Sulfur source tracing of sulfide and sulfate minerals in fluorite Mines of the Elika Formation (East of Mazandaran Province): Implications of sulfur isotope

Sulfur source tracing based on of sulfide (galena and pyrite) and sulfate (barite) mineralization in fluorite deposits of Elika Formation (East of Mazandaran Province) is studied. In present research. δ34S values vary between -1.82 – +12.49 ‰, +13.22 – +25.83 ‰ and +22.69 – +32.91 ‰ for galena, pyrite and barite, respectively. Regionally, although wide range of δ34S in sulfides is interpreted as isotopic heterogeneity of source and/or processes of reduced sulfur supply for sulfide mineralization in the studied area, but each deposit has narrow range of δ34S. Compared to sulfides, barites show isotopic homogeneity in heavier δ34S which are corresponding to evaporates from coexisted sea water (Middle-Upper Triassic; Paland Formation). Based on stratigraphic and mineralogical data of host rocks, co-existing evaporates of Triassic sea water and also diagenetic primary sulfates in matrix of host rocks (anhydrite, gypsum, barite) are introduced as the most probable sources of sulfur for sulfide mineralization in Shesh Rodbar and Era deposits. In contrast, contribution of organic matter and/or diagenetic primary pyrites had main role in generation of light δ34S values in Pachi Miana and Kamarposht deposits. Thermo-chemical reduction of digenetic primary sulfates and thermal decomposition of diagenetic primary sulfides as well as sulfur bonds in organic matter-bearing laminaes in the host rock are introduced as main processes for reduced sulfur supply in sulfide mineralization.