Garenstock-Augengneis
Back to Adula nappeRepresentation and status
- Color CMYK
- (0%,35%,29%,4%)
- Color RGB
- R: 245 G: 160 B: 175
- Rank
- lithostratigraphic Formation
- Validity
- Unit is in Use
Nomenclature
- Deutsch
- Garenstock-Augengneis
- English
- Garenstock Augengneiss
- Origin of the Name
-
Garenstock (GR), Vals
- Historical Variants
- 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)
Age
- Age at top
-
- Late Ordovician
- Age at base
-
- Late Ordovician
- Dating Method
- 446.4 bis 457.8 Ma (Cavargna-Sani 2013)
References
- Definition
-
(1923) :
-
S.100
- Definition
-
(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).