Slip histories of normal faults and landscape evolution in the European Alps

The European Alps are dissected by north-south trending normal fault systems which are the surface expression of orogen-parallel extension during convergence between European and Adriatic plates. However, the slip rate and time when normal faulting proceeded remain debated. Here I present thermochronological data and thermokinematic modelling on the most prominent normal faults of the European Alps, the Simplon, Brenner, and Katschberg normal fault. This allows us to constrain the time when they were active as well as their fault slip rates. Our results indicate that east-west extension in the Eastern Alps decreases towards the east in concert with decreasing north-south extension.

To the east of the Katschberg fault, the topography comprises a low-relief surface at an elevation of 2000-2200 m which has been formed in the Early Miocene. To decipher the exhumation history of this remarkable landscape we employ thermochronology on elevation profiles in this area and we compare the results to our profiles from the Ötztal which has one of the highest topographies of the European Alps.

In the last part I will compare the long-term erosion rates derived above to erosion rates on a millennial time scale derived by cosmogenic nuclides. Cosmogenic nuclides also allow us to calculate exposure ages, e.g. from glacially polished quartz veins. Our exposure ages on quartz veins are in concert with the model predictions for the timing of ice retreat after the last glacial maximum.