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现代地质 ›› 2019, Vol. 33 ›› Issue (05): 1015-1024.DOI: 10.19657/j.geoscience.1000-8527.2019.05.08

• 岩石学 • 上一篇    下一篇

川西地区热达门石英闪长岩锆石U-Pb年龄和岩石地球化学特征:岩石成因与构造意义

岳相元1(), 杨波2, 周雄1, 龚大兴1, 叶亚康1,3, 谭红旗1,3, 周玉1, 朱志敏1   

  1. 1.中国地质科学院 矿产综合利用研究所,四川 成都 610041
    2.四川省地质矿产勘查开发局 化探队,四川 德阳 618000
    3.成都理工大学 地球科学学院,四川 成都 610059
  • 收稿日期:2019-01-22 修回日期:2019-05-22 出版日期:2019-10-26 发布日期:2019-10-28
  • 作者简介:岳相元,男,工程师,1985年出生,岩石学专业,主要从事岩石学、矿床学、地球化学方面的研究。Email: yxyzhs@126.com
  • 基金资助:
    中国地质调查局项目“四川九龙-可尔因大型锂资源基地综合调查评价”(DD20190185)

Geochemical Characteristics and U-Pb Age of Redamen Granites in Western Sichuan, China: Petrogenesis and Tectonic Significance

YUE Xiangyuan1(), YANG Bo2, ZHOU Xiong1, GONG Daxing1, YE Yakang1,3, TAN Hongqi1,3, ZHOU Yu1, ZHU Zhimin1   

  1. 1. Institute of Multipurpose Utilization of Mineral Resources, Chinese Academy of Geological Sciences, Chengdu,Sichuan 610041, China
    2. Geochemistry Exploration Brigade of Sichuan Bureau of Exploration and Development of Geology and Minerals Resources,Deyang,Sichuan 618000, China
    3. College of Earth Sciences, Chengdu University of Technology, Chengdu,Sichuan 610059, China
  • Received:2019-01-22 Revised:2019-05-22 Online:2019-10-26 Published:2019-10-28

摘要:

川西地区热达门石英闪长岩体位于松潘—甘孜造山带北东侧。岩体的LA-ICP MS锆石U-Pb年龄为(206.4±1.4) Ma,侵位于晚三叠世。岩石SiO2含量为50.62%~56.66%,K2O/Na2O为0.32~1.20。铝饱和指数介于0.59~0.86之间,里特曼指数(σ)介于0.40~1.20之间,属于亚碱性准铝质系列岩石。岩体稀土总量∑REE介于81.45×10-6~222.39×10-6,LREE/HREE介于5.38~10.45之间,(La/Yb)N范围为5.98~12.99,δEu为0.66~1.01,δCe为0.81~0.93。岩石地球化学特征显示热达门岩石英闪长岩是在碰撞造山环境下,由岩浆上涌诱发下地壳物质部分熔融而形成的I型花岗岩。

关键词: 松潘—甘孜造山带, 热达门石英闪长岩, U-Pb年龄, 地球化学, 岩石成因

Abstract:

The Redamen quartz diorite is located in the northeastern part of the Songpan-Ganzi orogenic belt. LA-ICP-MS zircon U-Pb dating of the pluton yielded Late Triassic age of (206.4±1.4) Ma. The quartz diorite contains SiO2 contents of 50.62% to 56.66%, K2O/Na2O of 0.32 to 1.20, aluminum saturation index of 0.59 to 0.86, and Rittermann index of 0.40 to 1.20. The samples are subalkaline, metaluminous, and high-K calc-alkaline to calc-alkaline. Total REE (∑REE) contents are of 81.45×10-6 to 222.39×10-6, with LREE/HREE of 5.38 to 10.45 and (La/Yb)N values of 5.98 to 12.99. The rocks show Eu anomalies (δEu=0.66-1.01) and Ce anomalies (δCe=0.81-0.93). The Redamen quartz diorite may have emplaced in a collisional orogenic setting, via magma upwelling and partial melting of the lower crust.

Key words: Songpan-Ganzi orogenic belt, Redamen quartz diorite, U-Pb age, geochemistry, petrogenesis

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