GROTTE CARSICHE E LINEE DI COSTA SOMMERSE TRA CAPO SANTA PANAGIA E OGNINA (SIRACUSA, SICILIA SUD-ORIENTALE)

Abstract

Scicchitano G. & Monaco C., Karstic caves and submerged paleo-shorelines in the coastal area between Capo Santa Panagia and Ognina (Siracusa, south-eastern Sicily). (IT ISSN 0394-3356, 2005).
The aim of this work is the detailed survey of the submerged area in front of the shoreline between Capo S. Panagia e Ognina (Siracusa), in order to reconstruct the lateral extension and the continuity of the submerged morphological elements and to define their genesis and temporal evolution. This coastal stretch is characterized by the occurrence of several raised paleo-shorelines, related
to Late Quaternary high-stands. They are represented by cliffs and abrasion platforms carved on a Miocene-Pleistocene carbonatic
succession and are often linked to karstic levels (caves, channels, siphons, etc.). Several speleothems, such as stalagmites, stalactites,
columns, cave pearls, have been found in the caves. The submerged area is characterized by the same morphological features. The
sea-bottom is, in fact, characterized by at least two palaeo-cliffs of marine origin, the shallower one located at depths between -9÷12
m and -20÷22 m, the deeper one located at depths between -20÷25 m and -40÷45 m. The scarp located between -9÷12 m and -
20÷22 m is well preserved and shows a continuity of about 20 km. The scarp located between -20÷25 m and -40÷45 m is more
discontinuous and steeper. Several caves, channels and siphons, characterized by the occurrence of continental fossilized speleothems, have been found along these scarps, probably linked to palaeo-karstic levels. The detailed topographic survey of two caves has been carried out and a stalagmite has been sampled in order to determine its age and to reconstruct the relationships between sea-level rise and vertical tectonic motion of the area. The morphological analysis and the first dating results suggest that the two submerged palaeo-shorelines can be interpreted as the effect of Late Pleistocene sea level stands. At present they are submerged as a consequence of the sudden Holocene sea-level rise.