Missão Velha Formation
The Missão Velha Formation is an early Aptian geologic formation in northeastern Brazil's Araripe Basin where the states of Pernambuco, Piauí and Ceará come together. The formation is the middle stratigraphic unit of the Vale do Carirí Group, overlying the Brejo Santo Formation and overlain by the Abaiara Formation.
| Missão Velha Formation Stratigraphic range: Early Aptian ~120–118 Ma | |
|---|---|
| Type | Geological formation |
| Unit of | Vale do Carirí Group |
| Underlies | Abaiara Formation |
| Overlies | Breto Santo Formation |
| Thickness | 2–10 m (6.6–32.8 ft) |
| Lithology | |
| Primary | Sandstone |
| Location | |
| Coordinates | 7.3°S 39.1°W |
| Approximate paleocoordinates | 7.1°S 6.5°W |
| Region | Pernambuco, Piauí & Ceará |
| Country |  Brazil |
| Extent | Araripe Basin |
 Map of the Araripe Basin with the Missão Velha Formation in green | |
The formation comprises whitish fine-to-medium quartzose arenites, with subrounded to rounded grains, deposited in an alluvial fan environment during the syn-rift phase of the Araripe Basin.
The Missão Velha Formation has provided macrofossils of various genera of fish and reptiles as snakes, crocodylomorphs and turtles. Ichnofossils of dinosaurs were also discovered in the formation.
Geology
Fossil content
The following fossils were reported from the formation:[1]
- Fish
- Parvodus rugianus[2]
- Planohybodus peterboroughensis[2]
- Mawsonia cf. gigas[2]
- Acrodus sp.[2]
- Hybodus sp.[2]
- Lepidotes sp.[2]
- Neoceratodus sp.[2]
- Polyacrodus sp.[2]
- Vinctifer sp.[2]
- Lonchidiidae indet.[2]
- Reptiles
- Amphibians
- Ichnofossils
See also
References
- Missão Velha Formation at Fossilworks.org
- Brito et al., 1994
- Carvalho et al., 1995
Bibliography
- Geology
- Assine, Mario L. 1992. Análise estratigráfica da Bacia do Araripe, Nordeste do Brasil. Revista Brasileira de Geociências 22. 289–300. Accessed 2018-08-21.
- Bétard, François; Jean-Pierre Peulvast; Alexsandra de Oliveira Magalhães; Maria de Lourdes Carvalho Neta, and Francisco Idalecio de Freitas. 2017. Araripe Basin: A Major Geodiversity Hotspot in Brazil. Geoheritage _. 1–18. Accessed 2018-08-21.
- Scherer, C.M.d.S.; E.F. Jardim de Sá; V.C. Córdoba; D.d.C. Sousa; M.M. Aquino, and F.M.C. Cardoso. 2013. Tectono-Stratigraphic evolution of the upper Jurassic-Neocomian rift succession, Araripe Basin, Northeast Brazil. Journal of South American Geosciences _. 1–43. Accessed 2018-08-21.
- Paleontology
- Carvalho, I. d. S.; M. S. S. Viana, and M. F. L. Filho. 1995. Os icnofósseis de dinossauros da Bacia do Araripe (Crétaceo Inferior, Ceará-Brasil) - Dinosaur ichnofossils from the Araripe Basin (Lower Cretaceous, Ceará, Brazil). Anais da Academia Brasileira de Ciências 67. 433-442.
- Brito, P.M.; R.J. Bertini; D.M. Martill, and L.O. Salles. 1994. Vertebrate fauna from the Missão Velha Formation (Lower Cretaceous, N.E. Brazil), 139-140. Boletim do 3° sobre o Cretáceo do Brasil, Campus de Rio Claro/SP, UNESP.