L'abitato della media età del Bronzo di Gorgo del Ciliegio (Sansepolcro, Arezzo). Dati preliminari sul contesto paleoambientale

The settlement of Gorgo del Ciliegio (Sansepolcro-Arezzo) is situated on an ancient terrace on the left bank of the Afra Creek, at about 400 metres above sea level, near-by the tuscan-emilian Appennines divide. During the six last years (2001 -2006) an area of approximately 178 square meters was investigated, resulting in the fi ndings of a living fl oor with several structures (pole holes, combustion structures, pits of different typology), including a small food oven of particular interest. The pottery retrieved from the deposit is represented by cylindrical, troncoconic and globular vessels, among which milk boilers are present, carinated shapes (bowls, cups) and some sherds decorated in the Appennine styles, which has allowed for the attribution of the site to an early phase of the Middle Bronze 3 (BM3). The Middle Bronze Age people settled on a preserved portion of an alluvial surface (T1a) standing about 10 meters higher than the coeval active channel of the Afra Creek, whose deposits are bounded by the surface T2. This location ensured a relative protection from fl oods being, at the same time, close to a large water source. Sedimentological features of the alluvial gravels bounded on top by T1a and T2 surfaces, suggest a significantly different fl uvial style during the late Holocene compared to the modern Afra Creek. Before (e.g. T1a deposits) and during (e.g. T2 deposits) the human occupation at this site, the Afra Creek was characterized by a relatively wide (about 150 meters) valley with multiple shallow channels inside, fi lled by gravels. This style can be observed in some modern creeks of the Upper Tiber River basin, indicating local condition of channel overfilling. On the whole this ancient style contrasts with the modern one in which a few tens meter wide Afra Creek is deeply entrenched in the bedrock and still affected by erosive processes. Despite the different valley morphology attained during the late Holocene, the terracing of the Afra Creek recorded at the site, attests to successive readjustment of the river profile to repeated perturbation of base level possibly due to the active tectonic setting of the Upper Tiber River valley. The preliminary results of the archeozoological study demonstrate that the inhabitants of Gorgo del Ciliegio were involved in the rearing of mostly sheep-goats and pigs and cattle in the second place, and in the hunting of deer and roe-deer; domestic dogs were present on the site. Such a pattern and the geographic location of the site, might suggest that Gorgo del Ciliegio community mostly practised mobile pastoralism and the dogs may have been kept to assist with herding the animals. Preliminary pollen analysis of the archaeological soil, reveals a scarcity and a bad preservation of the pollen grains possibly due to a highly acidic environment. Nevertheless, few grains of Urticaceae point to local anthropic impact on the vegetation cover, fully consistent with the settlement activity.