Abstract: Arsenic mineralization takes place within the Eocene aged Isparta formation which is Jlyschoid in character. The mineralization occurs as a main vein that is 38 m in length, 1-2 m in thickness with 1-50 cm thick stockwork veinlets developed arround the main vein. It is found along a normal fault zone trending approximately N-S. Realgar-bearing cahile veins have a simple mineral paragenesis which consits of coarse-grained calcite, realgar, barite, pyriteand orpiment. Realgar-bearing calcite veins are epithermal (50-120 C) mineralizations related to Pliocene trachy andesitic-latitic Gölcük volcanism.