Magdalenian occupations between 20000 and 15000 cal BP in the Pyrenean foothills: test-pitting the Paleolithic sequence of Laa 2 cave (Arudy, Pyrénées-Atlantiques, France)

Because of its rich record of Magdalenian sites, the Arudy Basin is a key case for the study of resettlement dynamics in the Pyrenean valleys after the Last Glacial Maximum. Interpretations are, however, hampered by the ancient age of many excavations. The recently acquired data from Laa 2 cave contribute to filling this gap, although the excavation of the Paleolithic layers was restricted to a very small surface. Layer C5 documents a very early –but still poorly defined– reoccupation of the cave (20000-19500 cal BP) that probably took place shortly after the deglaciation of the lower valley. Layers C4 to C2 (18500-15000 cal BP) document the evolution of the Middle and Upper Magdalenian in a cool, humid and open landscape, although evidence of reforestation appears in layer C2. The species hunted include a large proportion of mountain ungulates in the earlier layers, but horse and reindeer increase in proportion in the later layers. Birds and foxes are also exploited, and the question of the presence of dogs is raised, although not conclusively. Lithic sources seem to diversify in the Upper Magdalenian, along with an evolution in the dimensions of lithic armatures. The osseous industry also shows evidence of changes in the design of armatures (presence of forked implements) and includes a single evidence of portable art (an engraved scapula). ; Par sa richesse en sites magdaléniens, le bassin d’Arudy est un lieu privilégié pour étudier les dynamiques de repeuplement des vallées pyrénéennes après le Dernier Maximum glaciaire, mais les interprétations sont limitées par l’ancienneté de nombreux travaux de terrain. La grotte de Laa 2 contribue à combler cette lacune, même si la fouille des niveaux paléolithiques a dû se limiter à une surface très réduite. La couche C5 montre une réoccupation précoce (20000-19500 cal BP), mal caractérisée, suivant sans doute de peu la déglaciation de la vallée. Les couches C4 à C2 (18500-15000 cal BP) documentent l’évolution du Magdalénien moyen et supérieur, dans un milieu frais, ...