现状及研究进展 |
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| 引用本文： | 秦建华,冉敬,沈敢富,杜谷.喜马拉雅河流Sr同位素异常源岩研究现状及研究进展[J].地球科学进展,2006,21(3):262-268. |
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| 作者姓名： | 秦建华 冉敬 沈敢富 杜谷 |
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| 作者单位： | 1. 成都地质矿产研究所,四川,成都,610082;成都理工大学,四川,成都,610059
2. 成都地质矿产研究所,四川,成都,610082 |
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| 基金项目： | 中国科学院资助项目;中国科学院广州地球化学研究所元素和同位素地球化学实验室基金 |
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| 摘 要： | 海洋Sr同位素的变化主要是由陆地河流注入的Sr同位素的变化所引起。在全球河流中，流经喜马拉雅山地河流（恒河—布拉马普特拉河）表现出与世界上其它河流明显不同的特点，具有高87Sr/86Sr、高\Sr\]的特征。恒河—布拉马普特拉河是世界上第四大河流，是当今世界海洋Sr的重要来源。国际上，目前人们对造成喜马拉雅河流Sr异常的原因（来源）的认识，仍存较大分歧。归纳起来，主要有3种认识：一是认为来源于硅酸盐岩；二是认为来源于碳酸盐岩的风化；三是认为来源于碳酸盐岩和硅酸盐岩的风化。近年来，作者对高喜马拉雅中央结晶岩系河流Sr同位素异常及其源岩进行的研究表明，高喜马拉雅河流Sr同位素受流域地质作用的强烈影响，呈现出高87Sr/86Sr、低\Sr\]的特点。对岩石和单矿物的研究表明，中央结晶岩系变质岩（片岩、片麻岩）和花岗岩黑云母中的87Sr/86Sr与\Rb\]成正比并具有高87Sr/86Sr、低\Sr\]的特征。黑云母矿物具有的易风化性，为高喜马拉雅河流放射性87Sr提供了主要来源。恒河—布拉马普特拉河的Sr异常（高87Sr/86Sr和高\Sr\]）则可能是反映了流经整个喜马拉雅造山带河流Sr混合平衡后的特征。
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| 关 键 词： | 海洋Sr同位素 喜马拉雅 河流Sr异常 源岩 |
| 文章编号： | 1001-8166（2006）03-0262-07 |
| 收稿时间： | 2005-03-10 |
| 修稿时间： | 2005-09-29 |
The Current Situation and Advance of Research on the Source Rock for the Strontium Isotope in the Himalayan Rivers |
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| QIN Jian-hua,RAN Jing,SHEN Gan-fu,DU Gu.The Current Situation and Advance of Research on the Source Rock for the Strontium Isotope in the Himalayan Rivers[J].Advance in Earth Sciences,2006,21(3):262-268. |
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| Authors: | QIN Jian-hua RAN Jing SHEN Gan-fu DU Gu |
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| Institution: | 1.Chengdu Institute of Geology and Mineral Resources, Chengdu 610082,China;2.Chengdu University of Technology, Chengdu 610059,China |
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| Abstract: | The variation of the marine Sr isotope is largely caused with the input of the river Sr isotope.In the global rivers,the rivers draining through the Himalayan(Ganga-Brahmaputra rivers) possess the typical Sr isotope character,i.e.high ~(87)Sr/~(86)Sr ratio and high \ concentration,which obviously differentiates from other rivers.The Ganga-Brahmaputra,the fourth largest river in the world,is important source for the marine Sr.Currently,it is still controversial for the source rock resulting in the Sr isotope anomaly in the Ganga-Brahmaputra rivers.Basically,there appear three opinions for the source rock,the first opinion advocates that the source rock is the silicate rock,the second the carbonate,and the third both the silicate and carbonate.In the recent years,our research has disclosed that the Sr in the High Himalayan rivers possesses the feature of the high ~(87)Sr/~(86)Sr ratio and low \ concentration,which is intensely affected by the specific geology in the drainage.The study on the metamorphic rocks(schist,gneiss) and the granites and the minerals indicates that in the biotite in the Central Crystal Series,the ~(87)Sr/~(86)Sr has the positive relationship with\,and that the biotite also has the high ~(87)Sr/~(86)Sr ratio and low \ concentration.The biotite is readily weathered and should be the primary source to the radioactive ~(87)Sr of the High Himalayan rivers.The Sr anomaly(high ~(87)Sr/~(86)Sr ratio and high \) in the Ganga-Brahmaputra is possibly attributed to the mixing balance of the rivers draining through the whole Himalayan. |
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| Keywords: | Marine Sr isotope Himalayan River Sr abnormally Source rock tracing |
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