The “Selinitsa-Drakos” coastal karstic system in the Messinian Mani Peninsula (southwestern Greece) in relation to the terrestrial geoenvironment

The studied coastal karstic system comprises “Selinitsa” Cave and “Drakos” Underground River. It is located in southwestern Greece across the western coastline of the Messinian Mani Peninsula. It is developed into limestones of Upper Senonian to Upper Eocene age belonging to the Mani geotectonic unit. “Selinitsa” is mainly developed above the sea level, whereas “Drakos” is under water down to -48 m. These two caves are now connected through a 28-m long narrow passage at depth of -28 m, thus creating a united karstic system. Both caves were initially separate and terrestrial. Today, the majority of cave passages of “Selinitsa” are terrestrial. In “Senitsa-Drakos” karstic system, sequential karstification base levels have been identified. These levels determined the karstic system development. “Selinitsa” passages are phreatic and vadose, whereas “Drakos” passages are only phreatic, acting as lifting tubes. The passage network of both caves presents dentritic pattern and comprises the hydrological equivalent of the surface drainage network. To the east of the karstic system, karst margin plains are present comprising karstified tectonic terraces, whereas above the “Selinitsa-Drakos” system manmade terraces exist for agricultural purposes.