La gestion des quartz diadases de lAlbigeois cristallin (Tarn) au Paleolithique moyen

摘要

Vein quartz composes 98% of the Lower and Middle Palaeolithic industries found in the gravelly clays of the Albi crystal system (France). The high density of micro-joint networks which affect this kind of material has strongly influenced knapping techniques. The main parallel or crossed directions of the cleavage planes, starting point of a splitting of the mineral into small plates or bevelled lenticular blocks, could have given preformed bases (cores), convertible into various tools such as bifaces, cleavers, knives, scrapers and burins. The high proportion of such objects in the assemblages studied excludes the assumption of an accidental process, as this particular type of texture has been systematically integrated in the shaping procedures. In addition, the impossibility of using recurrent laminar knapping techniques with jointed vein quartz may have led to the maintaining of a Mousterian tradition, whose minority forms on imported flint bear the innovative features of the Upper Palaeolithic.