地学前缘 ›› 2010, Vol. 17 ›› Issue (2): 140-145.

• 论文 • 上一篇    下一篇

小秦岭北缘马家洼石英脉型金钼矿床的辉钼矿
Re-Os年龄及其意义

 王义天, 叶会寿, 叶安旺, 李永革, 帅云, 张长青, 代军治   

  1. 1中国地质科学院 矿产资源研究所, 北京 100037
    2国土资源部 成矿作用与资源评价重点实验室, 北京 100037
    3河南省灵宝市地质矿产局, 河南 灵宝 472500
    4江西省赣西地质调查大队, 江西 南昌 330201
    5西北有色地质勘查局, 陕西 西安 710054
  • 收稿日期:2010-01-17 修回日期:2010-02-12 出版日期:2010-03-15 发布日期:2010-04-05
  • 作者简介:王义天(1969—),男,博士,研究员,主要从事构造与成矿研究。E-mail: wyt69@263.net
  • 基金资助:

    国家自然科学基金项目(40742009,40102019,40434011)

Re-Os age of  molybdenite from  the Majiawa Au-Mo deposit of quartz vein type  in the north margin of the Xiaoqinling gold area and its implication for metallogeny.

WANG  Xi-Tian, XIE  Hui-Shou, XIE  An-Wang, LI  Yong-Ge, SHUAI  Yun, ZHANG  Chang-Jing, DAI  Jun-Chi   

  • Received:2010-01-17 Revised:2010-02-12 Online:2010-03-15 Published:2010-04-05

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摘要：

马家洼金钼矿床位于小秦岭北缘,矿体发育在由近东西向脆韧性断裂构造带控制的石英脉中。对该矿床辉钼矿样品进行的Re-Os同位素年代学研究表明:模式年龄范围是232.5~268.4 Ma,等时线年龄为(232±11) Ma,即钼成矿作用时代为早、中三叠世。辉钼矿样品的Re含量范围是(0.474~0.791)×10-6,初始187Os／188Os比值为2.4±6.4,Re-Os同位素组成特征指示了成矿物质主要来源于地壳。马家洼石英脉型金钼矿床是区域伸展体制下构造-流体成矿事件的产物。在华北板块南缘太古宙基底岩系中的脆韧性断裂构造带中寻找印支期和燕山期石英脉型金钼矿床和钼矿床是一个新的找矿方向。

关键词: Re-Os年龄, 三叠纪, 石英脉, 成矿物质, 马家洼金钼矿床, 小秦岭

Abstract:

The Majiawa AuMo deposit discovered in recent years is located in the north margin of the Xiaoqinling gold area. The orebodies, the AuMobearing quartz veins, are controlled by eastwesttrending brittleductile fault belts. Precise ReOs dating of molybdenite from the Majiawa AuMo deposit has been carried out in this study, and the results show that the ReOs model ages range from 2325 Ma to 2684 Ma with a ReOs isochron age of (231±11) Ma, indicating the molybdenum mineralization occurred in the Triassic. The rhenium contents of molybdenite samples range from 0.474×10-6  to 0.791×10-6, and the initial 187Os/188Os is of 2.4±6.4, which indicate that oreforming materials were derived from the crust. The Majiawa quartz vein type of AuMo deposit was a product of tectonicfluid metallogenic event in the regional extensional regime. It is a new prospective to explore the Indosinian and Yanshanian quartz vein type of AuMo and Mo deposits within brittleductile fault belts developed in Archean basement at the south margin of the North China plate.

Key words: Re-Os age, Triassic, quartz vein, oreforming material, Majiawa Au-Mo deposit, Xiaoqinling

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