The hydrogeological structure of Salento is complex and diversified.This is due to a non-homogeneous territory and its permeability.
The Salento subsoil was in fact affected, around the Upper Cretaceous (65 million years ago) by the Karstism phenomenon. An intense and constant erosive activity exerted by water on the limestone rock.
The continuous action of water, over the years, has broken down the rock. This action has sometimes been facilitated by the existence of small, underground fractures, caused by tectonic movements.
This is the main cause that over the years has created the underground connections between the two seas, the Adriatic and the Ionian. Therefore the Salento subsoil is totally crossed by the sea itself.
Even more extraordinary is the coexistence of two stratums. A shallow, fresh water layer that floats on top of the deeper one, thanks to its lower density. The result is a stable water layering condition based on its salinity. The deeper layer, just above the sea level, rises vertically favouring the formation of a thicker central area occupied by the fresh water layer.
The Salento peninsula, which figuratively constitutes the heel of the boot, according to several authoritative studies, owes its name to its strategic position, as the term Salento in Messapian actually means Sea.
We can therefore conclude that beneath that imaginary line which connects Taranto to Ostuni to the extreme Santa Maria di Leuca, the sea extends or rather the two seas meet.
Salento, a unique land that hides wonders yet to be discovered.
Storica Cartina della Puglia La Tabula Peutingeriana
