Seefeld formation
The Seefeld Formation , also called Seefeld Strata , is a lithostratigraphic formation of the Upper Triassic in the Northern Limestone Alps and in the Eastern Alpine nappes of the Southern Limestone Alps . The type locality is near Seefeld in Tirol .
history
The term Seefeld layers goes back to Carl Wilhelm von Gümbel .
Definition and distribution area
The Seefeld formation has in isolated pools and recesses of the main dolomite - lagoon formed where hydrogen sulphide-containing water fauna die near the ground leaving. The basin formation is due to tectonic subsidence and the associated formation of half-trenches . In this respect, the Seefeld Formation is limited to local occurrences at certain levels within the main dolomite. The formation is partially overlaid by plate limestone, which represents the upper main dolomite. There are no occurrences of the formation west of the Lechtal Alps. Their main distribution area is between the Lechtal Alps and the Kaiser Mountains . There are also smaller deposits further east, for example in the Wiestal near Hallein or on the Ölberg near Alland near Vienna . The formation also occurs in the Drauzug . The bitumen content is between five and 45 percent. In terms of time, the Seefeld formation is dated to the norium, and to the type locality more precisely to the alum .
In order to classify the Seefeld formation, the suggestion was made to view the main dolomite as a group . According to this proposal, this group includes the lower main dolomite (Schloßbach formation), middle main dolomite (clearing formation), Seefeld layers (Seefeld formation) and upper main dolomite (Dachstein dolomite) in the Seefeld area .
Breakdown
In the Seefeld formation, a distinction can be made between a basin rim facies and a basin facies. The pool edge facies are characterized by carbonate and have a lower kerogen and bitumen content. The basin rim facies reach a thickness of 120 to 410 meters. The basin facies, which are up to 560 meters thick in the Seefeld area, consist of rocks rich in kerogen and bitumen, some with very fine stratification. Another characteristic of the pelvic facies are slide folds and slide breccia caused by gravity.
Fossil guidance and mining
The rocks of the Seefeld Formation were mined from around 1350 to 1964 near Seefeld. Petroleum , asphalt and, later, ichthyol were extracted from the rocks . The most important mining area was west of the Reither Spitze in the area of the Reither Jochalm . The name Ichthyol is derived from the ancient Greek word for fish ἰχθύς and comes from numerous finds of fossil fish, in particular the genus Pholidophorus occurs in the Seefeld formation , which looked similar to today's herrings , as well as the genera Paralepidotus , Semionotus and Saurichthys . Numerous plant remains , mainly from conifers , were also found. Conodonts are also important for the biostratigraphic classification . In 2013, the first Langobardisaurus outside of Italy was discovered above Seefeld .
Individual evidence
- ↑ 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 , page 198.
- ↑ Donato A. Donofrio, Rainer Brandner , Werner Poleschinski: Conodonts of the Seefeld formation. A contribution to the bio- and lithostratigraphy of the main dolomite platform (Upper Triassic, western Northern Limestone Alps, Tyrol) , Geol. Paläont. Mitt. Innsbruck 2003, Volume 26, pp. 91-107. PDF file
- ↑ Werner Poleschinski: Stratigraphy, facies and sedimentology of the Seefeld strata in the Seefeld / Tyrol area. A potential petroleum mother rock from the upper-north of the Northern Limestone Alps, dissertation, Innsbruck 1989, page 27.
- ↑ 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 , page 198ff.
- ↑ Donato A. Donofrio , Rainer Brandner , Werner Poleschinski: Conodonts of the Seefeld formation. A contribution to the bio- and lithostratigraphy of the main dolomite platform (Upper Triassic, western Northern Limestone Alps, Tyrol) , Geol. Paläont. Mitt. Innsbruck 2003, Volume 26, pp. 91-107. PDF file
- ↑ Werner Poleschinski: Stratigraphy, facies and sedimentology of the Seefeld strata in the Seefeld / Tyrol area. A potential petroleum mother rock from the Upper-North of the Northern Limestone Alps, dissertation, Innsbruck 1989, page 1ff.
- ↑ Ludwig Hörmann : Steinölträger und Steinölbrenner , in: Der Alpenfreund, monthly books for the dissemination of alpine knowledge among young and old in popular descriptions from the entire area of the alpine world and with practical waving for enjoyable trips to the same. HG Dr. Ed. Amthor, Volume 4, Gera 1872, p. 321ff. (online at haben.at)
- ↑ 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 , page 199.
- ↑ Werner Poleschinski: Stratigraphy, facies and sedimentology of the Seefeld strata in the Seefeld / Tyrol area. A potential petroleum mother rock from the upper-north of the Northern Limestone Alps, dissertation, Innsbruck 1989, pages 3, 102ff., 162.
- ↑ Sensational dinosaur discovery in Tyrol , in: Kurier , April 19, 2013, accessed on May 9, 2013.
- ↑ Saller, Franco; Renesto, Silvio; Dalla Vecchia, Fabio M .: First record of Langobardisaurus (Diapsida, Protorosauria) from the Norian (Late Triassic) of Austria, and a revision of the genus , Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen, Volume 268, Number 1, April 2013 , pp. 83-95 (13), DOI: 10.1127 / 0077-7749 / 2013/0319
Web links
Stratigraphic table of Austria 2004 (PDF; 381 kB)