ABSTRACT: In the close vicinity of Yellice (Çetinkaya-Sivas), ophiolitic rocks which were trusted tectonicallybefore Maastrichtian over Munzur limestones of Taurus platform form the basement. Post-tectonic basindeposits (Saya formation and Sincan group) cover them unconformably. Magmatic activity observed inthe field is characterized by granitic rocks of Upper Cretaceous and/or subsequent ages, and volcanicsof Plio-Quarternary. The ores which is the subject of this study, are mainly composed of magnetites andlocated within serpentinized ultramafic rocks of the ophiolites. Primary ore minerals of the Yellice area,consist of chromite, magnetite, machinavite droplets bearing pentlandite, pyrrhotite, cubanite lamellaebearing chalcopyrite and pyrite disseminations characterizing liquid magmatic phase. In addition to thisprimary paragenesis of chromite, magnetite and sulphide assemblages, secondary magnetite mineralsformed from iron elements released intensively from ferromagnesian minerals during serpentinizationprocesses which characterize subsequent phase. Small amount of pyrite and silicate minerals accompaniedwith 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. Losson ignition is 10.49 %. In this study area, the ore seen as lenses within serpentinites, comprises mainlymagnetite, and reveals an average grade of 18-20 % Fe3O4 with visible and probable tonnage of 125million tons. At the early stages of the iron formation, it had started to develop as disseminations withinultramafic rocks and gained intensity subsequently by the minerals formed by iron elements released fromthe ferromagnesian minerals such as olivine and pyroxene during the serpentinization processes of theultramafic rocks.