strati.ch - Lexique lithostratigraphique de la Suisse

Représentation et statut

Variantes historiques: Luzzone paragneiss (Galster et al. 2010), Luzzone Gneiss (Galster et al. 2012)

Âge au sommet

Termes génériques

Type de protolithe

Définition: Galster Federico, Epard Jean-Luc, Masson Henri (2010) : The Soja and Luzzone-Terri nappes: discovery of a Briançonnais element below the front of the Adula nappe (NE Ticino, Central Alps) Bull. Soc. vaud. Sci. nat. 92/2, 61-75

p.64: 2.1 Luzzone element: The Luzzone paragneiss mainly consists of well-bedded arkosic meta-sandstones and greenish micaschists. Conglomeratic intercalations, with pebbles of quartz or quartzo- feldspathic rocks scattered in the arkose or micaschist matrix, appear mostly near the top of the formation. Dark brown spots of an ankeritic carbonate are omnipresent, particularly abundant in the arkoses. In its upper part this formation may contain thin layers of brown dolomite.

This formation displays definite affinities with the Moosalp Formation, of Permian age, in central Valais ( Thélin 1982 p. 33-34, Genier et al. 2008). This is a characteristic lithostratigraphic unit of the external part of the Paleozoic Briançonnais paleogeographic domain, or, in tectonic terms, of the lowest tectonic elements of the Grand St-Bernard nappe south of Visp (Zone Houillère and the overlying St-Niklaus syncline). The Luzzone paragneiss passes upwards to a conglomeratic quartzite (with only quartz pebbles in the quartzite matrix) that is similar to some parts of the Late Permian Embd Member in the St- Niklaus syncline ( Genier et al. 2008).