Morphogenetic study of the Mavri Limni Valley – “Polylimnio” in Messinia (Greece)

The Mavri Limni Valley – “Polylimnio”, in Messinia (Greece) is developed on a hilly region, with main flow direction NE-SW to EWE-WSW. It concentrates large quantities of water throughout the year. The hypsometric difference between the beginning and the end of the most interesting, 1000 m long, part of the valley is 96 m. Downward the stream flow, numerous nick points (waterfalls) are present with their heights ranging from 0.8 m to 16 m. At the end of the falls 15 main lakes are formed. Due to the large number of lakes, the studied valley is well known as “Polylimnio”. The area belongs to the Olonos-Pindos geotectonic unit in which flysch and limestone successions dominate. The main characteristics of these limestones are their great dips (40–68°) and their alternate directions. Faults are observed parallel and perpendicular to the valley direction. The formation of the valley and its development resulted from tectonic fractures and continuous erosion in depth and width. Waterfalls development is mainly controlled by the faults. The observed retrograde erosion is an effect of relatively late tectonic uplifting of the wider area.