14. Quaternary Landforms and Sediments in the Northern Alpine Foreland of Salzburg and Upper Austria

This chapter highlights Quaternary landforms and sediments in the Northern Alpine foreland between Salzburg and Upper Austria—a region with a remarkable history of Quaternary research from the early pioneers in the twentieth century to the quantitative studies of today, making use of a range of modern (e.g., dating) techniques. Before any glaciers modified the region, the Mio-Pliocene landscape was dominated by massive accumulation of fluvial sediments originating from the still growing Alps in the hinterland to the Molasse basin in the foreland. Large parts of these deposits were later on eroded, reworked, and superimposed by glacial sediments during several Pleistocene cycles of glaciation and deglaciation. The sedimentary signatures of the regionally most important Salzach and Traun glaciers are exceptionally well preserved and can be traced from their inner-Alpine source areas, along their transport routes following the Salzach and Traun valleys, within several peripheral glacially shaped basins, and finally in the terminal moraines and adjacent outwash plains further north. In contrast to the Pleistocene Salzach Glacier that emanated from the Central Alps and formed a large piedmont glacier in the foreland, the branches of the Traun Glacier barely reached the foreland, because of a smaller ice accumulation zone in the Northern Calcareous Alps, predominantly on the high plateaus of Totes Gebirge and Hoher Dachstein. With the Traun-Enns-Platte and the Salzach-Inn confluence area, two important terrace systems north of the Quaternary ice margin developed. However, this unique landscape of glacial heritage constitutes a fragile and vulnerable system which needs to be protected.