Abstract
Six Cretaceous planktonic foraminiferal extinction levels allow good interbasinal correlation along the Brazilian continenta l margin. From base to top they are as follows: extinction of Favusella and Ticinella at the base and top of the Vraconian, respectively; extinction at Late Turonian of Gtobotruncana inomata and G. wilsoni in equatorial marginal basins and of Dicarinella hagni and D. imbricata in the Santos and Campos basins on eastern margin; the extinction of Dicarinella concavata at the Santonian-Campanian boundary: the extinction of Globotruncana fornicata at the Early-Late Maastrichtian. Three significant regional unconformities have been identified during Cretaceous marine sedimentation. The Jack of Late Campanian and Latest Maastrichtian-Earliest Paleocene sediments indicates a hiatus during these time intervals, caused, probably, by sea-level oscillations as suggested by erosional truncation of Santonian-lower Campanian and lower-upper Maastri htian sediments. The third unconformity, probably controled by tectonic and sedim entary factors related to the post-rift stage of the opening of the South/Equatorial Atlantic ocean, is represented by lack of Cenomanian sediments.
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