Early Weichselian dust storm layer at Achenheim in Alsace, France |
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| Authors: | DENIS-DIDIER ROUSSEAU GEORGE KUKLA LUDWIG ZÖLLER JANKA HRADILOVA |
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| Institution: | UniversitéMontpellier II, Paléoemironnements &Palynologie, Instilut des Sciences de l'Evolution (UMR CNHS 5554), case 61, pl. E. Bataillon. 34095 Montpellier cedex 05, France &Lamont-Doherty Earth Observatory of Columbia University, Palisades, N.Y. 10964, USA;Lamont-Doherty Earth Observatory of Columbia University, Palisades, N.Y. 10964, USA;Forschungsstelle Archäometrie der Heidelberger Akademie der Wissenschaften, c/o Max-Planck Instilut für Kernphysik, Postfach 103980, D-69029 Heidelberg, Germany;Geological Institute of the Czech Academy of Sciences. 135 Rozvojova, 16500 Praha-Suchdol, Czech Republic |
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| Abstract: | The cause of the rapid transition from lush grasslands and woodlands of the Early Glacial interstadiul to Pleniglacial barrens in Europe is still a mystery. In the loess sections of Bohemia and Austria this transition is associated with thin layers of fine-grained airborne dust known as 'markers', believed to be deposited by major contineiital-scale dust storms. Here we present evidence that a similar. sharply delimited layer with a minimum TL age of 64.9 ± 6.9 ka separates the autochthonous humus steppe soils from abiogenic sediments of the Achenheim 1 pedocomplex in France. The soil complex has been previously correlated on pedostratigraphic grounds with marine oxygen isotope stage (MIS) 5. Given its age and stratigraphic position, the dust layer correlates with the PKII marker in Bohemia. The rccogiiition of a marker in Achenheim suggests that the development of the Early Glacial steppe soils ended abruptly not only in central Europe, but also in Alsace, France, prior to 65 ka, possibly as a result of a single continental-scale dust storm. |
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