New speleothem dates from caves in Germany and their importance for the Middle and Upper Pleistocene climate reconstruction

Abstract

Twenty speleothems from caves of different karst regions (mainly from the Franconian-Swabian Alb and the Bavarian Alps) in Germany were dated with the TIMS-U/Th-method The samples were taken from stalagmites of various sizes.Beginning and end of the growth phases were determined by dating the base and the tip of each sample. The dates obtained fit into the general scheme of Pleistocene climate in Germany, where speloeothem growth is interrupted by cold periods. Some of the samples could not be dated because they suffered from secondary loss of uranium most probably due to leaching. Those samples belong to visibly older sinter generations. Leaching could have occurred under permafrost conditions when the caves were filled with ice or when groundwater was trapped in the caves below a permafrost cover.