The kind of rocks that are likely to contain diamonds have been found in the frozen mountains of Antarctica, say scientists. The continent might be teeming with “ice,” which is street slang for diamond jewelry. Although any kind of mining in Antarctica is currently prohibited, this discovery could have implications for the future.
Kimberlite is a bluish, igneous rock that sometimes contains diamonds. They are found in vertical structures known as kimberlite pipes, underground structures formed by the eruption of deep-origin volcanoes. Kimerlite is the most important commercial source of diamonds today. They are named after the South African town of Kimberley, the site of a major diamond rush in the 19th century.
Diamonds are made when pure carbon is compressed under extremely high heat and pressure, usually about 150km below the ground. Volcanic eruptions bring the diamonds to the surface, usually embedded in kimberlite.
Kimberlites have been discovered in the East Antarctic by an Australian-led team. The team was there to study the region’s geology, not to prospect diamonds. The type of mineral is identical to that found in other parts of the world where diamonds are mined.
Kimberlites are often found in mobile belts and continental rifts. The Pangaean super-continent of Gondwana consisted of the major landmasses of the Southern Hemisphere, including the areas we know today as South America, Africa, Madagascar, and Australia. The Indian subcontinent and the Arabian Peninsula were also parts of Gondwana but have moved to the Northern Hemisphere. Kimberlite was pushed to the surface of the Gondwana continent about 120 million years ago, which explains why it is found on distant parts of the globe today.
Group 1 kimberlites, the type that might contain diamonds, have been found in three samples taken from the slopes of Mount Meredith in the northern Prince Charles Mountains of Antarctica.
“These rocks represent the first reported occurrence of genuine kimberlite in Antarctica,” the team wrote. Kimberlite has been found on every continent except Antarctica, until now.
“Even amongst the Group One kimberlites, only 10% or so are economically viable, so its still a big step to extrapolate this latest finding to any diamond mining activity in Antarctica,” Dr Teal Riley, British Antarctic Survey geologist, tells the BBC.
Antarctica has been preserved for scientific research and for its wildlife. The 1991 Protocol on Environmental Protection to the Antarctic Treaty prohibits any extraction of mineral resources except for scientific research. The Protocol will be up for review in 2041, 50 years after it was implemented. It has been ratified by 33 countries including the U.S. and China, and 11 countries have signed but have not yet ratified.
Although the continent might have diamonds, commercial mining in Antarctica is still a long way away. Other minerals such as gold, coal, iron, copper, and platinum have previously been found in Antarctica, but have not been mined. The team found kimberlite, but they did not find any actual diamonds. The icy continent’s coldness and remoteness may make extraction of minerals prohibitively expensive.
By K. Elsner
British Antarctic Survey