The Corda Formation is a red sandstone geologic formation in the Parnaíba Basin in Tocantins, Brazil. It was formed during the Neoaptian to Eoalbian series of the Early Cretaceous.
| Corda Formation | |
|---|---|
| Stratigraphic range: Late Aptian-Early Albian ~ | |
| Type | Geological formation |
| Underlies | Sardinha Formation |
| Overlies | Itapecuru Formation |
| Lithology | |
| Primary | Red sandstone |
| Location | |
| Coordinates | 5°42′S 47°30′W / 5.7°S 47.5°W |
| Approximate paleocoordinates | 5°06′S 14°48′W / 5.1°S 14.8°W |
| Region | Tocantins |
| Country |  Brazil |
| Extent | Parnaíba Basin |
| Type section | |
| Named for | Corda River |
  Corda Formation (Brazil) | |
Large-scale fossil sauropod tracks have been reported from the formation.[1][2][3][4]
Origin edit
The Corda Formation is characterized by reddish sandstones, that were probably deposited in windy deserts and fast flowing freshwater streams. Therefore, fossils are very rare.[1]
Occurrence edit
This formation outcrops in the central part of the Parnaíba Basin, between the mouth of the Araguaia River in the west the Parnaíba River in the east.[1]
Lithology edit
The Corda Formation consists largely of red sandstone, with very fine to medium grain size, rich in zeolites and iron oxide. Where whinstones[clarification needed] are overlaying fragments of this rock are also present. Typical structures of wind dunes (cross bedding, ripples, and grain flow) are common. This is consistent with deposition in a desert system.[1]
See also edit
- List of dinosaur-bearing rock formations
- Sauropod tracks
- Romualdo Formation, contemporaneous fossiliferous formation of the Araripe Basin
- Itapecuru Formation, contemporaneous fossiliferous formation of the São Luis and Parnaíba Basins
References edit
Bibliography edit
- Alves, Y.M. 2010. Report on the Upper Permian and Lower Cretaceous fossiliferous localities vertebrates-bearing in the central north of Tocantins State, Brazil. Brazilian Geographical Journal: Geosciences and Humanities research medium, Uberlândia 1(2). 372–386. Accessed 2019-02-16.
- Leonardi, Giuseppe. 1994. Annotated Atlas of South America Tetrapod Footprints (Devonian to Holocene) with an appendix on Mexico and Central America, 1–248. Ministerio de Minas e Energia - Companhia de Pesquisa de Recursos Minerais, Geological Service of Brazil. Accessed 2019-03-25.
- Weishampel, David B.; Peter Dodson, and Halszka Osmólska (eds.). 2004. The Dinosauria, 2nd edition, 1–880. Berkeley: University of California Press. Accessed 2019-02-21. ISBN 0-520-24209-2