Dünnlenberg-Bank
Back to Kienberg-MemberRepresentation and status
- Color CMYK
- (0%,35%,73%,6%)
- Color RGB
- R: 240 G: 155 B: 65
- Rank
- lithostratigraphic Bed
- Validity
- Unit is in Use
- Status
- valid formal name
Nomenclature
- Deutsch
- Dünnlenberg-Bank
- Français
- Banc du Dünnlenberg
- Italiano
- Strato del Dünnlenberg
- English
- Dünnlenberg Bed
- Origin of the Name
-
Dünnlenberg (BL), südlich Liedertswil
- Historical Variants
-
Mergelhorizont III (Merki 1961), Dünnlenberg Bed (Pietsch et al. 2016)
Description
- Thickness
- 10 - 40 cm (Pietsch et al. 2016)
Hierarchy and sequence
- Superordinate unit
- Upper boundary
-
Oberes Kienberg-Member oder Liedertswil-Member.
- Lower boundary
-
Kienberg-Member
Age
- Age at top
-
- Late Anisian
- Note about top
-
Illyrien, Compressus- bis Evolutus-Zone
- Age at base
-
- Late Anisian
- Note about base
-
Illyrien, Compressus- bis Evolutus-Zone
- Dating Method
-
Ceratiten-Biostratigraphie: Compressus- bis Evolutus-Zone (Pietsch et al. 2016).
Geography
- Geographical extent
- Baselbieter und Aargauer Tafeljura, Faltenjura westlich Schinznach, Wutachgebiet.
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
-
Jura
:
- Kind of protolith
-
- sedimentary
- Metamorphism
- non metamorphic
References
- Definition
-
(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 Dünnlenberg Bed consists of grey or brownish marl, which can be dolomitic or calcareous. It lies within the upper part of the strata rich in crinoid and shell detritus, where macrofossil-poor mud- and wackestones and intervals only rich in shell detritus gradually and diachronously replace this facies. Therefore, it may belong to either the Kienberg Member or the Liedertswil Member. Although many outcrops show several marly horizons, only the lowermost horizon, which is thicker than about 5 cm is defined as Dünnlenberg Bed (Figs. 10, 11). In northern Switzerland ceratites were only found in the Dünnlenberg Bed and in the overlying marl of the uppermost part of the Kienberg Member (see biostratigraphic discussion). In gamma-logs the Dünnlenberg Bed is characterised by a positive peak (Figs. 10, 11). While the Leutschenberg Member and the Kienberg Member are characterised by decreasing clay content (Figs. 10, 15) the Dünnlenberg Bed often represents the first significant peak. Locally mostly less pronounced peaks may occur further up (e.g. Schafisheim; Fig. 15), which may correspond to the marl- and glauconite-bearing strata overlying the Dünnlenberg Bed.
- Definition
-
(2016) :
Reorganisation of the Triassic stratigraphic nomenclature of northern Switzerland: overview and the new Dinkelberg, Kaiseraugst and Zeglingen formations. Swiss J. Geosci. 109/2, 241-255
The Mergelhorizont (marl bed) III suggested by Merki (1961) as the limit between Oberer Trochitenkalk and Plattenkalk is believed by Pietsch et al. (2016) to be a time marker crossing the heterochronous, petrographically defined boundary between the Kienberg and Liedertswil Members. However, this horizon, often the lowermost in a succession of many thin shale intervals, is an excellent geophysical marker producing a distinct positive gamma-log peak. Recently named the Dünnleberg Bed (Pietsch et al. 2016), the occurrence of this marker is proved throughout Northern Switzerland.