Embd-Member
Retour à nappe de Siviez-MischabelReprésentation et statut
- Couleur CMYK
- (0%,47%,72%,8%)
- Couleur RGB
- R: 235 G: 125 B: 65
- Rang
- Membre lithostratigraphique (Sous-formation)
- Usage
- Ce terme est en usage.
- Status
- terme informel
Nomenclature
- Deutsch
- Embd-Member
- Français
- Membre d'Embd
- Italiano
- Membro di Embd
- English
- Embd Member
- Origine du nom
- Variantes historiques
-
ältere Quarzite (Jäckli 1950), Embd Member (Genier et al. 2008, Galster et al. 2010)
Description
- Épaisseur
- 20 m im Mattertal (Genier et al. 2008)
Hiérarchie et succession
- Unité hiérarchiquement supérieure
- Unités sus-jacentes
- Limite supérieure
-
Sous-le-Rocher-Member
- Limite inférieure
-
Moosalp-Formation
Âge
- Âge au sommet
-
- Permien tardif
- Âge à la base
-
- Permien tardif
Géographie
- Région-type
- Mattertal (VS)
Paléogéographie et tectonique
- Termes génériques
- Type de protolithe
-
- sédimentaire
- Métamorphisme
- monocyclique
Références
- Définition
-
(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).