| 碧口洋岛型火山岩的厘定及其构造意义 |
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| 引用本文： | 李永飞,赖绍聪.碧口洋岛型火山岩的厘定及其构造意义[J].西北地质,2006,39(4):1-9. |
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| 作者姓名： | 李永飞 赖绍聪 |
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| 作者单位： | 1. 沈阳地质矿产研究所,辽宁,沈阳,110032
2. 西北大学地质学系,陕西,西安,710069 |
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| 基金项目： | 国家自然科学基金项目(批准号:40234041)资助 |
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| 摘 要： | 通过对碧口铜钱坝南—托河乡南区段变玄武岩的地球化学分析,结果表明该套岩石由碱性和亚碱性的拉斑系列玄武岩组成,岩石的Nb、Ta、Ce含量,Ba/Ce、Ti/Y、Zr/Y值显示了洋岛玄武岩的地球化学特征。N-MORB标准化蛛网图和球粒陨石标准化图解表明,本区洋岛拉斑玄武岩和洋岛碱性玄武岩具有共同的岩浆源区。玄武岩的2Nb-Zr/4-Y、TiO_2-10MnO-10P_2O_5、Ti/Y-Ba/Zr与Ti/Y-Ba/Nb判别图解均表明,本区火山岩产生于大洋板内的构造环境,从而为该地区新元古代出现过洋盆提供了重要证据。
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| 关 键 词： | 洋岛火山岩 地球化学 碧口群 |
| 文章编号： | 1009-6248(2006)04-0001-09 |
| 收稿时间： | 2006-07-03 |
| 修稿时间： | 2006-12-01 |
Discrimination of OIB Volcanic Rocks of Bikou Group and Their Tectonic Implication |
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| LI Yong-fei,LAI Shao-cong.Discrimination of OIB Volcanic Rocks of Bikou Group and Their Tectonic Implication[J].Northwestern Geology,2006,39(4):1-9. |
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| Authors: | LI Yong-fei LAI Shao-cong |
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| Abstract: | Geochemical analysis of the volcanic rocks of the Bikou group from the southern Tongqianban- Tuohe region reveals that they are of the alkaline basalts and subalkaline tholeiitic basalts,which have an affinity to the typical ocean island basalts(OIB)in the contents of Nb,Ta,Ce and the Ba/Ce,Ti/Y and Zr/Y ratios.In addition,the N-MORB-normalized spider diagram and the Chondrite-normalized REE pattern show that the two kinds of rocks were generated from the same parental magmatic source.The tectonic discrimination diagrams of the 2Nb-Zr/4-Y,TiO_2-MnO-P_2O_5,Ti/Y-Ba/Zr and Ti/Y-Ba/Nb have fairly signified that the rocks occurred in an intra-oceanic tectonic setting,which would be a critical evidence to confirm an oceanic basin developed in the study region in the Neoproterozioc time. |
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| Keywords: | OIB volcanic rocks geochemistry Bikou group |
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