ABSTRACT: İn the northern parts of Otlukbeli thevolcaniclastic rocks which belong to Liassicaged Kelkit Formation, are found on thebottom. These rocks are overline by theHozbirik Yayla limenstones which are formedby micritic limenstones of Malm-LowerCretoceaus. The Otlukbeli Melange has beentrusted on these limenstones and was formedand located in the Aptian and Albian. All o theseunits are cross cut by the Sarıhan granitoid ofCampanian age. Youngest unit of the area isthe Sarıtaşlar Formation, which composed ofconglomerate,sansstone and shale alternation.The Mn mineralizationsin the area are found inthe radiolarites within the Otlukbeli Melange.The most important of these mineralizationsisthe Kuşkayası ore deposit. The vein shapeddeposit is 180 m. İn length, 2 m. İn averagethickness and has a width more than 40 m.in dip direction. The major ore minerals arebraunite, pyrolusite, psilomelane, bixibite andmanganite. The interpretation of geochemicaldiagrams prepared for major and traceelements contens revealed that the ore depositswas hydrothermal in origin. At present he oredeposits contains commercially more than12.000 tons of Mn.