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.