Geological, mineralogical, geochemical characteristics and genetic investigation of Akbaştepe (Sogut, Bilecik) Au-Ag mineralization

The Akbaştepe ore deposit is located in Sogut (Bilecik, NW Türkiye), the northern part of the Izmir-Ankara Suture Zone. This deposit shows a vein form, having a 2 km length and an average 5-meter thickness. The vein exhibits a sub-vertical position developed within the greenschist-type metamorphic rocks. Schist unit is composed of chlorite, epidote, actinolite, and quartz. The Hg-Te (coloradoite), Au-Te, pyrite, arsenopyrite, and scheelite minerals are mostly associated with Au in the ore zone. Smectite enhances in the ore zone, in contrast, chlorite is abundant in the parent rock, and there is a negative correlation between these minerals. Carbonatization-, Fe-oxidation-, and silicification-type alteration zone generally developed between the ore deposit and host rock. Au element shows a strong correlation with As, Hg, W, and Sb. In contrast, Au exhibits a low correlation with the base metals. The sub-vertical development of the Akbaştepe ore vein in a tectonic zone, lithology, mineralogy, and elemental characterization of this zone suggest an orogenic gold deposit.