Bugnei-Granodiorit
Back to Aar MassifRepresentation and status
- Index
- gamma-delta-B
- Color CMYK
- (0%,43%,52%,14%)
- Color RGB
- R: 215 G: 105 B: 110
- Rank
- lithostratigraphic Formation
- Validity
- Unit is in Use
- Status
- informal term
- Status discussion
Nomenclature
- Deutsch
- Bugnei-Granodiorit
- Français
- Granodiorite de Bugnei
- Italiano
- Granodiorite di Bugnei
- English
- Bugnei Granodiorite
- Origin of the Name
-
Bugnei (GR), E Sedrun
- Historical Variants
-
Bugneigranit (P. Niggli 1914, Staub 1914, Winterhalter 1930, Niederer 1932), Bugneigranodiorit (E. Niggli 1944), Bugneigranit = Bugneigranodiorit (Rutsch et al. 1966), Bugnei-Granodiorit (Bonanomi et al. 1992, Gisler 2018), Bugnei Granodiorite (Berger et al. 2017)
Description
- Description
-
Mineralbestand: Na-K-Feldpat, Plagioklas, Quarz, Biotit und akz. Minerale (Hornblende, Titanit, Orthit)
Hierarchy and sequence
- Superordinate unit
Age
- Age at top
-
- Middle Pennsylvanian
- Age at base
-
- Middle Pennsylvanian
- Dating Method
-
Ca. 310.6 Ma (Schaltegger, unpubl.)
Geography
- Geographical extent
- Lokal eng begrenzte, linsenförmige Intrusivmasse in südlichen Gneisen des östlichen Aarmassivs, zwischen Sedrun und Segnas.
Palaenography and tectonic
- Tectonic unit (resp. main category)
- Kind of protolith
-
- plutonic
- Metamorphism
- monocyclic
References
- Definition
-
(2017) :
Geological Map of the Aar Massif, Tavetsch and Gotthard Nappes. Geological Special Map 1:100'000, Explanatory Notes 129
p.59: The Bugnei Granodiorite is interpreted as belonging to the Clavaniev Zone, but is shown as a separate body on the present map sheet. This plutonic body is located north of Sedrun at the boundary of the Ausserberg-Avat Zone and the Clavaniev Zone. NIGGLI (1944) describes it as petrographically identical to the granodiorites of Val Russein (Russein Diorite and Munt Dado Granite). It contains large titanites and frequent allanite (i.e., it is genetically linked to and coeval with the plutonic rocks of the Fruttstock Group). He interpreted the Bugnei Granodiorite as the undeformed relictic portion of a larger body enveloped by schist of similar composition generated by an intense deformation of probable Alpine age (NIGGLI 1944). Similarly, LEU & WYSS (1992) and KELLER (1999) showed that the Bugnei Granodiorite is embedded in mylonites of the Clavaniev Zone.