Oldowan stone knapping and percussive activities on a raw material reservoir deposit 1.4 million years ago at Barranco Leon (Orce, Spain)

Barranco Leon (Orce, Andalusia, Spain) provides the oldest case of knapping and percussive activities on an ancient raw material reservoir deposit. This site has already proven to be one of the oldest and most significant Oldowan open-air sites in Europe (1.4 Ma), with an exceptionally rich flint and limestone lithic assemblage, in association with large and small faunal remains, including a tooth fragment attributed to Homo sp. All of these finds have been discovered after years of excavations from a clear stratigraphic succession, complimented by multidisciplinary analyses of environmental proxies. The analysis of the entire lithic collection presented here describes a tool kit composed of cores flakes and debris, hammerstones, and other macro-tools like heavy-duty scrapers and sub-spheroidal morphologies. This paper combines geological and sedimentological data with archeology, providing a new interpretation of site formation processes and how they shaped hominin activities at Barranco Leon. We examine the dynamics forming the depositional sequence and document taphonomic alterations of the archeological finds, while also analyzing their distribution over the excavation area. This information is key to understanding the nature of post-depositional phenomena and to evaluate primary versus secondary deposition. The positioning of the refitting items in the site highlights in situ action, reaffirming the importance of the Barranco Leon site as a raw material repository. The observation of a refitted lithic set provides information about knapping strategies and hominin behavior in this European Oldowan site.