Calcaire à Cladocoropsis (mirabilis)

Representation and status

Color CMYK

cf. Formation de Reuchenette

Color RGB

R: 145 G: 205 B: 215

Rank

lithostratigraphic Bed

Validity

Unit is in Use

Status

incorrect name (though informally used)

Nomenclature

Deutsch

Cladocoropsis-Kalk

Français

Calcaire à Cladocoropsis (mirabilis)

Italiano

Calcare a Cladocoropsis

English

Cladocoropsis Limestone

Origin of the Name

Nom dérivé de l'éponge stromatopore fossile Cladocoropsis mirabilis Felix 1906.

Historical Variants

Cladocoropsiskalke = Bryozoenkalk = calcaire à Bryozoaires (Renz 1931)

Components

• demosponges

Hierarchy and sequence

Units at roof

• Grenznerineen-Bank

Upper boundary

Marnes à Virgula supérieures / Formation du Twannbach

Stratigraphic discussion

niveau repère à la limite entre les Formations de Reuchenette et du Twannbach

Age

Age at top

• Late Kimmeridgian

Age at base

• Late Kimmeridgian

Dating Method

cf. Mouchet 1995, Colombié 2002

Geography

Geographical extent

Jura vaudois, neuchâtelois, bernois (Court, Tramelan) et soleurois (Oberdorf, Lommiswil).

Palaenography and tectonic

Tectonic unit (resp. main category)

• Jura :
  Juragebirge

Kind of protolith

• sedimentary

Metamorphism

non metamorphic

References

Definition

Rameil N. (2005) : Carbonate sedimentology, sequence stratigraphy, and cyclostratigraphy of the Tithonian in the Swiss and French Jura Mountains: a high-resolution record of changes in sea level and climate GeoFocus 13, 246

The sponge Cladocoropsis mirabilis is an important regional marker for the Kimmeridgian/Tithonian boundary interval. MOUCHET (1995) described high abundances in the upper Reuchenette Formation of all measured sections and cores, just below the upper virgula Marls and the Grenznerineenbank. This is confirmed by own observations (see Fig. 7.1). However, it is not sure if the abundance of Cladocoropsis mirabilis in the upper Reuchenette Formation is really a biostratigraphic event or only a facies dependent effect.