More than 64 sedimentary basins have been identified on the South American continent. According to their regional structural character and tectonic setting, they are classified in 4 super groups.

(1) About 20 interior or intracratonic basins occur on South American cratons (Guayanas, Brazilian, and Patagonian). In most cases, their sedimentary fill is Paleozoic or early Mesozoic. Rift or transverse grabens resulting from incipient sea floor spreading extend towards the continental margin.

(2) 17 basins are located along the Atlantic stable margin, and consist primarily of half grabens with downfaulted seaward blocks. These rifts (or pull-apart basins) were separated as results of the migration of the African and American continental blocks. Therefore the sedimentation is chiefly Cretaceous and Tertiary.

(3) On the western edge of South American cratons, almost 20 basins of downwarped blocks extend from Orinoco down to the Malvinas plateau in a relatively uninterrupted chain of retroarc basins, bordered by the Andean orogen. They lie on a flexured Precambrian and Paleozoic basement, and are highly deformed in the west (Subandean belt) due to the action of compressional forces caused by the tectonic influence of the Mesozoic Andean batholith.

(4) Westward, the Pacific margin is bordered by 27 foreland and forearc basins, which alternate from north to south on an unstable or quasi-stable margin, fringed by a trench and slope complex where the ocean crust is subducted beneath the continental plate.

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