Unconventional non-magmatic sulfur source for the Mazarrón Zn-Pb-Cu-Ag epithermal deposit (SE Spain) Esteban-Arispe, Iñaki Velasco-Roldán, Francisco Boyce, Adrian J. Morales Ruano, Salvador Yusta, Iñaki Carrillo Rosúa, Francisco Javier Unconventional epithermal volcanic-hosted SE Spain Stable and radiogenic isotopes Thermochemical sulfate reduction Depósitos eptiermales encajados en rocas volcánicas no convencional SE de España Termo sulfato-reducción Isótopos estables y radiogénicos Este documento corresponde a una versión PREPINT (versión enviada originalmente a la revista, previa a las modificaciones sugeridas por los revisores). El artículo final ha sido publicado originalmente por la revista Ore Geology Review de la Editorial Elsevier. La URL del mismo es: http://dx.doi.org/10.1016/j.oregeorev.2015.10.005 This is a PREPRINT version (pre-refereeing process version). The final article has been published in Ore Geology Review by Elsevier. The URL is: http://dx.doi.org/10.1016/j.oregeorev.2015.10.005 Geological evidence and mineralogical, fluid inclusion temperature and geochemistry data suggest that the Mazarrón Zn-Pb-Cu-Ag-Fe deposit is a volcanic-hosted epithermal deposit. It is hosted by dacites with advanced argillic alteration, argillic alteration, propylitic alteration and silicification halos. K-Ar dating of illite from the argillic alteration gives an age of 9.7 ± 1.2 Ma, which suggests that mineralization took place very close to the volcanism. The fluid inclusion study in the ore veins shows epithermal temperatures (between 190 and 260ºC), but moderate salinities, between 12 and 18 wt. % NaCl eq), compatible with mixing between surface waters and polygenic deep hydrothermal fluids. Two mineralization types are identified: iron sulfide mineral association and polymetallic mineral association (sphalerite-galena-chalcopyrite-fahlore bearing). According to isotopic data, the first mineralization was mainly formed by interaction between basinal fluids that leached Triassic sulfates (+ surface waters), and C-bearing reduced deep waters. This interaction developed a Thermochemical Sulfate Reduction (TSR) supporting extreme and geologically unusual fractionation, with a range up to +30‰ δ34S, and reaching +53‰ δ34S. The second mineralization event is compatible with the irruption of a magmatic fluid discharge. Although this study suggests that Mazarron could be classified as an intermediate sulfidation deposit, the genetic model includes processes such as TSR that are not typical features of volcanic-hosted epithermal deposits. 2015-11-23T14:49:17Z 2015-11-23T14:49:17Z 2015 info:eu-repo/semantics/preprint Esteban-Arispe, I.; Velasco-Roldán, F.; Boyce, A.J.; Morales-Ruano, S.; Yusta, I.; Carrillo-Rosúa, J. Unconventional non-magmatic sulfur source for the Mazarrón Zn-Pb-Cu-Ag-Fe epithermal deposit (SE Spain). Ore Geology Reviews: online (2015). [http://hdl.handle.net/10481/38950] (preprint version) 0169-1368 http://hdl.handle.net/10481/38950 10.1016/j.oregeorev.2015.10.005 eng http://creativecommons.org/licenses/by-nc-nd/3.0/ info:eu-repo/semantics/openAccess Creative Commons Attribution-NonCommercial-NoDerivs 3.0 License Elsevier