| Missão Velha Formation | |
| Type: | Geological formation |
| Age: | Late Jurassic ~ |
| Period: | Tithonian |
| Prilithology: | Sandstone |
| Region: | Pernambuco, Piauí & Ceará |
| Coordinates: | -7.3°N -39.1°W |
| Paleocoordinates: | -7.1°N -6.5°W |
| Unitof: | Vale do Carirí Group |
| Underlies: | Abaiara Formation |
| Overlies: | Breto Santo Formation |
| Thickness: | 100- |
| Extent: | Araripe Basin |
| Map: | Araripe Basin map - formations and resources.jpg |
The Missão Velha Formation is a late Jurassic 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.
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, as well as a tooth from an abelisaurid theropod.
See main article: Araripe Basin.
The following fossils were reported from the formation:[1]