Investigation of geology and geochemistry of Küre (Kastamonu) in terms of masside sulphide mineralizations

Metamorphic, volcanic, sedimentary and intrusive rocks are dominant in the study area located in the Western Section of the Pontide Geotectonic Unit. Liassic aged ultramafic rocks are the oldest unit of the study area. The Liassic basalt unit is of great importance in that it contains massive. ore minerals; pyrite, chalcopyrite, sphalerite, galena and to a lesser extent mineralizations tetraedrite. The gangue mineral accompanying the ore is quartz. In particular, structures such as massive structure, brecciated structure and breccia fill structure are observed. Alteration types; chloritization, carbonation, argillization, hematitization, limonitization and silicification. Sulfur isotope values measured between 5.8 and 8.4‰ from pyrite and chalcopyrite indicate that the sulfur in the Küre VMS deposit is of magmatic, meteoric and/or marine origin. Calculated equilibrium temperatures, It has been determined that the formation temperature of the Küre (Bakibaba-Mağaradoruk) VMS deposit varies between 294 °C and 434 °C, and the temperatures calculated using the chlorite electron microprobe analysis results obtained from basalt samples vary between 210-3960C. Oxygen isotope results ranging from 3.3‰ to 13.7‰ and Hydrogen ranging from -58 to -74 show that the hydrothermal solutions forming the Küre VMS deposit are of magmatic-marine origin. According to the mineral chemistry analyzes of the pyrites, the high Co and low Ni contents and the Zn/Cd ratios of sphalerites above 500 were also associated with a basaltic magmatic source. In the environmental studies of the Küre (Bakibaba-Mağaradoruk) mineralization, the distribution of basaltic rocks in volcanic arc and MORB environments indicates the back-arc environment. This mineralization represents the products of subalkaline basalt volcanism affected by subduction, formed from melts derived from a partially depleted mantle source, and significant Th/Yb enrichment in some samples indicates that the source is enriched by subduction components. Obtained data show that the deposit is Cyprus Type VMS deposit.