Under the ice of Antarctica, there are the Gamburtsev subglastic mountains, which were born more than 500 million years ago, when Supercontinent Gondwana formed.
Have you ever imagined the appearance of Antarctica under your thick ice cloak? Hidden underneath are spawned mountainsvalleys, hills and plains.
Some peaks, such as the imposing transantal mountains, rise above the ice. But others, like the mysterious and old Gamburtsev Subglastic Mountainsin the middle of the eastern Antarctica, they are completely buried.
The Gamburtsev mountains are similar in scale and shape to the Alps Europeans. But we cannot see them because the high alpine peaks and the deep glacial valleys are buried under kilometers of ice.
How did they come up? Normally, a mountainous chain stands in places where two tectonic plates collide with each other. But the eastern Antarctica has been tectonically stable for millions of years.
A new, published in Earth and Planetary Science Letters, reveals how this hidden mountain range came up more than 500 million years agowhen the Gondwana Supercontinent formed from the collision of tectonic plates.
The findings offer a new perspective on how mountains and continents evolve over geological time. They also help to explain why the interior of the Antarctica kept remarkably stable for hundreds of millions of years.
A buried secret
The Gamburtsev Mountains are buried under the highest point of the East Antarctic Cloak. They were first discovered by a Soviet expedition that used seismic techniques in 1958.
How the mountainous chain is ice -coveredIt is one of the least known tectonic characteristics of the earth. For scientists, it is deeply intriguing. How can such a large mountainous chain be formed and still preserved in the heart of an ancient and stable continent?
Most of the large mountainous chains are the tectonic collisions location. For example, Himalayas still rise today as Indian and Euro-Asian plates continue to converge, a process that began about 50 million years ago.
Plate tectonics models suggest that the crust that currently forms the eastern Antarctica comes from at least two large continents, over 700 million years ago. These continents used to be separated by a vast ocean basin.
The collision of these land masses was fundamental to the birth of Gondwana, a supercontinent that included what Africa, South America, Australia, India, and Antarctiva today is today.
The new study supports the idea that Gamburtsev mountains formed during this old collision. The colossal shock of continents triggered the flow of Hot and partially melted rock in the depths of the mountains.
As the crust was thickening and warming During the formation of the mountains, he became unstable and began to collapse under his own weight.
In the depths of the surface, the hot rocks began to flow to the sides, as squeezed toothpaste of a tubein a process known as gravitational spreading. This caused the mountains to partially collapse, preserving, however, a thick “root” of the crust, which extends to the earth’s cloak.
Crystal Time Capsules
To determine the moment of this dramatic rise and fall, the authors analyzed tiny zircon grains Found in sandstones deposited by rivers that ran from the old mountains more than 250 million years ago. These sandstones were recovered from the Prince Charles mountains, which stand out from the ice hundreds of miles away.
Zircons are often designated by “Time Capsules”Because they contain tiny amounts of uranium in its crystalline structure, which decomposes to a known rhythm and allows scientists to determine their age with great precision.
These zircon grains preserve a record of the chronology of mountain building: the Gamburtsev mountains began to rise about 650 million years ago, reached the heights of the Himalayas 580 million years ago and underwent a profound fusion and flow of the crust that ended about 500 million years ago.
Most mountainous chains formed by continental collisions are eventually worn out by erosion or remodeled by later tectonic events. Due to the fact that they were preserved by a deep layer of ice, the Gamburtsev subglasses are one of the best preserved Old mountain chains of the earth.
Although currently it is very difficult and expensive to pierce thick ice to collect direct samples from the mountains, the model offers new predictions to guide future explorations.
For example, recent fieldwork near the Denman Glacier, on the east coast of Antarcetado, revealed rocks that may be related with these old mountains. An deepened analysis of these rock samples will help rebuild the hidden architecture of the eastern Antarct.
Antarctica remains a continent full of geological surprises, and the secrets buried under your ice are just beginning to be revealed.
