Les séquences loessiques pléistocène supérieur d’Havrincourt (Pas-de-Calais, France) : stratigraphie, paléoenvironnements, géochronologie et occupations paléolithiques

Abstract

The upper pleistocene loess sequences of havrincourt (Pas-de-Calais, France). Stratigraphy, palaeoenvironments, geochronology and human occupations In connection with the future Canal Seine-Nord Europe (Seine-Scheldt), a large-scale rescue archaeological survey was conducted between 2008 and 2011 in northern France At Havrincourt (Pas-de-Calais), the discovery of several levels of Palaeolithic flint artefacts embedded in a relatively thick loess sequence (∼ 6-7m) preserved on a gentle slope facing north-east, has resulted in a rescue archaeological excavation on a total surface of 6 000 m2. Four Palaeolithic levels were uncovered in primary position. This sequence has been the subject of a continuous stratigraphic survey over nine months and an interdisciplinary approach combining pedostratigraphy, sedimentology, micromorphology, palaeontology, malacology, environmental magnetism, OSL and 14C dating. Based on this research, we propose: 1) a new pedostratigraphic reference sequence for Northern France, especially with regard to the Lower and Middle Pleniglacial periods (∼ 70-30 ka), 2) a new regional geochronological framework for the Last Glacial (luminescence and radiocarbon) as well as a revision of the regional pedostratigraphic and chrono-chmatic systems, and 3) the description and dating of a unique succession of periglacial horizons including five ice-wedge cast networks associated with tundra gley horizons representing a first regional reference sequence. In addition, the good preservation of archaeological levels, associated with the multidisciplinary analysis and dating of the pedosedimentary sequences leads to the chronostratigraphic and chrono-climatic interpretation of the four Palaeolithic levels including a unique occupation related to the Early Upper Palaeolithic (Early Gravettian). These results and new discoveries allow us to propose Havnncourt as a new pedostratigraphic and archaeological reference sequence for the Late Pleistocene of northern France and more broadly for the west-European loess area.