Palaeontology and stratigraphy of the latest Messinian-Lower Pliocene deposits in the Apennines: new insights from Molise (Southern Italy).

The reconstructed stratigraphic section allows to define the characteristics in term of fauna and sedimentology of the latest Messinian "Lago-Mare" episode and the following Early Pliocene marine transgression. The lower and the middle portions of the section register the latest Messinian "Lago-Mare" episode. In particular the lower laminated grey marls indicate the presence of a brackish lake-type palaeoenvironment evolving upper-section to fluvio-deltaic palaeoenvironments settled by typical "Lago-Mare" molluscan assemblages of hypo- and oligohaline gastropods (M. curvicosta, M. narzolina, Saccoia spp. and T. mutinensis) endemic of Mediterranean, and bivalves (Lymnocardiinae and Dreissenidae) of Paratethyan origin (Esu, 2007). Planktonic foraminifers often abundant, but represented mainly by small tests, are very likely reworked. In the upper portion of the section, marine transgression is evidenced firstly by clay deposits with mixed "Lago-Mare", very likely reworked molluscs and marine fauna, then by the overlying gravels with marine molluscs, and finally by the yellow silty sands containing marine elements. The record of G. margaritae (MPl2-MPl3 biozones: Iaccarino & Premoli Silva, 2007) allows the attribution of these latter deposits to the Zanclean (Early Pliocene).