In order to investigate the source of ore-forming materials of the Deneng copper polymetallic deposit,the authors analyzed pyrite,galena,chalcopyrite and chlorites by electron microprobe analysis and also investigated Pb,S isotope compositions of galena,sphalerite and pyrite.The results of electron microprobe analysis shows that the sulfur content in the sulfides of the Deneng copper polymetallic deposit is lower than the theoretical value.S/Fe ratios of pyrite are from 1.067 to 1.094 (1.083 on average),Co/Ni ratios are more than 1,and cubic crystal{100 } pyrite is developed.According to the study,the authors have drawn the conclusion that the sulfide crystallized under the conditions of high temperature and high oxygen fugacity.Chemical analysis of chlorite shows the mineral is rich in Fe and belongs to prochlorite.Calculation yielded the formation temperatures of chlorite in the range of 185℃and266℃,with an average of 221℃.This indicates that ore-forming fluids might have evolved to low sulfur fugacity under middle-low temperature,acidic and reduction condition after the metallogenic period.The sphalerite,galena and pyrite have stable Pb isotopic compositions:208Pb/204Pb ratios from 38.937 to 39.217,207Pb/204Pb ratios from 15.640 to 15.718 of and 206Pb/204Pb ratios from 18.521 to 18.601.Theμ values of sulfides are between 9.53 and 9.68 and the ω values are from 38.29 to 39.76.The authors thus infer that the source of Pb might have been mainly derived from the metamorphic rocks of Nyainqentanglha Group.The δ34S values of sulfides vary in the range of + 6.6‰～ + 9.3‰,indicating that the source of S was probably derived from granitic magma.%为了示踪德能铜多金属矿床成矿物质来源,本文利用电子探针技术对黄铁矿、黄铜矿、方铅矿和绿泥石进行了矿物化学成分分析,测定了硫化物闪锌矿、方铅矿、黄铁矿的Pb和S同位素组成.结果表明,硫化物中硫含量均低于理论值,其中黄铁矿S/Fe值为1.067～ 1.094(平均1.083),Co/Ni＞1,立方体{100}晶形发育,指示其形成于较高温度、较高氧逸度和低硫逸度环境;绿泥石为富铁蠕绿泥石,形成温度为185℃～266℃,反映中低温、酸性、还原条件环境.硫化物铅同位素组成较稳定,208 pb/204 Pb比值为38.937～ 39.217,207 pb/204 Pb为15.640～15.718,206pb/204pb为18.521～ 18.601,μ值9.53～9.68,ω值38.29～39.76,指示其铅可能来源于念青唐古拉群基底变质岩;硫化物δ34S值为6.6‰～9.3‰,反映硫可能来自花岗质岩浆.
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