The Wetterstein Formation is a regional geologic formation of the Northern Limestone Alps and Western Carpathians extending from southern Bavaria, Germany in the west, through northern Austria to northern Hungary and western Slovakia in the east. The formation dates back to the Ladinian to Carnian stages of the Late Triassic. The formation is named after the Wetterstein Mountains in southern Germany and northwestern Austria. The center of its distribution is in the Karwendel Mountains. It occurs in the Northern and Southern Limestone Alps and in the Western Carpathians.
The formation is composed of mostly reefal limestones and dolomites, the latter the result of widespread diagenesis. In many areas there is a frequent alternation of limestone and dolomite facies. Local variants to indicate the Wetterstein Formation include (Wetterstein Limestone), Wettersteindolomit ("Wetterstein Dolomite") and combinations thereof. The Wetterstein Formation reaches a maximum thickness of with major regional thickness variations. It forms part of the Austroalpine nappe tectonostratigraphic unit. The carbonate rock of the formation is from the Middle Triassic epoch of the Ladinian stage, comparable to the German stage in which Muschelkalk rock strata were formed.
The formation has provided numerous fossils of corals, sponges, bivalves, gastropods and other marine groups indicative of a shallow marine carbonate platform environment deposited at the northern end of the Tethys Ocean.
Naming
The Wetterstein Formation is named after the Wetterstein Mountains in southern Germany and northwestern Austria.
Alternative names for the whole formation or parts of it in stratigraphical (vertical) or facies (lateral) sense are: Wetterstein Limestone (Wettersteinkalk) Wettersteinkalk FormationWettersteinkalk Formation at Fossilworks.org Wettersteindolomit - used in Semmering and Kalkkögel, AustriaPiller & Erhart, 2004 Wetterstein Limestone FormationCsászár, 1997, p.23Wetterstein Limestone Formation at Fossilworks.org Wetterstein kalk/dolomit - used in the Northern Limestone Alps of Austria Wetterstein reef limestone FormationWetterstein reef limestone Formation at Fossilworks.org
The Swiss stratigraphical lexicon uses Wetterstein Formation as "informal, but used name" with the following historical variants:Wetterstein Formation at Strati.ch Wettersteinkalk (von Guembel 1861, Fraas 1910) Wettersteinkalk = Ladinische Stufe (Cornelius 1935) Wetterstein = Wettersteindolomit = Wettersteinkomplex (Stöcklin 1949) (Fellerer 1964, Kraus 1964) Calcaire de Wetterstein [sic] = Calcaire du Wetterstein = Formation de Wetterstein [sic] (Hirsch 1966) Wettersteindolomit, Wetterstein-Dolomit
Subunits Its subunits include: Messerstich Limestone Schlern Dolomite Marmolata Limestone Steinalm Formation Ramsau Dolomite Formation
Description
The Wetterstein Formation, with a total thickness of up to , is a major regional stratigraphic unit of the Northern Limestone Alps and Western Carpathians in Central Europe, spanning across four countries from southwestern Bavaria to northwestern Slovakia.
Extent
The formation crops out to the north of the Hohe Tauern window and is part of the Austroalpine nappes.
Stratigraphy In the Semmering area of Austria, where the name Wettersteindolomit is used, the formation is unconformably overlain by the Kapellener Shale and overlies the Reifling Formation, in the Kalkkögel and Radstadt Tauern the dolomite overlies the Partnach Formation and is overlain by the Raibl Formation, while in Tyrol the formation, called Wettersteinkalk/dolomit unconformably overlies the Gutenstein and Steinalm Formations and unconformably underlies the Reingraben Formation.
In the Aggtelek-Rudabánya mountains of Hungary, the formation, called Wetterstein Limestone Formation overlies the Reifling and Steinalm Formations and is overlain by the Szádvárborsa Formation.
Regional correlations In Austria the Wetterstein Dolomite correlates with the Alberg Formation of the Linz Dolomites, the Wetterstein kalk/dolomite with the lower part of the Hallstatt Formation of the Northern Limestone Alps and with the Schlern Dolomite, or Schlern Formation, in the Southern Limestone Alps.
In Hungary, the formation is time-equivalent with the Berva Formation of the Bükk, the Bódvavölgyi Ophiolite, Szentjánoshegy and Derenk Formations of the Aggtelek-Rudabánya range and the Csanádapáca Formation of the Békés Zone. In the Dinarides, the formation is time-equivalent with the Grivska Formation of Bosnia. The Kopaonik Formation in its eponymous mountain range in Serbia is considered a distal, more deep water equivalent of the Wetterstein platform sediments.Schefer et al., 2010, p.106
Diagenesis Dolomitization of the Wetterstein Carbonate Platform is a widespread phenomenon, especially in the Tirolic units of the Northern Calcareous Alps. At the Clessinsperre, the type locality for the underlying Steinalm Formation, intense dolomitization has altered the microfacies characteristics of the Wetterstein Carbonate platform – typical are fore-reef carbonates, later reefal and back-reefal carbonates topped by lagoonal carbonates, making the original features hardly visible.Gawlick et al., 2013, p.182
Fossil content Because, during dolomitisation, traces of fossils are largely lost as a result of recrystallisation, fossils in the Wetterstein dolomite are harder to distinguish, and even in thin sections may be barely recognizable. Wetterstein dolomite is rarely as bituminous as typical Main Dolomite and therefore tends to be much more pure and brighter-coloured. Otherwise, there are no fundamental differences with the Wetterstein limestone.
Among others, the following fossils have been described from the Wetterstein Formation: Group Unit Fossils Notes Sponges Wettersteinkalk, Austria Alpinothalamia bavarica, Follicatena cautica, Colospongia catenulata, Cryptocoelia zitteli, Solenolmia magna, Uvanella irregularis, Vesicocaulis alpinus, V. depressus, V. oenipontanus Karwendel reef at Fossilworks.org Wetterstein reef limestone, Hungary Paravesicocaulis concentricus, Senowbaridaryana triassicus, Vesicocaulis multisiphonatus Alshóhegy plateau at Fossilworks.org Brachiopods Wettersteinkalk, Austria Stolzenburgiella baloghi Siblik, 1994, p.370 Corals Gastropods Bivalves
See also Geology of the Alps Schrattenkalk Formation Hauptdolomit Formation List of types of limestone
Ansbachersandstein, contemporaneous ichnofossiliferous formation of Bavaria Benkersandstein, contemporaneous ichnofossiliferous formation of Bavaria Chañares Formation, fossiliferous formation of the Ischigualasto-Villa Unión Basin, Argentina Candelária Formation, contemporaneous fossiliferous formation of the Paraná Basin, Brazil Molteno Formation, contemporaneous fossiliferous formation of Lesotho and South Africa Pebbly Arkose Formation, contemporaneous fossiliferous formation of Botswana, Zambia and Zimbabwe Denmark Hill Insect Bed, contemporaneous fossiliferous unit of Queensland, Australia Madygen Formation, contemporaneous Lagerstätte of Kyrgyzstan
References
Bibliography
Further reading
External links World map at the time of the Early/Lower Triassic Cephalopod coquina beds in the Wetterstein Limestone