The Origin of the Caiyuanzi Pb–Zn Deposit in SE Yunnan Province, China: Constraints from In Situ S and Pb Isotopes

Located at the intersection of Tethys and Pacific Rim metallogenic belts, Laojunshan polymetallic province in SE Yunnan Province hosts many large-scale W–Sn Sn–Zn deposits. The newly discovered Caiyuanzi medium-sized Pb–Zn deposit is located northern part this has eight sulfide ore bodies. All bodies occur siliceous rocks Lower Devonian Pojiao Formation (D1p). are conformable with stratigraphy controlled by a lithologic horizon. ores have banded or laminated structures. minerals mainly pyrite, chalcopyrite, sphalerite, galena. In study, situ sulfur lead isotopes were used to constrain origin deposit. results show that δ34S values sphalerite range from 0.1‰ 6.0‰, an average 4.7‰. This signature reflects mixing between magmatic-derived reduced seawater sulfate sulfur. Pb characteristics galena, suggest come upper crust. Integrating data obtained studies including regional geology, S–Pb isotope geochemistry, we proposed hydrothermal formed sedimentary exhalative magmatic superimposition.