Rio Grande Rise
![The Rio Grande Rise separates the Brazil (north) and Argentine Basins (south) and is separated from the Vema Sill and Santos Plain (west) by the Vema Channel and from the Mid-Atlantic Ridge by the Hunter Channel (east).[1]](/uploads/202502/07/Rio_Grande_Rise_NOAA0919.jpeg)
The Rio Grande Rise is an aseismic ocean ridge in the southern Atlantic Ocean off the coast of Brazil. Together with the Walvis Ridge off Africa, the Rio Grande Rise forms a V-shaped structure of mirrored hotspot tracks or seamount chains across the northern South Atlantic. In 2013, Brazilian scientists announced that they found granite boulders on the Rio Grande Rise and speculated that it could be the remains of a submerged continent, which they called the "Brazilian Atlantis". Other researchers, however, noted that such boulders can end-up on the ocean floor by less speculative means.