Research on Metallogenic Model of Shuangpengxi Gold Copper Deposit in Qinghai

Shuangpenxi gold copper deposit is located in Tongren-Zeku metallogenic belt of Western Qinling.The ore bodies occurred in the outer contact skarn zone between Indosinian granodiorite and Carboniferrous-Permian Ganjia Formation carbonate.It is one of the typical skarn deposits.Metallic minerals in the ore include mainly pyrrhotite,pyrite,chalcopyrite,limonite,while gangue mineral are mainly quartz,calcite,tremolite,diopside.Ore-forming processes have experienced three stages of mineralization,skarn,quartz-sulfide and supergene.Research of stable isotope geochemistry of the ores indicates:δD varying from-56‰ to-49‰,δ18O varying from +9.2‰ to +9.4‰,implying that ore-forming fluids are magmatic water.δ34S vary from +5.1‰ to +6.6‰,suggests sulphur is derived from magma in depth.δ13C vary from-8.9‰ to-8.4‰,indicating δ13C is derived from deep magma.Skarn metallogenic model of Shuangpengxi gold copper deposit has been built initially combining geological characters,which has some useful significance to the ore prospecting work in the area.