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Deutsch: Tavetsch-Decke
Français: Nappe du Tavetsch
Italiano: Falda del Tavetsch
English: Tavetsch Nappe

The Tavetsch Nappe is an Upper Helvetic tectonic unit cropping out in a large part of the upper Surselva (Vorderrhein Valley). It shows two contrasting parts: In the west, a narrow crystalline “massif” (formerly “Tavetsch -Zwischenmassiv”), consisting mainly of paragneisses, lies between the Aar Massif in the north and the Gotthard Nappe in the south. In the east, this crystalline basement thins and terminates towards the east in the core of an anticline, surrounded by Permian Verrucano sediments. The continuation of these sediments is found in the Glarus Nappe Complex.

Tavetsch = Tujetsch (GR), Surselva

Somvixer Zwischenmassiv (Niggli & Staub 1914), Tavetscher Zwischenmassiv (Niggli 1944), Tavetsch-Zwischenmassiv, Tavetsch massive [sic] (Purdy & Stalder 1973), Tavetschermassiv (Büchi & Trümpy 1976), Tavetsch massif (Biino 1994), Tavetsch Nappe (Berger et al. 2017, Gouffon et al. 2024)

Deutsch: Schams-Deckenkomplex
Français: Complexe de nappes du Schams
Italiano: Complesso di falde dello Schams
English: Schams Nappe Complex

The Schams Nappe Complex is a Middle Penninic tectonic unit of eastern Switzerland encompassing a set of small nappes, which were folded after their emplacement around the Tambo-Suretta pair during the Niemet-Beverin post-nappe folding. The Schams Nappe Complex also contains different mélanges: to the west, in the lower limb of the Niemet-Beverin Backfold, the Knorren Mélange is in contact with the Tambo Nappe, while the Areua-Bruschghorn Mélange marks the boundary with the Tomül Nappe; to the east, in the upper (overturned) limb of the Niemet-Beverin Backfold, the Martegnas Mélange is in contact with the Arblatsch Flysch belonging to the Tomül Nappe.

The sedimentary sequences of the Schams Nappe Complex exhibit large facies variations and are rich in sedimentary syn-rift breccias of Middle Jurassic to Early Cretaceous age, indicating contemporaneous extension and sinistral strike-slip. The mid-Cretaceous to Cenozoic post-rift sediments are very similar to those found in the Falknis Nappe. Retrodeformation suggests that the Schams nappes formerly occupied an area north of the depositional area of the Tambo and Suretta Mesozoic. This is supported by facies arguments indicating that sediments in the originally northernmost paleogeographical position (now forming the Gelbhorn Nappe) suggest N-directed shedding of syn-rift breccias, and by the Subbriançonnais-type facies of the Triassic strata.

Schams = Val Schons (GR), Hinterrheintal

Schamser Decken (Zyndel 1912, Wyss & Isler 2007), Schamserdecken (Wilhelm 1933), Falde dello Schams (Sciesa 1991), nappes du Schams (Mayerat Demarne 1994), Schams Nappe Complex (TK500 / Gouffon et al. 2024)

cf. Schreurs 1990, Schmid et al. 1990

Deutsch: Bulle-Melangezone
Français: Zone de mélange de Bulle
Italiano: Zona di mélange di Bulle
English: Bulle Mélange Zone

The Bulle Mélange Zone, at the front of the Western Swiss Alps, lies between the Subalpine Molasse and the Prealps nappes (Gurnigel, Voirons or Préalpes Médianes nappes). It comprises the Infraprealpine Mélange (“wildflysch”) in which slivers are embedded. The four bigger slivers, of kilometer scale, have been defined as slices: Bois de Bouleyres and Montsalvens slices near Bulle, Pléiades Slice north of Montreux and Faucigny Slices north of Bonneville in Savoie. The lithologies of these slivers are of similar types to some of the Pillon Mélange Zone.

Bulle (FR)

dépression de Bulle = klippes jurassiques de la plaine de Bulle (de Girard 1901), Niederung von Bulle (Büchi 1923), Zone de la plaine de Bulle (Pasquier 2005), Bulle Mélange Zone (TK500 / Gouffon et al. 2024)

Deutsch: Arveyes-Decke
Français: Nappe d'Arveyes
Italiano: Falda di Arveyes
English: Arveyes-type slivers

Within the Upper Helvetic Pillon Mélange Zone, the Arveyes-type slivers (composed of a Dogger and Eocene series) occur between the Prealps nappes and the frontal folds of the Lower and Upper Helvetic nappes.

Arveyes (VD), Villars-sur-d'Ollon

série inférieure du Chamossaire [p.p.] (Sarasin & Collet 1907), nappe d'Arveyes (Lugeon 1946, Badoux & Gabus 1991), Diverticule d'Arveyes (Lombard et al. 1974), Arveyes-type slivers (TK500 / Gouffon et al. 2024)

Deutsch: Tonale-Decke
Français: Nappe du Tonale
Italiano: Falda del Tonale
English: Tonale Nappe

The Tonale Nappe follows the E–W striking part of the Tonale Fault (Insubric Fault) and is is characterized by a very distinct and lithologically variable association of predominantly sillimanite-bearing paragneisses, marbles, quartzites and amphibolites metamorphosed during the Variscan cycle (Tonale Gneiss Complex).

In the west, between Giubasco and Sondrio, the Tonale Nappe forms a steeply N-dipping narrow strip of mylonitic series that are part of the Southern Steep Belt (or “root zone” north of the Tonale Fault), bounded by the tonalites of the Bregaglia Intrusion to the north and Alpine mylonites and cataclasites of the Tonale Fault in the south. Between Sondrio and Tirano, it then represents the hangingwall of the Late Cretaceous Mortirolo Normal Fault. Further east, a second Late Cretaceous normal fault, the SE-dipping Pejo Normal Fault, accommodates top-E extension combined with a sinistral strike-slip component in the present-day map view. Finally, east of the Passo del Tonale, the Tonale Nappe displays a rock association that is lithologically distinct from the Tonale Gneiss Complex and that is referred to as the Ulten (or Ultimo) Unit. It overlies the Tonale Gneiss Complex along a pre-Alpine tectonic contact.

Monte Tonale (Italia)

Serie del Tonale = Tonale-Serie (Knoblauch & Reinhard 1939), Tonale-Serie (Weber 1957), Tonaleserie (Koenig 1967, Heitzmann 1974), Tonale Series (Vogel & Voll 1976), Berger & Mercolli 2007), Tonale-Zone, Tonale Nappe (TK500 / Gouffon et al. 2024)

Deutsch: Unterostalpin
Français: Austroalpin inférieur
Italiano: Austroalpino inferiore
English: Lower Austroalpine

The Lower Austroalpine comprises tectonic units that are derived from the former distal continental margin of the Adriatic plate, which was affected by Jurassic extensional detachment faults. The strongly deformed pre- and syn-rift strata became intensely reshaped and reworked during the closure of the Piemonte-Liguria Ocean and subsequent Alpine continental collision.

The facies of syn- and post-rift sediments of the Lower Austroalpine has remarkable similarities with those found in the Canavese area around the town of Ivrea, which is a part of the South Alpine derived of the western part of the Adria.

Unterostalpin (Hoek 1906), unterostalpine = grisonide Elemente (Roesli 1946), Unterostalpine Decken (Trümpy 1974), Lower Austroalpine = LAA (Furrer et al. 1985), Unterostalpin = UOA (Frank 1986, Naef 1987), Austroalpino inferiore (Montrasio et al. 2012), Lower East Alpine, Lower Austroalpine (TK500 / Gouffon et al. 2024)

Deutsch: Dorfberg-Decke
Français: Nappe du Dorfberg
Italiano: Falda del Dorfberg
English: Dorfberg Nappe

To the northeast of the Prättigau Half-Window, the crystalline Dorfberg Nappe is intercalated between the Arosa Zone and the Schiahorn Nappe as far as the Davoser See, respectively by the Silvretta Nappe further to Klosters.

Davoser Dorfberg (GR)

Dorfberg-Kristallin, Dorfbergschuppe = Davoser Dorfberg-Schuppe (Gees 1954), Davoser-Dorfberg-Decke (Giger 1985), Dorfbergkristallin (Giger 1986), Davoser Dorfberg-Decke (Giger 1985, Streckeisen 1986, Signer et al. 2018), Dorfberg-Zug (Pfiffner 2015), Dorfberg Nappe (TK500 / Gouffon et al. 2024)

Deutsch: Schlattain-Clavadatsch-Padella-Schuppen
Français: Écaille de Schlattain-Clavadatsch-Padella
Italiano: Scaglie di Schlattain-Clavadatsch-Padella
English: Schlattain-Clavadatsch-Padella Slices

The Schlattain-Clavadatsch-Padella Slices form small isolated klippes, located in the core of the synclinorium of the “Samedan Zone” and composed of Triassic to Late Cretaceous sediments. They were thrust onto the cover of the Err Nappe and therefore attributed to the Bernina Nappe Complex.

Alp Clavadatsch (GR)

Clavadatsch-Schuppe (Cornelius 1932), Clavadatschserie = Clavadatsch-Schlattainserie (Roesli 1945/1946), Clavadatsch-Serie (Staub 1946), Clavadatsch-Einheit (Handy et al. 1993), Schlattain-Clavadatsch-Padella Slices (TK500 / Gouffon et al. 2024)

Trais-Fluors-Schuppe p.p. (Cornelius ----)

Deutsch: Bernina-Deckenkomplex
Français: Complexe de nappes du Bernina
Italiano: Complesso di falde del Bernina
English: Bernina Nappe Complex

The Lower Austroalpine Bernina Nappe Complex includes a series of subunits which occupied a somewhat more proximal paleogeographically position than those of the Err Nappe Complex. Structurally, the Bernina Nappe Complex occupies a higher tectonic position compared to the Err Nappe Complex. The Julier and Bernina Nappes are considered as a single tectonic unit, but carry different names only because of their different location in relation to the Engadine Fault. The Ela Nappe and underlying Madulain Slices are also considered to be part of the Bernina Nappe Complex. The Mezzaun Slice is a rather isolated piece of this nappe complex located southeast of the Engadine Fault directly underlying the Upper Austroalpine units, which justifies its attribution to the Bernina Nappe Complex on structural grounds.

Piz Bernina (GR)

Julier-Berninadecke (Zyndel 1912), Berninadecke (Staub 1934), nappe du Bernina (Trümpy 1970 und 1976), Bernina system (Manatschal 1995), Ela/Bernina system (Manatschal & Nivergelt 1997), Bernina Nappe Complex (TK500 / Gouffon et al. 2024)

Deutsch: Saane-Decke
Français: Nappe de la Sarine
Italiano: Falda della Sarine
English: Sarine Nappe

The Sarine Nappe is an Upper Penninic tectonic unit of the Prealps. Although strongly resembling the Dranses Nappe lithologically, it is characterized by the presence of very fine-grained, lightcolored limestones with trace fossils (Chondrites isp.) and polymict micaceous conglomerates, often containing various crystalline rocks. The age of these rocks is latest Cretaceous to earliest Paleocene.

Vallée de la Sarine (BE)/(FR)/(VD) entre Saanen et Château-d'Oex

nappe de la Sarine (Caron 1972, Dapples 1998), Saanen-Decke, Sarine nappe (Slaczka et al. 1992), nappe de la Sarine (Gurnigel) (Plancherel 1998), Sarine Nappe (TK500, Gouffon et al. 2024)