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现代地质 ›› 2020, Vol. 34 ›› Issue (04): 635-652.DOI: 10.19657/j.geoscience.1000-8527.2020.04.01

• 矿床学 •    下一篇

内蒙古撰山子金矿床成岩成矿年代学与地球化学

欧阳鑫1,2(), 顾雪祥1,3(), 章永梅1,3,4, 刘丽1, 刘涛5, 王文东5   

  1. 1.中国地质大学(北京) 地球科学与资源学院,北京 100083
    2.中国自然资源经济研究院,北京 101149
    3.中国地质大学(北京)地质过程与矿产资源国家重点实验室,北京 100083
    4.南京大学 内生金属矿床成矿机制研究国家重点实验室,江苏 南京 210046
    5.中国地质调查局 哈尔滨自然资源综合调查中心,黑龙江 哈尔滨 150081
  • 收稿日期:2019-12-12 修回日期:2020-02-27 出版日期:2020-08-31 发布日期:2020-09-03
  • 通讯作者: 顾雪祥
  • 作者简介:顾雪祥,男,教授,博士生导师,1963年出生,矿床学专业,主要从事矿床学和矿床地球化学研究。Email: xuexiang_gu@cugb.edu.cn
    欧阳鑫,男,硕士,研究实习员,1994年出生,矿物学、岩石学、矿床学专业,主要从事矿床学、自然资源标准化研究。Email: ouyangxin@cugb.edu.cn
  • 基金资助:
    国家自然科学基金项目(41572062);国家重点研发计划“深地资源勘查开采” 项目(2018YFC0604003);中央高校基本科研业务费专项资金项目(2652017226);中国地质调查局项目“东北内蒙古沿边及特殊地区地质矿产调查”(DD20160078)

Metallogenic Chronology and Geochemistry of the Zhuanshanzi Gold Deposit, Inner Mongolia

OUYANG Xin1,2(), GU Xuexiang1,3(), ZHANG Yongmei1,3,4, LIU Li1, LIU Tao5, WANG Wendong5   

  1. 1. School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083,China
    2. China Academy of Natural Resources and Economics, Beijing 101149,China
    3. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083,China
    4. State Key Laboratory for Mineral Deposits Research, Nanjing University, Nanjing, Jiangsu 210046,China
    5. Harbin Natural Resources Integrated Investigation Center, China Geological Survey, Harbin, Heilongjiang 150081,China
  • Received:2019-12-12 Revised:2020-02-27 Online:2020-08-31 Published:2020-09-03
  • Contact: GU Xuexiang

摘要:

撰山子金矿床是华北板块与兴蒙造山带结合部位的一处中高温岩浆热液矿床,其形成时代与构造背景一直备受争议。对矿区内赋矿流纹岩、赋矿似斑状花岗岩以及截切矿体闪长岩开展的年代学和岩石地球化学研究结果表明,赋矿流纹岩、似斑状花岗岩的206Pb/238U谐和年龄分别为(264±3.8) Ma、(237±1.4) Ma;截切矿体闪长岩的206Pb/238U谐和年龄为(219±4.7) Ma;成矿时代可限定在 237~219 Ma之间,撰山子金矿床为三叠纪成矿。赋矿流纹岩具高钾、低镁的特征,富集 Rb、Th、U、K、Pb、Nd、Hf、Gd等元素,亏损 Ba、Nb、Ce、Sr、P和 Ti等元素。赋矿似斑状花岗岩具低磷的特征,富集 Rb、Th、U、K、Pb 等元素,亏损 Ba、Nb、Ta、Ce、Sr、P、Zr、Ti 等元素。截切矿体闪长岩具高钾、高镁、低磷的特征,富集 Rb、K、Sr等大离子亲石元素,亏损 Nb、Ta、P、Ti等高场强元素。综合分析认为,赋矿流纹岩形成于中二叠世古亚洲洋向华北板块俯冲的环境,赋矿似斑状花岗岩与截切矿体闪长岩产在中、晚三叠世华北板块与西伯利亚板块碰撞后的伸展环境。

关键词: 岩石地球化学, 锆石U-Pb定年, 撰山子金矿床, 内蒙古

Abstract:

Zhuanshanzi gold deposit is a medium-high temperature magmatic hydrothermal deposit in the combination of North China Plate and Xingmeng orogenic belt, while its depositionl age and tectonic setting are still in debate. In this study, an integrated analysis of isotope chronology and geochemistry for the Zhuanshanzi gold deposit was carried out. The results give a concordant age of (264±3.8) Ma for the ore-hosted rhyolite, (237±1.4) Ma for the ore-hosted porphyritic granite, (219±4.7) Ma for the ore-intercalated diorite. The ore-forming age is limited to 237-219 Ma. The Zhuanshanzi gold deposit is generated in Triassic.The petrogeochemical analysis shows that the (264±3.8) Ma rhyolite is characterized by high content of K2O and low concentration of MgO, with enrichment in Rb, Th, U, K, Pb, Nd, Hf, Gd and depletion in Ba, Nb, Ce, Sr, P, Ti.The (237±1.4) Ma porphyritic granite is characterized by low concentration of P2O5, with enrichment in Rb, Th, U, K, Pb and depletion in Ba, Nb, Ta, Ce, Sr, P, Zr, Ti. The (219±4.7) Ma diorite is characterized by high contents of K2O, MgO and low concentration of P2O5, with enrichment in Rb, K, Sr and depletion in Nb, Ta, P, Ti. In a word, the (264±3.8) Ma rhyolite is formed from the magma that remelting of the lower crust due to the upwelling of the lithospheric during the period that the paleo-Asian ocean subduction to North China Plate. The (237±1.4) Ma porphyritic granite and the (219.7±4.7) Ma diorite generated in the extensional environment after the collision between North China Plate and Siberian Plate.

Key words: petrogeochemistry, zircon U-Pb dating, Zhuanshanzi gold deposit, Inner Mongolia

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