Fig. 11

Structures of the Mischabel backfold, view from Sunnegga above Zermatt. Geological structures modified after Sartori (1987, 1990), Sartori et al. 2006, Steck (1989) and Steck et al. (1999, 2001). 1 Basement gneiss of the Siviez-Mischabel nappe, 2, 3 its sedimentary cover, 2 Carboniferous conglomerates, 3 Barrhorn Mesozoic-Eocene series, 4, 5 Frilihorn Mesozoic series, 4 Frilihorn quartzite, 5 Frilihorn dolomite, ↑ = younging upwards stratigraphic polarity, 6 CB Cimes Blanches nappe (Permo-Mesozoic series), 7 calcschist of the ophiolitic Tsaté nappe, 8 prasinite, meta-basite of the Tsaté nappe, 9 eclogitic Zermatt-Saas Fee ophiolitic nappe, 10 Dent Blanche basement nappe. Red lines are multiple folded thrust planes, F2 = axial surface of second-phase folds, F3 = axial surface of third-phase folds, F2 and F3 fold axes are oriented parallel to a NW-directed stretching lineation with top-to-NW shear indicators, F4 = axial surfaces of Mischabel back fold with its 22°W-plunging fold axis (stereogram (2) on Fig. 16), (1) stereogramm Alterhaupt and (6) Zermatt-Saas Fee on Fig. 17