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In the close vicinity of Yellice (Çetinkaya-Sivas), ophiolitic rocks which were trusted tectonically before Maastrichtian over Munzur limestones of Taurus platform form the basement. Post-tectonic basin deposits (Saya formation and Sincan group) cover them unconformably. Magmatic activity observed in the field is characterized by granitic rocks of Upper Cretaceous and/or subsequent ages, and volcanics of Plio-Quarternary. The ores which is the subject of this study, are mainly composed of magnetites and located within serpentinized ultramafic rocks of the ophiolites. Primary ore minerals of the Yellice area, consist of chromite, magnetite, machinavite droplets bearing pentlandite, pyrrhotite, cubanite lamellae bearing chalcopyrite and pyrite disseminations characterizing liquid magmatic phase. In addition to this primary paragenesis of chromite, magnetite and sulphide assemblages, secondary magnetite minerals formed from iron elements released intensively from ferromagnesian minerals during serpentinization processes which characterize subsequent phase. Small amount of pyrite and silicate minerals accompanied with these assemblages. In general, the average compositions of serpentinized ultramafic rocks are 20.34 % Fe2O3 (total Fe), 0.26 % MnO, 33.19 % MgO, 1.08 % CaO, 0.14 % Al2O3, 31.99 % SiO2, 0.18 % K2O, 0.08 % Na2O with 5678 ppm Cr2O3, 1772 ppm Ni, 191.7 ppm Co, 280 ppm V2O5 and 163 ppm TiO2. Loss on ignition is 10.49 %. In this study area, the ore seen as lenses within serpentinites, comprises mainly magnetite, and reveals an average grade of 18-20 % Fe3O4 with visible and probable tonnage of 125 million tons. At the early stages of the iron formation, it had started to develop as disseminations within ultramafic rocks and gained intensity subsequently by the minerals formed by iron elements released from the ferromagnesian minerals such as olivine and pyroxene during the serpentinization processes of the ultramafic rocks. [ABSTRACT FROM AUTHOR]