Datation radiocarbone directe et attribution culturelle des vestiges humains paléolithiques de la grotte d’Isturitz (Pyrénées-Atlantiques)
Authors: Henry-Gambier Dominique , Normand Christian , Pétillon Jean-Marc 
Published: February 2017

This paper presents new AMS radiocarbon dates from three human bones housed at the Musée des Antiquités Nationales (Saint-Germain-en-Laye) and found during the Saint-Périer excavations in the Isturitz cave. This cave, located in the foothills of the western Pyrenees, is a major site of the Franco-Cantabrian region. It is well-known for having yielded a major Palaeolithic sequence with rich Magdalenian levels indicating long and intense occupation by human groups during the Upper Palaeolithic. The cave is divided into two main chambers : the Isturitz chamber (or Grande Salle) and the Saint-Martin chamber (fig. 1). Research was conducted in Isturitz by E. Passemard between 1912 and 1923, by R and S. de Saint-Périer between 1928 and 1948 (Passemard, 1924 and 1944 ; Saint-Périer, 1930 and 1936 ; Saint-Périer and Saint-Périer, 1952), and by C. Normand and others since 1999. The excavations of E. Passemard and R. and S. de Saint-Périer yielded an important assemblage of human remains from both adult and immature individuals. The cultural attribution of these bones is problematic, especially because of the complexity of the stratigraphy and the ancient date of the excavations (fig. 2) ; although the bones come from different levels of the sequence discovered in the cave, they are usually attributed to the Magdalenian (Gambier, 1990-1991). More than 80% of this assemblage consists of fragmented elements of the skull and mandible ; anthropic modifications indicate a processing of corpses linked to either funerary or ritual, warlike practices (flesh removal, disarticulation, intentional breakage, sometimes shaping and engraving of the bones : Gambier, 1990-1991). While fragmentation limits the interest of these remains as regards the study of skeletal morphology, the anthropic modifications of the bones mean they are of major interest for understanding the mortuary behaviour of Upper Palaeolithic populations. Three samples (fig. 3) were selected among the human remains found in the Grande Salle by R. and S. de Saint-Périer. Two are from layer II (Middle Magdalenian) and one is from layer III (Upper Gravettian). They include : IST II-23-1937, a fragment (5.5 cm × 6.4 cm) of an adult parietal ; IST II-41-1933, a fragment (7.5 cm × 6.5 cm) of an adult frontal ; and IST III-53-1937, a fragment of an adult parietal (6.7 cm × 6.0 cm). These three fragments belong to three different adults. The bones were photographed and analysed prior to sampling. Sampling was done in areas without glue, consolidators, varnish or ink. They were submitted for AMS 14C dating at Groningen (Centre for Isotope Research, Groningen University). The results indicate that the two bones 45328 IST II-23-1937 and 45332 IST III-53-1937 are dated respectively in the range of 18461-17652 and 18043-17540 cal. BP, corresponding to the Middle Magdalenian. The third, 45329 Isturitz II -41-1933, is associated with a range of 16351-15174 cal. BP, contemporary with the Upper Magdalenian. The date obtained on the sample from layer III confirms the hypothesis of contamination of layer III, top of the Gravettian, by layer II, Middle Magdalenian. The assumption of the majority of human remains pertaining to the Middle Magdalenian is therefore admissible. The date obtained for the third sample is problematic because it falls within an interval corresponding to the Upper Magdalenian : it is close to the AMS date obtained on a fragment of antler barbed point (’ harpoon head’) from layer F1 (fig. 4 : 13095 ± 55 BP or 16441-15223 cal. BP ; Szmidt et al., 2009). Like the others, this bone sample had anthropic modifications, and therefore the date could have been expected to integrate the interval corresponding to the Middle Magdalenian. Therefore, either the reliability of that date is uncertain — but no arguments support this hypothesis — or the processing of the corpse and head in the Upper Magdalenian was, if not identical, in any case, at least similar to that attested in the Middle Magdalenian. Isolated human bones with anthropic modifications also exist in the Upper Magdalenian (Gambier, 1996) so this hypothesis cannot be ruled out. However, in the Grande Salle of Isturitz, the transition between Middle and Upper Magdalenian is visible in many categories of archaeological objects and fields of activity (flint and antler equipment, game hunted, ornaments and art : Pétillon, 2004 and 2006 ; Langlais, 2010 ; Laroulandie in Pétillon et al., to be published). These differences argue for major changes in human behaviour at the Middle-Upper Magdalenian transition. If the date on the human bone is reliable, it would mean that mortuary behaviour continued, at least partially, beyond these transformations. Other dates are necessary to further the discussion and the dating programme on human bones should be continued. However, the assumption that the majority of human remains at Isturitz pertain to the Middle Magdalenian is reinforced by these new dates.