The Corona Formation is a geologic formation of the Carnian Alps at the border of Austria and Italy. It preserves fossils dated to the Gzhelian stage of the Late Carboniferous period.Corona Formation at Fossilworks.org
The thick formation comprises deposited in a deltaic environment. The Corona Formation has provided fossils of fish, brachiopods, a bryozoan, an insect, fossil flora including trunks and ichnofossils ascribed to Limnopus. The tracks from the Corona Formation include the oldest record of tetrapod tracks from the Southern Alps. The rugose coral Amplexus coronae was named after the formation.
Description The Corona Formation was defined as a formation by Venturini in 1990.Ronchi et al., 2012, p.305 It is the lowermost Gzhelian unit in the late Pennsylvanian Pramollo Group, overlying the Kasimovian Pizzul Formation and overlain by the Auernig Formation in the Carnian Alpine border region of Austria and Italy. The mountains Monte Auernig, Monte Carnizza and the eponymous Monte Corona are composed of the formation. The formation is a thick succession, characterized by alternating quartz conglomerates, sandstones and mudstones. The conglomerates are coarse infillings of distributary channels in a deltaic environment.Marchetti et al., 2020, p.35 The formation is characterized by cyclothems (parasequences) of thick.Vai & Venturi, 1997, p.179
Fossil content The Corona Formation has provided fossils of: Fish Petalodontiformes Petalodontidae Petalodus ohioensisDalla Vecchia, 1988, p.54 Insects Palaeodictyoptera Dictyoneuridae Arltia carnicaBrauckmann & Hahn, 1983, p.246 Rugose corals Zaphrentis omaliusiHubmann et al., 2003, p.67 Lopholasma carbonaria Amplexus coronae Strophomenata Productida Rugosochonetidae Capillomesolobus pontebbanusPecar, 1986 Paramesolobus sp. Bryozoa Rhombocladia delicataErnst, 2005, p.70 Foraminifera Badyina lucidaVachard & Krainer, 2001, p.186 Hemidiscus sp.Vachard & Krainer, 2001, p.188 Ichnofossils LimnopusMarchetti et al., 2020, p.37
The tracks of Limnopus from the Corona Formation represent the oldest record of tetrapod tracks from the Southern Alps.
Flora The formation has also provided abundant, well-preserved and diverse plant assemblages in coal-rich levels of up to in the fine sandstones and shaly levels of the Corona Formation. Therein, sphenophyte trunks with a diameter of up to are preserved in situ.Kustatscher et al., 2018, p.38 The genus Lebachia, typically known from the Permian, is not found in other Carboniferous strata in the Alps.Ronchi et al., 2012, p.308 The flora is of importance as one of the earliest examples of rebound after the Carboniferous rainforest collapse.
Acitheca polymorphaRonchi et al., 2012, p.309 Annularia carinataKustatscher et al., 2018, p.39 Anthracoporella sp.Samankassou, 2003, p.205 Calamites carinatusKustatscher et al., 2018, p.40 Lepidodendron cf. subdichotum Linopteris neuropteroidesKustatscher et al., 2018, p.44 Neuropteris cordata Paripteris cf. linguaefolia Pseudomariopteris busquetii Alethopteris sp. Pecopteris sp. Polymorphopteris sp.
See also
List of fossiliferous stratigraphic units in Austria List of fossiliferous stratigraphic units in Italy Bajo de Véliz Formation, contemporaneous fossil flora-bearing formation of Argentina Ganigobis Formation, contemporaneous fossil fish-bearing formation of Namibia
References
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