The spreading of the karst phenomenon in the area is rather peculiar.
In spite of the favourable conditions available (extensive carbonate
rock exposures), surface karst is rather limited; the presence
of dolines is rather sporadic, and caves are all fossil and exhibit
large quantities of fills, most of which are not incised (see
for instance the Cala Bianca cave). However, intense water activity
appears to have existed in the past in some karst caves; but recent
movements that have affected this area have evidently brought
this activity to a halt. Coastal caves with mixed origin appear
to be well developed.
Cilento emerged as a result of the tectonic
phase occurred in the Middle-Pliocene period and later underwent
an over all uplift, alternated with moments of negative movement.
Otherwise it would be difficult to account for the existence of
caves below the sea level, one of which for instance, to the East
of Porto Infreschi, is at -16 metres. These movements are likely
to have been differential in nature and may have included tilting
phases, which may have been the cause of the interruption of water
circulation in some karst systems. The combination of these movements,
coupled with variations in the sea level, have led to the formation
of deposits exhibiting strand lines at different altitudes. During
the Quaternary era, several transgressive phases followed one
another in the southern part of the Cilento area. There are signs
of Calabrian, Sicilian, Thyrrenian and, most likely, even Versilian
seas.
Grotta di Cala Bianca
Exhibits of Calabrian deposits (dating back to 1-2 million years
ago) can be found at an altitude of over 400 metres, for instance
in San Antonio, where as Sicilian deposits (dating back to 500
thousand years ago) are found in Lentiscosa, 250 metres above
sea level and at Cala Bianca. Recent strand lines are rather consistently
found at altitudes ranging between 15 metres and the current sea
level. On top of sandy and conglomeratic deposits, these lines
exhibit notches or stripes with lithodomous burrows.
To appreciate the extent of the variations occurred in the basic
water level, it should also be noted that the Grotta degli Iscolelli,
opening at an altitude of 80 metres, shows no evidence of water
at a depth of 75 metres (that is an altitude of 5 metres above
sea level), even though it is almost 500 metres away from the
strand line.
