Distribution and chronology of Pleistocene permafrost features in France: Database and first results

• Published in: Boreas
• Main Authors: Bertran, Pascal, Andrieux, Eric, Antoine, Pierre, Coutard, Sylvie, Deschodt, Laurent, Gardère, Philippe, Hernandez, Marion, Legentil, Claude, Lenoble, Arnaud, Liard, Morgane, Mercier, Norbert, Moine, Olivier, Sitzia, Luca, van Vliet-Lanoë, Brigitte
• Other Authors: Institut national de recherches archéologiques préventives (Inrap), De la Préhistoire à l'Actuel : Culture, Environnement et Anthropologie (PACEA), Université de Bordeaux (UB)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), IRAMAT-Centre de recherche en physique appliquée à l’archéologie (IRAMAT-CRP2A), Institut de Recherches sur les Archéomatériaux (IRAMAT), Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS)-Université de Technologie de Belfort-Montbeliard (UTBM)-Université d'Orléans (UO)-Université Bordeaux Montaigne (UBM)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Domaines Océaniques (LDO), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Observatoire des Sciences de l'Univers-Institut d'écologie et environnement-Centre National de la Recherche Scientifique (CNRS), Labex Sciences Archeologiques Bordeaux (LaScArBx)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2014
• Subjects: SEA-ICE COVER; NORTHERN FRANCE; WEDGE CASTS; NW EUROPE; LOESS; SOIL; SAND; ENGLAND; RECORDS; QUARTZ; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Ice; permafrost; Sea ice; Tundra; wedge*
• Online Access: https://insu.hal.science/insu-00833781; https://doi.org/10.1111/bor.12025

International audience Numerous periglacial features (polygons, nets, soil stripes, ice-wedge pseudomorphs and sand-wedge casts, involutions) have been recorded in France by examining bibliographical sources and aerial photographs. These data show that a large part of France was affected by permafrost during the Pleistocene and only the southern Aquitaine Basin and Languedoc seem to have been beyond its maximum extent. The first OSL ages obtained from the aeolian infill of wedge structures indicate that at least two phases of thermal contraction cracking occurred in southwestern France between ∼25 and 36 ka. Chronostratigraphical data from loess in northern France indicate that these episodes correspond to the formation of ice-wedge networks associated with tundra gleys. In the latter region, two additional permafrost episodes probably occurred during the Last Glacial, the older one corresponding to the end of Marine Isotope Stage (MIS) 4 around 60 ka and the more recent one to MIS 2 around 19-16 ka. Although stratigraphical data indicate that these episodes were relatively short (about one millennium), relict permafrost may have existed for longer periods in northern France.