Membre de la Forclaz

Rappresentazione e statuto

Colore CMYK

(0%,11%,26%,31%)

Colore RGB

R: 175 G: 155 B: 130

Rango

Membro litostratigrafico (Sotto-formazione)

Uso

Unità in uso.

Status

termine formale valido

Discussione del statuto

Nomenclatura

Deutsch

Forclaz-Member

Français

Membre de la Forclaz

Italiano

Membro della Forclaz

English

Forclaz Member

Origine del nome

Ruisseau de la Forclaz (VD), Ormont-Dessous

Varianti storiche

Marnes et calcaires du torrent de la Forclaz (Badoux & Homewood 1978, Badoux & Gabus 1991), Forclaz member (Ringgenberg et al. 2001)

Descrizione

Potenza

30-50 m (Ringgenberg et al. 2001)

Componenti

• foraminferi
• bivalvi

Bositra buchi (Roemer 1836)

Gerarchia e successione

Unità di rango superiore

• Formation de la Grande Eau

Unità sovrastante

• Membre de Langy

Unità sottostante

• Membre des Grès de Passage

Età

Geomorfologia

• Bathoniano

Età alla base

• Bathoniano

Metodo di datazione

Foraminifères: Protopeneroplis striata (Weynschenk), Archeosepta platierensis (Wernli) (Badoux & Homewood 1978).

Geografia

Regione-tipo

Vallée de la Grande Eau, entre Le Sépey et la Forclaz

Paleogeografia e tettonica

• Dogger

Tipo di origine

• sedimentaria

Referenze

Definizione

Badoux H., Homewood P. (1978) : Le soubassement de la nappe du Niesen dans la région du Sépey (Alpes vaudoises). Bull. Soc. vaud. Sci. nat. 74/1, 15-23

Revisione

Ringgenberg Yann, Tomassi Alexander, Stampfli Gérard M. (2001) : The Jurassic sequence of the Niesen nappe in the region of Le Sépey - La Forclaz (Swirtzerland): witness of the Piemont rifting in the Helvetic paleogeographic domain. Bull. Soc. vaud. Sci. nat. 87/4, 353-372

p.360: 2.1.5. Forclaz member (Bathonian) Good outcrops of this member are only found in La Forclaz stream (map 1:25'000 n°1285, Les Diablerets, geographic coordinates: 571'600/133'325 to 571 '775/133'650). It is 30 to 50 m thick and composed of turbiditic sandy limestones which alternate with marls. The proportion sand/marls is 1:1 and Tabe sequences are present. The detritic elements point to a more basinal environment than for the other members: limestones with little quartz, feldspars and white micas but a lot of spicules, recrystallized echinoderms, Lenticulina, Nodosoaria and little or no resedimented platform fragments. Marls interbeds are sometimes full of Posidonia bronni or bositra and ichnofossil imprints. Homewood and Badoux (1978) found Protopeneroplis striata (WEYNSCHENK) and Archeosepta platierensis (WERNLI) which indicate a Bathonian age. The transition to the Langy member is gradual, the bed thickness and the detritic fraction increase upward.