Recent advances in the stratigraphy of the Upper Pleistocene of Westernmost Europe: La Haute Ville and Brehat Cliffs (Northern Brittany, France)

• Published in: Quaternary International
• Main Authors: Danukalova, Guzel, Lefort, Jean-Pierre, Osipova, Eugenia, Monnier, Jean-Laurent
• Other Authors: Institute of Geology of the Ufimian Scientific Centre, Russian Academy of Sciences, Centre de Recherche en Archéologie, Archéosciences, Histoire (CReAAH), Le Mans Université (UM)-Université de Rennes (UR)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Université de Nantes - UFR Histoire, Histoire de l'Art et Archéologie (UFR HHAA), Université de Nantes (UN)-Université de Nantes (UN)-Ministère de la Culture (MC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: [SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory; Thermokarst
• Online Access: https://hal-univ-rennes1.archives-ouvertes.fr/hal-01147547; https://doi.org/10.1016/j.quaint.2011.10.027

International audience A description of the different layers deposited in La Haute Ville and Brehat sites is given. Methodological considerations and comparisons with Russian, French and Netherlands stratigraphic scales are summarized. Malacological study shows the existence of shells deposited during the Early, Middle and Late Weichselian. In La Haute Ville, the upper part of the Lower and Middle Weichselian contains four soils which developed above an aeolian dune. Four malacozones have been separated. The groups of molluscs were classified according to their modern ecological preferences. The upper part of La Haute Ville Formation is observed in the lower part of the La Haute Ville cliff. This aeolian accumulation is completely decalcified. There is no fauna. The presence of colored quartz implies the existence of a warm climate. By comparison with other dunes of Brittany, it could be dated to the Early Weichselian. Comparison between the onshore and offshore data shows that the dune has never been as rich in carbonates as the loess or loess-like deposits. The Port Morvan Formation consists of four different soils interlayered with loams. All the soils are located at the level of the dome-like top of the dune. The disappearance of the soils towards the west and the east is associated with an undulation of the dune. The existence of four soils and the presence of molluscs living under broad leaved forests suggest a moderate climate. The cooling of the climate started at the end of the Port Morvan formation. These data allow correlation of this formation with the Middle-Lower Weichselian. The formation of Sables d'Or les Pins corresponds with true loess. It was deposited above the Port-Morvan formation which displays a clear erosion of its top. The top of this formation was affected by the development of a Holocene soil. A light grey layer represents a podzolic horizon. The lower boundary of these layers is affected by thermokarst Because of their location, their aeolian origin, the existence of thermokarst, ...