Falda di Antrona
Representation and status
- Index
- An
- Color CMYK
- N/A
- Color RGB
- R: 241 G: 239 B: 237
- Rank
- nappe
- Validity
- Unit is in Use
- Status
- valid
Nomenclature
- Deutsch
- Antrona-Decke
- Français
- Nappe d'Antrona
- Italiano
- Falda di Antrona
- English
- Antrona Nappe
- Origin of the Name
- Historical Variants
-
Antrona-Schieferstreifen (Gerlach 1869), Antrona-Synklinal (Gerlach 1880), branche d'Antrona (Argand 1911b), Muldenzone von Antrona = Antrona-Mulde (1952), Antrona-Mulde (Bearth 1956, Bearth 1957, Müller 1976), Mulde von Antrona (Bearth 1973), Zona di Antrona (Dal Piaz et al. 1992), nappe d'Antrona (Carrupt & Schlup 1998), Antrona ophiolitic nappe (Bill et al. 2001), Antrona unit (Keller et al. 2005), Antrona ophiolite nappe = Antrona unit (Steck et al. 2015), Antrona Nappe (TK500, Gouffon et al. 2024)
Description
- Description
-
Falda ofiolitica di origine piemontese.
Geography
- Geographical extent
- Laggintal, Zwischbergental, Valle di Bognanco, Valle d'Antrona, Valle Anzasca.
- Type area
- Valle d'Antrona (Italia)
Palaenography and tectonic
- Paleogeography
- Piemont Basin
- Tectonic unit (resp. main category)
- Kind of protolith
-
- tectonic
- Metamorphism
- monocyclic-polyphase
- Metamorphic facies
-
- greenschist facies (epizone)
- amphibolite facies
- eclogite facies
- Note on metamorphism
-
éclogitisation éoalpine (glaucophane, barroisite, omphacite), puis évolution rétrograde avec brève remontée en température mésoalpine (Carrupt & Schlup 1998)
References
- Definition
-
(2024) :
Tectonic Map of Switzerland 1:500000, Explanatory notes. Federal Office of Topography swisstopo, Wabern
p.68: The Antrona Nappe corresponds to the same oceanic rocks with eclogitic relics as that of the Zermatt - Saas Fee Nappe, except for the metacherts that are missing in the Antrona Nappe. Structurally, it is situated below the Monte Rosa Nappe, but above the Siviez-Mischabel Nappe and its probable extension in the Camughera Nappe (see Pl. II, western cross-section). This peculiar position between two Middle Penninic units raises questions concerning its kinematic history and paleogeographic origin. Because of its similarity to the Zermatt - Saas Fee Nappe, and assuming transport over the Middle Penninic nappes, the Antrona Nappe is thought to have an origin in the Piemonte-Liguria Ocean (e. g., Escher et al. 1997). However, a thrusting of the Middle Penninic nappes over the Antrona Nappe is also postulated, implying its attribution to the Lower Penninic and origin in the Valaisan oceanic Basin (e. g., Kell er & Schmid 2001, Pleuger et al. 2005).