Geological and mineralogical investigation of Kılıçören (Gümüşhane) Pb-Zn-Cu±Au±Ag mineralization

The study area is located in Madenin Sırtı region of Kılıçören village of Gümüşhane. The close vicinity of the mine site where general geological investigations are carried out is found in map sheets of Trabzon H43-b1 and Trabzon H43-b2. The Şenköy Formation, Berdiga Formation and Yazyurdu Formation outcrop throughout the field investigated. The mineralization found in the study area is developed within andesitic rocks of Early-Mid Jurassic age Şenköy Formation. The volcanic rocks fall in the fields of andesite, andesite/basalt, according to the chemical naming diagram of Nb/Y plotted against Zr/ TiO2*. It is determined that the volcanics have calc-alkaline character based on the AFM, SiO2 verses K2O and SiO2 verses Th-Co diagrams plotted. The directions obtained in both trace element and rare earth element distribution diagrams indicate that rocks derived from similar mantle source, and negative Eu/Eu* anomaly expresses development of plagioclase differentiation. Tectonic separation diagrams also show that volca nic rocks are calc-alkaline basalt and volcanic arc basaltic features. The mineralization is observed as a vein situated in the NW-SE trending fractures developed in andesites belonging to Early-Middle Jurassic Şenköy Formation. The veins observed in the field have the thicknesses ranging from a few centimeters - two meters and length continues for several meters. At the Madenin Sırtı area (at 2151 m. elevation), where the mineralization is best observed, there is an abandoned mine adit having 3 meters height, 2.5 meters width. The mine adit continues about 100 meters at the direction of N10W. The silicified ridge pointing to an epithermal system is about 5 meters in thickness and 50 meters long, having a bearing of K25B. In the field, besides to silicification, the alteration types such as hematitization, limonitization, chloritization and sulfurization have been identified in the rocks around the mine. The pyrite, chalcopyrite, galena, sphalerite, fahlerz and quartz form the paragenesis of mineralization. In the mineralization, which is developed in two different phases, the replacement, separation, inclusion and cataclastic textures are the most important texture types observed among ore minerals. Especially, the observation of space filling and comb textures in quartz-containing samples, indicates that the mineralization in the area is a vein-type ore developed in the epithermal system.