Leutschenberg-Member

Représentation et statut

Couleur CMYK

(0%,35%,71%,4%)

Couleur RGB

R: 245 G: 160 B: 70

Rang

Membre lithostratigraphique (Sous-formation)

Usage

Ce terme est en usage.

Status

terme formel valide

Nomenclature

Deutsch

Leutschenberg-Member

Français

Membre du Leutschenberg

Italiano

Membro del Leutschenberg

English

Leutschenberg Member

Origine du nom

Leutschenberg (AG), WSW Zeglingen

Variantes historiques

Unterer Trochitenkalk, Leutschenberg Member (Pietsch et al. 2016)

Description

Description

Bioturbierter, oft dolomitisierter Kalk (Mudstone bis Wackestone) an der Basis der Schinznach-Formation. Im unteren Teil treten lokal Crinoid- («Trochitenkalk») und Schalentrümmer auf.

Épaisseur

4 - 10 m (Merki 1961, Pietsch et al. 2016).

Composants

• crinoïdes

Hiérarchie et succession

Unité hiérarchiquement supérieure

• Schinznach-Formation

Unités hiérarchiquement subordonnées

• Fützen-Bank

Unités sus-jacentes

• Kienberg-Member

Unités sous-jacentes

• Zeglingen-Formation (Anhydritgruppe)

Limite supérieure

Kienberg-Member.

Limite inférieure

Stromatolitischer Dolomit der Zeglingen-Formation.

Âge

Âge au sommet

• Anisien

Âge à la base

• Anisien

Géographie

Extension géographique

Nordschweizer Jura.

Région-type

Aargauer Jura

Localité-type

• Leutschenberg (AG), W-Flank
  Particularités du site
  • Obergrenze
  • Untergrenze
  • typische Fazies
  Coordonnées
  • (2636950 / 1251250)
  Note
  • Merki 1961 Fig.8, Pietsch et al. 2016 Fig.8

Typusprofil

• Leutschenberg (AG), W-Flank
  Particularités du site
  • Obergrenze
  • Untergrenze
  • typische Fazies
  Coordonnées
  • (2636950 / 1251250)
  Note
  • Merki 1961 Fig.8, Pietsch et al. 2016 Fig.8

Paléogéographie et tectonique

• Trias du Jura

Paléogéographie

plateforme carbonatée nord-téthysienne :
Plateforme de Bourgogne, ... = Northern Tethyan Carbonate Platform (NTCP)

Termes génériques

• Jura :
  Juragebirge

Type de protolithe

• sédimentaire

Métamorphisme

non métamorphique

Faciès métamorphique

• dolomitisation secondaire

Références

Définition

Pietsch Johannes S., Wetzel Andreas, Jordan Peter (2016) : A new lithostratigraphic scheme for the Schinznach Formation (upper part of the Muschelkalk Group of northern Switzerland). Swiss J. Geosc. 109/2, 285-307

The Leutschenberg Member represents the lowermost part of the Schinznach Formation. It mainly consists of bioturbated mud- and wackestones. Bedding planes and burrows are often dolomitised. The basal strata are locally dolomitic (Disler 1914; Merki 1961) and overlie stromatolitic dolomites of the Zeglingen Formation (Fig. 8).

At some localities strata rich in crinoid and shell detritus occur near the base of the Leutschenberg Member (Figs. 8, 10). They are between 5 cm (Fig. 10; see Merki 1961; Gsell 1968) and about 2 m thick (Merki 1961). Merki (1961) called these strata ‘‘Basale Trochitenbank’’. They often represent the lowermost part of the Leutschenberg Member, but similar lithology may occur in middle part as well (Disler 1914; Merki 1961). Due to their multiple occurrence at different stratigraphic levels within the lower part of the Leutschenberg Member they cannot be defined as a single bed. The Basale Trochitenbank rather comprises different crinoid-detritus-rich strata. Where these strata occur at the base of the Leutschenberg Member, they often contain dolomite clasts originating from the underlying ‘‘Anhydritdolomit’’ representing the top of the Zeglingen Formation (Merki 1961).

The top of the Leutschenberg Member is defined by the first occurrence of successional float- to rudstones rich in crinoid and shell detritus above bioturbated mud- and wackestones (see below; Figs. 8, 10). Thus, the ‘‘Basale Trochitenbank’’ of Merki (1961) is defined to form part of the Leutschenberg Member.

Principales publications

Pietsch Johannes S., Wetzel Andreas, Jordan Peter (2016) : A new lithostratigraphic scheme for the Schinznach Formation (upper part of the Muschelkalk Group of northern Switzerland). Swiss J. Geosc. 109/2, 285-307