Petrographical, geochemical investigation and ore deposits potential of volkanic rocks around the Kibletepe (Arakli, Trabzon)

In the Kıbletepe (Araklı, Trabzon) and its surrounding areas at the eastern Black Sea Region, Late Cretaceous aged volcanic rocks consist of basalt, andesite and their pyroclastics that they are overlain by dacite, rhyolite and their pyroclastics at the basement cutting off by dykes of basalt and andesite. Limestone finds in the top level of the basalt, andesite and their pyroclastics constituting the basement of the study area. Quaterner aged debris flow covers all units sporadically.Late Cretaceous aged volcanic rocks generally are altered and the Zn-Cu mineralizations and various alterations related to ores are observed with in acidic pyroclastic rocks. Dacitic and rhyolitic rocks have hyalo-porphyric and spherulitic textures and consist of plagioclase, quartz and hornblende. The mineralization is observed in the form of stockwork, dissemine and breccia. The ore minerals include pyrite, sphalerite, chalcopyrite, and with less fahlers, digenite, covelline and malachite. Quartz, calcite and clay minerals are found as gang minerals. Exsolution lamellia texture was developed between sphalerite and chalcopyrite.The rocks hosting the ore have tholeitic-transitional characters and reflect geochemical properties of subduction related rocks with high LILE and low HFSE contents and high LILE/HFSE ratios. Sericitization, silisification, clay alteration and less carbonatization, chloritization, hematization and limonitization are generally observed in the wall rocks around the mineralizations. As clay minerals, illite, kaolenite, chlorite, simectite and less amount of interlayered illite/simectite were determined.As a result, the volcanics in the Kıbletepe reflect similarities to the hydrothermal alteration of the massive sulphide deposits in the eastern Black Sea Region and the ore are developed from hydrothermal fluids related to the eastern Black Sea island arc volcanism.Key Words: Hydrothermal Alteration, Kıbletepe, Late Cretaceous, Massive Sulphide, Volcanics