Geological and Geochemical Characteristics of the Shizishan Ore-Field in Anhui Province

The Shizishan ore field is the largest Cu-Au ore-field in the Tongling cluster, Anhui province. Several Cu-Au deposits, including Dongshizishan, Xishizishan, Datuanshan, Laoyaling, Dongguashan and Huashupo, are embedded in Upper Carboniferous to Middle Triassic strata and occur in the vicinity of intrusions. According to the temporal and spatial relationship between mineralization and igneous intrusions, three ore types can be distinguished: stratabound skarn type, skarn type and hydrothermal vein type. The two skarn types are economically most important. Mineralization of the Shizishan ore-field relates to Hercynian and dominant Yanshanian magmatism. The intermediate-acid intrusions are the main sources of the metals of the Cu deposits in the Shizishan ore-field. The main magma as quartz diorite, pyroxene monzodiorite and granodiorite are high calc-alkaline series rocks, which originate in orogen granite. The geochemical characteristics of the rock show the magma coming from the mantle with mixing of high Na₂O and K₂O country rock by assimilate-contamination during the magma intrusion into the crust. Therefore, the different magma rocks have a relationship to the rock genesis.