Abstract: Kumartaş formation, which outcrops in the northwest of Çankırı basin, laterallyand vertically grades in the overlaying Hançili formation. Syn-sedimentary structuresmostly normal faults observed within these units indicate existence of extensional tectonicsin Early - Middle Miocene in the Çankırı basin. These sedimentary units are laterfragmented by an east vergent tectonic sliver after early Pliocene.