Geochemical study of lower Eocene volcanic ash layers from the Alpine Anthering Formation, Austria

Samples of bentonite layers from altered volcanic ash layers of the Anthering Formation in Salzburg, Austria, which most likely covers the Paleocene/Eocene boundary, were analyzed for their chemical composition. The results of the major and trace element determination confirm the previously suggested appearance from at least two different primary localities. One sample has low abundances in TiO2 and Ir (0.77 wt.% and 47 ± 16 ppt, respectively), whereas all others have iridium concentrations between 200– 450 ppt. On the basis of the chemical composition the bentonite layers are distant equivalents of coeval ash deposits from the Fur and Balder Formation in Denmark and the North Sea, respectively, as was suggested from petrological and mineralogical investigations.