Correlazioni tra depositi a mammifari, depositi marini, linee di costa e terrazzi medio e tardo-pleistocenici nella Sicilia orientale

Abstract

In Eastern Sicily there are numerous Middle and Upper Pleistocene terraces. On the Iblean Plateau the sedimentary cover of Middle Pleistocene wave-cut platforms is made up of littoral calcarenites with commonplace Mollusks. In the Peloritani-Nebrodi Range gravels of coastal plain environment overlie Middle Pleistocene wave-cut platforms; relics of marine sediments have been found on the youngest Middle Pleistocene terrace only at Taormina. Among Late Pleistocene terraces, the one showing the maximum width includes Eutyrrhenian marine sediments with Strombus bubonius below the continental deposits covering, at the inner margin of the terrace, an old shoreline shown by recent excavations. In the Iblean Plateau this shoreline is represented by a narrow abrasion platform and littoral deposits with commonplace Mollusks and a species (Nassarius gibbosulus) which has been living in the Mediterranean since Tyrrhenian times. At Acquedolci and Taormina the shoreline is represented by an abrasion platform and a shoreline-furrow with Uthodomes holes and masses ofincrusting worms (Serpula), respectively. Mammal-bearing deposits have been correlated to marine sediments which are Lower, Middle and Upper Pleistocene in age. They have been correlated also to the terrace which includes eutyrrhenian marine sediments. The correlations of Mamma bearing deposits and marine deposits deeply modify the biostratigraphic schemes previously proposed. The large Mammal fauna can be attributed to two stratigraphic levels: the first, containing an endemic association of E mnaidriensis, an Elephant less reduced in size than E. falconer!, Micromammals, Amphibians, Reptiles and Birds, belongs to Lower Middle-Pleistocene. The second level, containing a less specialised fauna with E. mnaidriensis, Hippopotamus pentlandi, Cervidae, Bovidae and Carnivore, belongs to Late Middle-Upper Pleistocene times. A more careful chrono-stratigraphical attribution of Mammal-bearing deposits needs a more exact settlement of the marine sedimentary units attributed to Middle-Pleistocene. Following recent investigations a revision of some Mammal species becomes suitable. The old shoreline lying at the inner margin of the terrace Which includes eutyrrhenian marine sediments denotes a further marine cycle. In spite of the aminostratigraphy data, this shoreline for its morphological and palaeontological characters, seems to be the record of a sea-level oscillation belonging to the eutyrrhenian trangressive cycle. The problem of toe chronostratigraphical attribution of the shoreline is still to be solved.