Metallogenic model and geological features of Au(Cu-Ag) deposits related to volcanic-porphyry in the eastern region in Jilin Province

Au(Cu-Ag) deposits which are related to volcanic-porphyry can be divided into epithermal lowthermal Au(Ag) deposit and epithermal mesothermal porphyry Au(Cu) deposit in two subgroups.In the eastern region of Jilin Province.The characteristic mineral assemblage of epithermal deposits are pyrite,quartz,calcite,adularia and barite.The cause of formation is related to the high-K calc-alkaline volcanic rocks-porphyry(137 ～ 177Ma).The ore-forming fluid belongs to epithermal fluid oxidation,atmospheric precipitation mixed with a large degree in the process of mineralization.The characteristic mineral assemblage of mesothermal porphyry deposits is pyrite,chalcopyrite,magnetite and quartz.The cause of formation is related to the calc-alkaline volcanic-porphyry(130 ～ 140Ma).The ore-forming fluid belongs to mesothermal fluid reduction,atmospheric precipitation mixed with a large degree in the process of mineralization.because volcanic-porphyry has different depth of sources,its porphyry plays a diferent role in deposit's formation and its oreforming fluid has different character,it give different style of Au deposit.because volcanic-porphyry has different depth of sources,its porphyry plays a different role in deposit's formation and its ore-forming fluid has different character,it give different style of Au deposit.