Falda di Suretta

Rappresentazione e statuto

Index

Su, Sur

Colore CMYK

N/A

Colore RGB

R: 241 G: 239 B: 237

Rango

falda

Uso

Unità in uso.

Status

valido

Nomenclatura

Deutsch

Suretta-Decke

Français

Nappe de Suretta

Italiano

Falda di Suretta

English

Suretta Nappe

Origine del nome

Surettahorn (GR)

Varianti storiche

Suretta-Decke (Cornelius 1932), Surettadecke (Wilhelm 1933, Staub 1934, Spillmann 1993), Suretta-Decke (Staub 1946, Schmutz 1976), Falda Suretta (Godenzi 1963), Suretta nappe (Milnes & Schmutz 1978), falda Suretta (Sciesa 1991), nappe de Suretta (Mayerat Demarne 1994), Suretta Nappe (TK500 / Gouffon et al. 2024)

Nota sul nome

cf. Marquer et al. 1994, Marquer & Peucat 1994

Descrizione

Descrizione

Mittelpenninische Decke der Ostalpen, bestehend aus einem kristallinem Grundgebirge (Ortho- und Paragneise) mit seiner autochthonen Sedimentbedeckung (klastische und karbonatische Plattformsedimente).

"puissant ensemble de cristallin anté-carbonifère, avec des restes d'une couverture mésozoïque" (Trümpy 1976)

Gerarchia e successione

Unità di rango inferiore

• Finestre di Lanzada

Limite superiore

Avers-Decke: "Im Avers und im Valmalenco folgen darüber Kalkschiefer, welche ohne genaue lithologische und tektonische Trennung übergehen in inhomogene, sandig-tonig-kalkige Metasedimente, welche meta-ophiolithisches Material (Metaggabros, Prasinite, Serpentinite) und zugehörige südpenninische Sedimente (Radiolarit, Aptychenkalk, Palombini) enthalten (Montrasio 1984, Liniger & Nivergelt 1990, Liniger 1992)." (Spillmann 1993 S.14)

Geografia

Estensione geografica

Andeer, Surettahorn, Piz Timun, Valle di Lei, Piz Stella, Piz Duan, Val Bregaglia, sowie Val Malenco (Lanzada-Fenster).

Paleogeografia e tettonica

Paleogeografia

terrane brianzonese :

microcontinent briançonnais

Termini generici

• Suretta

Tipo di origine

• tettonico

Referenze

Revisione

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

p.75: The Suretta Nappe also has a Paleozoic basement of para- and orthogneisses intruded by the Permian Rofna Porphyry Complex, which consists of granitoids and effusive-type magmatites (Marquer et al. 1998). Its Permian – Mesozoic cover, again in Briançonnais facies, is largely of Triassic age. Locally the Triassic is overlain by Jurassic breccias. This cover crops out as thin layers; in one instance it follows a Suretta-internal thrust fault, in other instances they are infolded into narrow synclines that were subsequently backfolded in the upper limb of the north facing Niemet-Beverin Backfold, whose axial trace runs across the Suretta Nappe (Scheiber et al. 2012).
Two small windows (Lanzada Windows), dominated by sedimentary rocks typical for the Suretta Nappe, are located in the Val Malenco and surrounded by the Malenco-Forno-Lizun Nappe (Montrasio 1984, Montrasio et al. 2005). These windows also expose some small occurrences of metagabbro and ultramafics that are correlated with the Avers Nappe.

Pubblicazioni importanti

Milnes Alan G., Schmutz Hans-Ulrich (1978) : Structure and history of the Suretta nappe (Pennine zone, Central Alps): a field study. Eclogae geol. Helv. 17/1, 19-33