Porphyry Cu,Epithermal Ag-Pb-Zn,Distal Hydrothermal Au Deposits:a New Model of Mineral Deposit——Taking the Dexing Area as an Example

Based on the previous studies and detailed field investigations in the Dexing porphyry Cu deposit,the Yinshan Ag-Pb-Zn deposit and the Jinshan shear zone-hosted Au deposit in the Dele Jurassic volcanic basin in the northeastern Jiangxi Province,East China are proposed to be same metallogenic system in this paper.The Dexing is a typical porphyry Cu-Au-Mo deposit in which both ore-forming fluid and elements are derived from the granite porphyry.The Yinshan consists of porphyry Cu ore at the copular of quartz porphyry in the lower part and the vein type Ag-Pb-Zn ore in the upper part.The hydrothermal fluid was mainly derived from the magma in the early stage and was incorporated with more meteoric water in the late stage.Its ore-forming elements are mainly from the magma.The both Jinshan and the Hamashi,a quartz vein type gold deposit hosted by brittle fractures,are distal hydrothermal deposits,which were formed by mixed fluids of magmatic and meteoric water whereas the Au is mainly leached from the country rocks of Middle Proterozoic schists of the Shuangqiaoshan Group.These deposits spatially show a distinct zoning of porphyry Cu,epithermal Ag-Pb-Zn and distal Au from the granite porphyry of quartz porphyry outside.In this case we suggest a new model entitled in porphyry-epithermal-distal system model for the group of mineral deposits with genetic relationship.