Cordobés Formation
The Cordobés Formation is an Early Devonian (Pragian to Emsian) geologic formation of the Durazno Group in the Paraná Basin in the Durazno Department of central Uruguay. The shallow marine shales preserve trilobite, bivalve, gastropod and brachiopod fossils.[1][2]
| Cordobés Formation Stratigraphic range: Pragian-Emsian ~409–392 Ma | |
|---|---|
| Type | Geological formation |
| Unit of | Durazno Group |
| Underlies | La Paloma Formation |
| Overlies | Cerrezuelo Formation |
| Thickness | 92 m (302 ft) |
| Lithology | |
| Primary | Shale |
| Other | Fine sandstone |
| Location | |
| Coordinates | 33.0°S 55.0°W |
| Approximate paleocoordinates | 68.5°S 136.2°W |
| Region | Durazno Department |
| Country |  Uruguay |
| Extent | Norte Basin |
| Type section | |
| Named for | Arroyo Cordobés |
| Named by | Bossi |
| Year defined | 1966 |
  Cordobés Formation (Uruguay) | |
Description
The Cordobés Formation is characterized by reddish fine shale deposited in a shallow marine environment.
Fossil content
The following fossils have been reported from the formation:[1][3]
- Trilobites
- Acaste sp.
- Burmeisteria sp.
- Metacryphaeus sp.
- ?Calmonia sp.
- ?Paracalmonia sp.
- ?Pennaia sp.
- Lophophorata
- Strophomenata
- Australostrophia sp.
- Notiochonetes sp.
- Schuchertella sp.
- Rhynchonellata
- Derbyina sp.
- Australospirifer sp.
- Australocoelia sp.
- Lingulata
- Orbiculoidea sp.
- "Lingula" sp.
- Styliolina sp.
- "Serpulites" sp.
- Bivalves
- Modiolus sp.
- Modiomorpha sp.
- Goniophora sp.
- Pleurodapis sp.
- Nuculites sp.
- "Nuculana" sp.
- Gastropods
- Encrinaster sp.
- Plectonotus sp.
References
- Emsian Loc. 1 of Melo: Uraguayan outcrop belt at Fossilworks.org
- Daners et al., 2017
- Melo, 1988
Bibliography
- Daners, Gloria; Alain Le Hérissé; Pierre Breuer, and Gerardo Veroslavsky. 2017. Pragian–Emsian palynomorphs from the Cordobés Formation, Norte Basin, Uruguay: stratigraphically restricted and regionally correlative palynological events in the cool-water Malvinokaffric Realm. Palynology 41. 121–137. doi:10.1080/01916122.2017.1366115 ISSN 0191-6122
- Melo, J. H. G. 1988. The Malvinokaffric realm in the Devonian of Brazil. N. J. McMillan, A. F. Embry, and D. J. Glass, eds. Devonian of the World, Volume I, 669–703. Canadian Society of Petroleum Geologists. Calgary, Alberta, Canada.
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