西藏邦铺钼铜多金属矿床辉钼矿Re-Os年代学及地质意义  

Re-Os DATING OF MOLYBDENITE FROM THE BANGPU POLYMETALLIC DEPOSIT OF TIBET , AND ITS GEOLOGICAL SIGNIFICANCE

作　　者：周雄[1] 温春齐[2] 张贻[1] 周玉[1,2] 费光春[2] 张学全 

机构地区：[1]中国地质科学院矿产综合利用研究所,四川成都610041 [2]成都理工大学地球科学学院,四川成都610059 [3]西藏天仁矿业公司,西藏拉萨850000

出　　处：《矿物岩石》2013年第2期59-64,共6页Mineralogy and Petrology

基　　金：国土资源部公益性行业科研专项项目(201011013);"十一五"国家科技支撑计划项目(2006BAB01A04);中国地质科学院矿产综合利用研究青年基金(D0701S-3)

摘　　要：为精确厘定西藏邦铺钼铜多金属矿床的成矿年龄,对矿床中的6件辉钼矿进行了Re-Os同位素分析,获得其等时线年龄为14.92 Ma±0.18 Ma(MSWD=1.3),加权平均年龄为14.56±0.18(MSWD=6.0),与结合前人数据综合后的9个点获得的等时线年龄(14.67Ma±0.54Ma)、加权平均年龄(14.54 Ma±0.093 Ma)非常接近。已有研究表明,冈底斯成矿带成岩作用主要集中在13 Ma～18 Ma之间,成矿作用主要集中在13Ma～16Ma之间,成岩-成矿作用高峰期为15 Ma,因此,本次获得的9个点的等时线年龄(14.67Ma±0.54Ma)与冈底斯斑岩铜钼矿化时代具有一致性,其代表了该矿床真实的成矿年龄,表明该矿床为冈底斯碰撞成矿带后碰撞伸展阶段的重要的成矿产物。For the purpose of unravellng the mineralization time of the porphyry type molybdenum deposit in the Gangdese metallogenic belt,Tibet,five molybdenite samples from the Bangpu Mo-Cu polymetallic deposit are selected to carry out the Re-Os dating.The analysis yields an isochrone age of 14.92Ma±0.18Ma（MSWD=1.3）with a weighted mean age of 14.56Ma±0.18 Ma（MSWD=6.0）,consistent with the Re-Os isochron age of 14.67Ma±0.54Ma performed and provided by previous workers.It was shown that the rock-forming age mainly concentrated in 13 Ma～18Ma in the Gangdese belt,while the ore-forming age is in 13Ma～16Ma with a peak progress age of 15Ma.So,the age of 14.54Ma±0.093Ma presented the age of ore-forming of Mo and Cu of the Bangpu porphyry deposit,consistent with the mineralization of Gangdese metallogenic belt,indicating that mineralization occurred in the extension setting after the collision event of Gangdese belt.

关 键 词：RE-OS年龄 辉钼矿 斑岩铜矿 邦铺 西藏 

分 类 号：P578.291[天文地球—矿物学] P597.2[天文地球—地质学]