Windgällen-Formation

Rappresentazione e statuto

Varianti storiche: Windgällen-Formation (Schenker 1987), Windgällen Formation (Berger et al. 2017)

Unità di rango inferiore

Geomorfologia

Età alla base

Paleogeografia

placca continentale europea

Termini generici

Revisione: Berger Alfons, Mercolli Ivan, Herwegh Marco, Gnos Edwin (2017) : Geological Map of the Aar Massif, Tavetsch and Gotthard Nappes. Geological Special Map 1:100'000, Explanatory Notes 129

p.46: The Windgällen Formation is characterised by a large amount of rhyolitic, volcanic and volcaniclastic rocks and by a subvolcanic intrusive body (Figs.6, 7 a, FRANKS 1968 a). Locally, clastic metasedimentary rocks form the basis of the volcanic sequence. FRANKS (1968 a) stressed the similarity of these sedimentary rocks with those of the Bifertengrätli Formation, despite the lack of datable fossils. The rhyolites of the Windgällen Formation were dated at 299±2 Ma (U/Pb on zircon, SCHALTEGGER 1993) in agreement with the Late Carboniferous age of fossils in the Bifertengrätli Formation.
The particular tectonic position of the rocks of the Windgällen Formation was recognised early in the history of the Alpine geological studies (see FRANKS 1968 a and references therein). In fact, the Windgällen area is a huge Alpine recumbent fold with Late Carboniferous metasedimentary, volcanic and volcaniclastic rocks forming the core, and autochthonous Mesozoic sedimentary rocks the outer parts (Fig.7 a, HANTKE & BRÜCKNER 2011, FUNK et al.1983).