The Study Of The Metallogenic Characteristics And Genesis Of The Aqishan Pb-Zn Deposit,East Tianshan,Xinjiang

Aqishan lead-zinc deposit is located at east Tianshan metallogenic belt,Xinjiang,it is a newly discovered deposit.In this paper,through the study of ore deposit geological features,mineralogy,ore microscopy,rock geochemical study in Aqishan lead-zinc deposit,we got the following conclusions.(1)Review the controlling ore geological factors,including the stratum,rock body and structure,confirm the ore-forming geological body.By using of major and trace element analyze for magmatite and volcanic rocks from Aqishan lead-zinc deposit.The findings suggest that samples relative enrichment of large ion lithophile elements and depletion of high field strength element.And it also shown in research area magma sources were influenced by partial melting of crust material.(2)Through mineralogical study of garnet by electron probe.Garnet collected from Aqishan lead-zinc deposit has two obvious stages,The diagenetic environment of early garnet was weakly alkaline and reduced with high oxygen fugacity,the garnet of later stage diagenetic environment shifted from weakly alkaline to acidic and the oxygen fugacity decreased.Through the study of ore microscopy shown that garnet from prior to the mineralization and can provide space for the precipitation and the migration channel for ore-forming fluid.(3)Petrogenesis and tetonic discrimination analysis of granites and basalts,the granite belongs to I-type granite.In late Carboniferous,the tectonic setting for formation of the granite was volcanic arc,which was formed after collisional orogenic process and late extension.Tectonic setting of basalts was intraplate extensional environment on active continental margins.(4)Sulfur-lead isotope research of ore samples collected from Aqishan lead-zinc deposit.The result shown that the source of sulfur in ore is relatively uniform,which was came from deep source magma,with involvement of small amount organic reductive sulfur from Ymansu(C1y)Formation.The isotopic composition of lead characteristics shown that ore lead is normal causes radioactive lead,the ore-forming material of lead may mainly came from the mantle sources,besides it was influenced by the earth`s crust lead contamination in the process of the ore deposit formation.(5)Systematically combine with ore deposit geological features and testing & analyzing results of samples,we may get a preliminary conclusion that Aqishan lead-zinc deposit is submarine volcanic type.