ABSTRACT
Dated surfaces ƒ The first dating method uses soil sequences found on progressively exhumed marine surfaces or on dated fluvial terraces. The soils seen in Germany on Weichselian sediments (equivalent to the Würm in northern Europe) are identified as Luvisols (Kühn 2003). Actually, they are very special: firstly, they are differentiated in sandy parent materials and their argic B contains less than 15 per cent clay; secondly, their E horizon is limited to open, wedge-shaped cracks filled with sand inside the B. In France, in the Rhône valley, Luvisols are found on Riss terraces (between 110,000 and 128,000 years), while Albeluvisols and Planosols occur on older surfaces. On the terraces of the Allier river, the soils would have intermediate development (Jongmans et al. 1991): Eutric Cambisols on surfaces dated 13,000 years, Luvisols between 13,000 and 30,000 years and, lastly, Planosols on the oldest surfaces.
