Winterhorn-Granit
Back to Gotthard NappeRepresentation and status
- Index
- gamma-W
- Color CMYK
- (0%,41%,59%,10%)
- Color RGB
- R: 230 G: 135 B: 95
- Rank
- lithostratigraphic Formation
- Validity
- Unit is in Use
- Status
- informal term
Nomenclature
- Deutsch
- Winterhorn-Granit
- Français
- Granite du Winterhorn
- Italiano
- Granito del Winterhorn
- English
- Winterhorn Granite
- Origin of the Name
-
Nordflank des Winterhorn = Pizzo d'Orsino (UR), Realp
- Historical Variants
-
Winterhornaplitgranit (Ambühl 1929), Winterhorn-Granitaplit = Granit vom Harnischberg (Rutsch et al. 1966), Winterhorn-Granitaplit (Mercolli et al. 1994), Winterhorn-Granit = Winterhorn-Aplit = Winterhorn-Aplitgranit (Labhart & Renner 2012), Winterhorn Granite (Berger et al. 2017)
Hierarchy and sequence
- Superordinate unit
Age
- Age at top
-
- Early Permian
- Age at base
-
- Early Permian
- Dating Method
-
ca. 295 Ma
Palaenography and tectonic
- Paleogeography
- European continental plate
- Tectonic unit (resp. main category)
- Kind of protolith
-
- plutonic
- Metamorphism
- monocyclic
References
- Definition
-
(1929) :
Petrographie und Geologie des zentralen Gotthardmassivs südlich Andermatt. Schweiz. Min. Petr. Mitt. 9, 265-441
S.330
R. Müller & E. Niggli in: Rutsch et al. 1966: WINTERHORN-GRANITAPLIT (= Granit vom Harnischberg) (? Jungpaläozoikum ; Gotthardmassiv)
E. Ambühl (1929) in: Petrographie und Geologie des zentralen Gotthardmassivs südlich Andermatt. Schweiz. Min. Petr. Mitt., 9/2: 330-331.
Schon von v. Fritsch (1873: 19) als Granulit vom Harnischberg beschrieben (>>>). Stockartige Masse (0.5 auf 2km) eines feinkörnigen Aplitgranits im nördlichen Gotthardmassiv, nördlich des Winterhorns (684.350/160.000, LK 255, 4km südwestlich Hospental). Gegen die angrenzenden Paragneise (Gurschengneis) und stellenweise gegen den Gamsbodengranitgneis scharf abgegrenzt, stellenweise auf kurze Distanz in den Gamsbodengranitgneis übergehend. Nach R. A. Sonder (1921) grosse Aehnlichkeit mit aplitischen Abarten des Rotondo-Granits. Der Winterhorn-Granitaplit ist ein granatführender Muskowit-Granitaplit. Er ist an der Gotthard-Passstrasse nicht aufgeschlossen. Gehört wohl zu den spätpaläozoischen Graniten des Gotthardmassivs.
Literatur: K. v. Fritsch (1873), R. A. Sonder (1921: 339), E. Ambühl (1929: 330).
- Definition
-
(2017) :
Geological Map of the Aar Massif, Tavetsch and Gotthard Nappes. Geological Special Map 1:100'000, Explanatory Notes 129
p.73: At map scale, the Rotondo Granite, representing the largest granitic body of this group with an exposed surface of ~25 km2, has a pronounced, rounded shape, with sharp discordant contacts to the surrounding gneisses of the polycyclic metamorphic basement. Its microstructure is massive and essentially undeformed; locally garnet occurs. Due to this, it was suggested that the intrusion could be of Alpine age (HAFNER 1958). The other small granite bodies intrude along the boundaries of the two larger and slightly older Fibbia Granite and Gamsboden Granite. The close spatial link between the granites of the Pesciora Group and those of the Val Lavaz Group underline an almost continuous intrusive activity as suggested by the age relationship.
SERGEEV et al.(1995) obtained an U/Pb age on zircon of 294± 1,1 Ma for the Rotondo Granite and the Tremola Granite (Fig. 4). SERGEEV & STEIGER (1995) suggested an age interval of 5,5 Ma for the intrusion of the Rotondo, Winterhorn, Cacciola, Prosa and Tremola Granites with an average age of 294,5+3,5/–2 Ma. OBERLI et al.(1981) obtained an age of 292±11 Ma for the Cacciola Granite, and BOSSART et al.(1986) an age of 293+4/–5 Ma for the Sädelhorn Diorite, both in agreement with the ages of the granitic members of the group. This time interval corresponds well with Early Permian (Sakmarian, 295– 290 Ma).