Description

Context:

The Gamburtsev Subglacial Mountains (GSM) were formed more than 500 million years ago, when the Gondwana supercontinent was coming together. This information was released in Earth and Planetary Science Letters.

What are the Gamburtsev Subglacial Mountains (GSM)?

At the highest point of the East Antarctic Ice Sheet, the Gamburtsev Subglacial Mountains are a mountain range that is fully buried under the ice.
In 1958, a Soviet seismic mission was the first to find these mountains.
The Transantarctic Mountains can be seen through the ice to some extent, but the Gamburtsev Mountains are completely hidden under several kilometers of ice.
Mountains usually form where two tectonic plates meet, either by colliding or subducting. But East Antarctica has been tectonically stable for a very long time.
Geologists didn't understand how such a huge mountain range could live inside a stable craton.

Zircon “Time Capsules” and Dating Evidence

Scientists looked at zircon grains found in sandstones from the Prince Charles Mountains that were laid down by old rivers that came down from the mountains.
Trace uranium is found in zircons. This uranium decays at a known rate, which makes it possible to get an accurate age.

The results show:
Uplift began ~650 million years ago
Himalayan-scale peaks reached ~580 million years ago
Crustal melting and flow ceased ~500 million years ago.

Zircons

Zircons are often called “time capsules” because they contain minuscule amounts of uranium in their crystal structure, which decays at a known rate and allows scientists to determine their age with great precision.

Geological Significance

The mountains are about the same size as the Alps in Europe. They were formed through a complicated process of melting and strengthening the crust.
The mountains partly fell apart because of spreading gravity, but they still had a thick crustal root that went deep into the Earth's mantle.
This one-of-a-kind preservation tells us a lot about Antarctica's geological past.

Source: downtoearth

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Practice Question

Q. The Gamburtsev Subglacial Mountains, often referred to as the "ghost mountains," are significant because:

A. They are the tallest mountains in the Andes range
B. They lie buried beneath the Antarctic ice sheet and influence ice flow dynamics
C. They are the oldest known volcanic mountains on Earth
D. They separate the Arctic and Atlantic Oceans

Correct Answer: B. They lie buried beneath the Antarctic ice sheet and influence ice flow dynamics