Falda di Suretta
Back to Suretta nappeRepresentation and status
- Index
- Su, Sur
- Color CMYK
- N/A
- Color RGB
- R: 241 G: 239 B: 237
- Rank
- nappe
- Validity
- Unit is in Use
- Status
- valid
Nomenclature
- Deutsch
- Suretta-Decke
- Français
- Nappe de Suretta
- Italiano
- Falda di Suretta
- English
- Suretta Nappe
- Origin of the Name
- Historical Variants
-
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)
- Nomenclatorial Remarks
-
cf. Marquer et al. 1994, Marquer & Peucat 1994
Description
- Description
-
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)
Hierarchy and sequence
- Subordinate units
- Upper boundary
-
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)
Geography
- Geographical extent
- Andeer, Surettahorn, Piz Timun, Valle di Lei, Piz Stella, Piz Duan, Val Bregaglia, sowie Val Malenco (Lanzada-Fenster).
Palaenography and tectonic
- Paleogeography
-
Briançonnais Terrane
:
microcontinent briançonnais
- Tectonic unit (resp. main category)
- Kind of protolith
-
- tectonic
References
- Definition
-
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.
-
Finestre di Lanzada
- Name Origin
- Rank
- window
- Status
- informal term
- In short
-
The Lanzada Fensters, in the Val Malenco, are two small tectonic windows dominated by sedimentary rocks typical for the Suretta Nappe and surrounded by the Malenco-Forno-Lizun Nappe. These windows also expose some small occurrences of metagabbro and ultramafics that are correlated with the Avers Nappe.