Reichenhall formation

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Bizarre rock figures of the Reichenhall formation in the Tyrolean Hall valley

The Reichenhall Formation , formerly mostly Reichenhaller layers or Reichenhaller Kalke , is a lithostratigraphic formation of the lower and middle Triassic of the Eastern Alpine nappes of the Northern Limestone Alps . The formation, which is characterized by evaporites , represents the basal formation of the Eastern Alpine Triassic, which is predominantly dominated by carbonates.

history

The Reichenhall layers were first described by Carl Wilhelm von Gümbel in 1861. Johann August Edmund Mojsisovics von Mojsvár first used the term Reichenhaller Kalk in 1868.

Gypsum-containing breccia of the Reichenhall Formation

Definition and distribution area

The Reichenhall Formation comprises low-fossil carbonates, partly dark bituminous dolomites , which also contain gypsum and anhydrite . Some of the rocks are formed as Rauwacken , in addition there are also breccias . There are also layers with siciliclastic sediments such as sandstone and mixed rocks such as sandy dolomites. In the Northern Limestone Alps, the Reichenhall Formation is predominantly underlain by the Werfen layers , in the Lienz Dolomites by the Alpine Buntsandstein , in the Semmering region , in the Radstädter Tauern and in the Kalkkögeln by the Alpine Red Slate . At the top it goes over into the Gutenstein Formation and the Virgloria Formation . The boundary to the Gutenstein Formation is assumed to be in the area of ​​the snail Natiria stanensis. The formation is most developed in the Tyrolean Limestone Alps, in the Mieminger Mountains it is up to 220 meters thick, in the Karwendel up to 480 meters, but this could also be tectonic. Towards the east it largely recedes.

Subformations

The Drossa layers are a facial variant in the lying area of ​​the Reichenhall Formation. They occur in the Engadine Dolomites and extend into the Rätikon and Arlberg regions . They are characterized by an alternation between carbonate layers and sandy to silty layers in facies of the alpine red sandstone.

In the eastern part of the Northern Limestone Alps, a series of slate, dark limestone and rough-wake of the Reichenhall Formation has also been referred to as the Gutensteiner base layers .

Timeframe

The formation is placed in the Olenekium and Anisium . Precise dating is difficult due to the lack of key fossils, and the lower and upper limits are likely to be diachronic, i.e. the formation did not form exactly at the same time everywhere.

Individual evidence

  1. ↑ Hamid Chamanara: Geology, Stratigraphy (Reichenhall and Gutenstein Formation) and Tectonics in the Stanser Joch area , diploma thesis of the University of Innsbruck, 1994, p. 3.
  2. ↑ Alexander Tollmann : Analysis of the classical North Alpine Mesozoic. Stratigraphy, fauna and facies of the Northern Limestone Alps . Part II of the monograph of the Northern Limestone Alps, Verlag Deuticke, Vienna 1976, ISBN 3-7005-4412-X , p. 66ff.
  3. ↑ Christoph Spötl: Evaporitic facies of the Reichenhaller Formation (Skythl Anise) in the Haller Salzberg (Northern Limestone Alps, Tyrol), JB Geol. BA., Vol. 137, Vienna 1988, S153-168 PDF file , accessed on July 4, 2009.
  4. ↑ W. Schlager, W. Schöllnberger: The principle of stratigraphic turns in the layer sequence of the Northern Limestone Alps , communications from the Geological Society in Vienna 66.-67., 1973/74, pp. 168f. PDF file , accessed on July 4, 2009.
  5. ↑ Hamid Chamanara: Geology, Stratigraphy (Reichenhall and Gutenstein Formation) and tectonics in the Stanser Joch area , diploma thesis of the University of Innsbruck, 1994, p. 115.
  6. ↑ Alexander Tollmann: Analysis of the classical North Alpine Mesozoic. Stratigraphy, fauna and facies of the Northern Limestone Alps . Part II of the monograph of the Northern Limestone Alps, Verlag Deuticke, Vienna 1976, ISBN 3-7005-4412-X , p. 67.
  7. ↑ Alexander Tollmann: Analysis of the classical North Alpine Mesozoic. Stratigraphy, fauna and facies of the Northern Limestone Alps . Part II of the monograph of the Northern Limestone Alps, Verlag Deuticke, Vienna 1976, ISBN 3-7005-4412-X , p. 70.
  8. ↑ Alexander Tollmann: Analysis of the classical North Alpine Mesozoic. Stratigraphy, fauna and facies of the Northern Limestone Alps . Part II of the monograph of the Northern Limestone Alps, Verlag Deuticke, Vienna 1976, ISBN 3-7005-4412-X , p. 70.
  9. ↑ : W. Schlager, W. Schöllenberger The principle stratigraphic turning in the layer sequence of the Northern Limestone Alps . The Geological Society in Vienna 66.-67, 1973/74: 169. Releases PDF file accessed, 4 July 2009 .

Web links

Commons : Reichenhall Formation  - collection of images, videos and audio files