The high-resolution sequence stratigraphy and the mammal fossil record: a test in the Middle-Upper Pleistocene deposits of the Roman Basin (Latium, Italy)

In the Campagna Romana area Pleistocene vertebrate fossil remains are preserved both in continental and marine sedimentary successions. This fact favoured the identification of faunal complexes in agreement with the biochronologic setting proposed for the Plio–Pleistocene large mammal faunas of the Italian peninsula. At the same time, the detailed facies and sequence stratigraphic analyses carried out in the last years on such deposits have allowed establishment of a regional and local chronostratigraphic framework which sets some physical and temporal limits to the occurrence of faunal complexes. In this light, the study of the Pleistocene deposits of the Roman Basin, based on sequence stratigraphy and mammal biochronology approach, can constitute a significant tool to test the relationships among physical stratigraphic units, faunal complexes and faunal units. In the examined area, the fossiliferous levels are essentially found in transgressive fluvial and fluvio-palustrine deposits filling incised valleys (TST) and in highstand barrier island–lagoon deposits (HST). Excluding some cases where bones show a probable exhumation process, whole discovered mammal remains are mostly coeval with deposits containing them. Based on taphonomic considerations and on depositional and physical stratigraphic settings, a correlation scheme among Roman Pleistocene sequencestratigraphic units, local faunal complexes and Italian mammal biochrons is proposed. Nevertheless, many problems remain to be clarified before either the correlation between events and the geochronological framework, or the significance and the biochronological value of each faunal assemblage can be considered as definitive.