A crossroads between the Mediterranean and the Alps: Lithic technology, raw material procurement, and mobility in the Aurignacian of Riparo Bombrini

Riparo Bombrini is a collapsed rockshelter within the Balzi Rossi site complex, located at the intersection of the Maritime Alps, Northern Apennines, and Ligurian Sea. This unique environmental setting served as a crucial biogeographical corridor for human mobility along the Liguro-Provençal Arc during the Paleolithic. Multidisciplinary research at Bombrini identified three archaeological layers (i.e., A2, A1, and A0) overlying a semi-sterile Mousterian level. This paper explores the internal variability of the Protoaurignacian by analyzing lithic assemblages from layers A2 and A1, as well as a previously undescribed Early Aurignacian assemblage from layer A0. An analysis of assemblage integrity, lithic technology, and raw material procurement reveals distinct mobility and land-use strategies, despite technological uniformity. Remarkably, lithic production and use in both Protoaurignacian and Early Aurignacian layers frequently involved exogenous materials sourced from distances exceeding 150 km, with some reaching up to 450 km, spanning from the Rhône Valley to the Central Apennines. Variability in the procurement distance of discarded lithics and their changing reduction intensities highlight distinct patterns of logistical and residential mobility. Comparative analysis with regional sites indicates that foragers possessed sophisticated territorial knowledge, challenging the traditional view of the Protoaurignacian as the outcome of pioneering groups entering unfamiliar landscapes.