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Jureia Formation

Coordinates: 26°6′S 43°43′W / 26.100°S 43.717°W / -26.100; -43.717
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Jureia Formation
Stratigraphic range: Santonian-Maastrichtian
~86–66 Ma
TypeGeological formation
Unit ofFrade Group
UnderliesMarambaia Formation
OverliesItanhaém Formation
Thicknessup to 2,000 m (6,600 ft)
Lithology
PrimaryShale
OtherSiltstone, sandstone
Location
Coordinates26°6′S 43°43′W / 26.100°S 43.717°W / -26.100; -43.717
RegionSantos Basin, South Atlantic
Country Brazil
Type section
Named forJureia-Itatins Ecological Station

Location of the Santos Basin

The Jureia Formation (Portuguese: Formacão Jureia) is a geological formation of the Santos Basin offshore of the Brazilian states of Rio de Janeiro, São Paulo, Paraná and Santa Catarina. The predominantly shale with interbedded siltstones and fine sandstones formation dates to the Late Cretaceous period; Santonian-Maastrichtian epochs and has a maximum thickness of 2,000 metres (6,600 ft). The formation is a reservoir rock of the Merluza Field, the first discovery in the Santos Basin.

Etymology

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The formation is named after the Jureia-Itatins Ecological Station, São Paulo.

Description

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The turbidites of the Jureia Formation were deposited at the shelf edge of the Brazilian continental margin

The Jureia Formation is 952 to 2,000 metres (3,123 to 6,562 ft) thick,[1] and includes a succession of clastics between the coarse facies of the Santos Formation in the western proximal part and the fine-grained clastics of the Itajai-Açu Formation in the eastern distal part of the Santos Basin. The formation is characterized by dark grey to greenish and brown shales, dark grey siltstones, fine-very fine sandstones and light ochre calcisilts. The depositional environment is thought to be of a marine platform setting as pro-delta facies on the shelf edge.[2] The age based on palynomorphs and calcareous nannofossils is Late Cretaceous (Santonian-Maastrichtian).[3] Two new ostracod species were identified in the drilling cuttings of wells drilled into the Santonian-Campanian section, ?Afrocytheridea cretacea and Pelecocythere dinglei.[4]

The formation is the reservoir rock of the Merluza Field, the first discovery in 1979 of the Santos Basin.[5][6]

See also

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References

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  1. ^ Kiang Chang et al., 2008, p.32
  2. ^ Contreras, 2011, p.104
  3. ^ Clemente, 2013, p.23
  4. ^ Piovesan, 2010, p.177
  5. ^ "Santos Basin Fields". Archived from the original on 2017-09-07. Retrieved 2017-09-07.
  6. ^ Vieira, 2007, p.19

Bibliography

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