Geological Characteristics and Genesis of the Jingdonggou Gold Deposit in Pingwu County,Sichuan Province

Jindonggou gold deposit is a small gold deposit located in Pingwu County,north of Sichuan Province.Based on a studied geological characteristics of the Jindonggou gold deposit,the authors measured the homogenization temperature,salinity,chemical composition,as well as H and O isotopic compositions of the fluid inclusions of the quartz,measured S isotopic composition of the metal sulfide(pyrite,galena and sphalerite),and systematically discussed the metallogenesis of the gold deposit.The results show that the deposit belongs to epithermal gold deposit type.The ore-forming source comes from the epimetamorphic clastic rocks of Smx(Silurian System).This gold deposit is characterized by a poor content of sulfide minerals(below 1%).Metallogenic fluid is composed of atmospheric precipitation.The homogenization temperature of fluid inclusions ranges from 125 ℃ to 185 ℃,belonging to epithermal gold deposit type.The metallogenesis of the Jindonggou gold deposit is divided in to four stages,i.e.the formation of gold source bed in the sedimentation,the formation of derivative gold source bed in the regional metamorphism,the formation of the gold deposit in the hydrothermalism and hypergenesis.The regional shear zone movement is likely the major factor leading to activation,migration and concentration of Au.The conclusions are significant for realization of the deposit genesis and mineral exploration.