Cavardiras-Gruppe (prä- und frühvariszische Sedimente und Vulkanite)

Représentation et statut

Couleur CMYK

(22%,0%,13%,37%)

Couleur RGB

R: 125 G: 160 B: 140

Rang

Groupe lithostratigraphique

Usage

Ce terme est en usage.

Nomenclature

Deutsch

Cavardiras-Gruppe (prä- und frühvariszische Sedimente und Vulkanite)

Français

Groupe de Cavardiras

Italiano

Gruppo di Cavardiras

English

Cavardiras Group

Origine du nom

Val Cavardiras (GR), Disentis/Mustér

Variantes historiques

Visé, Cavardiras Group (Oberhänsli et al. 1988), Pre- and early Variscan metasedimentary and volcaniclastic rocks = Cavardiras Group (Berger et al. 2017)

Hiérarchie et succession

Unités hiérarchiquement subordonnées

• Val-Gliems-Formation
• Bifertenfirn-Formation

Unités sus-jacentes

• Rötifirn-Gruppe (frühvariszische Intrusiva)

Âge

Âge au sommet

• Paléozoïque

Âge à la base

• Paléozoïque

Paléogéographie et tectonique

Paléogéographie

continent européen

Termes génériques

• Aar

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.33: The Cavardiras Group comprises two formations, the Bifertenfirn Formation (PB) and the Val Gliems Formation (PGl). They consist of sequences of clastic, volcaniclastic and volcanic rocks of pre-Visean to Visean age showing a metamorphic overprint up to amphibolite-facies conditions. Deformation and metamorphism are older or coeval with the emplacement of plutonic rocks of the Rötifirn Group in Visean times (HÜGI 1941, FRANKS 1968 a, b). This suggests a Variscan age for the low-pressure /medium-temperature metamorphic overprint. Already OBERHÄNSLI et al. (1988) defined a Cavardiras Group to which they grouped volcanic, volcaniclastic and clastic sequences showing intense deformation. They assigned to the Cavardiras Group not only the Bifertenfirn and the Val Gliems Formations, as shown on the present map sheet, but they also included in this group the Diechtergletscher Formation and a sequence called “Oberaar 1” (in the present map sheet, part of the Oberaar-Furka Zone, see p. 25 f.). The geological relationships are only clear enough in the Bifertenfirn and Val Gliems Formations to permit reconstruction of their Variscan evolution. The stronger deformation in the Diechtergletscher Formation and of the “ Oberaar 1” sequence of OBERHÄNSLI et al.(1988) is consistent with the regional Alpine tectonic situation and therefore cannot be taken into account for an age estimation.