PATTERNS OF FOCAL MECHANISM AND SEISMIC PROVINCES IN BRAZIL

There is no clear difference in seismicity between the cratons and the Brasiliano fold belts. On the other hand, the Parana and Parnaiba intracratonic basins (both of Paleozoic origin) are almost aseismic as compared with the other main geological provinces. Earthquakes in Brazil, however, are not uniformly distributed and clusters of epicenters, probably related with more local features, Can be recognized. The same type of focaL mechanism has been found in each cluster.