Falda della Cima Lunga
Back to Cima-Lunga NappeRepresentation and status
- Color CMYK
- N/A
- Color RGB
- R: 241 G: 239 B: 237
- Rank
- nappe
- Validity
- Unit is in Use
- Status
- valid
Nomenclature
- Deutsch
- Cima-Lunga-Decke
- Français
- Nappe de la Cima Lunga
- Italiano
- Falda della Cima Lunga
- English
- Cima Lunga Nappe
- Origin of the Name
- Historical Variants
-
Cima Lunga-Lappen (Niggli et al. 1936), Cima-Lunga-Serie (Trommsdorff et al. 1975, Heinrich 1978, Stäuble 1978), Cima Lunga Zone (Pfeifer 1978), Cima-Lunga-Lappen (Hofmann & Bühl 1982), Cima Lunga unit (Merle & Le Gal 1988), Cima Lunga Einheit (Pfiffner 1999), Cima Lunga-Einheit (Giger 2000), falda Cima lunga, Cima Lunga zone, Cima Lunga mélange, Falda della Cima Lunga = Cima-Lunga-Decke (Schenker, Bl. Osogna), Cima Lunga Nappe (TK500 / Gouffon et al. 2024)
Description
- Description
-
Heterogenes Gneiskomplex (Mélange?) mit Eklogit-Relikten.
gneiss-dominated mélange-type unit, typically associated with mafic and carbonate rocks (Pfeifer 1978) ; eclogites-bearing mélange unit
- Thickness
- Mehrer hunderte von Meter mächtig und über 20 km lang (Pfeifer 1978).
Geography
- Geographical extent
- Zwischen Alpe Arami und Cima Gagnone (Val d'Efra).
Palaenography and tectonic
- Tectonic unit (resp. main category)
- Kind of protolith
-
- tectonic
- Metamorphism
- metamorphic
- Metamorphic facies
-
- amphibolite facies
- eclogite facies
References
- Definition
-
(2024) :
Tectonic Map of Switzerland 1:500000, Explanatory notes. Federal Office of Topography swisstopo, Wabern
p.52: The Cima Lunga Nappe is made up of paragneisses, orthogneisses, sheets of marble and calcschist as well as lenses of mafic and ultramafic rocks that locally have an incoherent character. Eclogitic mineral assemblages are widespread in the mafic and ultramafic rocks. Sheath folds around the disrupted competent mafic and ultramafic lenses suggest intense shearing within a shear zone at the base of the Maggia Nappe (Maino et al. 2021). The Cima Lunga Nappe shows lithological and deformational similarities to the Mergoscia Zone (see § 5.1). The contact between the Cima Lunga Nappe and the underlying Simano Nappe is tentatively defined by the calcschists and the higher degree of strain within the paragneisses. The boundary to the overlying Maggia Nappe follows generally the base of the orthogneisses of the Maggia Nappe. According to most authors, the Cima Lunga Nappe is connected in the east, to the Adula Nappe in the lower Valle Mesolcina. Several authors (e.g., Evans et al. 1979, Engi et al. 2001) consider the Cima Lunga Nappe to be an exhumed high-pressure nappe or a tectonic mélange from a subduction channel, such as the Adula Nappe (see below). According to Tagliaferri et al. (2023), the Cima Lunga Nappe is a pre-Variscan sedimentary sequence that was intruded by Permian magmas, which are the protoliths of the orthogneisses of the Simano Nappe; in this interpretation, Cima Lunga and Simano are two distinct lithologic units of a single nappe.