矿床地质2013，Vol.32Issue(3)：641-648,8.
西藏曲水县鸡公村石英脉型钼矿床成矿时代约束
Geochronological constraints on Jigongcun quartz-vein type molybdenum deposit in Quxu County, Tibet
摘要
Abstract
The Jigongcun molybenum deposit,located in the middle of the Gangdese metallogenic belt in Tibet,is a quartz-vein type molybenum deposit hosted in Qushui granodiorite batholith,with ore bodies controlled by the brittle reverse fault.In order to define the ore-forming time of Jigongcun molybenum deposit,the authors selected five molybdenite samples for Re-Os isotope analysis.The 187Re and 187Os values of molybdenite vary from 886.1 μg/g to 1063 μg/g and 331 ng/g to 395 ng/g,respectively,yielding five narrowly distributed Re-Os model ages ranging from 22.29 Ma to 22.81 Ma and an isochrone age of (21.8 ± 6.2) Ma (MSWD=2.2).The plotted isochrone age corresponds to the transitional period of the Gangdese orogenic belt from the post-India-Eurasia collision to strike-slip extension,earlier than the Gangdise porphyry Cu-Mo polymetallic metallogenic time (17～12 Ma).This study indicates that,during the transitional period of the Gangdise orogenic belt from continental collision to strike-slip extension,there might have existed intensive metallogenetic events (30～ 20 Ma),which could constitute a continuous mineralization sequence (only at that time) together with the later porphyry Cu-Mo polymetallic metallogenic epoch (17～12 Ma).The Re values of five molybdenites vary from 1410× 10-6 to 1691 × 10 6,much higher than the values of Mo-Cu deposits in China.This indicates that the metals of the Jigongcun molybdenum deposit might have had a deep-seated magma source (the lower crust to the upper mantle),which experienced remelting from the delaminated lower crust heated by the mantle.关键词
地球化学/辉钼矿Re-Os/鸡公村钼矿/冈底斯/西藏Key words
geochemistry/ molybdenite Re-Os/ Jigongcun molybdenum deposit/ Gangdese/ Tibet分类
天文与地球科学引用本文复制引用
张苏坤,郑有业,张刚阳,高顺宝,孙祥,于淼,郭俊卫,徐净..西藏曲水县鸡公村石英脉型钼矿床成矿时代约束[J].矿床地质,2013,32(3):641-648,8.基金项目
本文受教育部长江学者和创新团队发展计划(IRT1083)、中国地质调查局综合研究项目(1212011220927)、教育部博士点基金项目、中央高校基本科研业务费专项资金联合资助 （IRT1083）
