Stratigraphy and facies of an oligocene fringing reef (Castro Limestone,Salento Peninsula,Southern Italy)

Summary The coastline of the Salento Peninsula (Apulia region, Southern Italy) is characterized by a rocky shore with spectacular cliffs where the investigated fringing reef complex, the so called Castro Limestone, spectacularly outcrops for at least 40 km. As reconstructed from several measured sections, the Castro Limestone, which is Middle Chattian in age from our own data, disconformably mantles a tectonically deformed falaise of Cretaceous-Eocene rocks and is overlain by a remarkable erosional surface characterized by a very peculiar rhodolite rudstone. The Castro Limestone unit can be considered as a classic unconformity bounded depositional sequence representing, most probably, a shelf margin prograding complex, related to the major Middle Oligocene sea level lowstand. Stratigraphic and sedimentologic features, together with paleontological characters, allow recognition of a virtually complete range of reef environments across the reef profile. Several geomorphic zones and associated facies are described, from the most landward reef area (‘back reef’) across the reef flat and reef from downward to the fore reef slope, contributing to a better knowledge of the evolution of Oligocene reefs and reef communities in Italy and in the Mediterranean area.