Deutsch: Abgeschertes Nordalpines Vorland
Français: Avant-pays nord-alpin décollé
Italiano: Avampaese nordalpino distaccato
English: Detached North Alpine Foreland
The Detached North Alpine Foreland refers to the displaced sedimentary cover north of the front of the Helvetic units. Decoupling between the thrusted and deformed cover and the underlying basement took place in a décollement zone in the evaporites of Muschelkalk Group east of a line Porrentruy–Biel–Fribourg and of the Keuper Group further west. Deformation includes northwestward and northward displacement, thrusting and folding as well as strike-slip deformation. The northern boundary, which coincides with the front of Alpine deformation, is given by the outermost (distal) significant thrusting and folding. The easternmost clear evidence for décollement-related tectonics is given by the Lägern Anticline east of Baden with some more indications from seismic data found south of Bülach. Further to the east, displacement of the sedimentary cover along the decollement zone is presumed to gradually decrease. Accordingly, no precise eastern boundary can be drawn between the Detached North Alpine Foreland and the autochthonous South German Platform and a conceptual transition zone is defined instead.
Sheared-off North Alpine Foreland, Avant-pays nordalpin décollé, Detached North Alpine Foreland (TK500 / Gouffon et al. 2024)