| 西昆仑地区元古宙岩浆侵入作用及构造-岩浆演化过程 |
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| 引用本文： | 康磊,;校培喜,;高晓峰,;奚仁刚,;杨再朝,;过磊,;董增产.西昆仑地区元古宙岩浆侵入作用及构造-岩浆演化过程[J].西北地质,2014(4):1-12. |
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| 作者姓名： | 康磊 ;校培喜 ;高晓峰 ;奚仁刚 ;杨再朝 ;过磊 ;董增产 |
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| 作者单位： | [1]国土资源部岩浆作用成矿与找矿重点实验室,中国地质调查局西安地质调查中心,陕西西安710054; [2]中国地质大学(武汉)地质调查研究院,湖北武汉430074 |
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| 基金项目： | 中国地质调查局国土资源大调查研究项目（1212011085034,12120113044500）、国家自然科学基金项目（41202044、41002063）和陕西省自然科学基金项目（2012JM5004）联合资助 |
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| 摘 要： | 通过对西昆仑地区元古代侵入岩的岩石类型、形成时代和岩石地球化学资料的综合分析,探讨各个构造单元侵入岩形成期次、岩石成因及构造-岩浆演化过程。铁克里克断隆带元古宙中酸性侵入岩以A型花岗岩为主,是塔里木板块古老基底在高温低压条件下发生部分熔融的产物。西昆仑造山带古元古代和中元古代早期中酸性侵入岩为钙碱性I型花岗岩,是变玄武岩在低温条件下部分熔融条件下形成的,而古元古代晚期和新元古代中酸性侵入岩则是高温条件下老基底岩系部分熔融而形成的A型花岗岩。甜水海地块仅发育新元古代侵入岩,为S型花岗岩,是高温高压环境下甜水海地块古老基底部分熔融而形成。根据侵入岩岩浆演化规律,将西昆仑地区元古宙划为4个演化阶段:12 426~1 567Ma:以铁克里克断隆带A型花岗岩为代表的塔里木板块陆内演化,以西昆仑造山带钙碱性-拉斑质I型花岗岩为代表的陆缘弧。21 301~1 000Ma:铁克里克断隆带和西昆仑造山带均以陆内演化性质的A型花岗岩为主。31 000~851 Ma:甜水海地块S型花岗岩可能是陆-陆碰撞导致地壳加厚的产物,指示甜水海地块可能作为Rodinia超大陆的一员发生聚合拼接作用。4815~644 Ma:铁克里克断隆带和西昆仑造山带均存在碱性基性岩浆岩和A型花岗岩的双峰式侵入岩组合,指示塔里木地块和西昆仑地块可能作为Rodinia超大陆组成部分,在该阶段发生了裂解作用。通过对元古宙侵入岩的系统分析,西昆仑地区不同构造单元地壳演化有一定差异,经历了不同演化过程。
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| 关 键 词： | 西昆仑地区 元古宙 岩浆侵入作用 构造-岩浆演化 |
Proterozoic Intrusive Magmatism in West Kunlun Area and Its Inspiration to Tectonic-Magmatic Evolution |
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| Institution: | KANG Lei , XIAO Pei-xi , GAO Xiao-feng , XI Ren-gang , YANG Zai-chao, GUO Lei, DONG Zeng-chan (1. Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits, MLR, Xi＇ an Center of Geological Survey, CGS, Xi＇ an 710054, China 2. Geological Survey, China University of Geosciences, Wuhan 430074, China) |
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| Abstract: | According to rock types, ages and geochemical data of Proterozoic intrusive rocks, we studied the magmatic stages, petrogenesis and tectonic magmatic evolution of different structural units in West Kunlun area. Proterozoic intermediate-acid intrusive rocks in Tiekelike unit are characterized by A-type granitoids associated with partial melting of Tarim basement under low pressure and high temperature condition. While Paleoproterozoic and Early Mesoproterozoic intrusive rocks are I-type granites derived from partial melting of metabasalt in low temperature, late Mesoproterozoic and Neoproterozoic intermediate-acid rocks are dominated by A-type granit- oid intrusions related to partial melting of Kunlun basement under high temperature condition. Meanwhile, Tianshuihai unit only developed Neoproterozoic S-type granites and originated from partial melting of Tianshuihai basement in low temperature and high pressure. According to mag- matic evolution, Proterozoic West Kunlun area could be divided into four stages： （1）2426- 1567Ma. A-type granitoids in Tiekelike fault belt which formed Tarim intracontinental evolution, and calc-alkaline tholeiite I-type granitoids in Kunlun orogenic belt represent continental marginal arc; （2）1 301-1 000 Ma： A-type granitoids in Tiekelike belt and Kunlun belt indicating intraconti- nental evolution;（3）1 000-851 Ma. S-type granitoids in Tianshuihai belt indicating the collision and polymerization of Tianshuihai massif which may be a part of Rodinia supercontinent;（4）815- 644 Ma. bimodal magmatic rocks of alkali basic magmatite and A-type granitoids in Tiekelike belt and Kunlun belt, indicating the possibility of Tarim and West Kunlun block as components of the Rodinia and their breakup in this period. Consequently, according to the systematic analysis of Proterozoic intrusive rocks, it can be summarized that in West Kunlun area different structural u- nits have undergone uneven crustal evolution processes. |
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| Keywords: | West Kunlun area Proterozoic intrusive magmatism tectonic-magmatic evolution |
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