Experts say they've found evidence of a Brazilian "Atlantis," a continent that disappeared after Africa and South America separated 100 million years ago.

Scientists with the Geology Service of Brazil, working with Japanese researchers, reported the discovery of granite -- a rock that normally forms on dry land -- more than 8,000 feet beneath the sea in a region known as the Rio Grande Elevation, 900 miles off the coast of Brazil.

"It is unusual because it is granite rock," Geology Service Director Roberto Ventura Santos said. "And you don't find granite on the seabed. It is more usual to find it on the mainland."

"This could be Brazil's Atlantis," he said. "We are almost certain but we need to strengthen this hypothesis."

Experts say the find is thought to be continental crust but further confirmation will be needed. Scientists are expected to drill for more samples this year, The Daily Telegraph reported Tuesday.

"We began to see that the area could be a piece of the continent that disappeared into the sea millions of years ago," Santos said.

"We speak of Atlantis more in terms of symbolism," he said. "Obviously, we don't expect to find a lost city in the middle of the Atlantic.

"But if it is the case that we find a continent in the middle of the ocean, it will be a very big discovery that could have various implications in relation to the extension of the continental shelf."