BAO Tan1,2, YE Lin1, YANG Yu-long1,2, LI Zhen-li1,2
(1. State Key Laboratory of Ore Deposit Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China;
2. School of Chinese Academy of Sciences, Beijing 100049, China)
Abstract：Baoshan Cu-Mo-Pb-Zn-Ag polymetallic ore deposit, located in Hunan Province, South China, is one of the most famous deposits in Nanling non-ferrous metal belt. This deposit shows characteristics of multiple element mineralization, large ore reserve and typical zonation from skarn-type minerazation to distal hydrothermal veins. In this paper, we report the sulfur isotope compositions of ores to discuss the source of ore-forming material. The sulfur isotopic compositions of the sulfides show characteristic of δ34Spyrite>δ34Ssphalerite>δ34Sgalena, which indicates that sulfur isotope in ore-forming fluid have reached equilibrium. The sulfur isotopic compositions of the sulfides show characteristics of lower positive value and narrow change range. The values of δ34S are concentrated in the range of 1.5‰ to 4.5‰, with the peak value of 3‰, and are significantly lower than those of carboniferous carbonate rock (17.8‰－22.6‰). With the characteristic of magmatic sulfur, the sulfur in ore-forming fluid mainly came from Yanshanian granodioritic porphyry, whereas sulfur from strata contributed relatively little. In addition, the δ34S values of sulfide from the different ore-bearing stratas are roughly the same and the values of δ34S do not have zonation surround by granodioritic porphyry, indicating that the origin of sulfur should be coherent. As a consequence, We believe that Pb-Zn polymetallic mineralizations, situated in Ximengqiao formation of dolomite, Ceshui formation of sand-shale and Shidengzi formation of limestone, the Lower Carboniferous Series, have the same genetic relation and they should be the evolvement products of the same magmatic-hydrothermal system.
Key words: polymetallic ore deposit; sulfur isotope composition; magmatic sulfur; Baoshan, Hunan Province
ACTA MINERALOGICA SINICA Vol. 34, No. 2, 2014, Page 261-266
