Antarctica, the frozen continent at the bottom of the world, holds many secrets beneath its icy surface. Have you ever wondered what lies hidden beneath the thick blanket of ice that covers this vast landmass? Deep below the frozen expanse are rugged mountains, valleys, hills, and plains waiting to be discovered.
One of the most intriguing mysteries of Antarctica is the Gamburtsev Subglacial Mountains, a range that is completely buried under kilometers of ice. These ancient mountains, similar in scale and shape to the European Alps, were first discovered by a Soviet expedition in 1958 using seismic techniques. Despite their massive size, the Gamburtsev Mountains remain one of the least understood tectonic features on Earth due to being completely covered in ice.
Unlike most mountain ranges that form at the boundaries of tectonic plates, the Gamburtsev Mountains emerged over 500 million years ago in the heart of East Antarctica, a region that has been tectonically stable for millions of years. A recent study published in Earth and Planetary Science Letters sheds light on the origins of these hidden mountains and how they came to be preserved under the thick ice sheet.
The research suggests that the Gamburtsev Mountains formed during the collision of ancient continents that gave rise to the supercontinent Gondwana. The clash of tectonic plates triggered the flow of hot, molten rock deep beneath the mountains, leading to their gradual rise and eventual collapse under their own weight. This process, known as gravitational spreading, left behind a thick crustal “root” that extends into Earth’s mantle.
To unravel the timeline of these ancient mountains, scientists analyzed zircon grains found in sandstones deposited by rivers flowing from the Gamburtsev Mountains over 250 million years ago. These tiny crystals act as time capsules, preserving the history of mountain-building events that took place millions of years ago. The analysis revealed that the mountains began to rise around 650 million years ago, reaching their peak height by 580 million years ago before experiencing deep crustal melting and flow that ended around 500 million years ago.
Despite the challenges of drilling through the thick ice to directly sample the mountains, the study provides valuable insights that can guide future exploration. Recent fieldwork near the Denman Glacier uncovered rocks that may be linked to the ancient Gamburtsev Mountains, offering new opportunities to reconstruct the hidden architecture of East Antarctica.
Antarctica remains a continent full of geological surprises, and the secrets buried beneath its ice are just beginning to be unveiled. The discovery of the ancient Gamburtsev Mountains provides a glimpse into the dynamic history of this icy landmass and opens up new avenues for exploration and research.
This article was written by Jacqueline Halpin, Associate Professor of Geology at the University of Tasmania, and Nathan R. Daczko, Professor of Earth Science at Macquarie University. It was originally published on The Conversation under a Creative Commons license.
