From the Jura Arc to the Paris Basin: exploitation of jet as black raw material for making ornamental objects during the Magdalenian in the northwest Europe
Résumé
Jet is coalified wood widely used as a black raw material for making ornamental objects at the end of the Magdalenian (16.5-14 ka cal BP). This paper applies a multidisciplinary approach, including organic petrology methods, to the study of ornamental archaeological objects, in order to analyse Magdalenian jet exploitation (acquisition and transformation) and distribution modes in north-western Europe (Jura Arc and the Paris Basin). The results shed light on the exclusive use of jet for the production of symbolic objects (geometric beads, figurative pendants and elements of portable art) and show that jet-working techniques were adapted to the specific mechanical properties of the material (percussion and meticulous grooving, scraping and abrasion techniques). The petrographic characters of the analysed materials are surprisingly uniform and are all part of the Swabian Jura group of jet (so-called “Posidonia Shale”, Lias epsilon, Lower Toarcian). This uniformity reveals the importance of jet during the Magdalenian, materialized by a wide circulation of the material (at least 500 km, as far as the Paris Basin).