Le dolmen de Peyre Dusets (Loubajac, Hautes-Pyrénées) : mégalithisme, terre crue et pierre consacrée du Néolithique récent ouest-pyrénéen

International audienceThe North-Western Pyrenees offers a remarkable archaeological potential for the Neolithic period in a geo- graphical key sector of Western Europe, between the Atlantic Ocean and the Pyrenees, with natural passages to the Iberian Peninsula. However, the region has been excluded from major research with a noted absence from national overviews. In 2015, we developed a Collective Research Project (PCR) on the theme of Considering megalithism as a gateway, with the aim to improve our understanding of regional megalithism, its forms, its symbolism and its chronology, through multi-method and multi-scalar approaches and the Neolithic and recent Prehistory of the north-western Pyre- nees. Our study focused on the emergence of megalithic building and its development on a more global scale. Known as Pierre d'Uzès, the dolmen of Peyre Dusets is mentioned on the cadastral maps of Lourdes (1812) and Lou- bajac (1813) as a boundary marker between the two municipalities. E. Dufourcet describes the first excavation and a survey in a paper published in 1876. The dolmen is mentioned subsequently, but no other excavations seemed to have taken place The first study of the monument mentions a megalithic chamber composed of four monoliths including a cover slab and three orthostats, one of them can be interpreted as the chevet stone, facing the East. The four slabs are all of “Cauterets” granite, probably of the same origin from the Mindel moraine that outcrops to the south of the site. The architectural and geological studies, as well as a geophysical survey of the monument (electrical map and tomography) raises questions as to the chamber’s architecture, its position and the composition of the tumulus. A survey in 2019 aimed to answer these questions. Our work used an “evaluation” type approach that is minimally invasive and adapted to our research. We have made three surveys on the Peyre Dusets site. We were not able to document the sepulchral levels, due to the excavation. We did however survey the inside of the chamber that seems to have been slightly over-deepened, forming an elongated hollow in the direction of the length of the chamber. The excavation also provided details on how the monoliths were put into place, by demonstrating that blocks no 2 and no 3 were put in first. The orthostat simply stands on the local clay substrate, while the bedside slab is wedged in a pit dug into the clay. The pit has a double-layered filling. The lower part is made up of a dense array of different rocks (schist, granite and sandstone) almost exclusively yellow kneaded clay. The upper layer contains balls of yellow and white clay clearly visible during excavation with an average diameter of 8 to 10 cm and a few scattered stones. The radiocarbon dating places the monument’s construction in the recent Neolithic period (4735 ± 30 BP) and several clues suggest that the bedside slab was first a menhir erected before the building of the dolmen. The date is consistent with the known data for this type of monument in the area. A shale slab with a particular shape was discovered during the excavation of the chevet stone wedging pit. The slab’s form and the context of its discovery suggest that it is an anthropomorphic stele. The excavation of the tumulus revealed an earthen feature preserved to a height of nearly 1.80 m and built using the massive dirt technique. The preparation of the ground, the implementation of a foundation layer and the finely prepared character of the materials are all indicators of the investment made in the building of the monument. These results, placed in a more global setting renew research into megalithism in our region giving it its rightful place as a major reference for Neolithic studies. Beyond the discovery of the stele that mirrors the prestigious megalithic sites of Western European, the importance of the mound, the care and the investment brought to the building of the monument, renew our knowledge of megaliths and of the Neolithic in our region. Until recently, the vision shared and transcribed in archaeological literature, reflected more a history of the research carried out in the area than a historical reality. It depicted a landscape dotted with simple dolmens, walked by shepherds in small transhumant groups, away from everything and (especially) from the socio- economic phenomena that were playing out elsewhere at the time. Recent work on West Pyrenean megaliths, whether it falls within the framework of our research project that focuses on the dolmen of Peyre Dusets, or within the framework of preventive excavations as on the site of the CM10 in Lannemezan, offer a vision quite far from this “image d’Épi- nal”. They all show that the building of monuments in the area happened within strong technical and symbolic systems that led to major changes in the landscape, these dynamics being completely synchronous with those in play in the rest of Western Europe.Dans le cadre d’un projet collectif de recherche (PCR) portant sur le mégalithisme des Pyrénées nord-oc- cidentales, une opération de sondage a été effectuée sur le dolmen de Peyre Dusets (Loubajac, Hautes-Pyrénées). Ces travaux ont révélé une structure de type caussenarde datée du Néolithique récent régional (3 800-3 300 BC), construite autour d’un menhir préexistant et placée au centre d’un tertre de terre massive. En outre, l’exploration du pied de la dalle de chevet a révélé la présence d’une petite stèle anthropomorphe. Ces résultats, replacés dans une vision plus globale, viennent participer au renouveau des problématiques sur le méga- lithisme et permettent d’offrir pour notre région, restée trop longtemps à l’écart des grands pôles de recherche, un autre regard sur les sociétés néolithiques. Ainsi au-delà de la découverte de cette stèle qui apparaît comme un élément de premier ordre faisant écho à des sites prestigieux du mégalithisme ouest-européen, l’importance du travail de la terre, le soin et l’investissement apporté à l’édification du monument, participent à l’émergence d’une image renouvelée du mégalithisme et subséquemment du Néolithique de notre région. Il apparaît dès lors que la vision proposée par une large frange de la bibliographie disponible sur notre secteur, d’un territoire parsemé de dolmens simples de chronologie tardive et aux dépôts modestes, parcouru par de petits groupes de pasteurs transhumants à l'écart de tout et (surtout) des phénomènes socio-économiques en jeu ailleurs aux mêmes moments, est davantage le reflet d’un état de la recherche que d’une réalité historique. Aujourd’hui, il semble ressortir au contraire l’image de sociétés aux organisations territo- riales et sociales fortes, bien moins en marge des grands phénomènes sociaux-économiques ou symboliques visibles à des échelles plus larges et bien plus dynamiques que ce qui avait pu être évoqué jusqu'à présent