Fig. 4

Lower hemisphere equal area projections. Data of present study, Lützenkirchen and Loew (2011), and Schneider (1985) are shown. Legend in lower part of figure applies to both sub-figures. The sectors along the Bedretto tunnel, which correspond to the two sub-figures are indicated in Fig. 3b. Stereonet 10.4.2 was used to create plots (Cardozo and Allmendinger, 2013), contour lines according to Kamb method (Kamb, 1959). a Structural data of Tremola and Prato series: poles of foliation and fault zones (\(>10\) cm wide). Note that the part of the Tremola series affected by Quaternary gravitationally driven re-orientation of the structures (‘toppling zone’ between TM 0 and 355) is not shown. b Structural data of Rotondo granite: poles of foliation, fault zones (\(>10\) cm wide), G-SZ, and QB-SZ, and linear structural elements of fault zones (defined by striations), G-SZ, and QB-SZ. Contour lines are plotted for the shear directions in shear zones (G-SZ and QB-SZ), which are defined by stretched and recrystallized biotite or the intersection between the foliation plane and the plane normal to the boudin/swell axes (BSA)