Last Glacial palaeoenvironments at Lascaux, southwest France, with special emphasis on MIS 4 (Ognon II interstadial)

International audience; A deep sequence of Last Glacial peats and slope deposits at the foot of the Lascaux hill was investigated using a large array of methods (geology, geophysics, C-14 and OSL dating, palynology, macro-remain analysis, entomology). The peaty levels, OSL dated to between similar to 73 and 60 ka, are found Within a doline developed in a fluvial terrace of the Vezere River. These gyttja and chalky gyttja deposits covered by fen peat yielded abundant beetle and plant (seeds, pollen) remains. Palaeoecological reconstructions suggest a cool steppe with willow stands compatible with an interstadial of marine isotopic stage (MIS) 4, probably Ognon II (GI-192). Aquatic and hygrophilous plants (sedges), which reflect local vegetation, and their dependent insects are equally well represented in the record. The peats are covered by a sequence of slope deposits: a coarse-grained lower unit deposited during late MIS 4, overlain by a heavily decalcified sandy unit with a boreal soil complex correlated with early MIS 3, and finally, a coarse grained, calcareous unit formed during late MIS 3 and MIS 2 in connection with slope dynamics typical of periglacial environments. The palaeosols yielded a small Middle Palaeolithic lithic assemblage. (C) 2016 Elsevier B.V. All rights reserved.