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现代地质 ›› 2018, Vol. 32 ›› Issue (06): 1227-1241.DOI: 10.19657/j.geoscience.1000-8527.2018.06.11

• 岩石学 • 上一篇    下一篇

西天山呼斯特岩体矿物化学特征及其成岩成矿意义

何宇1(), 章永梅1,2(), 顾雪祥1,2, 彭义伟3, 程文斌3, 王冠南1, 万阈4, 袁鹏4   

  1. 1.中国地质大学(北京) 地球科学与资源学院,北京 100083
    2.中国地质大学 地质过程与矿产资源国家重点实验室,北京 100083
    3.成都理工大学 地球科学学院,四川 成都 610059
    4.新疆地矿局第七地质大队,新疆 乌苏 833300
  • 收稿日期:2018-01-11 修回日期:2018-04-19 出版日期:2018-12-10 发布日期:2018-12-20
  • 通讯作者: 章永梅,女,副教授,1984年出生,矿床学专业,主要从事矿床学与矿床地球化学研究。Email:zhangyongmei@cugb.edu.cn
  • 作者简介:何 宇,男,硕士研究生,1993年出生,地质工程专业,主要从事矿床学与矿床地球化学研究。Email:heyu@cugb.edu.cn
  • 基金资助:
    国家自然科学基金项目(41572062);科技部深地资源勘查开采专项(2018YFC0604003);中央返还两权价款资金综合研究项目(Y15-1-LQ04);中央返还两权价款资金综合研究项目(Y15-1-LQ02);中央高校基本科研业务费专项资金资助项目(2652017226)

Mineral Chemistry of Husite Pluton in West Tianshan, Xinjiang and Its Implications for Petrogenesis and Mineralization

HE Yu1(), ZHANG Yongmei1,2(), GU Xuexiang1,2, PENG Yiwei3, CHENG Wenbin3, WANG Guannan1, WAN Yu4, YUAN Peng4   

  1. 1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
    2. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China
    3. College of Earth Sciences, Chengdu University of Technology, Chengdu,Sichuan 610059, China
    4. No.7 Geological Team, Xinjiang Bureau of Geology and Mineral Resources, Usu,Xinjiang 833000, China
  • Received:2018-01-11 Revised:2018-04-19 Online:2018-12-10 Published:2018-12-20

摘要:

呼斯特岩体位于新疆西天山博罗科努岛弧带中北缘,是博罗科努成矿带东段典型的与矽卡岩矿床成矿有关的中酸性杂岩体。对岩体中的二长花岗岩、花岗闪长岩和暗色包体进行了系统的矿物化学研究,探讨了岩浆的成岩演化过程以及矿物成分与成岩成矿的关系。造岩矿物的化学成分研究表明,呼斯特岩体为典型的I型花岗岩,形成于与俯冲有关的大陆边缘弧环境,成岩物质来自壳幔混源,成岩过程中经历了岩浆混合作用。岩体形成于较高温度(738~770 ℃)、较低压力(0.57~1.42 kbar,1 kbar=0.1 GPa)和高氧逸度环境。二长花岗岩和花岗闪长岩的侵位深度(2.2~4.2 km)和高氧逸度有利于可克萨拉—艾木斯呆依铁铜矿床的形成。岩石中的黑云母相对富镁且氧化系数较高,角闪石富镁、富硅且化学成分变化较大,二者均表现出与铁铜矿化有关的成分特征。岩浆混合作用与矿床的形成关系密切,对区内斑岩-矽卡岩型多金属矿床的找矿具有指示意义。

关键词: 矿物化学, 成岩作用, 成矿意义, 呼斯特岩体, 新疆西天山

Abstract:

The Husite pluton is situated on the middle-northern margin of the Boluokenu island arc in the West Tianshan, Xinjiang, and is a typical skarn mineralization-related intermediate-felsic intrusive complex in the eastern Boluokenu ore belt. In this paper, we systematically studied the mineral chemistry of monzogranite, granodiorite and mafic enclaves from the Husite pluton, and discussed the magmatic evolution and the relationship between mineral composition and petrogenesis and metallogenesis. Rock-forming mineral compositions show that the Husite granites are typically I-type formed in a continental arc setting, and was mainly derived from partial melting of the lower crust with mantle-derived input. The Husite pluton was formed under relatively high temperature (738-770 ℃), low pressure (0.57-1.42 kbar) and oxidizing environment. The shallow emplacement (2.2-4.2 km deep) of oxidized monzogranitic and granodioritic magmas likely facilitated the Kekesala-Aimusidaiyi Fe-Cu ore formation. The Mg-enrichment and high oxidation coefficient of biotite, and the Mg-Si-enrichment and wide compositional range of amphibole in these rocks are both compositional features related to Fe-Cu mineralization. Magma mixing may have been closely related to the ore formation, and is also indicative for porphyry-skarn polymetallic prospecting in the region.

Key words: mineral chemistry, petrogenesis, mineralization significance, Husite pluton, West Tianshan, Xinjiang

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