Figure 7 (Large)

Figure 7 – 3D geological model, map view, and cross-section restoration of the D-D’ section from 22 Ma to the present. For each deformation stage, the corresponding active deformation phase is indicated by thicker line and distinct colour. Reverse faults are shown with a patterned style due to their high frequency and dense distribution. (A) At 22 Ma the massif is situated beneath the Helvetic, Penninics and Austroalpine nappes, as well as Paleogene sediments to the north. (B) At 18 Ma, the southern region of the massif was exhumed by the formation of steep reverse faults (red lines) and thrust faults (blue lines). (C) At 15 Ma, the exhumation of the basement units proceeded to the central region of the massif, with the formation of subvertical reverse faults and shallow-dipping thrusts. (D) At 10 Ma, the exhumation advanced to the northern region of the massif, with a strong reverse fault component. This phase resulted in the formation of the steep northern front of the massif and the passive up-doming of the overlying nappe stack. (E) From 10 Ma onwards, flat- to moderately SE-dipping thrust faults (blue lines) dissected the basement units. This resulted in an ‘en bloc’ exhumation (Herwegh et al., 2020, 2023; Nibourel et al., 2018, 2021b) of the basement units with ~9 km of shortening.