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- The post-breakup magmatism in Cabo Frio High, Campos Basin, Brazil: implications to a thinned lithosphere contribution in magma formationPublication . De Barros, Tatiele; Castro De Brito, Priscila; Corval Vieira, Artur; Valente, Sérgio De Castro; Miranda, AlanABSTRACT: The Cabo Frio High, limit between Campos and Santos basins, consists of an elevated structure characterized by intense magmatism. Through new petrographic and geochemical data, this paper brings new highlights on sources and evolutionary processes associated with volcanic events that affected this area during Santonian-Campanian drifting stage. Samples from three studied wells are pyroclastic ash, lapilli tuffs, basalts, scoria and diabases associated with subaerial explosive volcanism. Geochemically, they are alkaline rocks classified as basalts, alkaline basalts, foidites and tephriphonolites. The evolution of these rocks derives from geodynamic processes that occurred in shallow mantle depths (35 – 80 km) and involved mixing between a depleted, relatively shallow asthenospheric source (N-MORB) and the local subcontinental lithospheric mantle represented by the average composition of the lamprophyres at the Cabo Frio Structural High.