It covers the southern Brazilian states of Santa Catarina and Rio Grande do Sul and the Uruguayan departments Cerro Largo, Rocha and Treinta y Tres.
[4] The coastal ranges Serras de Sudeste in Brazil and Cuchilla Grande in Uruguay form the western boundary, underlain by the Sierra Ballena Shear Zone.
The onshore part of the basin is from north to south crossed by the Urussanga, Araranguá, Mampituba, Jacuí, Guaíba, Camaquã, Jaguarão/Yaguarón and Cebollatí Rivers.
[5] The basins of the South Atlantic margin started forming in the Early Cretaceous with the break-up of Gondwana, the southern part of the former supercontinent Pangea.
This tectonic movement resulted in a sequence of rift basins bordering the present-day South Atlantic on the Brazilian and southwestern African sides.
[8] The sedimentary succession of the Pelotas Basin is underlain by an extremely deformed (highly stretched, thinned and faulted) continental crust, covered by grabens that can achieve thicknesses of more than 20 kilometres (66,000 ft).
[9] The nature of the lower crust below the Pelotas Basin remains uncertain, but by analogy with the Namibian conjugate margin, it may correspond to a high-density igneous crust-mantle interface intruded by the Tristan da Cunha plume.
[14] The conglomerates, siltstones and diamictites of the Cassino Formation represent the top of the Gondwana break-up unconformity, dates to the Middle Aptian.
[16] The rapid subsidence from the Albian to Turonian created a wide marine platform with in the north elevated areas due to the doming of the Curumim Formation.
[29] De Santa Ana, Héctor; Goso Aguilar, César; Montaño, Jorge; Piñeiro, Graciela; Muzio, Rossana; Rossello, Eduardo; Perea, Daniel; Ucha, Nelson (2004).