It is represented by a succession of cyclic sedimentary packages of sandstones, siltstones and shales which bear extensive deposits of coal that has been extracted since 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.

The Rio Bonito Formation outcrops occur 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 the second-order stratigraphic supersequence called Gondwana I.

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.