Abstract: Limestone samples from three incomplete stratigraphic sections of the Upper Devonian Ayineburnu Formation in the Denizliköyü area, Gebze, northwestern Turkey produced conodont faunas, which can be correlated with established Famennian conodont zones. The sections (D, DN and DB) consist mainly of interbedded planar to nodular limestones and dark shales, indicative of slope sedimentation. The sections D and DN define an interval extending from the Lower marginifera Zone into the postera Zone, and fill the gap between the former studied sections of the Ayineburnu Formation. The section DB contains the Lower and Middle expansa Zones.
Keywords: Famennian, NW Turkey, Istanbul Zone, biostratigraphy, conodonts