Abstract: The NE-SW oriented, funnel-shaped area, which extends from Bolu in southwest to Kastamonu in northeast, and filled with Eocene to Post - Eocene deposits, has been named as Karabük - Safranbolu Tertiary basin.In its southwest section, both northern and southern and southern margins of the basin are tectonicin character, and therefore, much more narrower, The northwestern margin of basin displays diversecharacteristics such as thrust fault, overturned fold and angular unconformity.In the Karabük region, sediments of in this ba sin are shallow marine deposits of Lower Lutetianage and fluvial deposits. These rocks have been divided in six formations and four members, andnamed separately,The present shape of basin has been formed at the end of Upper Lutetian; it has characteristics of anintermontane basin. Since the Upper Pliocene time, it might has been uplifted at least twice.