Stratigraphische Begriffe für das Quartär des süddeutschen Alpenvorlandes

Abstract

This description of the Quaternary of the south German Alpine Foreland focuses on the classic morphostratigraphical terminology sensu PENCK & BRÜCKNER, with a methodological introduction by K.A. HABBE. These definitions correspond to the nomenclature used in the Quaternary literature of southern Germany mainly between 1950 and 2000. The manuscripts left by K.A. HABBE at his death in 2003 were edited by D. ELLWANGER, and the definitions were supplemented and commented by D. ELLWANGER and R. BECKER-HAUMANN. HABBE’s ideas and definitions illustrate that morphostratigraphy can still be a modern and meaningful approach to subdividing the Quaternary, not just to describe Quaternary (especially glacial) landforms on earth science maps, but also as a tool for soil scientists, regional planners, etc. However, morphostratigraphy is less appropriate for describing and characterising lithological units (in economic geology or hydrogeology, for instance). This is initially the province of lithostratigraphy. The two methods complement each other as regards sequence stratigraphy because discontinuities and sequences are considered together (ELLWANGER et al. 2003). It should be noted that morphostratigraphical units and lithostratigraphical formations are distinguished according to different criteria. Difficulties always arise when morphostratigraphical and lithostratigraphical procedures yield different chronostratigraphical classifications. A second problem of traditional morphostratigraphy is its strong focus on the terrace stratigraphy of the ice marginal to periglacial valleys. Morphogenetic processes primarily occurred not in these valleys, but in areas of glaciation, in glacial basins, overdeepened valleys, and lake regions. These are the main locations of major discontinuities that could form the basis for a spatial morphostratigraphical subdivision. By contrast, erosion and accumulation dynamics of different ages are often indistinguishable within the terrace layers, especially in main valleys. Third, some critical comments are necessary about the use of the glacial series, again with special reference to classic morphostratigraphy. It is applicable almost everywhere for Würmian sediments and is a good tool for correlating Riss deposits and for describing the third-last major glaciation (“Mindel” and “Hosskirch” to the east and west of the Lech, respectively). Problems arise, however, when it is applied to (older) cover gravels to postulate pre-glacial cycles of cold and warm stages. This tends to inhibit clarification of whether processes were controlled by climate (glaciation) or tectonics (orogeny): an essential question with regard to the glaciation of mountain regions like the Alps.