Mainhardt formation

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Lithostratigraphy by the Keuper group in the Germanic Basin
Part of the type profile on the Kümmelsbach near Mainhardt
"Blood stain marl"

The Mainhardt Formation ("Obere Bunte Mergel" in Baden-Württemberg, Unterer Burgsandstein in Bavaria) is a lithostratigraphic formation of the Keuper in the Germanic Triassic . The lithostratigraphic unit is underlain by the Hassberge Formation and overlaid by the Löwenstein Formation .

definition

The lower limit of the Mainhardt Formation is defined with the exposure of the sandstones of the Hassberge Formation, the upper limit with the onset of the sandstones of the Löwenstein Formation. The boundaries are facial and strongly diachronous . The average thickness is about 10 to 15 m. It rises in the Stromberg-Mulde up to 40 m. Here, however, the lying Hassberge formation is very thin with approx. 2 m. It wedges to the basin edges to the Vindelizisches Land between the Hassberge Formation and the Löwenstein Formation . Towards the basin it interlocks with the Weser formation . In southern Baden-Württemberg, the Mainhardt Formation was eroded before the Löwenstein Formation was deposited and is therefore missing erosively. The Mainhardt Formation consists of red and gray clay stones that lead some stone marl banks. The clay stones also contain layers of sulphate tubers. The Mainhardt Formation is dated to the Carnian ( Tuvalian ) of the Upper Triassic . The type profile of the Mainhardt Formation is in the Kümmelsbach near Mainhardt in the Schwäbisch Hall district in Baden-Württemberg . The name is derived from the Mainhardter Forest in northern Baden-Württemberg.

structure

A formal subdivision has not yet taken place, but it might be possible if the stone marl banks were switched on.

Storage room

The dump room was a shallow basin that was periodically flooded and dried up again. There was widespread deposition of gypsum and anhydrite in the form of tubers, which are mostly tied to certain horizons.

Fossils

So far, no fossils have been described from the Mainhardt Formation.

Individual evidence

  1. ↑ Beutler, p. 82

literature

  • Gerhard Beutler: Lithostratigraphy. In: German Stratigraphic Commission (Ed.): Stratigraphie von Deutschland IV - Keuper. Courier Forschungsinstitut Senckenberg, 253: 65-84, Stuttgart 2005 ISSN  0341-4116
  • Gerhard Beutler, Norbert Hauschke and Edgar Nitsch: Facies development of the Keuper in the Germanic Basin. In: Norbert Hauschke & Volker Wilde (Hrsg.): Trias - A whole different world of Central Europe in the early Middle Ages. Pp. 129–174, Verlag Dr. Friedrich Pfeil, Munich 1999 ISBN 3-931516-55-5
  • Edgar Nitsch: The Keuper in the Stratigraphic Table of Germany 2002: Formations and consequences. Newsletters on Stratigraphy, 41 (1-3): 159-171, Stuttgart 2005 ISSN  0078-0421

Web links

  • German Stratigraphic Commission (Ed.): Stratigraphische Tisch von Deutschland 2002 . Potsdam 2002, ISBN 3-00-010197-7 - PDF; 6.57 MB (large) (abbreviated STD2002)