Abstract: Strata of various facies of Middle Jurassic-Pliocene age invertal outcrop in the area between Ünye-Ordu-Koyulhisar-Reşadiye. Of these rocks, limestone of Middle-Upper Jurassic-Lower Cretaceous age forms the basement. Tuffite, andesiteflows, agglomerate, limestone and sandstone alternation of Cenomanian-Campanian age covers the limestone with an angularunconformity. That unit is cut by dacite and syenites especially at Gölköy and Ulubey areas. Tuffite-argillaceous limestone alternation at the north, sand, and argillaceous limestone alternation at the south overlie the previous unit. These two sequences ofMaastrichtian age are thought to have a lateral interfingering below the younger units. Paleocene aged tuffite, agglomerate andlimestone with coal seams, argillaceous limestone and sandstone alternation is deposited as a continuation of the units of Maastrichtian age. Limestone and at some places basalt cover these units with an angular unconformity. Then agglomerate and andesiteflows and sandstone with agglomerate beds are deposited. These units are of Eocene age. Various basaltic formations are developedduring Miocene-Pliocene period. These are followed by young alluvium and landslides.