Abstract: The Koyunbabafault is located on the western margin ofÇankırı basin (Central Anatolia) where the neotectonic evolution is debated. The fault is located between Early-Middle Miocene Hançili formation of Çankırı basin and the ophiolitic rocks of Neo- Tethyan suture zone. The type ofthe Koyunbabafault, however, is interpreted differently in some studies.The Koyunbaba fault has variably sized slickensides with well-developed slickenlines. The fault comprises NW-SE trending fault planes dipping between 25-40° to the SW. Slickenlines trend NE-SW with plunging SW. The surface displays undulations with centimeters to meters wave length. Slickenlines and undulation axes are parallel to each other. Cataclastic zone that occurred, in the footwall block ofthe Koyunbaba fault is characterized by breccias and cataclasites. The zone includes mesoscopic and microscopic brittle kinematic indicators (tensiongashes, inclined planar structures, asymmetric deformed elements, Riedelfractures) indicating that hanging wallmoved to southwest and Koyunbabafault is a normal fault. Thisfinding supports the existence ofa tectonic sliver having normal and thrust faults on the western and eastern margins respectively.