Eriwis-Bank
Representation and status
- Color CMYK
- (13%,25%,0%,22%)
- Color RGB
- R: 195 G: 170 B: 220
- Rank
- lithostratigraphic Bed
- Validity
- Unit is in Use
- Status
- valid formal name
Nomenclature
- Deutsch
- Eriwis-Bank
- Français
- Banc d'Eriwis
- Italiano
- Strato di Eriwis
- English
- Eriwis Bed
- Origin of the Name
-
Waldstück Eriwis, nordwestlich von Schinznach (AG)
- Historical Variants
-
Pleydellien-Bank, Pleydellienbank, Erimis-Bank [sic] (Jordan et al. 2008), Eriwis Bed (Reisdorf et al. 2011)
Description
- Description
-
Einige cm dicker Kondensationshorizont der Aalensis Subzone. Bräunlich, manchmal rötliche, dunkelgraue Mergellagen, welche lateral in einen mergeligen Kalkstein übergehen können. Dieser phosphoritische, kondensierte Horizont ist charakterisiert durch die Häufigkeit an Ammoniten und Belemniten. Die Eriwis-Bank ist klar von dem darüberliegenden Opalinus-Ton abzutrennen.
- Thickness
- 0 – 0,3 m (Reisdorf et al. 2011).
Components
- ammonites
Hierarchy and sequence
- Superordinate unit
- Units at roof
- Units at floor
- Upper boundary
-
Opalinus-Ton
- Lower boundary
-
Die Eriwis-Bank bildet die Dachbank des Gross-Wolf-Members.
Age
- Age at top
-
- late Toarcian
- Note about top
-
Levesquei-Z., Aalensis-Sz.
- Age at base
-
- late Toarcian
- Note about base
-
Levesquei-Z., Aalensis-Sz.
- Dating Method
-
Ammoniten (Aalensis-Zone)
Geography
- Geographical extent
- Umgebung von Moutier bis östlicher Faltenjura.
- Type area
- Aargauer Jura
Palaenography and tectonic
-
- Liassic of the Jura Moutains
- Paleogeography
-
Northern Tethyan Carbonate Platform
:
Plateforme de Bourgogne, ... = Northern Tethyan Carbonate Platform (NTCP) - Tectonic unit (resp. main category)
-
-
Jura
:
Juragebirge
-
Jura
:
- Kind of protolith
-
- sedimentary
- Sequence
-
Kondensationshorizont
- Metamorphism
- non metamorphic
References
- Definition
- (2008) : Jurassic. Swiss Jura Mountains In T. McCann (Ed.), The Geology of Central Europe. Volume 2: Mesozoic and Cenozoic (pp. 880–889). London: The Geological Society of London.
- Definition
-
(2011) :
The Staffelegg Formation: a new stratigraphic scheme for the Early Jurassic of northern Switzerland Swiss J. Geosci. 104/1, 97-146
Only a few centimetre thick, condensed horizon of the Aalensis subzone (see Etter 1990 ; Wetzel and Reisdorf 2007 ; Reisdorf et al. subm. ; cf. Etzold 1980). Occasionally brownish, sometimes reddish, dark grey marl layer which may pass laterally into a marly limestone (Figs. 11 11 , 12 , 13 , 15 16 , 17 , 18 , 23 ). This phosphoritic condensed horizon is characterised by its abundance of ammonites (especially the genera Cottes- woldia and Pleydellia , among others also C. aalensis ZIETEN 1832) and belemnites (Jordan 1983 ; Etter 1990 ; Nagra 1992 ; cf. Etzold et al. 1989 ). Based on these characteristics, the Eriwis Bed is clearly and visibly separated from the overlying Opalinus-Ton (see Jordan 1983 ; Etter 1990 ; Reisdorf 2001 ). The latter is characterised by dark grey to black, partially silty to sandy terrigenous mudstone and marl with mica (Etter 1990 ; Reisdorf 2001 ; Wetzel and Allia 2003 ). In the Schafisheim well the lithostratigraphic boundary between the Gross Wolf Member and the Opalinus-Ton is set below a 15 cm thick, reworked horizon that contains iron ooids and Mid-Jurassic foraminifera. This mudstone horizon is noteworthy because it also contains corroded ammonites of the Late Toarcian ( Cotteswoldia aalensis ZIETEN 1832; Tröster 1987 ; Nagra 1992 ).