Deep beneath the thick ice that covers East Antarctica, scientists are revealing new discoveries about a mystery that has been hidden beneath the continent’s frozen exterior for half a billion years.
According to newly published research, clues to the formation of a mountain range the size of the Alps tucked away below Antarctic ice are being revealed, offering geologists a unique glimpse at the processes behind their formation.
The Gamburtsev Subglacial Mountains, initially discovered by Soviet scientists during an expedition in 1958, have puzzled researchers for decades. Now, these massive features beneath Antarctica’s frozen surface, which were formed long ago during the birth of the supercontinent Gondwana, are finally revealing their secrets, as reported in a new study that sheds new light on the geological forces that helped to shape and ultimately stabilize the heart of Earth’s southernmost continent.
Secrets Below Antarctic Ice
While many of Antarctica’s mountain ranges are only partially covered by the thick ice that shields the continent, the Gamburtsev Mountains remain entirely concealed beneath the highest part of the East Antarctic Ice Sheet.
Soviet scientists first reported the discovery of these mountains using seismic techniques during a 1958 expedition. This expedition revealed an extensive mountain range comparable to the European Alps, albeit one that is entirely hidden below Antarctica’s frozen surface. The origins of this massive hidden mountain range quickly became one of the greatest unsolved mysteries of Earth’s ancient tectonic past.
“For scientists, it’s deeply puzzling,” researchers Nathan Daczko and Jacqueline Halpin recently wrote at The Conversation. “How could such a massive mountain range form and still be preserved in the heart of an ancient, stable continent?”
The Gamburtsev Mountains: A Geological Mystery
Mountain ranges normally form within the areas where tectonic plates collide. This fundamental reality points to one of the most intriguing mysteries about the Gamburtsev Mountains: the fact that East Antarctica has been tectonically stable now for hundreds of millions of years.
The apparent contradiction between known tectonic activity underlying mountain formation and the stability Antarctica has seen for eons led to many questions about how such a large mountain range could not only form, but also survive in an area with no signs of active tectonic collisions.
Now, in a study by Daczko and Halpin, the authors suggest that the origins of the Gamburtsev Mountains can be traced back more than 500 million years, to when ancient continental masses collided to form Gondwana.
“Our findings offer fresh insight into how mountains and continents evolve over geological time,” the authors recently wrote. “They also help explain why Antarctica’s interior has remained remarkably stable for hundreds of millions of years.”
According to Halpin and Daczko, millions of years ago, partially molten rock flows beneath the continent’s surface led to a thickening and uplifting of the crust. Eventually, the thickened crust collapsed beneath its own weight, resulting from a process known as gravitational spreading. However, a dense root of crust still remained anchored within the Earth’s mantle, which preserved the range.
Reconstructing the Geologic Past
In their study, the scientists analyzed zircon grains embedded in sandstone deposits found in the Prince Charles Mountains, which are a great distance from the Gamburtsev Mountain range. Like veritable time capsules, these zircon deposits helped Halpin and Daczko determine that the Gamburtsev Mountains reached their peak height by around 580 million years ago, with deep crustal melting that ended slightly more recently by around 500 million years ago.
While most mountains are eroded over time by weather or reshaped by successive tectonic events, the Gamburtsev Mountains, by contrast, have remained largely untouched thanks to the protective shielding of the large quantities of ice above them.
Entombed within ice for most of their existence, the Gamburtsev Mountain range’s unique preservation makes it one of the best-preserved ancient mountain systems.
Going Beneath Antarctic Ice
Although their incredible preservation for eons makes them an ideal target for geologists’ study, sampling these deeply frozen mountains would be difficult since drilling through kilometers of ice would be extremely costly.
However, Halpin and Daczko note that recent fieldwork undertaken near the Denman Glacier revealed surface rocks that are believed to potentially be linked to the Gamburtsev range, which could allow scientists a rare opportunity to study the geology of what is arguably one of Earth’s most mysterious buried mountain ranges.
Such findings continue to reveal surprises about the hidden history of Earth’s southernmost continent, much of which remains inaccessible due to the large quantities of ice that cover it. In the future, as new ice-penetrating technologies and more advanced geological modeling become available, scientists hope to begin unraveling more of the secrets that remain frozen beneath Antarctica’s icy exterior.
“Antarctica remains a continent full of geological surprises,” the study’s authors recently wrote, “and the secrets buried beneath its ice are only beginning to be revealed.”
The team’s new study, “Gondwanan continental collision drives gravitational spreading and collapse of the ancestral East Antarctic mountains,” appeared in Earth and Planetary Science Letters.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.