Geomorphological and environmental transformations during the recent prehistory: a reconstruction of the landscape and the peopling of the territory southeast of Rome

The territory of the suburbs of Rome between Via Prenestina and Via Appia and up to the slopes of the quiescent volcano of the Alban Hills has been the focus of extensive archaeological investigations carried out by the Soprintendenza Speciale per i Beni Archeologici di Roma, in particular in 1999-2007. This research found evidence of the presence of Final Neolithic and Eneolithic settlements as well as Eneolithic necropolises. At the same time the Dipartimento di Scienze Geologiche of the Universita di Roma Tie carried out a territorial survey that, thanks to the stratigraphic sections discovered by the archaeological investigations, led to a revision of the knowledge about the primary volcanic deposits and lahars arising from the crater of the Albano Lake, referable to the Holocene. Several lahars have periodically contributed to modifying the morphology of the territory, but at the same time have created wide spaces, open and fertile, that have contributed to the intensive development of human occupation in this territory. Several settlements, referable to the Final Neolithic and the full Eneolithic and up to the Bronze Age, have been identified, particularly in the district of Torre Spaccata/Osteria del Curato, along Via Tuscolana. At Quadrato di Torre Spaccata, in an area of more than one hectare, habitation structures have been found built on the tuff layer of Villa Senni and on the lahar deposit above it. A rectangular hut was partially removed by the construction of a roman paved road. The settlement of Osteria del Curato-Via Cinquefrondi covers an area of about two hectares. It has been covered by a thick stratification related to the periodic lahars from Albano Lake that allowed its preservation. Numerous postholes excavated in the lahar indicate the presence of habitation structures. In a wide area enclosed by a small trench were three tombs, one of which belonged to an adult missing the cranium, two ritual pits with ovicaprine remains, and the burial of a dog without the cranium. Other burials were present within the area of the settlement. In the same southeastern part of Rome numerous 'a grotticella' necropolises document the diffusion of the Rinaldone facies. At Lucrezia Romana, along the slope of a small hill, a necropolis with 69 tombs has been excavated. At Polite delle Sette Miglia some tombs with a monumental structure and rich grave goods, which included accurately made vessels and silver objects, were identified. A short distance away in the Romanina locality, on a wide fiat area formed by the lahars of the Ciampino plain, another necropolis with 42 'a grotticella' tombs is still under excavation. Numerous tombs are of a monumental type with quadrangular access shafts. The opening of the chamber was closed by large lahar or lava slabs. The ipogea, excavated in the lahar, allowed a better preservation of the skeletal remains. At Quadraro-Via Lucrezia Romana, near the area of the necropolis, large portions of a settlement whose development started in the Final Eneolithic and carried on up to the Final Bronze age have been brought to light along a strip of several hundred metres. The presence of sands in the earliest stratifications suggests frequent overflows of the water courses, damaging the settlement. Flooding caused the restructuring of the banks of the ancient water courses, with deeper excavations of their beds as well as an attempt to make embankments and to drain the area. Several structures may be identificated, including alignments of stones, postholes, in part also referred to habitations. The importance of this site lies in its abundant evidence regarding the transformation of the territory as a consequence of the recurrent emissions of lahars. Palaeobotanical data, provided by pollen and macrofossil analyses, document a significant change in the vegetational landscape, characterized by a progressive increase in forest cover between 5000 and 3000 years BCE. The examined territory is currently being investigated from a geological and palaeoenvironmental point of view with the aim of identifying the extension of the lahars indicated by the clearing of large areas following the improving of archaeological excavations in the southeastern part of the Roman area.