| 浙东白垩纪双峰式火山岩Sr、Nd同位素组成及其成因意义 |
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| 引用本文： | 邢光福,杨祝良,薛怀民,赵 宇,陶奎元.浙东白垩纪双峰式火山岩Sr、Nd同位素组成及其成因意义[J].地质论评,1999,45(7):796-804. |
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| 作者姓名： | 邢光福 杨祝良 薛怀民 赵 宇 陶奎元 |
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| 作者单位： | 中国地质科学院南京地质矿产研究所，210016 |
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| 摘 要： | 浙东白垩纪火山岩以发育双峰式岩石组合为特征，其成因一直是有争议的问题。本文从其两端元岩石——玄武岩和流纹岩的Sr，Nd同位素特征出发，论证了玄武岩起源于经过俯冲来源的物质交代(或混染)的富集型地幔楔，流纹岩主要由古老变质基底重熔生成，并与玄武岩岩浆发生过低度混合。在混合过程中，玄武岩的Sr同位素组成基本未受到影响，Nd同位素组成可能发生一定的变化；流纹岩的Sr同位素组成则有明显改变。
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| 关 键 词： | 成因意义 Sr，Nd同位素 双峰式火山岩 白垩纪 浙东 |
Sr and Nd Isotopic Compositions and Petrogenetic Implications of Cretaceous Bimodal Volcanic Rocks in Eastern Zhejiang,China |
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| Xing Guangfu,Yang Zhuliang,Xue Huaimin,Zhao Yu and Tao Kuiyuan.Sr and Nd Isotopic Compositions and Petrogenetic Implications of Cretaceous Bimodal Volcanic Rocks in Eastern Zhejiang,China[J].Geological Review,1999,45(7):796-804. |
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| Authors: | Xing Guangfu Yang Zhuliang Xue Huaimin Zhao Yu and Tao Kuiyuan |
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| Institution: | Nanjing Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences, Nanjing,210016 |
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| Abstract: | There outcrop characteristic Cretaceous bimodal volcanic rock assembl ag es in eastern Zhejiang, but their geneses have always been in dispute.This paper di scusses the Sr and Nd isotopic features of the two end members ,the basalts and the high K rhyolites, and demonstrates that basalts were derived from ric hed mantle wedge through metasomatism of fluids (or contaminatio n of components) from subducted slab, whereas rhyolites were formed by remelting of the old metamorphic basement.Low degree mixing took place between basic and felsic ma gmas, which not only resulted in important variation of Sr isotopic composition in the rhyolites,but probably also affect ed the N d isotopic composition of basalts to a certain degree,but had not evidently chan g ed their Sr isotopic compositions. |
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| Keywords: | petrogenetic implication Sr and Nd isotopic compositions bimodal volcanic rocks Cretaceous eastern Zhejiang |
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