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Stratigraphic data and 40 Ar- 39 Ar ages for the Early Cretaceous Parana-Etendeka flood basalts indicate that the main magmatic episode lasted for several m.y. (129-134 Ma) and was linked to the northward opening of the South Atlantic Ocean, but with some earlier magmatism (135-138 Ma) found inland far from the eventual oceanic rift. The regional distribution of distinct high-Ti/Y (Urubici, Pitanga, Paranapanema, Ribeira) and low-Ti/Y (Gramado, Esmeralda) magma types in the lavas and associated dyke swarms implies that magma generation occurred over a wide area and involved different mantle sources. Low MgO contents (3-7 wt%) indicate extensive fractional crystallisation, and upper crustal assimilation was important in the evolution of the Gramado magmas. However, Parana basalts that are considered to be uncontaminated by crust have trace element and isotope characteristics (e.g. Nb/La 1000 km 3 ) that can be correlated across the Atlantic Ocean accompanied the final magmatic phase in the southeast Parana and the Etendeka. The flood basalts post-date most estimates for the Jurassic-Cretaceous boundary, ruling out any link to a faunal extinction.