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现代地质 ›› 2019, Vol. 33 ›› Issue (02): 271-283.DOI: 10.19657/j.geoscience.1000-8527.2019.02.03

• 矿床学与岩石学 • 上一篇    下一篇

黑龙江省毛家屯花岗岩中碱性暗色矿物特征及其地质意义

秦锦华1,2(), 刘翠1(), 邓晋福1, 段培新1, 郭娜3   

  1. 1.中国地质大学(北京) 地球科学与资源学院,北京 100083
    2.中国地质科学院 矿产资源研究所,北京 100037
    3.中国地质调查局 西安矿产资源调查中心(原武警黄金五支队),陕西 西安 710100
  • 收稿日期:2018-03-21 修回日期:2018-11-20 出版日期:2019-05-08 发布日期:2019-05-08
  • 通讯作者: 刘翠
  • 作者简介:刘 翠,女,副教授,1973年出生,矿物学、岩石学、矿床学专业,主要从事岩浆作用与成矿方向研究。Email: liucui@cugb.edu.cn
    秦锦华,男,博士研究生,1992年出生,矿物学、岩石学、矿床学专业,主要从事岩浆作用与成矿方向研究。Email: qjh1992@qq.com
  • 基金资助:
    中国地质调查局项目“侵入岩1/5万专题地质填图试点及新方法填图(DD20160123(DD-16-049, D1522))”“全国陆域及海区地质图件更新与共享(DD20190370)之中国典型地区洋陆转换的火成岩记录”;中国地质调查局项目(1212011121075);中国地质调查局项目(1212010911028);中国地质调查局项目(12120114020901);国家自然科学基金青年基金项目(NSFC40802020)

Characteristics and Geological Significance of Alkaline Melano-minerals in Maojiatun Granite, Heilongjiang Province

QIN Jinhua1,2(), LIU Cui1(), DENG Jinfu1, DUAN Peixin1, GUO Na3   

  1. 1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
    2. Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China
    3. Xi’an Mineral Resources Survey Center(No.5 Gold Geological Party of PAP),China Geological Survey,Xi’an,Shaanxi 710100,China
  • Received:2018-03-21 Revised:2018-11-20 Online:2019-05-08 Published:2019-05-08
  • Contact: LIU Cui

摘要:

碱性暗色矿物作为具有特殊指示意义的矿物,其存在对岩浆演化过程具有重要的意义。毛家屯花岗岩体位于兴蒙造山带东部的小兴安岭—张广才岭南段,岩体内部发育碱性暗色矿物。以毛家屯岩体内部发育的碱性暗色矿物为研究对象,进行了矿物学和矿物化学电子探针分析。研究表明,碱性角闪石的类型为铁-镁铝钠闪石,具有富碱,尤其富钠、富硅、富铁、贫钙、镁、钛等特征。辉石的类型为霓辉石,化学特征上高硅-高钠,高铁,低钛、镁、铝、锰。碱性暗色矿物主岩为碱性岩,成因类型为铝质A型花岗岩类。毛家屯花岗岩碱性角闪石具有很低的M值,证明其来源于地壳物质的熔融。毛家屯花岗岩中碱性角闪石的特征指示,在结晶过程中,岩浆体系处于封闭还原条件,且岩体从中央到边部存在偏酸性和偏基性组分分带现象。结合前人的同位素和年代学方面的分析资料,认为毛家屯碱性花岗岩形成于造山后期伸展转换环境中。

关键词: 黑龙江毛家屯, 碱性暗色矿物, 成因, 造山后伸展, 碱性花岗岩

Abstract:

Existence of alkaline melano-minerals is of great indicative significance for magmatic evolution processes. The Maojiatun alkaline granite body is located at the southern part of the Little Xing’an range-Zhangguangcai range, which represents the eastern part of the Xingmeng orogenic belt. The intrusion is characterized by the presence of alkaline melano-minerals with high contents of alkali and iron. In this study, we analyzed the mineralogical and EPMA chemical characteristics of the alkaline melano-minerals in the Maojiatun granite. Our study shows that the amphibole is iron magnesium-alumina natrium amphibole, and is featured by being Si, Na and Fe rich, and Ca, Mg and Al poor. The pyroxene is aegirine-augite, which is characterized by having high Si, Na and Fe, and low Ti, Mg, Al and Mn. We have determined that the host rock is alkaline magmatite, and the genetic type is aluminum-type A granite. Maojiatun alkaline granite has low M value, which indicates that it may have come from the remelting of juvenile crust. During crystallization, the magma system may have been under a closed and reducing condition, and there is a distinct zonation of acid and basic rocks from the center to margin of the intrusion. We concluded that the Maojiatun alkaline granite was formed in a late orogenic transition setting.

Key words: Maojiatun in Heilongjiang Province, alkaline dark mineral, genesis, post-orogenic extension, alkaline granite

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