Scientists have found clues to the formation of the mysterious Gamburtsev Subglacial Mountains, also known as "ghost mountains, buried deep beneath the ice sheet surrounding Dome Argus, the highest ice feature in Antarctica.

Discovered in 1958, the enigmatic mountain range has long puzzled scientists as to how and when it was formed.
A recent study by an international team of researchers led by Dr Fausto Ferraccioli of the British Antarctic Survey provides the first comprehensive view of the mountains' architecture and possible origins.

Using magnetic, radar and gravity data from extensive aerial surveys and combined with dating evidence from zircons taken from core samples and other sediments, the researchers created a model to determine the Gamburtsev's origins.

"The model suggests that a collision of continents about 1 billion years ago produced a thick crust, uplifting the Gamburtsev region and producing high mountainous topography," says Emeritus Professor John Veevers, from the ARC National Key Centre for Geochemical Evolution and Metallogeny of Continents at Macquarie University, who is not part of the study but wrote a commentary on the project.

Recent radar data reveal that the area is cut into jagged mountain ranges and valleys, similar in size and shape to the European Alps. This kind of topography, however, is usually associated with recently uplifted features, not those found in the middle of ancient geologically inactive continents.

"This uplifted area collapsed under its own weight and was worn almost flat by erosion, while the underlying crustal base (known as the root) remained intact," Veevers says.

The scientist further explained that the rifting, where the Earth's crust is gradually pulled apart, occurred about 250 million years ago during the Permian period, and again 100 million years ago, forming an extensive rift valley system similar to the Great Rift Valley in East Africa.

About 250 million years ago, there was an early uplift, as revealed by a pattern of rivers that drain outward from an ancestor of the Gamburtsevs into Antartica, Africa and India, which were then joined, Veevers said.

"Erosion, first by rivers and later by the first glaciers around 34 million years ago, then carved the steep peaks and valleys into the Gamburtsev," he says. "Finally around 14 million years ago this rugged topography was frozen in time by the growth of the East Antarctic Ice Sheet, where its discovery came as a big surprise."

Ferraccioli and team's research is published Tuesday in the journal Nature.