Upper Muschelkalk
The Upper Muschelkalk is a lithostratigraphic subgroup of the Muschelkalk of the Germanic Triassic . The lithostratigraphic unit is underlain by the Middle Muschelkalk subgroup and overlaid by the Keuper . The deposits of the Upper Muschelkalk document fully marine conditions and connections to the Tethys Ocean . Limestone-rich sandstones were sedimented in the eastern edge areas.
definition
The lower limit of the superior shell limestone is by inserting the Trochitenkalk - Formation defined. The upper limit is the onset of the Erfurt formation , the lower limit of which is defined by the bonebed . The lower limit of the Upper Muschelkalk is biostratigraphically placed in the Upper Anisium , the upper limit lies in the lower Ladinium . Due to the endemic fauna in the area of the Germanic Triassic , a precise biostratigraphic correlation with the Alpine Triassic is difficult. Finds of individual ammonites from the Tethys region indicate a location of the lower limit of the Ladinium above the Spinosus Zone, which in southern Germany lies within the Meißner Formation . The lower limit of the Ladinium is currently drawn at 242 million years.
structure
The Upper Muschelkalk in Germany is divided into nine lithostratigraphic formations . However, the nine formations are usually not on top of each other, but represent each other regionally:
- Trochitic Limestone Formation ,
- Meissner formation ,
- Warburg formation ,
- Rectangular limestone formation ,
- Rottweil formation
- Schengen formation
- Irrel formation
- Gilsdorf formation
- Grafenwoehr formation , pebbly, feldspar-rich or carbonate quartz sandstones on the eastern edge of the basin. It stretches from the Middle Muschelkalk to the Lower Keuper.
Storage room
The rocks of the Upper Muschelkalk contain a fauna rich in species and individuals, which indicate fully marine conditions. Only the Rottweil formation, which is formed at the top of the Upper Muschelkalk and only at the southern edge of the basin, contains algae laminites and faunas, which again indicate euryhaline conditions, i.e. This means that the faunas were very tolerant of fluctuations in salinity. Irrel and Gilsdorf formations denote rocks of the western edge of the basin. The Schengen Formation and Quaderkalk Formation are rocks of the Siercker Schwelle (Saarland) and a threshold in Franconia.
literature
- Manfred Menning, Reinhard Gast, Hans Hagdorn, Karl-Christian Käding, Theo Simon, Michael Szurlies and Edgar Nitsch: Time scale for Permian and Triassic in the Stratigraphic Table of Germany 2002, cyclostratigraphic calibration of the higher Dyas and Germanic Trias and the age of the Roadium stages to Rhaetium 2005. Newsletters on Stratigraphy, 41 (1-3): 173-210, Stuttgart 2005 ISSN 0078-0421
- Hans Hagdorn and Theo Simon: The Muschelkalk in the Stratigraphic Table of Germany 2002. Newsletters on Stratigraphy, 41 (1-3): 129-142, Stuttgart 2005 ISSN 0078-0421
- Norbert Hauschke & Volker Wilde (eds.): Trias A whole different world from Central Europe in the early Middle Ages. 647 pp., Verlag Dr. Friedrich Pfeil, Munich 1999 ISBN 3-931516-55-5
Individual evidence
- ^ Heinz W. Kozur: The correlation of the Germanic Buntsandstein and Muschelkalk with the Tethyan scale . In: Central Journal of Geology and Paleontology, Part I . Year 1998, issue 7/8. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart 1999, p. 701-725 .
- ↑ Peter Brack, Hans Rieber, Max Urlichs: Pelagic succesions in the Southern Alps and their correlation with the Germanic Middle Triassic . In: Central Journal of Geology and Paleontology, Part I . Year 1998, issue 7/8. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart 1999, p. 853-876 .
- ↑ International Chronostratigraphic Chart v2017 / 02. Retrieved October 1, 2017 .
- ↑ James G. Ogg, Gabi M. Ogg, Felix M. Gradstein: A Concise Geologic Time Scale . A Concise Geologic Time Scale, 2016, doi : 10.1016 / B978-0-444-59467-9.01001-3 .