| 西藏蛇绿岩的超高压矿物：FeO、Fe、FeSi、Si和SiO2组合及其地球动力学意义 |
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| 引用本文：白文吉,杨经绥,方青松,颜秉刚,张仲明.2002.西藏蛇绿岩的超高压矿物：FeO、Fe、FeSi、Si和SiO2组合及其地球动力学意义[J].地球学报,23(5):395-402. |
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| 作者 | 单位 | | 白文吉 | 中国地质科学院地质研究所,北京,100037 | | 杨经绥 | 中国地质科学院地质研究所,北京,100037 | | 方青松 | 中国地质科学院地质研究所,北京,100037 | | 颜秉刚 | 中国地质科学院地质研究所,北京,100037 | | 张仲明 | 中国地质科学院地质研究所,北京,100037 |
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| 基金项目:国家自然科学基金项目(49972073) |
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| 中文摘要:在西藏雅鲁藏布江蛇绿岩带的东段，出露罗布莎蛇绿岩块和豆荚状铬铁矿床。从豆荚状铬铁矿石中查明60－70种伴生矿物，其中包含FeO、Fe、FeSi、Si和SiO2组合。根据超高压－高温实验，该组合应形成于地球外核与下地幔之间的D“层，是地球外核的液态铁与镁硅酸盐钙钛矿（MgSiO3)相互化学反应的产物。西藏该超高压矿物组合揭示了蛇绿岩地幔活动可能深达地球外核。罗布莎蛇绿岩的该矿物组合可能是地幔－外地核之间的产物，或者是被对流作用，亦是被起源于D“层的地幔柱活动带到上地幔的。铬铁矿在地幔中结晶，并捕获了该矿物组合。 |
| 中文关键词:西藏 蛇绿岩 超高压矿物 FeOFeFeSi和SiO2组合 |
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| Ultra-High Pressure Minerals: FeO, Fe, FeSi, Si and SiO2 Assemblage from Ophiolite in Tibet and Its Earth Dynamic Significance |
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| Abstract:The Luobusa ophiolite and its chromite deposits outcrop in the eastern section of the Yarlung Zangbo River ophiolitic zone. About 60～70 types of associated minerals including FeO,Fe, FeSi, Si and SiO 2 have been found from the podiform chromitite in Tibet. Based on high pressure and high temperature experimental data, this mineral assemblage was formed in D″ layer between the outer core and the lower mantle, being a product of chemical reaction between liquid iron of the outer core and magnesian silicate pe rovskite (MgSiO 3) of the lower mantle. The existence of these high pressure minerals implies that the deep mantle activity of ophiolite might have affected the Earth's outer core, and that the chemical reaction between the outer core and the lower mantle might have happened. The ultra high minerals were formed in D″ layer and brought up to the upper mantle by mantle plume generated from D″ layer. |
| keywords:Tibet ophiolite ultra-high pressure mineral FeO, Fe, FeSi, Si and SiO2 assemblage |
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