The Açu Formation is an Early Cretaceous (Albian) geologic formation of the Potiguar Basin in Ceará, northeastern Brazil. The formation comprises coarse-grained sandstones deposited in a fluvio-deltaic environment. The Açu Formation, belonging to the Apodi Group, has provided fossils of an indeterminate rebbachisaurid.
| Açu Formation | |
|---|---|
| Stratigraphic range: Albian ~ | |
| Type | Geological formation |
| Unit of | Apodi Group |
| Underlies | Jandaíra Formation |
| Overlies | Alagamar Formation |
| Lithology | |
| Primary | Sandstone |
| Location | |
| Coordinates | 5°48′S 38°06′W / 5.8°S 38.1°W |
| Approximate paleocoordinates | 11°54′S 10°54′W / 11.9°S 10.9°W |
| Region | Ceará |
| Country |  Brazil |
| Extent | Potiguar Basin |
  Açu Formation (Brazil) | |
Description edit
The Açu Formation was deposited in a passive margin setting, overlying the Alagamar Formation and is overlain by the Jandaíra Formation. In the petroleum producing Potiguar Basin, the formation is a reservoir rock.[1]
Fossil content edit
The following fossils were reported from the formation:[2]
- Reptiles
- Dinosaurs
- Carcharodontosauria indet.
- Maniraptora indet.
- Megaraptora indet.
- Rebbachisauridae indet.[3]
- Spinosauridae indet.
- Dinosaurs
See also edit
References edit
- ^ Maraschin et al., 2010, p.87
- ^ Açu Formation at Fossilworks.org
- ^ Gomes da Costa Pereira et al., 2020
Bibliography edit
- Gomes da Costa Pereira, Paulo Victor; Theo Baptista Ribeiro; Stephen Louis Brusatte; Carlos Roberto Dos Anjos Candeiro; Thiago da Silva Marinho, and Lilian Paglarelli Bergqvist. 2020. Theropod (Dinosauria) diversity from the Potiguar basin (Early-late Cretaceous Albian – Cenomanian), Northeast Brazil. Cretaceous Research in press. Article 104517. . doi:10.1016/j.cretres.2020.104517
- Maraschin, Anderson; Ana Maria P. Mizusaki; P.M. Vasconcelos, and Ruth Hinrichs. 2010. Depositional age definition of the Açu Formation (Potiguar Basin, northeastern Brazil) through 40Ar-39Ar dating of early-authigenic K-feldspar overgrowths. Pesquisas em Geociencias 37. 85-96. Accessed 2020-06-18.