地学前缘 ›› 2011, Vol. 18 ›› Issue (1): 207-215.

• 论文 • 上一篇    下一篇

滇西马厂箐斑岩型铜钼(金)矿床成岩成矿时代研究

和文言,莫宣学,喻学惠,李勇,黄行凯,和中华   

  1. 1地质过程与矿产资源国家重点实验室; 中国地质大学(北京) 地球科学与资源学院, 北京 100083
    2云南黄金矿业集团股份有限公司, 云南 昆明 650224
  • 收稿日期:2010-08-10 修回日期:2010-12-20 出版日期:2011-01-15 发布日期:2011-01-15
  • 作者简介:和文言(1986—),男,硕士研究生,矿物学、岩石学、矿床学专业。Email:vaneyoung.he@gmail.com
  • 基金资助:

    国家重点基础研究发展计划“973”项目“三江特提斯复合造山与成矿”下属子课题“三江岩浆作用与壳幔交换成矿制约”(2009CB421002)

Geochronological study of magmatic intrusions and mineralization of Machangqing porphyry CuMoAu deposit,Western Yunnan Province

  1. 1State Key Laboratory of Geological Processes and Mineral Resources; School of Earth Sciences and Resources,China University of Geosciences(Beijing), Beijing 100083, China
    2Yunnan Geology and Mineral Resources Co. Ltd, Kunming 650224, China  
  • Received:2010-08-10 Revised:2010-12-20 Online:2011-01-15 Published:2011-01-15

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摘要：

滇西马厂箐铜钼(金)矿床是金沙江—哀牢山构造带与喜马拉雅期富碱斑岩有关的典型斑岩型矿床之一。富碱斑岩侵入体为多期、多阶段岩浆活动形成的复式岩体,已有的研究资料表明岩浆活动时限在64～29 Ma。文中提供的锆石LAICPMS UPb和辉钼矿ReOs同位素年代学研究资料显示,马厂箐含矿岩体锆石UPb年龄(封闭温度约800 ℃时)为(3793±082) Ma,代表了富碱斑岩的成岩年龄;辉钼矿的ReOs年龄(封闭温度约500 ℃)为(3472±05) Ma,代表成矿时代。该研究结果与前人确定的晚期富碱斑岩岩浆活动的时间(32 Ma)相近,也与前人获得的蚀变黑云母KAr定年(封闭温度300 ℃)结果(351±08) Ma相近,因此可以认为成矿作用与岩体快速冷却过程中发生成矿流体大量分离和出溶有关。成岩作用与成矿作用的时间跨度大约为2 Ma。因此,金沙江—哀牢山多金属成矿带的斑岩型铜钼矿床是与富碱斑岩成岩作用近同期成矿作用的产物,成矿作用时限集中在40~35 Ma左右。

关键词: 关键词：滇西, 马厂箐铜钼金矿床, 新生代富碱斑岩, 成岩年龄, 成矿年龄

Abstract:

 The Machangqing porphyry CuMoAu deposit is one of the typical deposits associated with the alkalinerich porphyry in the JinshajiangAilaoshan tectonic belt of the Himalayan epoch. Alkalite intrusive rock is a superimposed intrusive complex formed by multiperiodic and multistage magmatic activities. The time limit of magmatic activity is 6429 Ma. In situ zircon LAICPMS UPb ages and molybdenite ReOs ages indicate that the age of orebearing granite prophyry is 3793±082 Ma, whereas the mineralization age is 3472±05 Ma, which shows that the mineralization mainly related to the later magmatic activity. The closeness among zircon UPb, molybdenite ReOs, and KAr ages in the Machangqing porphyry indicates that the oreforming system cooled from about 800 ℃(zircon crystallization temperature) through 500 ℃(closure temperature for ReOs in molybdenite) to below 300 ℃(closure temperature for Ar in biotite) in a very short period. The duration of the Machangqing giant oreforming system is less than 2 Ma. The porphyry copper and molybdenum deposit of JinshajiangAilaoshan mineralization belt was the product of the synmineralization, and the mineralization time limit focused on 4035 Ma.

Key words: Western Yunnan, Machangqing CuMoAu deposits, Cenozoic porphyry rich in alkali, age of magmatic intrusion, age of mineralization

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