Düssi-Diorit
Back to Aar MassifRepresentation and status
- Index
- delta-D
- Color CMYK
- (0%,51%,49%,16%)
- Color RGB
- R: 215 G: 105 B: 110
- Rank
- lithostratigraphic Formation
- Validity
- Unit is in Use
- Status
- informal term
Nomenclature
- Deutsch
- Düssi-Diorit
- Français
- Diorite du Düssi
- Italiano
- Diorite del Düssi
- English
- Düssi Diorite
- Origin of the Name
-
Chli Düssi (UR)/(GR)
- Historical Variants
-
Düssi diorite (Franks 1968), Düssi-Fruttstockdiorit, Düssi-Fruttstock-Diorit, Diorit des Düssistocks, Düssi Diorite (Berger et al. 2017), Düssi-Diorit (Gisler 2018)
Hierarchy and sequence
- Superordinate unit
Age
- Age at top
-
- Middle Pennsylvanian
- Age at base
-
- Middle Pennsylvanian
- Dating Method
-
308 +/-2 Ma (U/Pb Zirkon ; Schaltegger & Corfu 1992), 307.1 +/-1.6 Ma (Schaltegger, unpubl.)
Geography
- Geographical extent
- Brunnital, Cuolm da Tgietschen, Griesserental.
- Type area
- Chli Düssi und Fruttstock, NE bzw. W Brunnital
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.40: The Düssi Diorite (also called the Düssi-Fruttstock Diorite in the literature) is a heterogeneous body composed of cumulate-like hornblende gabbro to hornblende diorite and hornblende- or biotite-quartz monzonite. The more mafic components show mingling structures in more acid magmas at the scale of metres or decametres (SCHALTEGGER et al.1991). The Düssi Diorite and the Brunni Granite intrude the Ofenhorn-Stampfhorn and Straligenstöckli Gneiss Complexes of the Sustenhorn Zone, whereas the Central Aar Granite intrudes the Brunni Granite along its southwestern border. Further occurrences of dioritic rocks are described by EUGSTER (1951) at the Cuolm da Tgietschen, and in the Griesserental by SIGRIST (1947), both interpreted here as continuation of the Düssi Diorite. The Düssi Diorite has an U/Pb zircon age of 308 Ma (SCHALTEGGER & CORFU 1992), overlapping in error with the below-mentioned age of the Voralp Granite. Furthermore, SCHALTEGGER et al.(1991) reported the occurrence of a large dioritic enclave in the Central Aar Granite, the Schöllenen Diorite in the Reuss valley, which is coeval with the Düssi Diorite.