Underneath miles-deep ice sheets covering Antarctica lies the largest mountain range no one on Earth has ever seen. Even though a few of its tallest points peek through in some places, relatively few people know of the entire range’s existence.
However, geologists studying it have long argued about how and when these buried peaks were formed. A team of geologists propose a new explanation in an article in the journal Earth and Planetary Science Letters.
“The ice conceals some of Earth’s most enigmatic features,” according to the paper. One such feature is the Gamburtsev Subglacial Mountains, which rises over 9,000 feet above sea level and is covered by about 10,000 feet of ice. Its highest point is considered the coldest place on Earth. The range is equivalent in size and shape to the Swiss alps.
Creation of the Antarctica Mountains
Many geologists think these features were created when multiple tectonic plates that include what is now known as Africa, South America, Australia, India, and Antarctica collided to create a supercontinent called Gondwana. However, beyond that event, there is less agreement.
“…the timing and three-dimensional structure of the collisional zone, known as the Kuunga Orogen, remain highly controversial,” according to the paper.
The new study provides a bit more detail. The authors propose that the tectonic plates collision first uplifted the Gamburtsev Mountains when they had ground together. The tectonic collision then unleashed a flow of molten rock beneath the mountains. As that molten layer became hotter and thicker, the mountains above it collapsed under their own weight. The base of the mountains now rest upon the Earth’s mantle, the layer beneath the planet’s crust.
Read More: What the Mysterious Bloop Taught Us About Antarctica
Rock Beneath the Ice Sheet
The geologists tracked this massive activity by looking at tiny objects — zircon grains deposited by rivers flowing from the mountains more than 250 million years ago. These grains act as geologic timers, because they contain uranium, which decays at a rate scientists can use to measure their age.
According to the grains found at various points of the range, the mountains begin their rise about 650 million years ago, reached Himalayan heights by 580 million years ago, then completed their sinking by about 500 million years ago. A massive layer of ice has covered them since, making them one of the best preserved mountain ranges on the planet, because the ice shields them from the erosion that wears down more exposed mountains.
The scientists could learn more about the range’s composition by drilling through the ice to extract rock samples. However, that is a long and expensive process. They are now looking at exposed rocks from Antarctica’s east coast to get a hint of what kinds of rock might lie beneath the massive ice sheet.
Read More: Did an Ancient Civilization Ever Live in Antarctica?
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Before joining Discover Magazine, Paul Smaglik spent over 20 years as a science journalist, specializing in U.S. life science policy and global scientific career issues. He began his career in newspapers, but switched to scientific magazines. His work has appeared in publications including Science News, Science, Nature, and Scientific American.
