The Japan Agency for Marine-Earth Science and Technology and the Brazilian government have made an announcement about the discovery of a large mass of granite on the seabed off the coast of Rio de Janeiro, suggesting a continent may have existed in the Atlantic Ocean.
Granite normally forms only on dry land, so its existence beneath the Ocean is strong evidence that a continent used to exist in the area where the legendary island of Atlantis, mentioned in antiquity by Plato in his philosophical dialogues, was supposedly located, a Brazilian official has said.
Legend has it that, the island, host to a highly developed civilization, sunk into the sea around 12,000 years ago. But no trace of it has ever been found.
The finding was possible because of a Shinkai 6500 manned submersible operated by the Japanese agency, the Japan Times reported.
The seabed where the granite mass was discovered is estimated to have sunk into the sea several tens of million years ago.
Also discovered in the area around it was a large volume of quartz sand - which is also not formed in the sea. The bedrock is believed to consist mainly of basalt rock. No man-made structures, however, have been found there.
The agency assumes that the area was above sea level until about 50 million years ago but became submerged over a period spanning several million years, based on fossils found in the nearby seabed and other data.
According to the agency, the Rio Grande Rise is the only plausible area that could possibly have been dry land in the past.
But experts remained cautious about jumping to conclusions about Atlantis.
Shinichi Kawakami, a professor at Gifu University versed in planetary sciences, said the granite could have been a part of a big continent before it separated into what is now Africa and South America.
Kawakami said researchers must look further into the composition of the granite and see if it matches the granite now found in Africa or South America.