Nappe du Tsaté

Rappresentazione e statuto

Index

Ts

Colore CMYK

N/A

Colore RGB

R: 241 G: 239 B: 237

Rango

falda

Uso

Unità in uso.

Status

valido

Discussione del statuto

Nomenclatura

Deutsch

Tsaté-Decke

Français

Nappe du Tsaté

Italiano

Falda del Tsaté

English

Tsaté Nappe

Origine del nome

Alpage du Tsaté (VS)

Varianti storiche

nappe du Tsaté (Sartori 1987, Escher et al. 1988, Marthaler & Stampfli 1989), zone du Combin auct., Upper ophiolitic units = Combin Zone Auct. = Tsaté nappe (Dal Piaz et al. 2015), Tsaté nappe (Steck et al. 2015), «zone du Combin» auct., Tsaté Nappe (TK500, Gouffon et al. 2024)

Descrizione

Descrizione

Unité tectonique la plus élevée du domaine pennique de Suisse occidentale, constituée de serpentinites (métapéridotites), gabbros et basaltes (ophiolites piémontaises), surmontés de radiolarites et d'une épaisse série de calcschistes dont la succession stratigraphique a été largement chamboulée lors de l'orogenèse alpine.

Cf. Sartori & Marthaler 1994, Escher et al. 1997

The Tsate nappe overthrusts the Zermatt-Saas nappe and is affected by blueschist to greenschist facies metamorphism. Ophiolitic rocks are represented by slices and lenses imbricated with calcschists (Marthaler, 1984; Lagabrielle, 1987; Kunz, 1988).

Gerarchia e successione

Unità di rango inferiore

• unité de la Luette
• unité du Pleureur

Limite superiore

Chevauchement de la nappe de la Dent Blanche.

Geografia

Estensione geografica

Métapéridotites: Pointe du Tsaté, Cabane des Dix.

Paleogeografia e tettonica

Paleogeografia

Bacino Piemontese

Termini generici

• Tsate

Tipo di origine

• tettonico

Metamorfismo

monociclico

Facies metamorfica

• facies a scisti verdi
• facies a scisti blu

Osservazioni sul metamorfismo

Pas de témoins d'une phase de haute pression, contrairement à la Zone de Zermatt-Saas.

Referenze

Definizione

Sartori Mario (1987) : Structure de la zone du Combin entre les Diablons et Zermatt (Valais). Eclogae geol. Helv. 80/3, 789-814

Revisione

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

p.70: The Tsaté Nappe crops out in southern Valais and in the Valle d’Aosta. It comprises oceanic metasediments, mainly calcschists and black shales of Cretaceous age, and ophiolitic rocks of Jurassic age. They originate from the Piemonte-Liguria Ocean. This nappe is characterized by a chaotic aspect and metamorphism under conditions of blueschist facies followed by greenschist facies. It is interpreted as the result of the formation of an accretionary wedge at the foot of the active Adriatic margin and the subsequent subduction below this continental plate (Marthaler & Stampfli 1989, Stampfli et al. 1998, 2002). Depending on the location, the Tsaté Nappe overlies the Mont Fort, Siviez-Mischabel or Zermatt - Saas Fee nappes, in some cases with small units (Theodulgletscher and Etirol-Levaz slices, Mont Emilius Nappe and Châtillon-St-Vincent Slices) between the two nappes. It is overlain by the Dent Blanche Nappe west of Valtournanche (lateral valley of the Valle d’Aosta) and by the Sesia Nappe further east.
Some authors (e. g., Bucher et al. 2004, Dal Piaz 1988, 1999, Dal Piaz et al. 2015, Pleuger et al. 2007) group the Tsaté Nappe with the Frilihorn, Gornergrat and Cimes Blanches nappes under the term “Combin Zone”, which was defined by Argand (1909) in an even broader sense.

Pubblicazioni importanti

Kunz Pierre (1988) : Ophiolites penniques et sédiments associés dans la région d'Arolla (val d'Hérens, Valais, Suisse). Eclogae geol. Helv. 81/1, 115-124

Marthaler Michel, Stampfli Gérard M. (1989) : Les Schistes lustrés à ophiolites de la nappe du Tsaté : un ancien prisme d'accrétion de la marge active apulienne? Schweiz. Min. Petr. Mitt. 69/2, 211-216

Materiale e vario