Écailles de Châtillon–St-Vincent

Representation and status

Historical Variants: fenêtre de Châtillon-Zermatt (Argand 1906a), lembo Austroalpino meridionale di Chatillon (Dal Piaz et al. 1992a), Châtillon-St-Vincent Slices (TK500, Gouffon et al. 2024)

Subordinate units

Tectonic unit (resp. main category)

Kind of protolith

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

p.69: The Mont Emilius Nappe, the Etirol-Levaz Slice, the Châtillon-St-Vincent Slices (Dal Piaz 1999 and ref. therein) and the Theodulgletscher Slice (Bucher et al. 2020), located between the Zermatt - Saas Fee Nappe and the Tsaté Nappe, comprise eclogitic continental basement rocks. Due to the similarity of their pre-Alpine lithology with that of the Dent Blanche and Sesia nappes, their origin is probably the Adriatic continental margin. However, these units occupy a lower structural level than the Dent Blanche and Sesia nappes that belong tectonically to the Salassic domain. They exhibit a tectono-metamorphic history similar to that of the Zermatt - Saas Fee Nappe, including the Early Eocene age for their high-pressure metamorphism (Dal Piaz et al. 2001, Weber et al. 2015). These units likely derived from extensional allochthons, formed during the Jurassic opening of the Piemonte-Liguria Ocean in a more distal position than the Cervinia Terrane from which the Salassic nappes originate (see chap. 7).