L'attribution chronoculturelle des "objets arciformes" du Paléolithique supérieur. Apports de la datation directe de l'ébauche du Petit Cloup Barrat (Cabrerets, Lot, France) et discussion autour de l’hypothèse badegoulienne

International audienceLe Petit Cloup Barrat cave (Cabrerets, Lot, France) is located on the hill of Pech Merle, 800 meters from the famous palaeolithic cave art. It is opened on the edge of a collapse doline of 500 m2. Since 2003, the different excavations (Castel and Chauvière's excavations, then Castel's excavations) have revealed an important Upper Palaeolithic stratigraphy, with several archeological assemblages. More than ten millennia have been recorded discontinuously in the various sedimentary complexes, with occupations dating from the end of the Gravettian to the Middle Magdalenian.The layer 4 of the deposit yielded an “arciform object” prefom (so-called "omega-like shape open ring”) made in antler. Until now, this morphotype was known only through the ten specimens discovered at the end of the 19th century in Le Placard cave (Vilhonneur Charente, France) and that of the so-called "Cave à Endives" archaeological collection (André David'collection, Cabrerets, Lot). The direct dating of this preform using AMS radiocarbon method (17,720 ± 90 BP or 21,770-21,122 cal BP) was carried out in the Oxford laboratory. According to the chronological frameworks now available for the French south-west, it seems to refer to the Badegoulian technical traditions. The implications of the absolute chronological positioning of this original object are important, first on the scale of the Petit Cloup Barrat and as well as the Upper Palaeolithic “arciform objects”.At Le Petit Cloup Barrat, Badegoulian occupations have been identified since 2003 inside the cave, following the discovery of lithic (raclettes) and osseous remains (antler flakes). They were discovered in the layer c8a1. This layer is constituted by a remarkable sedimentary signature and was dated by AMS radiocarbon method from a faunal remain (18,595 ± 150 BP or 22,876-22,101 cal BP). The direct 14C dating of the open ring prefers to fill a gap in the radiometric chronology of the outer area of the main excavation sector, confirming the presence of Badegoulian, already suspected through the recurrent demonstration of lithic "markers" on the heart and the bottom of the layer 4. Moreover, the direct 14C dating of the "omega-like shape open ring” is consistent with another AMS date, in layer 4, from an antler flake produced by knapping (17,800 ± 80 BP or 21,838-21,292 cal BP), a technical waste characteristic of the Badegoulian. These two dates are older than one of a splinter fragment from the same layer, and produced by grooving (16,100 ±70 BP or 19,629-19,208 cal BP). Both, they refer to the anteriority of the use of knapping in comparison to the groove and splinter technique, according to the general evolutionary model proposed elsewhere, without excluding, for the moment, the possible of coexistence of other elements resulting from these two modes of blank production, at least on the scale of the sedimentary unit which contains them. The bone industry data are added here to other observations about typo-technological analysis of lithic industry and radiometric data to confirm the diachrony in the layer 4.The direct radiocarbon date of the "omega-like shape open ring” preform from Le Petit Cloup Barrat and its technical examination also provide a substantial complement to the study of this rare and original object. The results can be extended to the other “arciform objects”, considered until then as Magdalenian, and constitute a first step towards their chrono-cultural re-contextualization. First, if the allocation to Badegoulian of the "arciform object" type would be to confirme, it would increase a corpus constituted by elements which, for most of the currently available series, are suffering from the disconnection between the blank production and the different typo-functional categories (eye needles, awls, chisels and projectile points). Then, the direct dating of "omega-like shape open ring” prefom of Le Petit Cloup Barrat encourages a critical re-reading of the typological assemblages yielded by Le Placard cave, according to the radiometric framework from the Badegoulian assemblages of this famous palaeolithic site. As these assemblages served to seriate the Magdalenian times, they need a reassessment, using AMS radiocarbon method, in addition to “arciform objects” with others morphotypes such as “spiked single bevelled points” and “Lussac-Angles points”.La couche 4 du Petit Cloup Barrat (Cabrerets, Lot) a livré l’ébauche d’un objet arciforme (ou « anneau ouvert ») en bois de cervidé. Ce morphotype n’était jusqu’à présent connu qu’au travers des dix exemplaires mis au jour dans la grotte du Placard (Vilhonneur, Charente) et de celui de la série dite de la « Cave à Endives » (Collection André David, Cabrerets, Lot). Sa datation directe par SMA (17720 ± 90 BP, soit 21770-21122 cal. BP), réalisée au laboratoire d’Oxford, semble renvoyer, selon les cadres chronologiques aujourd’hui disponibles pour le sud-ouest français, aux traditions techniques badegouliennes. Cette datation est par ailleurs cohérente avec la mesure d’âge obtenue au sein du même ensemble à partir d’un éclat de bois de renne débité par percussion lancée, déchet technique caractéristique de la méthode de production des supports au Badegoulien. Au-delà d’un nécessaire travail de critique archéo-stratigraphique de la couche 4 qui semble, d’après les données typo-technologiques et radiométriques, témoigner d’une diachronie insoupçonnée jusqu’ici (Magdalénien moyen, inférieur, Badegoulien et Solutréen), la datation directe de l’ébauche d’anneau ouvert du Petit Cloup Barrat et son examen technique apportent un complément important à l’étude de ce type d’objet. Ces résultats, étendus aux autres objets arciformes considérés jusqu’alors comme magdaléniens, constituent une première étape vers la re-contextualisation chrono-culturelle d’un morphotype aussi rare qu’original