Metallogenic Material Source and Genesis of the Jilinbaolige Pb-Zn-Ag Deposit, the Great Xing’an Range, China: Constraints from Mineralogical, S Isotopic, and Pb Isotopic Studies of Sulfide Ores

Abstract

The Jilinbaolige Pb-Zn-Ag polymetallic deposit is located in the eastern part of Inner Mongolia and in the central-southern part of the Great Xing’an Range, in which several large-sized Pb-Zn-Ag deposits have been found. The Jilinbaolige deposit, which occurs mainly at the contact zone between Yanshanian granite intrusion and sedimentary strata, shows strong NE-to-NNE structural control. The deposit includes three ore-forming stages: (1) the arsenopyrite–pyrite–chalcopyrite–sphalerite stage, (2) the galena–sphalerite–quartz stage, and (3) the pyrite–calcite–quartz stage. In this study, we present a systematic study on the mineralogical and geochemical characteristics (including major elements, S isotopes, and Pb isotopes) of the main sulfide ore minerals in the Jilinbaolige Pb-Zn-Ag deposit in order to evaluate the metallogenic environment, ore-forming material source, and genesis of this polymetallic deposit. The sulfide typomorphic characteristics, ore fabric, and thermometry suggest that the genesis of sulfides in the deposit is closely related to magmatic-hydrothermal activity. The early stage of mineralization might have evolved from a high-temperature hydrothermal environment. The sulfur isotopic results show that the δ34S values in the Jilinbaolige deposit range from 2.3‰ to 6.1‰, with an average value of 3.98‰, indicating that the sulfur originated from magmas with both mantle and crustal components. The Pb isotopic compositions (206Pb/204Pb = 18.214–18.330, 207Pb/204Pb = 15.478–15.615, 208Pb/204Pb = 37.957–38.292, μ = 9.24–9.50, ω = 34.49–36.49) of the sulfide ores suggest that that the lead is of crust-mantle mixed origin. The comparison between the S and Pb isotopic compositions of the Jilinbaolige deposit and the polymetallic deposits from the central-southern parts of the Great Xing’an Range suggests that these deposits have a similar metallogenic source, which is closely related to the Yanshanian granite and medium-temperature hydrothermal fluids. These ore-bearing hydrothermal fluids that evolved from deep magmatic sources migrated along the contact and fracture zones and during the subsequent gradual decrease in temperature, and the metallogenic components were deposited in the relatively open fracture and fissure space. Our results provide insights for further mineral prospecting in the south-central part of the Great Xing’an Range.