• Source: Saubach Formation

The Saubach Formation is a geological formation in Austria and Germany, dating to about 180–174 million years ago. It was described originally as Saubachschichten in 1975, and classified as part of the Lower Jurassic Adnet Group.




Description


This formation is part of a near-shore to epicontinental marine-influenced deposits, coeval in age with the Sachrang Formation, that was more likely a linked pelagic deposit. After the drowning of the local Rhaetian reef slope and in the adjacent basin, Sinemurian–Toarcian local members were formed as a sequence of increasingly near pelagic sedimentation during the middle and late Liassic. The Coeval on the lowermost part Scheck Member has evidence of a series of large scale tectonic activities culminating during the late Pliensbachian and early Toarcian, probably linked to the Vulcanism of the adjacent Irkut Basin. In contrast to the "Adneter Mergel", the Saubach Formation lacks grey marls. In the type area, located at the Saubachgraben near Hintersee (largely destroyed and buried) consists of predominantly red sequences. In some locations, such as Gaissau, the Saubach Formation is dominated by red condensed limestones with only minor marl intercalations. In 1997 the name Saubach Formation was suggested, representing originally a series of Green Bituminous Marls on the Unken Sincline, identical to the strata of the Saubach Member of the Adnet Group. Later it was shown that the Saubach Member and the Saubach formation belong to a unique entity, that can be called by both names, and represent a series of marls deposited on marginal marine to Pelagic environments, linked with the Red Marl of the Sachrang Formation.




Fossil content


On Scheibelberg appears with a relatively sharp boundary of just banked and slightly bulbous, greenish gray, rarely also slightly reddish Marl overlaid with Limestone and marl. This sequence was interpreted as the main outcrop of the Saubach formation. Switched along these strata in the Saubach Formation are up to 5 m thick bitumen Marbles. There are fossils of Belemnnites, Ammonites and Echinoderms, where Ostracodans and Foraminifera are only to be found very isolated. A group of Bioclastic wackestone is present, and consists of a micro-matrix with plenty of thin shell remains scattered loosely. Furthermore, are Echinoderm remains, Ostracodes, foraminifera, radiolaria and represented spiculae. Authentic Pyrite is found in patches to observe. There is an alternate deposition composed mostly by bioclastic wackestone with Echinoderm remains, and other with Mudstone, with abundant echinoderms, foraminifera, Gastropods, echinid spines and pebble spicules. A series of greenish-gray marl Lime facies is rich in Ammonites, including the species Collina cf. gemma, linking the deposit to the Lower Toarcian. The Biota recovered on the Type strata of the formation suggest that the Saubach Formation was deposited with influence of deeper waters.




= Sporomorphs

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Several plant leaves and fragments of wood weren't identified.




= Gastropoda

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= Cephalopoda

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= Crustacea

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= Ophiuroidea

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= Crinoidea

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= Holothuroidea

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See also


List of fossiliferous stratigraphic units in Austria
Toarcian turnover
Toarcian formations




References

Kata Kunci Pencarian:

• Saubach Formation
• Marne di Monte Serrone
• Whiteaves Formation
• Krempachy Marl Formation
• Lava Formation
• Ciechocinek Formation
• Röddinge Formation
• Rya Formation
• Djupadal Formation
• Erfurt–Leipzig/Halle high-speed railway