Steigerwald formation

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Lithostratigraphy by the Keuper group in the Germanic Basin
Teaching mountain layers with red and gray clay marls and stone marl banks

The Steigerwald Formation (formerly also Lehrberg layers in Bavaria, Untere Bunte Margel in Baden-Württemberg) is a lithostratigraphic formation of the Keuper in the Germanic Triassic . The lithostratigraphic unit is underlain by the Stuttgart Formation and overlaid by the Hassberge Formation . Towards the basin, the Steigerwald Formation meshes with the Weser Formation .

definition

The lower limit of the Steigerwald Formation is drawn when the sandy layers of the Stuttgart Formation are exposed. The upper limit is defined by the reinstallation of the sandstones of the Hassberge Formation . The Steigerwald formation mainly comprises red-brown, also greenish-gray, massive claystones with sulphate layers, dolomite layers and thin individual sandstone layers. The thickness is on average about 20 to 25 m, the formation wedges out towards the basin edges towards the Vindelician Land . The Steigerwald Formation is dated to the Carnian ( Julium to Tuvalium ). The type locality of the Steigerwald formation is the brickworks mine Neustadt / Aisch ; the type region is the Steigerwald .

structure

No further subdivision has been made so far; According to the lithological classification, a subdivision into a Rote Wand and a Lehrberg subformation would be appropriate.

Storage room

The sediments of the Steigerwald Formation were deposited in a wide plain that was occasionally flooded and dried up again. Sulphate layers were deposited in the remaining basins. With their fauna, the dolomite layers indicate phases in which the area was covered by fresh water for a long time.

Fossils

The green-gray and red-brown clay stones are fossilized. Only the dolomite layers contain z. T. a rich fauna of snails (Gastropoda), freshwater mussels ( Unionida ), ostracods (Ostracoda) and bones of vertebrates.

Individual evidence

  1. ↑ Beutler, p. 81.

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)