Embd-Member

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Representation and status

Color CMYK
(0%,47%,72%,8%)
Color RGB
R: 235 G: 125 B: 65
Rank
lithostratigraphic Member (Subformation)
Validity
Unit is in Use
Status
informal term

Nomenclature

Deutsch
Embd-Member
Français
Membre d'Embd
Italiano
Membro di Embd
English
Embd Member
Origin of the Name

Embd (VS)

Historical Variants

ältere Quarzite (Jäckli 1950), Embd Member (Genier et al. 2008, Galster et al. 2010)

Description

Thickness
20 m im Mattertal (Genier et al. 2008)

Hierarchy and sequence

Superordinate unit
Upper boundary

Sous-le-Rocher-Member

Lower boundary

Moosalp-Formation

Age

Age at top
  • Late Permian
Age at base
  • Late Permian

Geography

Type area
Mattertal (VS)

Palaenography and tectonic

Tectonic unit (resp. main category)
Kind of protolith
  • sedimentary
Metamorphism
monocyclic

References

Definition
Genier Florian, Epard Jean-Luc, Bussy François, Magna Tomas (2008) : Lithostratigraphy and U-Pb zircon dating in the overturned limb of the Siviez-Mischabel nappe: a new key for Middle Penninic nappe geometry. Swiss J. Geosci. 101/2, 431–452

p.441: The lower part of the [Bruneggjoch] formation, mostly in sharp contact with white or green micaschists of the Moosalp Formation, is composed of massive, green, fine grained, microconglomeratic or conglomeratic quartzite (Fig. 7D). It is the typical rock extracted from the Kalpetran quarry to build roofs in the region. This quartzite is easy to access in the Embd locality (630.05/118.40/1415 m). In this locality, it is well exposed and the contacts with the surrounding formations can be easily observed. Consequently we propose to call Embd Member this quartzite type, as it has until yet not been named. This member is around 20 metres thick along the Mattertal. Characteristic conglomerates with pink quartz pebbles (Briançonnais Verrucano-type; Trümpy 1966), occurring in various places (Embd, Törbel), are part of this quartzite. It crops out on the west side of the Mattertal in a zone of plurikilometre long extension, forming the core of the St-Niklaus syncline. This quartzite contains broken microcline grains (2–5%, 0.5–2 mm) with albitic rims and pressure shadows composed of quartz and phengite. The matrix is composed of quartz (75–55%, 0.01–0.3 mm), subidiomorphic phengite (25–40%, 0.05–0.5 mm) and accessory albite (0.1–0.2 mm).

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