Stratigraphy and tectonics of an Internal Unit of the southern Apennines: implications for the geodynamic evolution of the peri-Tyrrhenian mountain belt

Abstract

The Parasicilide succession is a key element of the southern Apennine orogen, being originally located in the distal portion of the Apulian palaeomargin, at the Neotethys ocean-continent transition. The succession, presently included in the upper nappe complex of the thrust belt, has been described elsewhere as a `broken formation'. However, detailed investigations carried out in the Sele Valley point out that there the Parasicilide Unit is characterized by a coherent stratigraphy. Therefore, in the study area, these rocks form a coherent sheet of distal continental margin/oceanic sedimentary cover material included within the peri-Tyrrhenian mountain belt. Stratigraphic and structural constraints obtained from both pre-and syn-orogenic deposits - the latter including both foredeep and thrust-top basin sediments - suggest that the pre-orogenic part of the Parasicilide succession subsided into the Apennine foredeep in the first part of the Burdigalian. The studied rocks were then involved in thrusting prior to late Burdigalian/early Langhian times