The Carbonate Platform and Fossils
edited by Medica Assunta Orlando
The territory of Salento has a relatively recent geological origin. Its main structure was, in fact, formed around the end of the Mesozoic Era, and consists of a series of platforms, platform edges and basin of the Jurassic-Cretaceous Era, between 98 and 65 million years, with a thickness of close on 6 km., with the widest samples found in the central-western region and ending in the eastern edges of the Serre Salentine.
The Calcari di Altamura, or high limestone cliffs, originated in this environment and contain fossils of rudists, marine bivalve bioconstructing molluscs, which became extinct around 65 million years ago and in some exceptional cases, fossilized fish remains.
| At the end of the Cretaceous Era and the beginning of the Palaeocene Era, it has been proven that land generally emerged throughout Puglia. In the Salento area this emergence lasted for a significant period of time, ending in the Miocene Era (24 million years) with some instances of the sea spilling over the land, especially in the northwest-southeast direction where during the Eocene period, a system of coral barrier lagoons developed (35-30 million years). The subsequent submersions of the territory led to the most famous formation of the Salento area: Lecce stone (24-5 million years), which alternates with marine environments, now deep, now shallow, at times narrow, dominated by enormous sharks, dolphins, whales, sirenians and marine reptiles. |
In the Pliocene Era (5-2 million years), after an initial submersion characterized by the formation of Leuca, the Salento area once again returned to above-sea-level conditions, although large areas continued to undergo periods of submersion. The establishment of Leuca is characterized by rare structures formed of folds created by drifting, unconsolidated sediments (slumping); the establishment of Uggiano la Chiesa is characterized by abundant remains of molluscs, fish, echinoids and crustaceans, typical of these entrance areas.
The Quaternary Era began with a new continental episode which was soon interrupted by a new marine sedimentation that mainly dated to the Late Pleistocene Era, up until 800-700 thousand years, when the land of the Salento area had finally completely emerged from the sea. However at the beginning of the Quaternary Era, many of the interior areas were already above sea level.
The great ice ages of the Pleistocene Era contributed, throughout this era, to these alternating submersions and emergences from the sea. But that is another matter!
Further studies:
P. Sansò, G. Selleri, Caratteri geologici della penisola salentina, in L'Uomo e la Pietra nel Salento preistorico. Guida alla comprensione e alle escursioni sul territorio , a cura di M. A. Orlando, Maglie, 2007.
F. Gianfreda, La Geologia del Salento. Le unità stratigrafiche, in L'Uomo e la Pietra nel Salento preistorico. Guida alla comprensione e alle escursioni sul territorio, a cura di M. A. Orlando, Maglie, 2007.
A. Varola, Nuove scoperte fossili nelle formazioni rocciose del Salento, in Le scienze geo-archeologiche e bibliotecarie al servizio della Scuola, a cura di M. A. Orlando, Monteroni, 2005.
