西藏邦铺斑岩型钼铜多金属矿床含钼铜脉石英的激光显微探针^(40)Ar/^(39)Ar年龄及地质意义  

LASER MICROPROBE ^(40)Ar/^(39)Ar DATING ON VEIN QUARTZ CONTAINING Mo AND Cu IN THE BANGPU PORPHYRY-TYPE Mo-Cu POLYMETALLIC DEPOSITS,TIBET

作　　者：周雄[1,2] 温春齐[1] 温泉[1] 费光春[1] 曹盛远 周玉[1] 吴鹏宇[1] 

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]中国地质科学院矿产综合利用研究所,四川成都610041 [3]四川省地质矿产开发局一○九地质队,四川龙泉610100

出　　处：《矿物岩石》2011年第1期43-48,共6页Mineralogy and Petrology

基　　金："十一五"国家科技支撑计划项目(2006BAB01A04);成都理工大学矿物学;岩石学;矿床学国家重点(培育)学科建设项目(SZD0407);中国地质科学院矿产综合利用研究所青年基金(D0701S-3)

摘　　要：采用激光显微探针40Ar/39Ar微区定年方法,对西藏邦铺钼铜多金属矿床中含矿脉石英进行微区年代测定,获得等时线年龄为13.9 Ma±0.9 Ma(MSWD=29),其下限(13 Ma)代表了成矿年龄。该年龄略晚于二长花岗斑岩结晶年龄(13.9 Ma±0.3 Ma,MSWD=3.05),表明邦铺矿床成岩成矿作用是一个连续的岩浆作用过程。同时对冈底斯斑岩铜矿带成岩-成矿年龄进行统计学研究,获得冈底斯斑岩铜矿带成岩-成矿作用高峰期为15 Ma,成岩-成矿年龄线性方程为Y岩=1.291X矿+7.785(R2=0.291),充分说明邦铺矿床与冈底斯斑岩铜矿一样,是一次大规模爆发成矿的过程,成矿事件发生具有高度的统一性与集中性。Continuous laser microprobe 40Ar/39Ar technique has been used to analyze the ore-bearing vein quartz,in the Bangpu porphyry-type Mo-Cu polymetallic deposits.A 40Ar/39Ar isochron gives out an age of 13.9 Ma±0.9 Ma（MSWD=29）,representing the age of mineralization which is somewhat lower than the crystallization age（13.9 Ma±0.9 Ma,MSWD=3.05） of monzonite granite-porphyry,and indicating that the rock-forming and ore-orming process is a continuous magmatic process.Meanwhile,a statistic study of rock-forming and ore-forming ages of Gangdese porphyry copper belt shows that its peak progress age is 15 Ma with the linear equation of Yrock=1.291Xore＋7.785（R2=0.291）,suggesting that the formation of Bangpu deposit is the same as the Gangdese belt,characterized by explosive ore-forming progress with uniform and intensive ore-forming events.

关 键 词：激光显微探针 40AR/39AR年龄 脉石英 斑岩型 钼铜多金属矿床 西藏邦铺 

分 类 号：P597.3[天文地球—地球化学]