Corda Formation
| Corda Formation Stratigraphic range: Lower Cretaceous (neoaptian to eoalbian) | |
|---|---|
| Type | Geological formation |
| Lithology | |
| Primary | red sandstone |
| Location | |
| Coordinates | 05º46´S-47º31´W[1] |
| Region | Parnaíba Basin in the State of Tocantins |
| Country | Brasil |
The Corda Formation is a Mesozoic geologic formation. Fossil sauropod tracks have been reported from the formation.[1][2]
Origin
The Corda Formation is characterized by deposits of windy deserts and fast flowing freshwater streams. Therefore fossils are very rare.[1]
Occurrence
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
The Corda Formation consists largely of red sandstone, with very fine to medium grain size, rich in zeolites and iron oxide. Where whinstones 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
- List of dinosaur-bearing rock formations
- Sauropod tracks
References
- ↑ 1.0 1.1 1.2 1.3 1.4 Alves, Y.M. (2010). "Report on the Upper Permian and Lower Cretaceous fossiliferous localities vertebrates-bearing in the centralnorth of Tocantins State, Brazil". Brazilian Geographical Journal: Geosciences and Humanities research medium, Uberlândia 1 (2): 372–386.
- ↑ Weishampel, David B.; Dodson, Peter; Osmólska, Halszka. The Dinosauria (2nd ed.). Berkeley: University of California Press. p. 861. ISBN 0-520-24209-2.