Guichón Formation
Guichón Formation Stratigraphic range: Aptian-Santonian ~ | |
---|---|
Type | Geological formation |
Unit of | |
Underlies | Mercedes Formation |
Overlies | |
Thickness | Up to >100 m (330 ft) (in wells) |
Lithology | |
Primary | Sandstone |
Other | Conglomerate |
Location | |
Coordinates | 32°00′S 57°42′W / 32.0°S 57.7°WCoordinates: 32°00′S 57°42′W / 32.0°S 57.7°W |
Approximate paleocoordinates | 38°24′S 30°00′W / 38.4°S 30.0°W |
Region | Paysandú Department |
Country | ![]() |
Extent | Norte Basin |
Type section | |
Named for | Guichón |
![]() ![]() Guichón Formation (Uruguay) |
The Guichón Formation is a Late Cretaceous geologic formation of the in Uruguay. Dinosaur remains are among the fossils that have been recovered from the formation.[1]
Description[]
The Guichón Formation comprises mainly pink-greyish to reddish sandstones, which contain moderate to well-sorted, subrounded, fine to medium-sized grains in a pelitic matrix. These sandstones (which compositionally are feldspathic wackes) are either massive or may instead exhibit parallel lamination, cross-lamination and graded bedding. These lithologies were deposited in southwest-trending alluvial–fluvial systems comprising low-sinuosity channels traversing through sandy plains. Subordinate to the already mentioned sandstones are conglomeratic and pelitic lithologies, interpreted as channel-fill and overbank deposits, respectively. It is inferred that the Guichón Formation was deposited in warm, semi-arid climatic conditions.[2] The formation has been correlated to the Puerto Yeruá Formation of northwestern Argentina.[3]
The formation reaches a thickness of more than 100 metres (330 ft) in wells perforating the formation.[4] It is overlain by the Mercedes Formation and overlies the .[5]
Fossil content[]
The following fossils have been reported from the formation:[2][6]
- Fossil eggs
See also[]
- List of dinosaur-bearing rock formations
- List of fossiliferous stratigraphic units in Uruguay
References[]
Bibliography[]
- Journal of South American Earth Sciences 33. 68–79. ; , and . 2012. First sauropod (Dinosauria: Saurischia) remains from the Guichón Formation, Late Cretaceous of Uruguay.
- Zoological Journal of the Linnean Society 163. S173–S198. , and . 2011. A new specimen of Uruguaysuchus aznarezi (Crocodyliformes: Notosuchia) from the middle Cretaceous of Uruguay and its phylogenetic relationships.
- Estudio composicional de sedimentitas silicoclásticas y paleosuelos de la Formación Mercedes (Cretácico Superior), Uruguay. Revista de la Asociación Geológica Argentina 68. 615–626. Accessed 2020-08-23. ; , and . 2011.
- Nuevos hallazgos de restos de dinosaurios y consideraciones sobre la edad de la Formación Guichón - New findings of dinosaur remains and considerations on the age of the Guichón Formation. Revista Sociedad Uruguaya de Geología 15. 11–23. Accessed 2018-09-07. ; ; ; ; , and . 2009.
- The Dinosauria, 2nd edition, 1–880. Berkeley: University of California Press. Accessed 2019-02-21. ISBN 0-520-24209-2 ; , and . 2004.
- . 1972. Lista de los vertebrados fósiles del Uruguay, I. Chondrichthyes, Osteichthyes, Reptilia, Aves - List of the fossil vertebrates of Uruguay, I. Chondrichthyes, Osteichthyes, Reptilia, Aves. 1. 23–35.
- . 1934. Neue Saurier-Zähne aus der Kreide von Uruguay - New saurian teeth from the Cretaceous of Uruguay. 1934. 183–189.
- Geologic formations of Uruguay
- Cretaceous System of South America
- Cretaceous Uruguay
- Albian Stage
- Aptian Stage
- Cenomanian Stage
- Santonian Stage
- Turonian Stage
- Sandstone formations
- Conglomerate formations
- Fluvial deposits
- Ooliferous formations
- Paraná Basin
- Fossiliferous stratigraphic units of South America
- Paleontology in Uruguay
- Geography of Paysandú Department