LITHOLOGICAL SELECTION IN POLYGENIC GRAVELS OF NOTARCHIRICO (EARLY ACHEULEAN, SOUTHERN ITALY)

The several human occupations attested at Notarchirico (Venosa, southern Italy) date back to 610-695 ka, among the oldest ones in Western Europe at the MIS 17/MIS 16 transition.Open-air occupations were at the top or in proximity of polygenic pebbles/cobbles formed in fluvio-lacustrine environment, which made available various knappable material. Prevalent larger limestone lithotypes, together with smaller silicified calcarenites (flysch chert), nodular chert (carbonate platform) and radiolarite (basin) originated from the outer geological units of the Southern Apennine. The technological study of the lithic assemblages identified pebbles with percussion marks or broken, pebble tools, Large Cutting Tools (bifaces, cleavers, unifacial tools, pick), cores, flakes, flake-tools and retouched nodules. A selection of archaeological and geological lithic samples was studied to verify the archaeological hypothesis of the exploitation of local polygenic pebble/cobble lags to produce artefacts, as well as the hypothesis of lithological selection. Petrographic analysis of samples as such, coupled with thin section microscopy for geological samples, as well as colorimetric (spectrophotocolorimeter) and geochemical (pXRF) analyses were carried out. The results show that the lithotypes of the pebble/cobble lags are compatible with those of the artefacts. Moreover, pre and post depositional black patina due to wetland conditions further prove local exploitation. Preferential use of limestone cobbles, with some exception, for Large Cutting Tools and silicified calcarenites to produce very small flakes indicate adaptation to local raw materials. The relative abundance of flysch chert among artefacts, compared to the other chert varieties, is interpreted as a consequence of its abundance among chert lithotypes. The size/shape of the pebbles/cobbles was the main limiting factor in the choice of raw materials for lithic artefacts.