Fig. 3
Faults mapped at the surface above the Bedretto tunnel and orientations of selected faults (Fxx) in the Bedretto tunnel more than 1,000 m underneath. Short lines crossing the Bedretto tunnel indicate traces of faults in the tunnel as recorded by Schneider (1985). a Rose diagram of faults mapped at the surface, mean strike: 50°, b Schmidt’s net (lower hemisphere) of fault orientation in the tunnel between Tm 3,500 and 5,218 (Rotondo granite). Mean weighted (see Priest 1993 for procedure) orientation: 326/85 (azimiuth of dip direction/dip angle), according mean strike: 56°. c Orientation of lamprophyre dikes (335/77) and shear zones/cleavage (349/74), same tunnel section, data by Schneider (1979)