新疆阿尔泰蒙库铁矿床的辉钼矿Re-Os年龄及意义  

Re-Os Age of Molybdenite from the Mengku Iron Deposit in Altay,Xinjiang and Its Implication for Metallogeny

作　　者：杨富全[1] 张志欣[1] 屈文俊[2] 耿新霞[1] 吕书君[3] 柴凤梅[4] 姜丽萍[4] 刘锋[1] 

机构地区：[1]中国地质科学院矿产资源研究所国土资源部成矿作用与资源评价重点开放实验室,北京100037 [2]国家地质实验测试中心,北京100037 [3]中国地质大学,北京100083 [4]新疆大学地质勘查与工程学院,乌鲁木齐830046

出　　处：《地质学报》2011年第3期396-404,共9页Acta Geologica Sinica

基　　金：国家自然科学基金项目(编号40672065);"十一五"国家科技支撑计划重点项目(编号2006BAB07B02-01);国土资源大调查项目(编号1212010786006;1212010786004)联合资助的成果

摘　　要：蒙库大型铁矿位于阿尔泰南缘麦兹盆地,赋存于晚志留世-早泥盆世变质火山-沉积岩系中,容矿岩石为石榴石矽卡岩、变粒岩、浅粒岩和大理岩。矿体总体顺层分布,空间上与矽卡岩密切相关。对1号矿体含黄铁矿辉钼矿石英大脉中辉钼矿Re-Os同位素年代学进行了研究,7件样品的Re-Os同位素模式年龄为(261.6±3.7)～(264.0±3.6)Ma,加权平均值为262.9±1.4Ma,等时线年龄为261±6.9Ma,表明蒙库矿区在中二叠世晚期存在一次热液活动和铜钼矿化事件,同时也限定了铁主成矿时间早于中二叠世,可能是早泥盆世。辉钼矿样品的Re含量为(22.74～35.69)μg/g,指示钼铜成矿物质具有壳幔混合的特征。The Mengku large-size iron deposit occurs in metavolcanic-sedimentary sequence of the Upper Silurian-Lower Devonian Kangbutiebao Formation in the Maizi Basin of south Altay,with the host rocks being garnet skarn,granulitite,leucogranulitite and marble.Ore bodies are largely concordant with the bedding of the strata,and the distribution of the ore bodies is spatially related to skarn.Precise Re-Os dating of molybdenite from the pyrite-molybdenite-quartz large vein in the No.1 orebody of the Mengku iron deposit has been carried out in this study.The results show that the Re-Os model ages of seven samples rang from（261.6±3.7）Ma to（264.0±3.6）Ma,weighted mean ages of（262.9 1.4）Ma with a Re-Os isochron age of（261±6.9）Ma.Re-Os dating of molybdenite suggests that the hydrothermal activity and Cu-Mo mineralization in the Mengku deposit occurred in the late Middle Permian.The ages of 261±6.9 Ma of molybdenite provide the latest time of mineralization ages and the iron main mineralization perhaps took place in the Early Devonian.The rhenium contents of molybdenite samples range from（22.74～35.69）μg/g,which indicate that Mo-Cu was derived from both mantle and crust.

关 键 词：Re-Os年龄 二叠纪 铁矿床 蒙库 阿尔泰 

分 类 号：P618.31[天文地球—矿床学] P597.3[天文地球—地质学]