The Juréia Formation ( pt, Formacão Juréia) is a

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

of the

Santos Basin The Santos Basin ( pt, Bacia de Santos) is an approximately large mostly offshore sedimentary basin. It is located in the south Atlantic Ocean, some southeast of Santos, Brazil. The basin is one of the Brazilian basins to have resulted from th ...

offshore of the

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

ian states of

Rio de Janeiro Rio de Janeiro ( , , ; literally 'River of January'), or simply Rio, is the capital of the state of the same name, Brazil's third-most populous state, and the second-most populous city in Brazil, after São Paulo. Listed by the GaWC as a b ...

São Paulo São Paulo (, ; Portuguese for 'Saint Paul') is the most populous city in Brazil, and is the capital of the state of São Paulo, the most populous and wealthiest Brazilian state, located in the country's Southeast Region. Listed by the GaWC a ...

, Paraná and Santa Catarina. The predominantly

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4) and tiny fragments (silt-sized particles) of other minerals, especial ...

with interbedded

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...

s and fine

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

s formation dates to the

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the ...

period;

Santonian The Santonian is an age in the geologic timescale or a chronostratigraphic stage. It is a subdivision of the Late Cretaceous Epoch or Upper Cretaceous Series. It spans the time between 86.3 ± 0.7 mya (million years ago) and 83.6 ± 0.7 mya. The ...

Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval from ...

epochs and has a maximum thickness of . The formation is a

reservoir rock A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the presence ...

of the Merluza Field, the first discovery in the Santos Basin.

Etymology

The formation is named after the

Juréia-Itatins Ecological Station The Juréia-Itatins Ecological Station ( pt, Estação Ecológica da Juréia-Itatins) is an ecological station (ESEC) in the state of São Paulo, Brazil. It fully protects a well-preserved area of Atlantic Forest and associated ecosystems along th ...

, São Paulo.

Description

The Juréia Formation is thick,Kiang Chang et al., 2008, p.32 and includes a succession of clastics between the coarse facies of the

Santos Formation The Santos Formation ( pt, Formacão Santos) 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 conglomeratic sandstone formation with inter ...

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

s, dark grey

s, fine-very fine

s and light ochre calcisilts. The depositional environment is thought to be of a marine platform setting as pro-delta facies on the shelf edge.Contreras, 2011, p.104 The age based on

palynomorph Palynology is the "study of dust" (from grc-gre, παλύνω, palynō, "strew, sprinkle" and '' -logy'') or of "particles that are strewn". A classic palynologist analyses particulate samples collected from the air, from water, or from deposit ...

s and calcareous

nanofossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

s is

(

).Clemente, 2013, p.23 Two new

ostracod Ostracods, or ostracodes, are a class of the Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 70,000 species (only 13,000 of which are extant) have been identified, grouped into several orders. They are small crustaceans, typic ...

species were identified in the drilling

cutting Cutting is the separation or opening of a physical object, into two or more portions, through the application of an acutely directed force. Implements commonly used for wikt:cut, cutting are the knife and saw, or in medicine and science the scal ...

s of wells drilled into the Santonian-

Campanian The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian s ...

section, '' ?Afrocytheridea cretacea'' and '' Pelecocythere dinglei''.Piovesan, 2010, p.177 The formation is the

of the Merluza Field, the first discovery in 1979 of the Santos Basin.Vieira, 2007, p.19

References

Bibliography

* * * * * {{DEFAULTSORT:Jureia Formation Geologic formations of Brazil Santos Basin Cretaceous Brazil Upper Cretaceous Series of South America Maastrichtian Stage of South America Campanian Stage Santonian Stage Shale formations Siltstone formations Sandstone formations Turbidite deposits Reservoir rock formations Petroleum in Brazil Formations Formations Formations Formations Tupi–Guarani languages

Etymology

Description

See also

References

Bibliography