Falda del Sambuco

Représentation et statut

Couleur CMYK

N/A

Couleur RGB

R: 241 G: 239 B: 237

Rang

unité tectonique

Usage

Ce terme est en usage.

Status

valide

Nomenclature

Deutsch

Sambuco-Decke

Français

Nappe du Sambuco

Italiano

Falda del Sambuco

English

Sambuco Nappe

Origine du nom

Val Sambuco (TI)

Variantes historiques

Sambuco-Teillappen (Hasler 1949), Cristallino di Sambuco (Bianconi 1965), cristallino antico di Sambuco = Cristallino di Sambuco = lobo parziale di Sambuco (Bianconi 1971), unità di Sambuco, Sambuco element = Sambuco spoon [Sambuco klippe] (Masson & Steck 2015)

Remarques nomenclatoriales

Sambuco était un village ennoyé par le lac de barrage homonyme

Description

Description

"A forma di chiglia schiacciata, con nucleo di anfiboliti di origine magmatica e involucro di rocce para (micascisti granatiferi, ecc.) contenenti letti di gneiss di origine magmatica (gneiss occhiadini, ecc.) e di rocce miste." (Bianconi 1971)

Eigenständige Decke (Berger et al. 2007) oder nördlicher frontaler Lappen der Maggia-Decke (Masson & Steck 2015).

Géographie

Extension géographique

Lepontin

Région-type

Val Sambuco - Lago del Sambuco (TI) - Lavizzara [non Sambuco (Cueno, Italia)]

Références

Révision

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

p.49: The Maggia and Sambuco nappes occupy the NNW–SSE oriented transverse synformal zone in the middle of the structural Lepontine Dome, but are not in cartographic continuity. These two units are made up of similar basement rocks intruded by Variscan granitoids (Late Carboniferous) but, in contrast to the Maggia Nappe, the Sambuco Nappe has a thin sedimentary cover, the facies of which have a Helvetic affinity (Steck et al. 2019). These units have undergone polyphase deformation (e. g., Maxelon & Mancktelow 2005) which makes the interpretation of their relationships with each other and with adjacent units difficult. Some authors see them as structurally continuous, at the top of the nappe stack, others as tectonically distinct units, at different structural levels (see discussion in Berger et al. 2005a, Steck et al. 2013, 2019). Some authors (e. g., Berger et al. 2005a, Schmid et al. 2004) consider these two nappes as Middle Penninic because they are located above units originating from a subduction zone (Cima Lunga Nappe and Mergoscia Zone), implying a Briançonnais origin. This upper position is contested by Maxelon & Mancktelow (2005) and Steck et al. (2019). Moreover, their sedimentary cover and the latest Carboniferous age of their magmatic rocks are more in concordance with a paleogeographic origin in the European margin that justifies placing the Maggia and Sambuco nappes in the Lepontic domain. In addition, by grouping the Simano and the Cima Lunga nappes (§ 5.8), Tagliaferri et al. (2023) proposed the existence of a lateral continuity between the Maggia Nappe and the Adula Nappe.