Data from 100 seismic-refraction profiles recorded on the extra-Andean part of the Argentine continental margin are presented in ten schematic structure sections and two generalized structure maps. The results are correlated with previously reported measurements in the offshore Buenos Aires province and the Argentine basin, and with seismic-refraction measurements, bore holes, and surface geology on land.

Between Buenos Aires and the southern end of Tierra del Fuego four of the major subsurface elements of Argentina extend eastward under the continental shelf; from north to south they are: (1) the Rio Salado basin, (2) the Bahia Blanca basin, (3) the San Jorge basin, and (4) the Magellan basin. Another sediment-filled depression, the Malvinas basin, was discovered lying between the Falkland Islands and Tierra del Fuego. The Rio Salado, Bahia Blanca, and Malvinas basins extend out to the edge of the continent and have been filled without barriers to sediment transport at the seaward ends.

The overall effect of bending appears to be well demonstrated by the arcuate trends of the main structural elements and the tectonic lines of extra-Andean Patagonia, for the most part NNW-SSE with a complementary W-E direction. The data are consistent with the supposition of a mass drifting westward with some clockwise rotation.