Banc du Ponthoud

Representation and status

Color CMYK

Cf. Membre de Mussel

Color RGB

R: 245 G: 170 B: 170

Rank

lithostratigraphic Bed

Validity

Unit is in Use

Status

informal term

Nomenclature

Deutsch

Ponthoud-Bank

Français

Banc du Ponthoud

English

Ponthoud Bed

Origin of the Name

Le Ponthoud, quartier du SW de Bellegarde-sur-Valserine (France), juste en aval du viaduc autoroutier.

Historical Variants

Ponthoud Bed (Pictet et al. 2016)

Description

Thickness

Max. 60 cm dans la région de Bellegarde-sur-Valserine.

Hierarchy and sequence

Superordinate unit

• Calcaires lités

Units at roof

• Grès des Vernettes

Age

Age at top

• Late Aptian

Note about top

Zone à Hoplites jacobi + L. tardefurcatum

Age at base

• Late Aptian

Note about base

Zone à Deshayesites nodosocostatum

Dating Method

Biostratigraphie des ammonites (Pictet in prep.)

Geography

Type area

Jura méridional

Palaenography and tectonic

Tectonic unit (resp. main category)

• Jura :
  Juragebirge

Kind of protolith

• sedimentary

Metamorphism

non metamorphic

References

Definition

Pictet Antoine, Delamette Michel, Matrion Bertrand (2016) : The Perte-du-Rhône Formation, a new Cretaceous (Aptian-Cenomanian) lithostratigraphic unit in the Jura mountains (France and Switzerland). Swiss J. Geosc. 109/2, 221-240

From the base to the top of the Mussel Mb, five subunits have been identified (Fig. 8). The second one, the Ponthoud Bed (S8, Figs. 4, 8d–e), is a 1 m thick green coquina-rich limestone, which is composed by a quartz and phosphate-rich packstone (Fig. 8e). The Ponthoud Bed delivered an heterotrophic fauna with numerous sponges, bryozoans, echinids, bivalves, gastropods, brachiopods, and rare ammonites (Fig. 8f; ~6 taxa; Pictet and Renevier 1854–1858; Pictet and Campiche 1858–1871) showing a strong affinity with the fauna of Clansayes (Kilian and Leenhardt 1890; Jacob 1905; Moullade 1965).