ABSTRST: In the `investigated, area» which, is located Eastern Black. Sea region» volcanic: rooks, dominate in general.The oldest un.it cropping out in. `the area is Santonian-Maastrichtian aged Hemşindere formation, which is. composed of .andésite, basait, dacite lava and pyroclasts with intercalations of sand.st.one,marl and red limestone. This formation having a significant lateral distribution regionally,, is cut in places by the bacis and acidic intrusive rooks. The. Hemgmdere formation, is overlain Paleocene aged Rize formation which is composed of alternation of white-bordeaux colored marl, claystone and limestone. Further upwards, the Lower-middle Eocene aged Kaplıca formation.» which is. composed of thick `bedded .and coarse sandstone, and marl, follow the sequence by a slight, unconformity.The Kaplıca formation passes upward into the.Melyat formation composing of andesitic -basaltic lava,, tuff and agglomerates.. .Al these units are overlain by the Sarmadan aged Pazar fonnatioa which contains fossflifereous sandstone and marl and. conglomerates.» clay and sand by an angular unconformity. On the- Other hand, the Flio-Ouaternary (?) aged! Hamidiye formation is composed by sandstones and. conglomerates. The youngest deposits of the .area, are the Quaternary aged terrace . .alluviums* It is understood according to `the. organic geochemical analyses carried out on the samples taken from, the outcropping source rocks of `the area, `that,, no significant source rock faciès has developed, .in the in.vestiga.ted area. The existence of petroleum seapages from sea in. the town, of Çayeli, is known for long time,. These seapages might be explained by the possibility that, the generated petroleum in the bottom sediments of Black Sea has migrated through the surface along the active faults