Dongguashan Cu-Au deposit is one of representative and typical deposits in Tongling, Anhui Province, China. The upper orebodies of the Dongguashan deposit are obviously hosted in the Carboniferous limestone. They are mainly stratabound skarn-type orebodies in bedded or bedded-like. The lower orebodies are rigidly controlled by the magmatic intrusions and the contact zones between the magmatic intrusions and wallrocks, and developed in veins or venlet-disseminated. The ore types of the upper stratabound skarn orebodies are mainly quartz-sulfides who contain copper and gold. delta(34)S values of sulfur-bearing minerals in the ores suggested sulfur isotope equilibrium reached in hydrothermal systems. Contrasting to the sulfur isotope composition of typical deposits in the world, the delta(34)S values of sulfide and the delta(34)S values of sulfate of the Dongguashan deposit are respectively different from Sedex-type deposit and VHMS-type deposit, while both values of the Dongguashan deposit are closed to porphyry deposit. Based on mineral paragenesis, physicochemical conditions and the reservoir effect of sulfur isotope given by Zheng and Hoefs (1993), it is indicated that H(2)S is the most effective sulfur-bearing species in the sulfide stage (X(H2S) > 0. 99), which suggested that the reservoir effect of sulfur isotope would hardly influence the delta(34)S(Sigma S) values of hydrothermal system. Applying the ohmoto' s medol, it is obtained that the Delta(34)S values for sulfur fractionation between hydrothermal solution and magmatic melt range from 0 parts per thousand to + 5 parts per thousand. So the sulfur isotope composition of hydrothermal solution come front magma could range from +0. 3 parts per thousand to 12. 0 parts per thousand according to the sulfur isotope composition of whole magamatic rocks. Delta(34)S values for sulfur fractionation between sulfate and hydrothermal solution range front + 5. 0 parts per thousand to + 19. 0 parts per thousand in high temperature (600 similar to 350 degrees C) front silicate stage to oxide stage. Delta(34)S values for sulfur fractionation between pyrite and hydrothermal solution range front -1 parts per thousand to 0 parts per thousand in high temperature (450 similar to 350 degrees C), 0 parts per thousand to + 1. 5 parts per thousand in low temperature (350 similar to 200 degrees C), from oxide stage to sulfide stage. So that the theoretical delta(34)S values of sulfur isotope composition of sulfur-bearing minerals crystallized from hydrothermal solution are basically consistent with the actual delta(34)S values of ore minerals in Dongguashan deposit, which indicate that the sulfur of ore minerals should derived front magma. Combined with the pioneers' researches on regional and ore deposit geology, it is suggested that the Dongguashan deposit was a stratabound Cu-Au skarn deposit which closely related to the Yanshanian magmatism. The relative high delta(34)S values of the magma and its related hydrothermal solution imply that the magma hybridized sulfate developed widely in regional sedimentary. Although the regional sedimentary rocks experienced sedimentation front sea water and reduction caused by anaerobic bacteria in diagenetic stage, but there is no sulfur isotopic evidence conserved for the Dongguashan deposit experienced Hercynian submarine depositional mineralization.
