Açu Formation

Açu Formation Stratigraphic range: Albian ~112–100 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Unit of
Underlies
Overlies
Lithology
Primary	Sandstone
Location
Coordinates	5°48′S 38°06′W / 5.8°S 38.1°W / -5.8; -38.1Coordinates: 5°48′S 38°06′W / 5.8°S 38.1°W / -5.8; -38.1
Approximate paleocoordinates	11°54′S 10°54′W / 11.9°S 10.9°W / -11.9; -10.9
Region	Ceará
Country	Brazil
Extent
Açu Formation (Brazil)

The Açu Formation is an Early Cretaceous (Albian) geologic formation of the in Ceará, northeastern Brazil. The formation comprises coarse-grained sandstones deposited in a fluvio-deltaic environment. The Açu Formation, belonging to the , has provided fossils of an indeterminate rebbachisaurid.

Description[]

The Açu Formation was deposited in a passive margin setting, overlying the and is overlain by the . In the petroleum producing , the formation is a reservoir rock.^[1]

Fossil content[]

The following fossils were reported from the formation:^[2]

• Reptiles
  • Dinosaurs
    • Carcharodontosauria indet.
    • Maniraptora indet.
    • Megaraptora indet.
    • Rebbachisauridae indet.^[3]
    • Spinosauridae indet.

See also[]

• Crato Formation
• Romualdo Formation
• Malhada Vermelha Formation
• Missão Velha Formation

References[]

Bibliography[]

• 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. 37. 85-96. Accessed 2020-06-18.