地质学报2011，Vol.85Issue(6)：955-964,10.DOI:11-1951/P.20110517.1002.001
黔东南石英脉型金矿毒砂Re-Os同位素定年及其地质意义
Re-Os Isotope Dating of Arsenopyrite from the Quartz Vein-Type Gold Deposit,Southeastern Guizhou Province, and Its Geological Implications
摘要
Abstract
The quartz vein-type gold deposit in southeastern Guizhou, being one of the important parts of the Xuefeng polymetallic ore belt, has showed the potential prospect for exploration. However, there still have been disputes on understanding of mineralized mechanism, especially the origin of metallogenetic materials, mineralization epoch, and geochronology and geodynamical setting of mineralization. The gold-bearing minerals (arsenopyrites) collected from two main gold deposits (Pingqiu and Jinjing) in the region were used to conduct Re-Os dating. The results show that the altered slate type arsenopyrites from the Pingqiu gold deposit yield an isochron age of 400 + 24 Ma, with an initial 187Os/188Os ratio of 1. 24±0. 57 (MSWD=0. 96) ; while large quartz vein-type arsenopyrites from the Jinjing gold deposit yield an isochron age of 174±15 Ma, with an initial 187Os/188Os ratio of 8. 04±0. 45 (MSWD=1. 07). The former age belongs to Caledonian period, and is consistent with the formation age of EW-trending shearing zone in the region; the latter belongs to Indosinian-Yanshanian period, and may be associated with the contemporaneous tectonic-magma activities as revealed by widely exposed intermediate-acid rocks in the Xuefeng area and the concealed intrusive bodies in southeast Guizhou Province. It is firstly reported using sulphide Re-Os isotopic dating that at least two important gold mineralizations occurred in Calidonian and Indosinian-Yanshanian periods. In addition, the initial 187Os/188Os ratios also suggest that the metallogenic materials derived from the crust rock.关键词
Re-Os定年/毒砂/蚀变岩型/石英大脉型/金矿床Key words
Re-Os dating/ arsenopyrite/ altered slate type/ large quartz vein-type/ gold deposit引用本文复制引用
王加昇,温汉捷,李超,丁伟,张锦让..黔东南石英脉型金矿毒砂Re-Os同位素定年及其地质意义[J].地质学报,2011,85(6):955-964,10.基金项目
国家重点基础研究发展计划项目(编号2007CB411401),国家科技部专项(编号KCZX20100104)联合资助成果. （编号2007CB411401）
