STRATIGRAPHIC AND TECTONIC FEATURES OF THE MIDDLE PLEISTOCENE SEDIMENTARY AND VOLCANIC DEPOSITS IN THE AREA OF ROME (ITALY)

Abstract

The analysis of a large number of stratigraphic logs from boreholes, as well as an extensive field survey, suggests that the Middle Pleistocene sedimentary deposits in the area of Rome can be subdivided into two groups, each one characterised by a different stratigraphy and tectonic setting: a north-eastern sector, corresponding to the eastern urban area of Rome, and a south-western sector, corresponding to the Ponte Galeria area. In the north-eastern sector, the distribution of sediments is influenced by vertical block faulting showing a predominantly north-south trend, superimposed on a Middle Pleistocene NE–SW extensional tectonic domain. In the south-western sector, we suggest that the “Ponte Galeria Formation” auct. can be subdivided into two depositional sequences that can be linked to isotope stages 19 and 21. In addition, a sedimentary hiatus is proposed at the top of the Ponte Galeria sequence. It corresponds to the deposition of a continental succession in the north-eastern sector before the emplacement of pyroclastic deposits from the Colli Albani and Sabatini volcanic Districts. The correlation between these two depositional sequences, that have been identified, and the oxygen isotope time scale allowed us to extend our investigation across to the urban area of Rome, where we have recognised six sedimentary cycles, all of Pleistocene age, which have been tentatively related to particular isotopes stages.