Sulfur isotopic compositions of the Huize super-large Pb-Zn deposit, Yunnan Province, China: Implications for the source of sulfur in the ore-forming fluids

The Huize Pb-Zn deposit of Yunnan Province, China, is located in the center of the Sichuan-Yunnan-Guizhou Pb-Zn-Ag district. Four primary orebodies (orebody No. 1, No. 6, No. 8 and No. 10), with Pb+Zn reserves from 0.5 Mt to 1 Mt, have been found at depth in this deposit. This paper provides new data on the sulfur isotopic compositions of the four orebodies. The data show that the principal sulfide minerals (galena, sphalerite and pyrite) in the four orebodies are enriched in heavy sulfur, the delta S-34 values between 10.9 parts per thousand and 17.7 parts per thousand and where delta S-34(pyrite) > delta S-34(sphalerite)> delta(34)S(galen)a. The delta S-34 values of sulfide are close to that of the sulfates from the carbonate strata within the region. The similarity in sulfur isotope composition between sulfides and sulfates indicates the sulfur in the ore-forming fluids was likely derived by thermochemical sulfate reduction of sulfates contained within carbonate units. (C) 2006 Published by Elsevier B.V.