Fig. 16

Simplified structural map (modified from Schmid et al. 2004) including new and published peak temperature estimates based on RSCM (Beyssac et al. 2002; Erne 2014; Girault et al. 2020; Hafner 2016; Lahfid et al. 2010; Mair et al. 2018; Negro et al. 2013; Nibourel et al. 2018; Wiederkehr et al. 2008) and calcite-dolomite thermometry data (Herwegh and Pfiffner 2005). Inferred isograds representing peak Alpine metamorphic conditions are shown for the Lower Helvetic domain, normalised to the 1500 m elevation level, assuming a constant geothermal gradient of \(25\,^{\circ }\text{C/km}\) (see Nibourel et al. 2018, for a discussion). a–d New and published elevation-normalised (1500 m elevation level) \(T_p\) plotted along four massif-perpendicular transects of unit length. Maximum projection distance = 10 km; Projection angle (trend): \(058^{\circ }\) (A), \(070^{\circ }\) (b–d). The approximate positions of major detachments such as the Urseren-Garvera zone, the Windgällen-Färnigen zone and the Pfaffenchopf thrust are highlighted with black and red arrows. Profile edge coordinates are (lat/lon): a \(46.7779^{\circ }\text {N}/8.1588^{\circ }\text {E}\), \(46.5328^{\circ }\text {N}/8.4423^{\circ }\text {E}\) b \(46.8748^{\circ }\text {N}/8.4224^{\circ }\text {E}\), \(46.5680^{\circ }\text {N}/8.5342^{\circ }\text {E}\) c \(46.9441^{\circ }\text {N}/8.6996^{\circ }\text {E}\), \(46.6374^{\circ }\text {N}/8.7708^{\circ }\text {E}\) d \(47.0298^{\circ }\text {N}/9.0437^{\circ }\text {E}\), \(46.7225^{\circ }\text {N}/9.1392^{\circ }\text {E}\)