Évolution des niveaux archéologiques en contexte périglaciaire

Abstract

In addition to the study of the climatic setting and sedimentation in cave and rockshelter entrances, the Gavarnie project permitted the development of a series of experiments dedicated to documenting post-depositional modifications of archaeological remains in periglacial environments. Experiments ran over a period of 3–5 years and documented: 1) the lateral and vertical dispersals of an assemblage deposited on the scree slope of a cave entrance, 2) the displacement, re-orientation, and size sorting of archaeological pieces situated on a solifluction sheet, and 3) the movement of a group of artefacts during the melting of snow cover. Displacement measurements are linked with the experimental site’s climatic record to determine the influence of part of freeze/thaw cycles and summer storms on overall modifications. The results indicate that initial artefact distribution – discrete cluster or dispersed scatter – influences the degree of displacement by solifluction. The stages of deformation of the archaeological structures are documented. A computer simulation based on flint orientation measurements indicates that the time interval needed to obtain a linear fabric of artefacts displaced by solifluction is about twenty years. Finally, the comparison between results from experiments conducted in the alpine zone and those obtained in the snow zone shows the particular degradation pattern specific to each environment. As a whole, these results provide present-day comparisons for evaluating the degree of natural modification at a number of European Palaeolithic sites.

Keywords

• experimental archaeology
• Palaeolithic
• periglacial solifluxion
• simulation
• site formation processes