Abstract: The Upper Cretaceous Yavcaformation crops out as a narrow belt in vicinity ofthe Arslanköy town (NWMersin). This region represents the northernpassive margin of the Menderes-Taurides Block, and have been come in nappe movement overtheMenderes-Taurides Blockduring the Late Cretaceous.The Yavcaformation deposited in the slope and basin plain environment overlies the Campanian slumped micritic limestone belonging the upper level of the Cehennemdere Formation. Over the basal conglomerate including pebbles from Cehennemdere Formation, claret-red-colored planktic foraminifera bearing micritic limestone deposited in this slope environment evolved as a result ofthe movement ofthe basin marginfault. This Carbonate facies is conformably overlain by the Clastic facies that is delineated in Coarse Clastic and Fine Clastic subfacies. Initially, Fine Clastic subfacies comprising grey-green colored, laminated claystone andfinegrained sandstone alternations are observed. Then due to repeated activity ofthe basin margin faults, CoarseClastic subfacies that contains an alternations of conglomerate-sandstone are deposited. The sedimentarypackages in this subfacies start with clast supported conglomerates, and pass in matrix supported conglomerates - sandstone towards the basin interior in the direction ofsediment transportation. The Yavcaformation ends`with claystone andfine-grained sandstone alternations deposited in the deep sea environment including the slumped micritic limestone blocks.Coarse-grained sediments, slumps and deformed beddings indicate the submarine slope environment evolution in the western part ofthe study area. Disappearance ofthese properties through the east in the short distance shows that slope environment passed in the deep sea environment.