Gerstenhübel-Bank

Representation and status

Color CMYK

cf. Effingen-Member

Color RGB

R: 190 G: 195 B: 185

Rank

lithostratigraphic Bed

Validity

Unit is in Use

Status

informal term

Status discussion

Nomenclature

Deutsch

Gerstenhübel-Bank

Français

Banc du Gerstenhübel

Italiano

Strato del Gerstenhübel

English

Gerstenhübel Bed

Origin of the Name

Gerstenhübel, Veltheim (AG)

Historical Variants

Gerstenhübelkalk (Jäckli 1966, Hantke 1967), Gerstenhübel-Schicht (Gygi 1969), Gerstenhübel Beds (Gygi 2000b, Gygi 2000c), Gerstenhübel-Kalkschicht

Nomenclatorial Remarks

Schon von F. Mühlberg ausgeschieden. Hübel = Hügel, Berg, Erhebung

Description

Description

Wohlgeschichtete (in Bänken von 20 cm bis 30 cm), leicht mergelige Kalksteine mit spärlichem Vorkommen von Fossilien. Eine rund 10 m mächtige, feingeschichtete Mergelkalkbankabfolge wird im Steinbruch Jakobsberg von Gygi (1969) als Gerstenhübel-Bank 1) bezeichnet und mit dem Riffgürtel der Günsberg-Formation weiter im Westen korreliert (Gygi 2000). Innerhalb des insgesamt 230 m mächtigen Effingen-Members der Bohrung Küttigen-1 (Ref. 3) identifizieren Albert et al. (2007) eine 28 m mächtige Kalkbankabfolge, welche rund 88 m über der Basis einsetzt, als Gerstenhübel-Bank.

Geomorphology

Prominente morphologische Rippe innerhalb des Effingen-Members.

Thickness

Bis 12 m; 16 m (Wetzel & Strasser 2001) ; 13,4 m an der Typlokalität (Gygi 1973)

Components

• protists

Hierarchy and sequence

Superordinate unit

• Effingen-Member

Units at roof

• Effingen-Member

Units at floor

• Effingen-Member

Age

Age at top

• middle Oxfordian

Age at base

• middle Oxfordian

Dating Method

Bifurcatus-Zone : Amoeboceras cf. serratum (Sowerby) (Atrops et al. 1993, Gygi 2000b)

Geography

Geographical extent

Erlinsbach - Holderbank - Chestenberg - Villigen (AG).

Type area

Nördlicher Kt. Aargau

Type locality

• Gerstenhübel (AG)
  Site particularities
  • Obergrenze
  • Untergrenze
  • typische Fazies
  Site accessibility
  • Steinbruch, Tongrube
  Coordinates
  • (2654100 / 1252500)
  Note
  • Steinbruch Jakobsberg, N von Wildegg (Gygi 1969 S.66 Pl.17 Profil RG37, Gygi 2000c)

Type profile

• Gerstenhübel (AG)
  Site particularities
  • Obergrenze
  • Untergrenze
  • typische Fazies
  Site accessibility
  • Steinbruch, Tongrube
  Coordinates
  • (2654100 / 1252500)
  Note
  • Steinbruch Jakobsberg, N von Wildegg (Gygi 1969 S.66 Pl.17 Profil RG37, Gygi 2000c)

Palaenography and tectonic

• Malm of the Jura Mountains

Paleogeography

Argovian Basin

Tectonic unit (resp. main category)

• Jura :
  Juragebirge

Kind of protolith

• sedimentary

Sequence

The onset of the 16 m thick limestone deposits of the Gerstenhübel Beds represents a flooding followed by highstand sedimentation with increased carbonate production. A few metres above the top of the Gerstenhübel Beds, a 5 - 10 cm thick mudstone bed is capped by a limonite/pyrite crust up to 3 mm thick. Burrows and borings in this hardground suggest a multiphase formation. The sequence-stratigraphic significance of this horizon is debatable; Pittet (1996) interepreted it as maximum-flooding surface, whereas Allenbach (2001c) suggested a type II sequence boundary (SB Ox6) and sediment by-passing. (Wetzel & Strasser 2001)

Metamorphism

non metamorphic

References

Definition

Gygi R. A. (1969) : Geologische Beschreibung des Aargauer-Jura und der nördlichen Gebiete des Kantons Zürich.

Definition

Gygi R. A. (2000) : Annotated index of lithostratigraphic units currently used in the Upper Jurassic of northern Switzerland. Eclogae geol. Helv. 93/1, 125-146

p.130: Gerstenhübel Beds (Gygi 1969) ; Thick limestone succession within the Effingen Member of the Wildegg Formation The Gerstenhübel Beds (Gerstenhübel-Schicht) were named by Gygi (1969. p. 66). The type locality is the hill called Gerstenhübel (coordinates 654.100/252.500) 2 km south-southeast of Veltheim. Canton Aargau. LK 1089. Aarau. where the unit was quarried for some time. The names Veltheim and Gerstenhübel are not indicated on the map LK 1089, Aarau. The Gerstenhübel Beds are the succession no. 37 in section RG 37 of Gygi (1969. Pl. 17). This is the type section. The Gerstenhübel Beds are a well-bedded succession of