S and Pb Isotope Geochemistry of the carbonate-hosted Au-Ag-Zn +/- Pb deposits in the Maden Village (Ulukisla-Nigde), Central Taurides, South Turkey

The Maden Village carbonate-hosted Au-Ag-Zn +/- Pb deposits in the Bolkar Mountains that are part of the Tauride platform, south of Turkey, contain significant none- sulfide ore and relicts of sulfide bodies. The deposits hosted in the Upper Triassic carbonate rocks of the Bolkar Mountains are controlled by E-W trending and 36-45 degrees S-dipping faults, and karst- related structures. The deposits is a formed by supergene oxidation of primary sulfide minerals during complex interaction of tectonic uplift, karst development, changes in the level of the water table and weathering. Zn (Pb) carbonates, Zn-hydrosilicates and associated hydrated phases directly replace the primary ore bodies or fill cavities and pods along fractures within marble are genetically related to the uplift of Tauride block during Oligo-Miocenc period. The supergene deposits recharacterized by open space and karst-filling feature. Direct replacement of primary sulphide is accompanied by distal precipitation of non-sulphide minerals in cavities. The mineralogy of non-sulfide minerals consist of cerussite, anglesite, smithsonite, limonite, pyrolusite, psilomelane, manganite, chalcophanite, beudantite, goethite, lepidocrocite, hemimorphite, mimetite, corkite and native gold. In the sulfide ore bodies of Maden Village deposits, the delta S-34 isotope values of galena vary from 3.0 to 5.8 parts per thousand V-CDT and imply that sulphur originated from a mixture of different sources (meteoric, magmatic hydrothermal fluids). The lead isotope data for galena showed mean values of 18.991,15.701, and 39.056 for Pb-206/Pb-204,Pb-207/Pb-204, and Pb-208/Pb-204, respectively. The distribution of the lead isotope ratios shows a cluster in the deposit that is related to the upper crust. The fluid inclusions in sphalerite show that the homogenization temperatures values of up to 290 degrees C, at a salinity of 6.2 wt.% NaCl equiv. In this study, we propose that ore forming fluids were originally derived magmatic hydrothermal fluids, and that they were mixed with low salinity meteoric water. The re-modified sulfide Pb-Zn mineralization resembles a 'residual and karst fill' sub type of nonsulphide zinc deposits. Au and Ag bearing minerals in the supergene environment consist of native gold hosted in limonite and Ag-bearing cerussite and anglesite.