Membre des Grès de Passage

Representation and status

Color CMYK

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

Color RGB

R: 175 G: 155 B: 130

Rank

lithostratigraphic Member (Subformation)

Validity

Unit is in Use

Status

incorrect name (though informally used)

Nomenclature

Deutsch

Grenzschichten-Member

Français

Membre des Grès de Passage

Italiano

Membro dei Grès de Passage

English

Grès de Passage Membre

Historical Variants

Grès de passage (Badoux & Gabus 1991), Grès de Passage member (Ringgenberg et al. 2001)

Description

Thickness

6-26 m (Ringgenberg et al. 2001)

Hierarchy and sequence

Superordinate unit

• Formation de la Grande Eau

Units at roof

• Membre de la Forclaz

Units at floor

• Membre de la Leyderry

Age

Age at top

• Bathonian

Note about top

?

Age at base

• Bathonian

Note about base

?

Dating Method

par encadrement

Geography

Type area

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

Palaenography and tectonic

Kind of protolith

• sedimentary

References

Definition

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: 2.1A. Grès de Passage member (Bathonian?) This member forms the transition between the Leyderry and the Forclaz members. It is around 6 m thick on the Sépey-Diablerets road and 26 m in La Forclaz gorge. It is formed by metric and decimetric calcareous turbidites, which consist of quartz, feldspars and many micritic clasts containing echinodermic fragments, spicules, foraminifers (Lenticulina, Trocholina and Syphovalvulina) and ooliths with quartz and feldspar cores. As in the Raverette member, the granulometry of the beds become finer and their thickness decreases upward. Tabd Bouma sequences can be identified.