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现代地质 ›› 2021, Vol. 35 ›› Issue (02): 504-513.DOI: 10.19657/j.geoscience.1000-8527.2020.069

• 岩石学 • 上一篇    下一篇

青海团宝山花岗岩年代学、地球化学特征及其地质意义

张保涛1,2(), 胡兆国1(), 姜晓平1, 王向伟3, 孙璐伟3, 张扬1, 王小玉1, 赵晓博1, 郭伟1   

  1. 1.中国冶金地质总局 山东正元地质勘查院, 山东 济南 250013
    2.中国冶金地质总局 矿产资源研究院, 北京 100131
    3.山东正元地质资源勘查有限责任公司, 山东 济南 250101
  • 收稿日期:2019-07-19 修回日期:2020-06-22 出版日期:2021-04-25 发布日期:2021-05-25
  • 通讯作者: 胡兆国
  • 作者简介:胡兆国,男, 硕士, 高级工程师, 1983年出生, 地质矿产勘查专业, 主要从事矿产勘查工作。Email: 278968540@qq.com
    张保涛,男, 硕士, 工程师, 1987年出生, 矿物学、岩石学、矿床学专业,主要从事矿物学、岩石学、矿床学研究。Email: zhbaotao@163.com
  • 基金资助:
    中国地质调查局地质调查项目(DD20179604);中国地质调查局地质调查项目(12120113033011)

Geochronological and Geochemical Characteristics of Tuanbaoshan Granite Pluton in Qinghai and Geological Implications

ZHANG Baotao1,2(), HU Zhaoguo1(), JIANG Xiaoping1, WANG Xiangwei3, SUN Luwei3, ZHANG Yang1, WANG Xiaoyu1, ZHAO Xiaobo1, GUO Wei1   

  1. 1. Geological Exploration Institute of Shandong Zhengyuan, China Metallurgical Geology Bureau, Jinan,Shandong 250013, China
    2. Institute of Mineral Resources, China Metallurgical Geology Bureau, Beijing 100131, China
    3. Shandong Zhenyuan Geological Resources Exploration Co. Ltd., Jinan,Shandong 250101, China
  • Received:2019-07-19 Revised:2020-06-22 Online:2021-04-25 Published:2021-05-25
  • Contact: HU Zhaoguo

摘要:

青海省团宝山花岗岩位于南祁连东段,侵位于古元古代化隆群中。为了解其侵位时代、岩体成因和产出构造环境,利用LA-ICP-MS锆石U-Pb定年和地球化学测试方法对团宝山花岗岩岩体样品进行分析。获得其锆石U-Pb年龄为(776±8) Ma;该岩体SiO2、Al2O3和K2O含量较高,而FeOT、MgO和CaO含量较低,K2O/Na2O大于1,富集Rb、Th等元素,亏损Ba、Zr等元素,具明显的负铕异常,表现为轻稀土富集型稀土配分模式。该岩体为分异程度较高的过铝质钙碱性岩,具S型花岗岩特征,为晚元古代中期陆陆碰撞的产物;源岩为泥质岩或杂砂岩,侵位后在晋宁运动末期和加里东运动中期经历过岩浆热事件。

关键词: 花岗岩, 晚元古代, 同碰撞, 团宝山, 青海省

Abstract:

The Tuanbaoshan granite pluton is located in the eastern South Qilian, and is emplaced into the Paleoproterozoic epimetamorphic rocks. Samples from the granite pluton are LA-ICP-MS zircon U-Pb dated and geochemically analyzed to constrain its emplacement age, petrogenesis and tectonic setting. The zircon U-Pb dating yielded weighted mean age of (776±8) Ma. The rocks contain relatively contents of SiO2, Al2O3 and K2O, and relatively low contents of FeOT, MgO and CaO, with K2O/Na2O>1. The Tuanbaoshan granites are enriched in Rb, Th, and depleted in Ba and Zr, with chondrite-normalized LREE-enriched patterns. Based on these characteristics, we suggest that: the Tuanbaoshan granites are calc-alkalic highly-differentiated S-type, and were emplaced in a Late Proterozoic continent-continent collision setting. Source rocks of the Tuanbaoshan granites may have been argillaceous sandstone or graywacke, and the pluton may have subsequently experienced two magmatic events during the end of Jinning movement and the Mid Caledonian movement.

Key words: granite, Late Proterozoic, syn-collision, Tuanbaoshan, Qinghai

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