Fig. 9

a Early N-dipping NNW-vergent thrust (S2, coordinates: \(46.7833^{\circ }\text {N}/8.4474^{\circ }\text {E}\), see Fig. 3c for location). b Steep SE-dipping spaced crenulation cleavage S3 in the Middle Jurassic limestones, overprinting a pronounced S0–S2 composite foliation (coordinates: \(46.6523^{\circ }\text {N}/8.1714^{\circ }\text {E}\), see Fig. 3c for location). c Steep main foliation (S3) in both Triassic marly beds (left) and their crystalline substratum (right). The sub-vertical orientation of the stratigraphic contact indicates significant SSE-block up movements along S3 (coordinates: \(46.7587^{\circ }\text {N}/8.4027^{\circ }\text {E}\), see Fig. 3c for location). (d) Sketch of an array of post-S3 NNW-vergent thrusts (S4) at the basement-cover interface near Erstfeld (coordinates: \(46.8409^{\circ }\text {N}/8.6264^{\circ }\text {E}\), see Figs. 3d and 7 for location). e (left) Structural measurements related to NNW-vergent shearing during D2–D4. Poles to fault planes (circles) and associated stretching lineations (crosses) are highlighted. (right) Schematic sketch illustrating the geometric relationship between S2 and S4 at the basement-cover contact during progressive deformation and block rotation associated with S3 at the northern massif front