An outline of the geology and petroleum systems of the Paleozoic interior basins of South America

Although large sedimentary provinces, the South,American intracratonic basi ns have not been characterized yet as repositories of significant mineral a nd energy wealths, compared to their counterparts in the Northern Hemispher e. In the Parana Basin, heart of industrialized Brazil, hydroelectric power de rived from waterfalls developed on the Cretaceous basaltic cover, gemstones and rich soils both derived again from the basalts, and groundwater from J urassic eolian sandstones are the main resources. Bituminous shales, and mo re recently, gas discoveries constitute secondary resources; gas seems to c haracterize the Argentinian Chaco-Parana. Basin. In the Solimoes Basin, the development of significant reserves of gas, and less noticeably of oil, is hampered by the remoteness of the area and lack of a nearby market. For th e same reasons, in the Amazonas Basin large reserves of evaporites lie unto uched in the subsurface, recent gas discoveries made near the capital jungl e of Manaus point to a brighter future for their exploitation. In the Parna iba Basin, situated in a remote semi-arid region of Brazil, groundwater is the main exploited mineral resource. Considering their geological characteristics, the small amount of explorati on performed in these basins is in sharp contrast with their petroleum pote ntial. Some of their deposits have barely been scratched, suggesting that t hese areas may be profitable for bold investors.