Rio Bonito Formation

Rio Bonito Formation Stratigraphic range: Permian
Type	Geological formation
Location
Region	São Paulo, Paraná, Santa Catarina, Rio Grande do Sul and Uruguay
Country	Brazil Uruguay

The Rio Bonito Formation is a geological formation of the Paraná Basin of Permian age. It is represented by a succession of cyclic sedimentary packages of sandstones, siltstones and shales being the bearer of extensive deposits of coal that is extracted from the 19th century.^[1] The Rio Bonito Formation was deposited in a coastal environment, formed by rivers, deltas, bays and estuaries with tidal plains, barrier islands and shallow marine platform, at a time when the Paraná Basin was a large gulf of the ancient supercontinent Gondwana. This gulf was open to the southwest, to the old ocean Panthalassa. The range of the Rio Bonito Formation outcrops occurs mainly in the eastern border of the Paraná Basin, in a narrow band in the states of São Paulo, Paraná, Santa Catarina, Rio Grande do Sul and Uruguay.^[2] The Rio Bonito Formation belongs to supersequence stratigraphic second-order supersequence called Gondwana I.^[3]

Glossopteris Flora

Glossopteris Flora, it is considered a global guide to fossil sequences Gondwana, having been developed and become the dominant flora of the southern Permian to early Triassic, having become extinct at the end of this period. This flora is not only the main fossil content of the Rio Bonito Formation coals, the coal extracted as in Australia and South Africa's first work to record the occurrence of horizons megaflora associated with coal seams within a paleogeographic approach and palaeoclimatic in the Paraná Basin, was the study by White in 1908. This allowed a large correlation between Gondwana coal deposits in southern Brazil and those registered in South Africa, Australia, India and Antarctica, including showing that the latter has been in latitude near the south pole less than today, allowing the occurrence of an extensive flora.

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