Long-lasting tectonic activities of the Lepontine Dome. New evidence from low-temperature thermochronology

- We identified formerly unknown Neogene cooling patterns in the Lepontine Dome.
- Exhumation styles changed on small-scale within the study area (less than 40 km).
- Large-scale folding in the dome was related to long-lasting north-south compression.
- Exhumation patterns across the dome changed towards uniform exhumation at ~ 6-4 Ma.

To investigate the Neogene exhumation history of the central European Alps, we apply low-temperature thermochronology in combination with thermal history modelling. Fission track and (U-Th-Sm)/He ages on apatites from the central Lepontine Dome (Ticino, Switzerland) indicate higher exhumation rates in the centre of the dome and rather moderate exhumation at the northern and southern boundaries since Neogene times. We present a model for explaining the latest stage exhumation of the central Lepontine Dome and show that (I) both episodic and continuous exhumations are found on small-scale throughout the Neogene, (II) compressional tectonics control the exhumation until the Late Neogene, (III) the exhumation regime changes between 6 and 4 Ma and (IV) increasing hinterland exhumation rates at the Mio-Pliocene boundary cannot be related to tectonic structures of the dome and they are thus explained by climatic changes.