Nappe de Morcles

Representation and status

Historical Variants: Gebirgsmasse der Dent de Morcles (Gerlach 1871), pli couché de la Dent de Morcles (Boussac 1912), Morcles-Aravis-Decke = Aravis-Morcles-Decke = Decke Aravis-Morcles (Rutsch et al. 1966), Morcles-Deckfalte (Büchi & Trümpy 1976), nappe de Morcles-Aravis (Maire 1977), nappe de Morcles = pli parautochtone de Morcles (Plancherel 1998), Morcles Nappe (TK500 / Gouffon et al. 2024)

Description: FR: Nappe de l'Helvétique inférieur de Suisse occidentale et de Savoie, formée d'un grand pli couché chevauchant le massif cristallin des Aiguilles Rouges et sa couverture sédimentaire (par)autochtone.

Subordinate units

Age at top

Age at base

Geographical extent: Massifs du Grand Muveran, des Dents de Morcles, du Grand Chavalard, des Dents du Midi, du Haut-Giffre et de Platé (+ Mont-Joly, Croisse-Baulet, Aravis, Bornes), ainsi que val d'Illiez et val de Morgins.

Paleogeography

European continental plate

Tectonic unit (resp. main category)

Kind of protolith

Definition: Gouffon Yves (Editor) (2024) : Tectonic Map of Switzerland 1:500000, Explanatory notes. Federal Office of Topography swisstopo, Wabern

p. 35: The Morcles Nappe consists of the same Jurassic–Cenozoic sedimentary series as the Chaines Subalpines Nappe. It is defined inside the bend that the Rhône forms at Martigny, and consists of a large recumbent fold overlying the northeastern end of the Aiguilles Rouges Massif. This large fold extends on the other side of the Rhône, in the Dents du Midi area.
According to Epard (1990), the Morcles and the Chaines Subalpines nappes are both rooted on the External Mont Blanc Massif and its continuation in the most internal part of the Belledonne Massif. They are separated from each other by the continuous thrust fault of the Chaines Subalpines Nappe over the Morcles Nappe (Pfiffner et al. 2010) between the Mont Buet and Samoëns south of the Swiss-French border.