Revisiting the Acheulean Occupations of Vale do Forno (Lower Tagus, Alpiarça, Portugal): The Vale do Forno 1 Site

Abstract In the Lower Tagus River basin, works carried out by Henri Breuil and Georges Zbyszewski during the 1940s, and by Luís Raposo and colleagues at the end of the twentieth century, led to the discovery of significant concentrations of Acheulean remains in Vale do Forno (Alpiarça, Portugal). Aiming to renovate the investigation of a core area of the Portuguese Lower Palaeolithic, a systematic revision of the sites from Vale do Forno was conducted. In this work, we present updated data regarding Vale do Forno 1, chronologically placed between Marine Isotopic Stages 9 and 7. Discovered in 1987, the site’s lithic assemblage ( n = 252 artefacts) was exhumed in a thin gravel bed, within the basal channel sandy deposits of the Upper Sands unit of the terrace T4 of the Lower Tagus. Being mainly composed of elements related to the production phase, the series is essentially the result of expedient and short knapping sequences that occurred in a shallow channel environment, based on the exploitation of local raw materials. Elementary débitage schemes directed toward the production of medium-sized flakes are recognised, complemented by some unifacial peripheral patterns aimed at obtaining small-sized products. Additionally, the presence of large cutting tools testifies to the parallel development of façonnage operational sequences. These are only represented by the end products, which were usually defined in an expedient manner. Overall, the Vale do Forno 1 lithic assemblage displays features similar to those typically recorded in other Acheulean Iberian sites.