Abstract:The Zaozigou gold deposit, the most famous super large gold deposit in the Xiahe—Hezuo gold district witch in the West Qinling gold province, Gansu Province, has undergone continuous exploration and mining during the late two decades, with proved resources of more than 150 t. Although several investigations have conducted on this deposit, the ore- forming material sources remain disputed. Thus, we performed systematic trace elemental and H—O—Pb—S isotopic studies on fresh samples from drill hole SDZK8314, with main aims to reveal the sources of deep fluids and ore- forming materials in the Zaozigou gold deposit. Trace element data of various ores show similar partition curves, characterized by that the ore- bearing rocks have significantly lower ΣREE and higher K and Sr contents than surrounding rocks. In addition, the gold grade in various ores displays an obviously positive correlation with their contents of K2O. Lead isotopes show n(208Pb)/n(204Pb) ratios varying from 38. 23~39. 19 for quartz diorite porphyrite, 38. 23~39. 19 for pyrite and arsenopyrite, and 37. 75~38. 63 for stibnite, suggesting multi- sources and mixed lead characteristics, with corresponding variation trend from upper crust to orogenic belt (even mantle). H—O isotopes show that the ore- forming fluids of the Zaozigou gold deposit derive mainly from magmatic water, as well as the mixture of atmospheric precipitation during the later metallogenic stage. Sulfur isotopes show δ34S range from 14. 7 to -7. 0, with an average value of -10. 3. Through comparison with previous studies, we argue that the sulfur in ores is from magmatic and hydrothermal fluids, with partial low value sulfur from contaminated surrounding rocks. Accordingly, we propose that the formation of the Zaozigou gold deposit is closely correlated with the late magmatic—tectonic activity, and the ore- forming materials are originated from deep quartz diorites.