Garenstock-Augengneis

Retour à nappe de l'Adula

Représentation et statut

Couleur CMYK
(0%,35%,29%,4%)
Couleur RGB
R: 245 G: 160 B: 175
Rang
Formation lithostratigraphique
Usage
Ce terme est en usage.

Nomenclature

Deutsch
Garenstock-Augengneis
English
Garenstock Augengneiss
Origine du nom

Garenstock (GR), Vals

Variantes historiques
Augen- und Injektionsgneise Typ. Garenstock (Frischknecht et al. 1923), Grobkörniger Augengneis, Typus Garenstock (Kopp in: Jenny et al. 1923), --- (Egli 1966), Garenstock augengneiss (Cavargna-Sani 2010), Garenstock Augengneiss (Cavargna-Sani 2013 p.34)

Âge

Âge au sommet
  • Ordovicien tardif
Âge à la base
  • Ordovicien tardif
Méthode de datation
446.4 bis 457.8 Ma (Cavargna-Sani 2013)

Références

Définition
Jenny (1923) : -

S.100
Révision
Cavargna-Sani Mattia (2013) : The Adula nappe: stratigraphy, structure and kinematics of an exhumed high-pressure nappe. Thèse de doctorat, Université de Lausanne, 153 p.

p.34: The Garenstock Augengneiss (Fig. 9a) is an Ordovician (Chapter 3.4) granitoid that is characterised by a prominent augen texture of K-feldspar in a mica-rich matrix occurs in the northern part of the Adula nappe. The augen texture is not present everywhere, and a transition to an augen-free gneiss can be observed locally. The gneiss composition is quartz, K-feldspar, plagioclase, white mica, biotite, garnet, epidote, zircon, apatite, and ilmenite. Metric to decimetric mafic boudins and lenses (Garenstock mafic rocks, Fig. 9b) are locally abundant within the augengneiss (Fig. 9b). Eclogite relicts are sometimes present in these boudins. A lithologic description of the Garenstock Augengneiss can be found in Kopp (in Jenny et al. 1923) and Egli (1966).

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