Flints of the Gravettian Workshop of Mugarduia Sur (Sierra de Urbasa, Wester Pyrenees, Spain)

Abstract

Nodular silicifications which were exploited during Prehistoric times can be found in Sierra de Urbasa plateau (Navarra). These flints, hosted in marls, marl-limestone and bioclastic calcarenites of the Thanetian (Paleocene, Cenozoic), contain benthonic foraminifera (Nummulites heberti and Discocyclina seunesi), pertaining to marine environments of shallow external platform. The outcrops are arranged along a 100-300 m thick and around 10 km long. The flints, which arise in discontinuous layers parallel to the stratification, present nodular morphologies in dark colours (usually 5-20 cm). They are fine grain flints composed of micro and cryptocrystalline quartz with carbonate relicts and a distinctive microdolomitization. Although the existence of flint outcrops has not been cited in the geological literature until present, the relation between archaeological sites and the outcrops has been described for us in recent investigations about Mugarduia. The prehistoric flint workshop is installed above the stratum itself or in its vicinity. We analyzed the lithic material that came from an intact archaeological deposit stratified discovered in the workshop, carried out in the fieldworks of the 80’s by I. Barandiaran and A. Cava. There were collected 995 retouched artefacts, around 400 cores and around 53,000 residues from the workshop. The analysis of the retouched artefacts of the mentioned collection allows the identification of seven flint types: Urbasa (local, mostly massive and showing a variable external aspect), Flysch, Trevino, Gaintxurizketa, Salies de Bearn, Urgonian, Loza (allochthonous all them). Allochthonous flint represents 7.8% of the retouched industry. This is a huge quantity taking into account the flint samples were collected from workshop context in the surroundings of Urbasa’s natural outcrops. We aim to study the nature and variability of the identified flints through geochemical and mineralogical methods and the management of the resources considering aspects of typology, typometry and technology.