كاني سازي طلا در ليستونيتهاي ايران مركزي

Gold Mineralization in Central Iran Listvenites

Listvenites are formed during the CCVrich fluids ultramafics interactions. Commonly, these carbonatized ultramafic rocks (especially serpentinites) are characterized by quartz and Mg-Fe-Ca carbonates assemblage. Gold mineralization in these rocks had been a new target for exploration during the past decades. There are two main ophiolitic belts in Central Iran, Dehshir-Surk-Nain belt and Jandagh-Anarak belt. Hydrothermal alterations have produced listvenites and finally birbirites (silicified serpentinites) in ultramafic members of these ophiolites. In Dehshir, listvenites and paralistvenites are outcropped along the ophiolite belt and are barren. In Surk, listvenitization is followed by bribirites formation and gold mineralization has a close association with ferrite chromites. There is pyrite mineralization in highly silicified serpentinites with Au-Hg anomaly in Main ophiolites. In Jandagh serpentinites, talc-carbonate rocks are formed during carbonatization. Trace amounts of gold anomaly are detected in these rocks. Anarak old ophiolites have widespread listvenitization. Various minerals and ore minerals with multistage paragenesis are characteristic. In addition to geochemical anomaly, gold mineralization is detected as visible gold.