OSLO - A type of rock that often bears diamonds has been found in Antarctica for the first time in a hint of mineral riches in the vast, icy continent that is off limits to mining, scientists said on Tuesday.
A 1991 environmental accord banned mining for at least 50 years under the Antarctic Treaty that preserves the continent for scientific research and wildlife, from penguins to seals.
Writing in the journal Nature Communications, an Australian-led team reported East Antarctic deposits of kimberlite, a rare type of rock named after the South African town of Kimberley famed for a late 19th century diamond rush.
"These rocks represent the first reported occurrence of genuine kimberlite in Antarctica," they wrote of the finds around Mount Meredith in the Prince Charles Mountains.
No diamonds were found during the geological work that is allowed on the continent. Kimberlite, a volcanic rock from deep below the Earth's surface, has now been discovered on all continents.
Geologists doubted the find could be commercial, largely due to Antarctica's remoteness, cold and winter darkness. Teal Riley of the British Antarctic Survey said less than 10 per cent of deposits of similar kimberlite were economically viable.
"It's a big leap from here to mining," he told Reuters.
Minerals including platinum, gold, copper, iron and coal have previously been found in Antarctica.
The Antarctic Treaty is binding only on its 50 signatories but has the backing of major powers, including the United States and China. Many expect the ban on mining to be extended in 2041.
"There is likely to be little opposition to an extension of this prohibition, despite the potential discovery of a new type of Antarctic 'ice'," Nature Communications said in a statement.
Another expert said it was unclear. "We do not know what the Treaty Parties' views will be on mining after 2041 or what technologies might exist that could make extraction of Antarctic minerals economically viable," said Kevin Hughes, of the Scientific Committee on Antarctic Research.
Riley said there was a fine line between geological mapping and prospecting with an eye to mining. Nations including Russia, Ukraine and China have been more active in surveying Antarctica in recent years.
The kimberlite deposit is also confirmation of how continents drift.
The region of East Antarctica was once part of a continent known as Gondwana connected to what is now Africa and India, which also have kimberlite.