NW-trending lineaments across Brazilian margin: a discussion upon their origin and implications for the Albian-Maastrichtian paleobiogeography and paleoecology of the South Atlantic

Since the eighties, several groups of NW-trending lineaments running from the coast up to the Mid Ocean Ridge have been recognized across the South Atlantic Brazilian margin from analyses of gravity SEASAT data (Bostrom, 1989). The direction of sea floor spreading has remained remarkably constant around a ENE-trending since 84 m.y B.P. (Nurnberg & Muller, 1991; Mello & Dias, 1996). Therefore, at least for the time elapsed between the Upper Cretaceous and the Present, these features can not be straightly attributed to the divergence between South America and Africa plate since they show remarkable cross cutting relation with the EW- trending fractures zones. In this paper we briefly discuss some ideas concerning the origin of such features and some implications for the Upper Cretaceous paleobiogeography and paleoecology of the South Atlantic.