Geology and Geochemistry of the Nage Cu-polymetallic Sulfide ore Deposit,Southeast Guizhou Province,China

The Nage Cu polymetallic ore deposit locates in the southwestern Jiangnan orogenic belt,a transitional zone of the Yangtze craton and the cathaysia.The ore body occurs in metamorphosed sedimentary rocks of the Jialu(Qbj) and the Wuye(Qbw) formations of the Qingbaikou System,and is controlled by north-to-south orientated F1 fault and west-to-east orientated F2 fault.Studies had revealed that magmatic activities of the neoproterozoic were very active in this region,ultra-basic rocks,basic rocks,and acid intrusive rocks were widely developed,and the largest magmatic rock of this region is the Motianling granite.The ores apparently relate with the magmatic activities of neoproterozoic and usually can be found in the Nage and Jiabang diabase.The H and O isotopic compositions of quartz indicated that the ore-forming fluids mainly came from magmatic water and partially assimilated with metamorphic water;the S isotopic compositions of sulfides implicated that the ore-forming sulfur is of anatectic origin;the Pb isotope ratios suggested the Nage and Jiabang diabase and the metamorphosed sedimentary rocks are the parent-material for the deposit,while the magmatic activities provided necessary thermal energy.After summarized the geology and geochemistry data,we believed that the Nage Cu polymetallic deposit is a magmatic-hydrothermal polymetallic deposit.