Oberer Teil des Helvetischen Kieselkalkes (s.l.)

Rappresentazione e statuto

Varianti storiche: Oberer Kieselkalk (Spörli 1966, Mojon 1982 S.60), Upper Kieselkalk (Föllmi et al. 2007)

Unità di rango inferiore

Geomorfologia

Età alla base

Metodo di datazione: Ammoniten-Biostratigraphie der umrahmenden Einheiten (Föllmi et al. 2007)

Termini generici

Tipo di origine

Revisione: Föllmi Karl B., Bodin Stephane, Godet Alexis, Linder Pascal, van de Schootbrugge B. (2007) : Unlocking paleo- environmental information from Early Cretaceous shelf sediments in the Helvetic Alps: stratigraphy is the key! Swiss J. Geosci. 100, 349-369

p.9: The upper Kieselkalk is less thick than its lower counterpart and reaches maximally approximately 50 m (Fig. 2; Funk 1969, 1971; Funk et al. 1993). It is very similar to the lower Kieselkalk with regards to its facies and consists in proximal areas of a coarse grained sandy and siliceous, heterozoan carbonate, which becomes finer grained and more pelagic in the outer shelf area. It displays a well-expressed shallowing upward trend in distal platform areas grading from a fine-grained, marly carbonate at its base into a very coarse crinoidal limestone at its top (“Echinodermen-Breccie” of Kaufmann 1867; see also Funk 1971). The general progradation of shallow-water carbonates shown by the shallowing-upward trend classifies the platform-related part of the upper Kieselkalk as a highstand systems tract.
Its age is well defined by the ammonite biostratigraphy of the underlying Lidernen Member and overlying Altmann Member and is limited to the younger part of the ligatus zone and the older part of the following balearis zone.