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

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Representation and status

Color CMYK
(22%,0%,13%,37%)
Color RGB
R: 125 G: 160 B: 140
Rank
lithostratigraphic Group
Validity
Unit is in Use

Nomenclature

Deutsch
Cavardiras-Gruppe (prä- und frühvariszische Sedimente und Vulkanite)
Français
Groupe de Cavardiras
Italiano
Gruppo di Cavardiras
English
Cavardiras Group
Origin of the Name

Val Cavardiras (GR), Disentis/Mustér

Historical Variants

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

Hierarchy and sequence

Subordinate units
Units at roof

Age

Age at top
  • Paleozoic
Age at base
  • Paleozoic

Palaenography and tectonic

Paleogeography
European Continent
Tectonic unit (resp. main category)

References

Definition
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.

  • Val-Gliems-Formation

    Name Origin

    Val Gliems (GR), Sumvitg

    Rank
    lithostratigraphic Formation
    Status
    informal term
    Nomenclatorial Remarks
    <p>Knotenschiefer, Konglomeratgneis</p>
    In short

    Prä- und frühvariszische Konglomerate, Arkosen, Grauwacken und Tonschiefer (bzw. Paraschiefer und -gneise, Phyllite, Knotenschiefer) des Aar-Massivs, vereinzelt mit kalkigen Einlagerungen. Kontaktzone am Rand. Bildet eine steilstehende Faltenstruktur im östlichen Val Russein.

    Age
    Early Paleozoic
    Show details

    • Metapelitische Abfolge (Val-Gliems-Fm.)

      Rank
      petrographic facies
      Status
      informal term
      In short
      Metapelitische Einlagerungen in der Val-Gliems-Formation.
      Age
      Early Paleozoic
      Show details

    • Metavulkaniklastische Abfolge (Val-Gliems-Fm.)

      Rank
      petrographic facies
      Status
      informal term
      In short
      Regelmässig aufgebaute, zyklische vulkanoklastiche Abfolge der Val-Gliems-Formation : basale konglomeratische Lage, dacitischer Tuff, ignimbritischer Tuff (Schlacken-Fiamme). Diese Abfolge wird durch die Einlagerung von Peliten unterbrochen.
      Age
      Early Paleozoic
      Show details

  • Bifertenfirn-Formation

    Name Origin

    Bifertenfirn (GL), am Tödi

    Rank
    lithostratigraphic Formation
    Status
    informal term
    In short

    Prä- und frühvariszische Metasedimente und Metavulkanite des Aar-Massivs.

    Age
    Early Paleozoic
    Show details
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