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 PreꞒ Ꞓ O S D C P T J K Pg N ↓
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 / -7.3; -39.1
Approximate paleocoordinates	7.1°S 6.5°W / -7.1; -6.5
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

late Early Cretaceous (105 Ma)

Main article: Araripe Basin

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
  • Turtles
    • Pelomedusidae indet.[2]
  • Dinosaurs
    • Sauropoda indet.[2]
    • Theropoda indet.[2]
  • Loricata
    • Mesosuchia indet.[2]
  • Snakes
    • Lacertilia indet.[2]
• Amphibians
  • ?Amphibia indet.[2]
• Ichnofossils
  • Carnosauria indet.[3]
  • Ornithopoda indet.[3]
  • Dinosauria indet.[3]

See also

• Crato Formation
• Romualdo Formation

References

1. Missão Velha Formation at Fossilworks.org
2. Brito et al., 1994
3. 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.