Geology, mineralogy and alteration features of Gökseki Yaylası (Kürtün-Gümüşhane) Pb-Zn-Cu mineralization

The study area is located in the northern zone of the Eastern Pontide Orogenic Belt, in the Gökseki Plateau region within the Sarıbaba village of the Kürtün district of Gümüşhane and within the borders of Giresun G41-c3 map sheet. The oldest geologic units in the study area are the Hamurkesen and Berdiga Formations, Çatak Formation disconformably overlies them, and all the rocks cut by Kazıkbeli Granitoid. Gökseki Plateau mineralization is observed along the cracks and fracture lines of andesites in the Late Cretaceous Çatak Formation. In order to determine the paragenesis of the mineralization, ore microscopy studies were carried out by prepared polished thin sections. It was determined that the mineralization paragenesis consists of pyrite, chalcopyrite, galena, sphalerite, quartz, calcite, epidote, hematite, limonite, malachite, azurite, chalcosine and covelline minerals. In the mineralization that developed in two stages, important textures were observed such as replacement, inclusion, exsolution, and cataclastic textures. During field studies, silicification, epidotization, hematitization-limonitization, and sulfurization type alterations were observed in the mineralization areas. Paragenesis-succession, texture and alteration types observed in the field obtained as a result of ore microscopy studies are similar to other mineralizations in the region (Gümüşhane). This is also supported by the types of ore and host rock alteration observed in the study area. Therefore, it shows that mineralization, which is the subject of this study, maybe vein-type mineralization developed in the epithermal system. Keywords: Epithermal, Inclusion, Lead-Zinc, Kürtün, Replacement