Kuroko type VMS beds around Espiye and Lahanos Cu-Zn bed
ETİ Bakır, Giresun, Turkey
Study area located in the middle of the eastern pontid structure association has been formed as a result of severe volcanic activity in Upper Cretaceous - Eocene time interval. As a result of this volcanic activity, a thick volcano-sedimentary sequence has occurred. This sequence composed of their lava and pyroclasts with change from basalt to dacite. Sometimes these are accompanied by sedimentary units such as limestone, mudstone, sandstone and marl.
In very old times in the region there were many massive operated-consumed, partially produced, continuing production and exploration activities sulphite beds. The most important ones from north to south are Agalik, Karaerik, Karilar, Lahanos, Killik, Kizilkaya and Karakishla. These beds are similar to each other in terms of host rock alterations, shape and mineral paragenesis and mineral relationship.The best representation of Kuroko type VMS beds in the region, continuing production and exploration activities of Lahanos Cu-Zn bed as in the past located within the borders of Shahinyouva village, about 25 km away from Espiye.
In the study area upper Cretaceous volcano-sedimentary rocks are observed. These volcanic arc products rocks have composed of dacite and their pyroclasts. Units from bottom to the top are sorted as Dacitic tuff, purple tuff - mudstone, dacite, dacitic tuff-breccia- purple tuff-breccia-purple tuff. Biotitic dacite intrusion is being monitored in the northwestern part of the area. In this bed, Network-spun ore under the massive ore body didn’t develop well. Macroscopically, massive ore contains pyrite, chalcopyrite, sphalerite, galena, calcite and bornite. As a result of detailed mineralogical studies of the bed, the main ore minerals are pyrite, chalcopyrite, sphalerite, tennantite, tetrahedrite, bornite. A lesser value of marcasites, galenite, energite, luzunite, idait, chalcone are accompanied by these minerals. Additionally, trace elements such as covelline, grinocite, geocronite, emplectite, vittichenite, tetradimite / tellurobismuthine, bismuthine, hecite, altaite, mavsonit, nabit-gold-elektrum are also observed. Gangue minerals are barite, quartz and clay minerals and less value of carbonates.