A glacial refuge in the Pays de la Loire? An isotopic study at the Solutrean level of the Grotte Rochefort

International audienceRochefort cave (Saint-Pierre-sur-Erve, France) is one of the largest caves of the group called "les grottes de Saulges" which are all found along a 1.5 km stretch of the Erve River. Since 2001, an excavation has been carried out in the large chamber which led to the identification of a remarkable Solutrean level with its lithic and faunal assemblages and the presence of art on plaquettes. Stratigraphy and radiocarbon dating give an age between 19,000 and 20,000 BP and the remarkable homogeneity of this unit excludes any possible mix-up with previous or later chronocultures. Fauna and palaeoenvironmental data certify a cold and dry environment during the Last Glacial Maximum (LGM, OIS 2), in which some protected areas favourable to more temperate species still remained. Thus, if reindeer (Rangifer tarandus) and horses (Equus ferus) dominate in the faunal corpus, alpine ibexes (Capra ibex), woolly rhinoceroses (Coelodonta antiquitatis), mammoths (Mammuthus primigenius), arctic foxes (Alopex lagopus), Red fox (Vulpes vulpes), wolves (Canis lupus), brown bear (Ursus arctos), wild cats (Felis sylvestris) and wild boars (Sus scrofa) are also found. Araeozoological analysis point to a seasonal hunting camp.Stable isotopes analysis of bone collagen from a sample of the fauna of this site indicates a variety of environments for the horse, a specialized diet for reindeer and a variation within the usual values for the remaining species. However, stable isotope values depend not only on diet, but also on basal values in soils and vegetation, which in turn depend on climate. In accordance with the paleoenvironmental interpretation, the stable isotopes of the Rochefort fauna do not differ substantially from those of sites further south in the Dordogne, a refuge in the LGM, suggesting the possibility of a seasonal refuge in this northern area, closer to the front of the Arctic ice cap