Contribuição da Geofísica Para o Entendimento das Causas do Magmatismo Cenozóico da Província Borborema (Ne-Brasil)

In this work we propose two alternative models for the origin of Cenozoic volcanism in the Borborema province. One is a mechanism for small-scale convection (Edge Driven Convection-EDC) at the interface between the continental lithosphere and oceanic lithosphere. The other is the possibility that the region of the South American Plate, which corresponds to northeastern Brazil, has passed on a "heat ridge" in the range between 80 and 20 Ma. The mechanism of EDC is favored by the fact that the disturbance capable of generating mantle magmatism follows the movement of the plate. This justifies the maintenance of magmatism over a long period in the same geographical area with a direction parallel to the eastern shore, as is the case of magmatism along the<br>Macau-Queimadas alignment. The model of "heat ridge" is very disadvantaged by the lack of a Cenozoic magmatism spread throughout the Borborema province with the progression of age from northeast to southwest.