Abstract: Upper pPaleocene Güzeller formations is the oldest Tertiary unit which lies uncobformably on theauthochthonous and allochtonous units in the Bolkardağ region, south of Ereğli. Güzeller formation is conformablyoverlain by the Karaburun formation of Upper Paleocene-Middle Eocene age. The Paleogene rocks are overlain with anangular unconformity by te Neogene Kıraman formation and Karaisalı limestone. The youngest sediments in the regionare of Quarternary age.South of the studied area the Tertiary rocks are mainly marine sediments, they are bordered in the north by postMiocene aged terrigenous sediments.