An intense controversy on chronostratigraphy of upper Miocene-lower Pliocene deposits and the Messinian Salinity Crisis in the Dardanelles area led to a systematic investigation of calcareous nannoplankton content of 10 key-sections representative of the most relevant regional Kirazli and Alcitepe formations. Our study shows clearly that the Kirazli Formation deposits predate the Messinian Salinity Crisis while those of the Alcitepe Formation postdate this outstanding event, which severely impacted the region as widely known around the Mediterranean Basin. Fluvial canyon cutting or gap in sedimentation linked to the peak of the Messinian Salinity Crisis separates the two formations. Detailed palaeoenvironmental investigations (based on the fluctuation and distribution pattern of dinoflagellate cysts, pollen grains and calcareous nannoplankton) allow us to reconstruct the regional palaeogeography before, during and after the Messinian Salinity Crisis. The gathered data do not indicate any marine corridor between the Eastern Mediterranean Sea and Eastern Paratethys through the Marmara Sea region at the time of the Messinian Salinity Crisis. (C) 2009 Elsevier B.V. All rights reserved.