Multi‐phase late‐Neogene exhumation history of the Aar massif, Swiss central Alps

Abstract The late‐Neogene evolution of the European Alps was influenced by both tectonic and climatically driven erosion processes, which are difficult to disentangle. We use low‐temperature thermochronometry data from surface and borehole samples in the Aar massif–Rhône valley (Swiss central Alps) to constrain the exhumation history of the region. Multiple exhumation events are distinguished and linked to regional‐scale tectonic deformation (before 5 Ma), short‐lived climatically driven orogen contraction (between 4 and 3 Ma), and glacial valley carving since c . 1 Ma. Compared with previous studies, we clearly show the existence of two separate exhumation phases in the Late Miocene–Pliocene and better constrain the onset of glacial valley carving. The hydrothermal activity and geothermal anomalies currently observed in the borehole have been local and short‐lived, with only a minor influence on thermochronometric observations. We thus suggest that late‐stage glacial valley carving may have triggered topography‐driven fluid flow and transient hydrothermal circulation.