EFEMÇUKURU (TÜRKIYE)

Efemçukuru is an intermediate sulfidation epithermal gold deposit hosted within Upper Cretaceous phyllite and schist at the western end of the Izmir-Ankara Suture Zone in SW Türkiye. The host rocks are locally silicified to hornfels and cut by moderately N- to NE-dipping faults that are exploited by rhyolite dykes and epithermal veins. Two major veins host mineralization, Kestanebeleni and Kokarpinar, with the former containing the bulk of the ore. Vein mineralogy is variable but primarily consists of quartz, rhodonite (commonly replaced by rhodochrosite), adularia and sulfide assemblages including pyrite, galena, chalcopyrite and sphalerite. Spectacular, high grade banded crustiform-colloform textures characterize the veins in addition to multi-stage breccias that were likely the result of shallow-level boiling. Most of the gold is very fine (2.5 to 50 microns), occurring as free grains in quartz and carbonate, and as inclusions in sulphide minerals. Lower grade mineralized stockworks occur peripheral to the ore shoots, and are most strongly developed in hanging wall rocks.