Late Cenozoic exhumation and drainage evolution of the Central and Western Alps revealed by detrital thermochronology

The relations between climate, tectonics and topographic changes are still not fully understood. During the Late Cenozoic, the glacial cycles affecting the European Alps are held responsible for a strong increase in Alpine relief. Detrital samples of the circum-Alpine foreland depocenters were analyzed with detrital thermochronology, namely the apatite fission track and (U-Th-Sm)/He dating methods. The new thermochronological data contradict a long-term exhumational equlibrium for the Central and Western Alps, as frequently postulated in Alpine literature. In fact, distinct Alpine regions differ severely in their exhumation pattern. Also the drainage pattern was more complex than previously assumed, with a proto-Rhine draining via the Rhine Graben towards the North Sea in Pliocene times.