大兴安岭南段道伦达坝铜钨多金属矿床年代学研究:来自石英包裹体40Ar-39Ar年龄的证据  

Chronology of the Daolundaba Cu-W Polymetallic Deposit,Southern Great Xing’an Range:Evidence from Quartz Fluid Inclusion 40Ar/39Ar Age

作　　者：张雪冰 包长甲 吴世山 ZHANG Xuebin;BAO Changjia;WU Shishan(School of Geology and Mining Engineering,Xinjiang University,Urumqi Xinjiang 830047,China)

机构地区：[1]新疆大学地质与矿业工程学院,新疆乌鲁木齐830047

出　　处：《新疆大学学报（自然科学版）（中英文）》2021年第1期83-90,共8页Journal of Xinjiang University(Natural Science Edition in Chinese and English)

基　　金：新疆维吾尔自治区自然科学基金(2018D01C042).

摘　　要：道伦达坝铜钨多金属矿床位于大兴安岭南段西坡中部,矿体形态规模受断裂构造控制,矿床成因类型为中高温热液脉型.本文应用双真空分步加热炉对钨锡矿化伴生的石英中流体包裹体开展40Ar-39Ar定年研究,得到黑钨矿-锡石-石英脉中石英样品(DL)流体包裹体40Ar-39Ar反等时线年龄为(140.6±2.2) Ma,与前人获得的LA-ICP-MS锡石U-Pb年龄(134.7~136.8 Ma)趋于一致,指示石英包裹体40Ar-39Ar年龄具有较好的地质意义,表明应用分步加热技术对含有富钾流体包裹体的石英矿物开展40Ar-39Ar定年研究可以获得有效的年龄结果.The Daolundaba Cu-W polymetallic deposit,located in the middle part of the west slope of SGXR,is a hydrothermal vein type deposit controlled by fractures,and Cu-W orebodies hosted in silty slate and biotite granite.In this study,we analyzed quartz crystals coeval with wolframite mineralization with an ArgusⅥnoble gas mass spectrometer using the furnace step-heated technique,and provide chronological data for metallogenic theory studies.Fluid inclusion 40Ar-39Ar dating of quartz samples(DL)from wolframite±cassiterite-quartz vein yields an inverse isochron age of(140.6±2.2)Ma.The inverse isochron age is good agreement with LA-ICP-MS cassiterite U-Pb ages indicates that the 40Ar-39Ar ages for quartz is geologically meaningful.Moreover,this study shows that the 40Ar-39Ar step-heated technique is effective for analyzing quartz with ingrown K-rich fluid inclusions and yield meaningful 40Ar-39Ar age.

关 键 词：大兴安岭南段 道伦达坝矿床 石英包裹体40Ar-39Ar定年 地质意义 

分 类 号：P581[天文地球—岩石学]