Un point de technologie chasséenne

The study of lithic Chasséen industries from Drôme, Aude and Haute-Savoie (France) shows that thermal treatment of chert was a very common practice during this period. It was specially useful to prepare very standardized bladelets, a well-known Chasséen production. Chert was heated in the shape of prepared cores with most of cortex removed, and some flakes. Different kinds of cherts, with various textures, could be treated, that is to say that Chasséen men controlled perfectly this technique of preparation. The quite lack of reddening upon theses bladelets implies that the cores and flakes lied into a thick layer of clay and sand. The heating structures were probably these pitshearths often described in excavations of Middle Neolithic of Southern France. This was the opportunity to summarize all we know about thermal alteration of cherts. Several points, yet unexplained, are analysed again. There is no sound hypothesis upon the thermal luster of heated cherts : this point needs presently a very specific mineralogical research. Modifications of cherts — like reddening, luster, potlids, polyedral fractures, and whitening — do not appear at random, but always in two successive phases. First, all mechanical qualities of cherts are improved until a sudden, definitive alteration, when appear sugary texture and pot-lids : this is a general, unchanging process for all cherts. Variations in thermal behaviour of siliceous rocks were often pointed out : they can be explained by the influence of granulometric characters only. Micritic cherts are sooner improved and altered by heating than coarse-grained ones. Last, macroscopic changes of heated materials are sufficient to establish this treatment : there is no need heavier analysis such as D.T.A., E.S.R. or T.L. measuring.Masson Annie. Un point de technologie chasséenne. In: Comptes rendus d'activités annuelles. Association régionale pour le développement des recherches de paléontologie et de préhistoire et des Amis du Muséum, tome 22, 1984. pp. 31-41