The Paraná Basin (
Portuguese: Bacia do Paraná,
Spanish: Cuenca del Paraná) is a large
cratonicsedimentary basin situated in the central-eastern part of
South America. About 75% of its areal distribution occurs in Brazil, from
Mato Grosso to
Rio Grande do Sul states. The remainder area is distributed in eastern Paraguay, northeastern Argentina and northern Uruguay. The shape of the depression is roughly
elliptical and covers an area of about 1,500,000 km2 (580,000 sq mi).
The
Paraná River, from which the Paraná Basin derived its name, flows along the central axis of the Paraná Basin and drains it.
Description
The Paraná Basin stretches from the Brazilian state of
Mato Grosso in the north to northern Argentina and Uruguay in the south. The southern portion in Uruguay is locally known as Norte Basin.[6][7]
Pioneer studies
The first study on the Brazilian side of the Paraná Basin dates from 1841, when a
Brazilian Imperial Government Mission prospected for
coal. Turning point in the basin's geological understanding was the "White Report", published in 1908 by the American
geologistIsrael C. White, head of the "Comissão de Estudos das Minas de Carvão de Pedra do Brasil" (Commission for Studies on Brazilian Coal Mines). One of the main results of these studies, besides the reconnaissance for coal, was the discovery of Mesosaurusfossils within
Permian black
shales (
Irati Formation), and the Glossopteris flora within the
Permian coals. White was one of the first to propose the equivalence between the
South American Permian strata and similar rocks of the
Karoo Basin in
South Africa.[10]
The Paraná Basin is a typical
intra-cratonic flexural basin, although during the Paleozoic it was a
gulf that opened to the southwest. The basin genesis is related to the
convergence between the former
Gondwanasupercontinent and the
oceanic crust of the former
Panthalassa ocean. The basin formed, at least during the Paleozoic
Gondwanide orogeny, as a
foreland basin.[1][11][14] In the
Permian and
Triassic the area between Asunción and Río Grande was uplifted in connection to the Gondwanide orogeny effectively splitting the basin in the two.[15]
The sedimentary column of the Paraná Basin was divided by Milani in 1997,[17] into six second order
allostratigraphic supersequences (in the sense of Vail, 1977).[18] These sequences define the
stratigraphic framework of the basin and are bound by distinct depositional hiati, caused by
erosive events.[1]
The major
glaciation that covered almost all southern portions of
Gondwana, known as
Karoo Ice Age. The glaciation's apex was reached during the
Mississippian (Early Carboniferous), stopping any further
sedimentation until the onset of deglaciation during the Westphalian (Late Carboníferous). Left behind were huge glacial deposits, which are composed mainly by sandstones,
diamictites,
conglomerates and muddy rocks, grouped in the
Itararé Group. Typical glacial
facies are widespread, e.g.,
varvites.
During the
Middle Permian the waning
glaciation allowed the flourishing of the Glossopteris flora in the sandstones of the
Rio Bonito Formation and the development of huge
coal deposits, extracted in southern Brazil and Uruguay since the 19th century.
Finally, during the Late Permian the
Irati Formation was deposited, represented by
bituminous shale, a potential petroleum source rock, and famous worldwide for its Mesosaurusfauna. The top of this supersequence defines the end of the marine phase.[1]
Gondwana II Supersequence
This Triassic supersequence marks the beginning of continental sedimentation. The
Santa Maria Group comprises the
Candelária,
Caturrita and Santa Maria Formations. In the
Santa Maria Formation, it bears an important
reptile and
mammal fauna, that can be correlated to the African continent.[1]
The great
desertification of the still united Gondwana supercontinent, the "Botucatu desert" with an area up to 1,200,000 km2 (460,000 sq mi). The large
sanddune fields left behind thick, coarse to fine sandstones beds, the
Botucatu Formation, housing the important
Guaraní Aquifer, one of the world's largest
aquifer systems.
Above the Botucatu Formation, a large igneous province was formed by the
Serra Geral Formation, part of the
Paraná and Etendeka traps, enormous flood
basalts that occurred 137 to 127 million years ago, associated with the
rifting of Gondwana and the opening of the
South Atlantic Ocean. Until today, the surface area still reaches more than 1,000,000 square kilometres (390,000 sq mi). The thickness of the flood basalts amounts to 2,000 m (6,600 ft) and their area extends to the Etendeka basin in
Namibia and
Angola even into Southwestern Africa.[1]
The Guaraní Aquifer is one of the world's largest
aquifer systems and an important source of
fresh water in
Argentina, Brazil,
Paraguay and
Uruguay. The lithology of the Aquifer consists mainly of highly
permeable sandstones of the Botucatu and Pirambóia formations. The aquifer covers 1,200,000 km2 (460,000 sq mi) with an estimated volume of about 37,000 km3 (3.0×1010 acre⋅ft) of water.[23]
Energy resources
Coal: The Brazilian coal resources are estimated at 32 billion
metric tons (32
Pg), classified as bituminous to sub-bituminous coal and are mainly associated with sandstones of the Rio Bonito Formation. The major producers are located in
Rio Grande do Sul and
Santa Catarina states and minor producers are located in
Paraná and
São Paulo states.[24]
Natural gas: There is one
gas field in the Paraná Basin, the
Barra Bonita Field, located in Paraná state and discovered in 1996, with estimated reserves of about 496,000,000 m3 (1.75×1010 cu ft).[25]
Oil shale: Since 1972
Petrobras extracts
hydrocarbons from the Irati Formation
oil shales in São Mateus do Sul, a city in the Brazilian state of
Paraná, using the
Petrosix process, a Petrobras
patent. The Irati Formation reserves are estimated at 700,000,000 bbl (110,000,000 m3) of oil, 9 million metric tons of
liquefied gas (LPG), 25 cubic kilometers (8.8×1011 cu ft) of
shale gas and 18 million metric tons of
sulfur in the states of São Paulo, Paraná, Santa Catarina and Rio Grande do Sul.[26]
^White, David (1908) Flora Fóssil das Coal Measures do Brasil, pp. 337-617 + 14 estampas (inglês) IN: White, I.C. (1908) "Commissão de Estudos das Minas de Carvão de Pedra do Brazil”, Relatório Final, Parte III, Imprensa Nacional, Rio de Janeiro, Brazil, 617 pg. (Relatório bilíngue, em português e inglês). Edição facsimilar de 1988, DNPM
Vail, P.R.; R.M. Mitchum, and S. Thompson. 1977. Seismic Stratigraphy and global change of sea level, part 3: relative changes of sea level from coastal onlap. AAPG Memoir 26. 205–212. .
Mantovani, Marta S.M., and Benjamin B.
De Brito Neves. 2010. Neoproterozoic-Cambrian tectonics, global change and evolution: a focus on south western Gondwana, 257–272.
Elsevier.
Milani, E.J.; J.H.G. Melo; P.A. Souza; L.A. Fernandes, and A.B. França. 2007a. Bacia do Paraná. Cartas Estratigráficas - Boletim de Geociências da Petrobras, Rio de Janeiro 15. 265–287. .
Milani, E.J.; A.B. França, and R.Á. Medeiros. 2007b. Roteiros Geológicos, Rochas geradoras e rochas-reservatório da Bacia do Paraná. Boletim de Geociências da Petrobras, Rio de Janeiro 15. 135–162. .
Milani, E.J. 1997. Evolução tectono-estratigráfica da Bacia do Paraná e seu relacionamento com a geodinâmica fanerozoica do Gondwana sul-ocidental (PhD thesis), ..
Universidade Federal do Rio Grande do Sul.
Melo, J.H.G. 1988. The Malvinokaffric realm in the Devonian of Brazil. CSPG Memoir 14. 669–704. .
Zalán, P.V.; S. Wolf; M.A.M. Astolfi; I.S. Vieira; J.C. Conceição; V.T. Appi; E.V. Santos Neto; J.R. Cerqueira, and A. Marques. 1991. The Paraná Basin, Brazil. AAPG Memoir 51. 707–708. .
Zanotto, O.A.; C.R. Becker, and E.M. Durães. 2008. Barra Bonita - Primeiro Campo de Gás na Bacia Do Paraná, .. 44º Congresso Brasileiro de Geologia – Anais; Curitiba, Brasil.
Franco, María Jimena; Mariana Brea; Óscar Orfeo, and Alejandro F. Zucol. 2013.
La paleoflora de la Formación Ituzaingó, Argentina. El Neógeno de la Mesopotamia argentina, Asociación Paleontológica Argentina, Publicación Especial 14. 41–55. Accessed 2018-09-03.
MacGregor, J.H. 1908. Mesosaurus brasiliensis nov. sp.. Commission for Studies on Brazilian Coal Mines - Final Report, Imprensa Nacional, Rio de Janeiro, Brazil _. 301–336. .
White, I.C. 1908. Comissão de Estudos das Minas de Carvão de Pedra do Brasil – Relatório final: Commission for Studies on Brazilian Coal Mines - Final Report, 301–617. Imprensa Nacional, Rio de Janeiro, Brazil.
External links
Wikimedia Commons has media related to Paraná Basin.