The Eastern Alps are divided into several geomorphological principal domains, which are characterized by distinct elevation and slope angle distributions. High and rugged reliefs correlate with substantial exhumation since Miocene times and recent uplift; they characterize the western and central parts of the Eastern Alps. In the eastern part, remnants of paleosurfaces are preserved due to limited erosion (Early Miocene Nock surface metamorphic lithologies) or predominant subsurface erosion by karstification (Early Oligocene Dachstein surface in the Northern Calcareous Alps). In the course of Miocene lateral tectonie extrusion the paleosurfaces were fragmented due to tectonic block segmentation, and uplifted to different elevations. Longitudinal depressions follow important fault zones, which were active during extrusion tectonics. Polycyclic piedmont benchland formation, as proposed by several authors, was no important process during the uplift history of the Eastern Alps. A general west-east gradient can be established in terms of summit and mean elevations. This is mainly an expression of the Miocene tectonic processes. The geomorphological evolution of the Eastern Alps is sketched for three Miocene time levels starting with the Oligocene/Miocene boundary. The western Eastern Alps were already mountainous in Late Oligocene times. In the eastern part of the Eastern Alps, a northward-directed drainage system was fundamentally changed by the extrusion event. Thus, a new, east-directed drainage system established in Middle Miocene time, following the main tectonic lines. It formed the basis for the present-day drainage system in the eastern part of the Eastern Alps, whereas the drainage system of the western part did not experience fundamental changes since Late Oligocene times except a reduction of the catchment area of the Paleo-Inn river.
|Number of pages||36|
|Journal||Zeitschrift fur Geomorphologie|
|Publication status||Published - Mar 1 2000|
ASJC Scopus subject areas
- Geography, Planning and Development
- Earth and Planetary Sciences (miscellaneous)