«Phyllitgneiszone»

Rappresentazione e statuto

Varianti storiche: Phyllitgneis (Schmidegg 1959, Hoernes & Purtscheller 1970), nördliche Phyllitgneis-Zone (Trümpy 1972), --- (Amann 1985, Rockenschaub 1990), Phyllite gneiss zone, Phyllitgneiszone (TK500 / Gouffon et al. 2024)

Descrizione: ... mit zahlreichen Einlagerungen von Muskowitgranitgneisen, Augengneisen, Amphiboliten und Diabasen

Unità di rango inferiore

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

p.91: In the Rätikon mountain range, the base of the Lechtal Nappe contains locally Permian metasediments that are adjacent to the northern boundary of the “Phyllitgneiszone” that represents the northern, strongly retrogressed and phyllonitic part of the Silvretta Nappe (Gruber et al. 2010). This has led some authors to propose that parts of the Mesozoic of the Lechtal Nappe originally represented the cover of the Silvretta Nappe (e. g., Eisbacher et al. 1990). However, the majority of the sedimentary nappes of the Bajuvaric Nappe System originated from south of the Silvretta and Ötztal nappes (e. g., Auer & Eisbacher 2003). Where the Tirolic-Noric Nappe System is concerned, stratigraphic contacts with some Paleozoic sediments (“Grauwackenzone”) do exist in an area east and outside the map sheet (Plöchinger 1980).

p.92: A top-N Alpine thrust of secondary importance separates this high-grade basement [of the Silvretta Nappe] from a narrow belt of low-grade basement referred to as the “Phyllitgneiszone” (including the Landeck Quartzphyllites) that is nowadays also considered to be a part of the Silvretta Nappe (Gruber et al. 2010). It has a lower grade of pre-Alpine metamorphism and has been intensely sheared during the Alpine orogeny (Rockenschaub 1990).