Ore-forming processes of the Qixiashan carbonate-hosted Pb-Zn deposit, South China: Constraints from sulfide trace elements and sulfur isotopes

The Middle-Lower Yangtze River Valley Belt (MLYRB) in South China contains many stratabound Fe-Cu-Pb-Zn deposits hosted Middle-Upper Carboniferous carbonates. origin and nature of the ore fluids are poorly constrained (syngenetic vs. epigenetic). Trace elements sulfur isotope compositions sphalerite galena from Qixiashan carbonate-hosted Pb-Zn deposit (Eastern MLYRB) help to clarify ore-fluid source metallogenic processes. Three types sphalerites have been distinguished (black a, zoned b light color c). High Fe Mn contents early black (Sp-a) were possibly derived preceding Fe-Mn-rich sulfide layer or sediments ore-bearing strata via replacement at 274–315 °C. (Sp-b) has a dark Fe-Cu-rich core (321–348 °C) overgrown by Fe-Cu-poor rim (285–314 °C). Sp-b rims compositionally similar Sp-a, Therefore, represents transition stage poor copper rich (Sp-c) fluids. light-color late is characterized Fe-Mn depletion, as well Ga, Cu, Cd Sn enrichments. Ga-rich Sp-c was precipitated mixing Ga-bearing sulfate metalliferous fluid 146–255 We considered be epigenetic that undergone multistage ore-forming processes, which (?34S: –3.7‰ +7.8‰) sourced seawater (+22‰) thermochemical reduction (TSR).