Liedertswil-Member

Representation and status

Color CMYK

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

Color RGB

R: 245 G: 160 B: 70

Rank

lithostratigraphic Member (Subformation)

Validity

Unit is in Use

Status

valid formal name

Status discussion

Nomenclature

Deutsch

Liedertswil-Member

Français

Membre de Liedertswil

Italiano

Membro di Liedertswil

English

Liedertswil Member

Origin of the Name

Liedertswil (BL)

Historical Variants

Plattenkalk, Nodosus-Kalk, Liedertswil Member (Pietsch et al. 2016)

Description

Description

Grauer, plattiger bis gebankter, mikritischer Kalk (ehem. «Plattenkalk» oder «Nodosus-Kalk») mit Dolomitschlieren und -lagen. Das Liedertswil-Member besteht im unteren Teil aus Kalken reich an schaligem Detritus und makrofossilarmen Mud- und Wackestones in oberen Teil.

Thickness

25 - 35 m (Fischer et al. 1971) ; von 1.5 m in der Bohrung Weiach bis max. 25 m (Pietsch et al. 2016)

Hierarchy and sequence

Superordinate unit

• Schinznach-Formation

Subordinate units

• Eptingen-Bank
• Dünnlenberg-Bank

Units at roof

• Stamberg-Member

Units at floor

• Kienberg-Member

Upper boundary

Stamberg-Member

Lower boundary

Kienberg-Member

Age

Age at top

• Earliest Ladinian

Age at base

• Late Anisian

Dating Method

Compressus- und Evolutus-Zone (Pietsch et al. 2016)

Geography

Geographical extent

Nordschweizer Jura.

Type area

Östlicher Faltenjura

Type locality

• Dünnlenberg (BL), südlich Liedertswil
  Site particularities
  • Obergrenze
  • Untergrenze
  • typische Fazies
  Site accessibility
  • Grat
  Coordinates
  • (2620930 / 1248530)
  Note
  • Merki 1961, Herold 1992, Pietsch et al. 2016 Fig.11

Type profile

• Dünnlenberg (BL), südlich Liedertswil
  Site particularities
  • Obergrenze
  • Untergrenze
  • typische Fazies
  Coordinates
  • (2620930 / 1248530)
  Note
  • Merki 1961, Herold 1992, Pietsch et al. 2016 Fig.11

Palaenography and tectonic

• Triassic of the Jura Mountains

Paleogeography

Northern Tethyan Carbonate Platform :
Plateforme de Bourgogne, ... = Northern Tethyan Carbonate Platform (NTCP)

Tectonic unit (resp. main category)

• Jura :
  Juragebirge

Kind of protolith

• sedimentary

Conditions of formation

The Liedertswil Member documents the highstand and the first phase of regression. In Northern Switzerland and adjacent southern Germany, ceratite ammonite findings are restricted to the Dünnleberg Bed proper and some overlying horizons (Pietsch et al. 2016) at the base of the member.

Metamorphism

non metamorphic

References

Definition

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 Liedertswil Member consists of limestones rich in shell detritus in the lower part and macrofossil-poor mud- and wackestones in the upper part. As discussed above, crinoid detritus may occur in some strata of the lower part. In most sections the Dünnlenberg Bed lies little above the base of the Liedertswil Member. Above the Dünnlenberg Bed other marl layers may occur. Locally ceratites can be found in these layers (see above; Braun 1920; Merki 1961). Strata above and below the marl layers may contain glauconite (Merki 1961; Herold 1992; Brüderlin 1969). Especially the upper part of the Liedertswil Member is often dolomitised. In some regions the dolomitised Liedertswil Member contains chert nodules (e.g. Braun 1920; Merki 1961). Within the lower parts often bedding planes and burrows are dolomitised similar to underlying members. The top of the Liedertswil Member is defined by the change from (dolomitic) limestone with single dolomitic strata to a both laterally continuous and pure dolomite. Due to the diagenetic nature of the upper boundary of the Liedertswil Member, the level of the boundary varies within the Schinznach Formation. It is therefore possible that the normally overlying Stamberg Member directly rests on the Kienberg Member, if dolomitisation is used as classification criterion and if dolomitisation affected the uppermost strata rich in crinoid detritus. In that case the Liedertswil Member is not developed as such. The oolitic interval around the boundary interval between the Liedertswil Member and the Stamberg Member is defined as Eptingen Bed. Depending on dolomitisation-depth it lies either in one or in both of these members.

Important 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