新疆阿尔泰阔克锌铜多金属矿床成矿作用OA

The Kuohe is a newly discovered polymetallic zinc-copper deposit in the Supute area of southern Altay in re-cent years.It includes a polymetallic zinc-copper mineralization system related to marine volcanic activity(miner-alization zones Ⅰ-Ⅳ)and a copper mineralization system related to magmatic hydrothermal process of diorite porphyrite(mineralization zone Ⅴ).The polymetallic zinc-copper mineralization system related to marine volca-nic activity is hosted in the Lower Devonian Kangbutiebao Formation volcanic-sedimentary rock series.The min-eralization zones and ore bodies are parallel to the bedding.The mineralization is mainly disseminated,veinlet,and stockworks types,the main metallogenic elements are zinc,copper,lead,gold,and silver,and has undergone the epidote stage,quartz-zinc-copper stage,and quartz-polymetallic gold stage.For the scientific issue of the metallogenesis of this mineralization system,studies on the geological characteristics of the deposit,in-situ sulfur isotope,microthermometry of fluid inclusions,and hydrogen and oxygen isotopes of quartz have been carried out.The results show that the δ34S values of sulfides range from-1.30‰ to 10.23‰,with an average of 4.20‰,indicating that the ore-forming material originated from marine volcanic rocks or volcanic gases.The homogeni-zation temperature of the quartz-polymetallic gold stage is 161～410℃,the fluid salinity w(NaCl)eqv is 0.20％～14.64％,and the density is 0.55～1.01 g/cm3,suggesting that the ore-forming fluids were a H2O-CO2-NaCl system that evolved from high to low temperature,medium to low salinity and medium to low density.The δDSMOW of quartz is-140‰ to-90‰,and the δ18OH2O value is-3.0‰ to 3.2‰,indicating that the ore-forming fluids were a mixture of deep-circulating seawater and magmatic water.Due to the decrease in temperature and pressure,water-rock exchange reactions,fluids mixing and other factors,gold,copper,and zinc minerals precipitated.In summa-ry,the polymetallic zinc-copper deposit(mineralization zones Ⅰ-Ⅳ)is a volcanic hydrothermal deposit formed within a marine volcanic-related mineralizing system.