Abstract: During this study, fosil assemblages like Meandrospira cf. dinarica Kochansky - Devide and Pantic, Glomospirella sp., Planiinvoluta sp., Turriglomina sp., Aulotortus sp., Spirorbis phlyctaena Bronnimann - Zaninetti, Duostominidae, Hydrozoa, Halobiasp.,Daonella sp. indicating Anisien - Ladinien; Valvulina sp., Trocholina sp., Textularia sp., Pseudocyclammina sp., Ophthalmidiidae,Protopeneroplis striata Weynschenk, Conicocurnubia sp., Salpingoporella sellii (Crescent), Labyrinthina mirabilis Weynschenk, Valvulina gr. lugeoni Septfontaine, Kurnubia cf. palastiniensis Henson indicating Upper Dogger - Malm; Globotruncana sp., Globotruncaniidae molds indicating Upper Cretaceous and Stafellidea, Hemigordiopsidae, Mizzia sp. indicating Upper Permian were determined from the samples collected in Deresinek formation of Middle Carboniferous - Upper Permian age which is situated at thenorth of Sultandağlan.Based on the determined fossils, lithological features and structural setting, two tectonic slices with different stratigraphy wereidentified within the Deresinek formation. Of these, the lower one comprises of Middle Triassic - Cretaseous rocks and is tectonically overlain by the another one, comprising rocks of Upper Permian.In this study, the lower slice and its upper level of Upper Cretaceous age were named as Deresinek and Eber der e formations,respectively. In the upper slice, a formation of Upper Permian age, Kocatepe, was differentiated.