Giuv-Syenit

Retour à massif de l'Aar

Représentation et statut

Index
sigma-G
Couleur CMYK
(0%,60%,47%,16%)
Couleur RGB
R: 215 G: 85 B: 115
Rang
Formation lithostratigraphique
Usage
Ce terme est en usage.
Status
terme informel

Nomenclature

Deutsch
Giuv-Syenit
Français
Syénite du (Piz) Giuv
Italiano
Sienite del (Piz) Giuv
English
Giuv Syenite
Origine du nom

Piz Giuv (UR)

Variantes historiques

Giuvsyenit = Giufsyenit (Rutsch et al. 1966), Piz Giuv syenite (Franks 1968), Giuv-Syenite [sic] (Purdy & Stalder 1973), Syenit vom Piz Giuf, syenite from Val Giuv, Giuf-Syenit, Giuv Syenite (Berger et al. 2017), Giuv-Syenit (Gisler 2018)

Remarques nomenclatoriales

Müller 1865, Heim 1891, Weber 1904

Description

Description

Mineralbestand (Hauptfazies): rund 50 Vol.% Mikroklin-mikroperthit, 10% Oligoklas-Albit, 7% Orthoklas und Mikroklin, 5% Quarz, 15% Hornblende, 10% Biotit und 3% Apatit, Titanit und Orthit.

Épaisseur
Ca. 13 km lang, mit eine Maximalbreite von 1 km in der Gegend des Piz Giuv.

Hiérarchie et succession

Unité hiérarchiquement supérieure

Âge

Âge au sommet
  • Viséen
Âge à la base
  • Viséen
Méthode de datation

334.0 +/-2.5 Ma (Schaltegger & Corfu 1992)

Géographie

Extension géographique
Östlichen Aarmassiv zwischen Oberalppass und Brunnifirn (Schijenstock, Piz Giuv, Piz Ault).

Paléogéographie et tectonique

Termes génériques
Type de protolithe
  • plutonique

Références

Révision
Berger Alfons, Mercolli Ivan, Herwegh Marco, Gnos Edwin (2017) : Geological Map of the Aar Massif, Tavetsch and Gotthard Nappes. Geological Special Map 1:100'000, Explanatory Notes 129

p.37: The Giuv Syenite forms a continuous elongated band stretching from the Oberalppass in the west to the Brunnifirn in the east (HUBER 1948). The mainly strongly foliated syenite to quartz monzonite has a central facies with large K-feldspar phenocrysts outlining magmatic flow structures (Fig. 5). Its southern margin is characterised by an increasing degree of deformation (LABHART 1977). WEBER(1904) and HUBER (1948) reported detailed petrographic descriptions of the Giuv Syenite and of a variety of dykes associated with it (Fig. 5). WEBER (1904) described an intrusive contact of the Central Aar Granite with the Giuv Syenite. SCHALTEGGER et al.(1991) defined the geochemical characteristics of the Giuv Syenite as ultrapotassic and linked this body genetically with the shoshonitic basic and acid rocks of the Punteglias Granite Complex. The age of the Giuv Syenite is 334±2 Ma (Fig. 4, SCHALTEGGER & CORFU 1992). The western termination of the syenite is characterised by its dissolution into apophysis and slices (WEBER 1904). It is therefore not unexpected that the Giuv Syenite wedges out at depth and was not encountered in the Gotthard Base Tunnel (GUNTLI et al. 2016).

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