Abstract: The Gaozhuang gold deposit is an important gold deposit in southwestern Henan Province and has been studied by other researchers. However, the metallogenic province and epoch as well as ore types of the gold deposit are still poorly understood. In this paper, we performed Re-Os dating of pyrrhotite in the Gaozhuang gold deposit. The determined Re-Os age was 137±2 Ma, indicating the deposit was formed in the Late Yanshan Epoch. We also analyzed S and Pb isotopic and REE compositions of the gold-bearing mineral (pyrrhotite), the host strata (the Huoshenmiao Formation of the Erlangping Group) and the intrusive rock (the pluton rock mass). The δ34SCDT  value of ore sulphide was between -3.0‰ and -1.5‰ with an average value of -2.24‰, which suggests that sulfur may come from the deep source since its δ34SCDT  value was close to that of the original mantle sulfur (0±3‰), and that the sulfur ore may originate from the surrounding volcanic rock strata. Ratios of 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb for ore sulfides ranged in 17.10617.505, 15.46915.602 and 37.83538.194, respectively. The 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios for the Tangping intrusion ranged in 18.244319.2382, 15.594815.6935 and 38.504239.6163, respectively. And the 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb ratios for the host strata were of 18.176818.6692, 15.607115.8019 and 38.375939.0809, respectively. The above almost indistinguishable Pb isotopic ratios and their variation trend for the ore-lead, host strata and intrusion suggest that the ore-forming material is provided by both the host strata and the intrusion. The chondrite normalized REE distribution curves of the ore minerals were very similar to those of the Huoshenmiao Formation of the Erlangping Group, and they were all flat. The above results allow us to propose that the Gaozhuang gold deposit was formed in the Late Yanshan Epoch in the intracontinental metallogenic stage after the Qinling collisional orogeny. And the ore-forming material of the Gaozhuang gold deposit mainly comes from the host strata.

Key words: Re-Os dating, S and Pb isotopic and REE tracing, intracontinental mineralization, Gaozhuang gold deposit, southwestern Henan, China