Trace elements and sulfur isotopic composition of sedimentary pyrite on con-straining ore genesis of Huangjindong gold deposit
The Huangjindong gold large-scale deposit is located in the northeastern Hunan ore cluster,Jiangnan orogen-ic belt,and the ore bodies mainly occur in the slate of the Neoproterozoic Lengjiaxi Group,and auriferous quartz vein is the main ore type. In order to further restrict the sources of gold and sulfur in the ore-forming system,re-veal the role of wallrock to the mineralizing system,and finally make a better understanding of the genesis This paper focuses on the sedimentary pyrite from slate of the Lengjiaxi Group,systematic analyses including petrog-raphy,microstructure using electron probe,laser in situ trace elements and sulfur isotope were conducted. The re-sults show that sedimentary pyrite occurs as assemblages and the individuals is mostly of hundreds to thousands of μm in size. LA-ICP-MS trace element analytical results show that w(As) concentrations vary from 796×10-6 to 10 667×10-6,and invisible w(Au) is mostly less than 1.0×10-6. In situ S isotope analytical results reveal that δ34S value of sedimentary pyrite mainly ranges from-10.7‰ to-4.7‰,which is similar to the hydrothermal pyrite in the ore (δ34S=-14.2‰ to-0.5‰). All results suggest that the majority of Au is sourced from wallrock,indicating Au is mainly associated with deep processes. During the fluid-rock interaction processes,sedimentary sulfur add-ed to the mineralization system,which gives implications for the interpretation of S isotope composition of hydro-thermal pyrite in Huangj indong deposit.
sedimentary pyriteIn-situ trace elements and S isotopeHuangjindongnortheastern Hunan ore clusterJiangnan orogenic belt
国家科技期刊平台
NSTL
万方数据
