Cordobés Formation Explained

Cordobés Formation
Type:	Geological formation
Period:	Emsian
Age:	Pragian-Emsian ~
Prilithology:	Shale
Otherlithology:	Fine sandstone
Namedfor:	Arroyo Cordobés
Namedby:	Bossi
Year Ts:	1966
Region:	Durazno Department
Coordinates:	-33°N -55°W
Paleocoordinates:	-68.5°N -136.2°W
Unitof:	Durazno Group
Underlies:	La Paloma Formation
Overlies:	Cerrezuelo Formation
Thickness:	92m (302feet)
Extent:	Norte Basin

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]}

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
  • Tentaculites sp.
• 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.

See also

• List of fossiliferous stratigraphic units in Uruguay

References

Bibliography

Notes and References

1. http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=37078 Emsian Loc. 1 of Melo: Uraguayan outcrop belt
2. Daners et al., 2017
3. Melo, 1988