Unterer Teil der Schrattenkalk-Formation

Torna a Elvetico centrale

Rappresentazione e statuto

Index
c4-5u
Colore CMYK
(31%,0%,13%,24%)
Colore RGB
R: 135 G: 195 B: 170
Rango
Membro litostratigrafico (Sotto-formazione)
Uso
Unità in uso.
Status
termine scorretto (informale)

Nomenclatura

Deutsch
Unterer Teil der Schrattenkalk-Formation
Français
Partie inférieure de la Formation du Schrattenkalk
Italiano
Parte inferiore della Formazione dello Schrattenkalk
English
Lower part of the Schrattenkalk Formation
Varianti storiche

Unterurgon bzw. Unterer Caprotinenkalk (Baltzer 1906), Oberes Barrémien = Unterer Schrattenkalk (Urgonfazies) (Furrer 1938), Unterer Schrattenkalk (Schindler 1959), Lower Schrattenkalk Member (Föllmi et al. 2007)

Descrizione

Descrizione

Hellgrau anwitternder, dickbankiger, fossilarmer Kalk.

Geomorfologia
Helle Felswand.
Potenza
Bis über 100 m (Föllmi et al. 2007)

Gerarchia e successione

Unità di rango superiore
Unità sovrastante

Età

Geomorfologia
  • Aptiano iniziale
Età alla base
  • Barremiano tardo
Osservazioni sulla base

Mitte spätes Barremian 

Paleogeografia e tettonica

  • Cretacico medio
  • Kreide (Helv.)
Paleogeografia
North Tethyan Shelf (Helv.) :
marge continentale européenne
Termini generici
Tipo di origine
  • sedimentaria
Metamorfismo
non metamorfo

Referenze

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.11: The lower Schrattenkalk reaches a maximal thickness of over 100 m and is composed of carbonate pack- and grainstone rich in ooids, peloids, benthic foraminifera (e.g., miliolids, orbitolinids), green algae, rudists (e.g., Requienia), bryozoans, brachiopods, bivalves, echinoderms and corals. This unit is characterized by a strong progradational trend (Fig. 2) and by a rather rapid transition (within a few kilometers; Fichter 1934; Bollinger 1988) into the outer shelf marls and marl-limestone alternations of the Tierwis Formation [Hurst Beds]. The entire succession is considered as a second-order systems tract, which may form one single sequence with the underlying Drusberg Member and the Chopf Bed (Funk et al. 1993). It is not excluded that third-order sequence-stratigraphic subdivisions may be present within the lower Schrattenkalk, as is the case in the Vercors area (Arnaud et al. 1998).
The age of the lower Schrattenkalk is indicated by the ammonite fauna of the Chopf Bed and by orbitolinids in the overlying Rawil Member (see below) and can be constrained as sartousiana to oglanlensis zones. A diachrony of its base along a proximal-distal axis is highly probable and due to the progradational character of this unit.

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