The east and northeast Brazil shelves of the Southwest Atlantic harbor some
unique conditions for tropical passive margins with western boundary curre
nts. The narrow and open shelf is almost entirely covered by carbonate sedi
ments due to little freshwater input and the coast is impacted by the South
Equatorial Current (SEC). The wide Abrolhos bank of the east Brazil shelf,
presents more diverse conditions, as it forms a physical barrier to the Br
azil Current, and upwelling and land input become more significant. The mai
n characteristics of the coast and shelf and findings on biogeochemical, se
dimentation, and paleoceanographical processes, addressed by the Joint Ocea
nographic Projects (JOPS) campaigns, are summarized.