Sedimentuntersuchungen an unterpleistozänen Schmelzwasserablagerungen und Periglazialschottern im Riß-Iller-Gebiet, deutsches Alpenvorland

Abstract

The Lower Pleistocene meltwater deposits at the contact of the Rhine- and Illergalcier (Baden-Württemberg, Bavaria) and the periglacial sediments occurring below them are described. The research is focused on the analysis of the petrography of the pebble-size fraction and of the sand-size heavy mineral assemblages of the Biber-, Donau- and Günz-age deposits. The results confirm that the periglacial sediments can be distinguished clearly from the glaciofluvial material by arguments of the petrography. However, a systematic change of the lithology also within the glaciofluvial material can be inferred from the high number of the investigated samples. Within the gravel fraction the amount of crystalline rocks, radiolarite and hornstone increases towards the younger accumulation units, whereas the content of calcareous components decreases. Concerning the heavy minerals the amount of instable minerals as Garnet and Hornblende decreases, while the portion of Staurolite increases remarkably towards the younger deposits. In the paper at hand these results are interpreted with respect to the paleogeography, in order to figure out the river development of the Riß-Iller-tract.