The Florianópolis Formation () 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 expo ...

of the

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

offshore of the

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

ian states of

Rio de Janeiro Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...

São Paulo São Paulo (; ; Portuguese for 'Paul the Apostle, Saint Paul') is the capital of the São Paulo (state), state of São Paulo, as well as the List of cities in Brazil by population, most populous city in Brazil, the List of largest cities in the ...

, Paraná and Santa Catarina. The predominantly

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

formation with interbedded

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

s and

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. Although its permeabil ...

s dates to the

Early Cretaceous The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...

period;

Albian The Albian is both an age (geology), age of the geologic timescale and a stage (stratigraphy), stage in the stratigraphic column. It is the youngest or uppermost subdivision of the Early Cretaceous, Early/Lower Cretaceous epoch (geology), Epoch/s ...

epoch and has a thickness in the type oil well of .

Etymology

The formation is named after the city of

Florianópolis Florianópolis () is the capital and second largest city of the state of Santa Catarina (state), Santa Catarina, in the South Region, Brazil, South region of Brazil. The city encompasses Santa Catarina Island and surrounding small islands, as we ...

, Santa Catarina.

Description

The Florianópolis Formation is thick in the type oil well, and consists of reddish, fine to coarse-grained

s with a clay matrix, reddish

mica Micas ( ) are a group of silicate minerals whose outstanding physical characteristic is that individual mica crystals can easily be split into fragile elastic plates. This characteristic is described as ''perfect basal cleavage''. Mica is co ...

ceous

s and

s. These clastic units are thought to represent

alluvial Alluvium (, ) is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluvium is also sometimes called alluvial deposit. Alluvium is ...

environments distributed along the western Brazilian basin margin, along the Santos Hinge Line. These alluvial environments were gradational towards the east, with the shallow marine carbonates of the

Guarujá Formation The Guarujá Formation () is a formation (geology), geological formation of the Santos Basin offshore of the Brazilian states of Rio de Janeiro (state), Rio de Janeiro, São Paulo (state), São Paulo, Paraná (state), Paraná and Santa Catarina (s ...

, and further to the open basin with the siltstones of the Itanhaém Formation. Biostratigraphical data and its relations with the Guarujá Formation point towards an Albian age.Clemente, 2013, p.22 The formation is laterally equivalent to the Goitacás Formation of the

Campos Basin The Campos Basin is one of 12 coastal sedimentary basins of Brazil. It spans both onshore and offshore parts of the South Atlantic with the onshore part located near Rio de Janeiro. The basin originated in Neocomian stage of the Cretaceous peri ...

to the north.Contreras, 2011, p.102 The formation is the

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 presenc ...

of the Pirapitanga Field in the Santos Basin.Vieira, 2007, p.9

References

Bibliography

* * * {{DEFAULTSORT:Florianopolis Formation Geologic formations of Brazil Santos Basin Cretaceous Brazil Lower Cretaceous Series of South America Albian Stage Sandstone formations Shale formations Siltstone formations Alluvial deposits Reservoir rock formations Petroleum in Brazil Geography of Paraná (state) Geography of Rio de Janeiro (state) Geography of Santa Catarina (state) Geography of São Paulo (state)

Etymology

Description

See also

References

Bibliography