地学前缘 ›› 2009, Vol. 16 ›› Issue (6): 303-317.

• 论文 • 上一篇    下一篇

天山石炭纪火山岩系中含有富Nb岛弧玄武岩吗？

夏林圻,夏祖春,徐学义,李向民,马中平   

  1. 中国地质调查局 西安地质矿产研究所, 陕西 西安 710054
  • 收稿日期:2009-02-12 修回日期:2009-09-02 出版日期:2009-12-16 发布日期:2009-12-10
  • 作者简介:夏林圻(1942—),男,研究员,博士生导师,岩石学专业。Email: geologyx@pub.xaonline.com
  • 基金资助:

    中国地质调查局综合研究项目(1212010611804);国家自然科学基金项目(40472044)

 Do the Tianshan Carboniferous volcanic successions contain Nbenriched arc basalts?

 JIA Lin-Qi, JIA Jie-Chun, XU Hua-Xi, LI Xiang-Min, MA Zhong-Beng   

  1. Xian Institute of Geology and Mineral Resources, China Geological Survey, Xian  710054, China
  • Received:2009-02-12 Revised:2009-09-02 Online:2009-12-16 Published:2009-12-10

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摘要：

中国西北部天山石炭纪—早二叠世裂谷火山作用代表了一个新近被认可的大火成岩省。有人认为,在天山石炭纪火山岩系中发育有富Nb岛弧玄武岩、埃达克岩和高镁安山岩组合。然而,该岩石组合具有与典型富Nb岛弧玄武岩、埃达克岩和高镁安山岩不同的化学和同位素特点,表明其并非是岛弧岩石组合。这一推断的岛弧岩石组合实际上是大陆板内火山岩组合,由未遭受地壳混染、受到地壳轻微混染和遭受地壳强烈混染的大陆火山岩组成。

关键词: 天山石炭纪裂谷火山岩;地壳混染;富Nb岛弧玄武岩;高镁安山岩;埃达克岩;大火成岩省;中国西北

Abstract:

The Tianshan CarboniferousEarly Permian riftrelated volcanism in northwestern China represents a newly recognized large igneous province. It has been deemed that an assemblage of Nbenriched arc basalt, adakite and highMg andesite occurred in the Tianshan Carboniferous volcanic successions. Divergent chemical and isotopic characteristics between this rock assemblage and the typical Nbenriched arc basalts, adakites and highMg andesites reveal that the former is not arc related. This postulated arcrelated assemblage is indeed an intracontinental volcanic assemblage that consists of crustally uncontaminated, lesscontaminated and strongly contaminated continental volcanic rocks.

Key words: Tianshan Carboniferous riftrelated volcanics; crustal contamination; Nbenriched arc basalts; highMg andesites; adakites; large igneous province; Northwest China