`Antarctic mountains date back to dinosaur age`
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Last Updated: Monday, November 21, 2011, 21:53
  
Washington: The root of the mysterious range of Antarctic mountains completely hidden under the continent's massive ice sheet may be over 200 million years old dating back to the dinosaur age, scientists have claimed.

Researchers on a project to understand the Gamburtsev Subglacial Mountains in East Antarctica better, said the mountains rise up to 10,000 feet above the planet's surface, but are covered by up to 15,750 feet of ice.

"This icy coat makes them the least understood mountain range on Earth," researcher Fausto Ferraccioli, a geophysicist at the British Antarctic Survey, said.

"It is very fitting that the initial results of Antarctica's Gamburtsev Province project are coming out 100 years after the great explorers raced to the South Pole," said Alexandra Isern at the National Science Foundation.

"The scientific explorers of the Antarctica's Gamburtsev Province project worked in harsh conditions to collect the data and detailed images of this major mountain range under the East Antarctic Ice Sheet. The results of their work will guide research in this region for many years to come."

What details scientists have gathered about the mountains provide conflicting evidence about how they got there and how old they are. For instance, nearby rocks suggest they are very ancient, but their steep, rugged shapes, which resemble the Alps, are what one would expect of young mountains.

To learn more about their origins, the team collected new data from the Gamburtsev region by flying about 120,000km with two aircraft equipped with ice-penetrating radars, lasers and magnetic and gravity meters.

Magnetic anomalies seen throughout the Gamburtsevs match those of about one-billion-year-old rocks seen to the north that predate the evolution of animals and plants on Earth.

This suggests the root of this mountain range was born around that time from collisions of several continents or microcontinents, findings corroborated by gravity and other data, the team reported in journal Nature.

The research then suggested that rifting events between 250 and 100 million years ago, back when dinosaurs roamed the Earth, triggered the uplift of these mountains. Specifically, the rise of rock along the flanks of these rifts and the buoyant root of these mountains forced the land upward.

Rivers and glaciers then cut deep valleys, giving these mountains their rugged shapes. The East Antarctic Ice Sheet, which currently covers one-tenth of Earth's crust, then entombed the range, preserving them as they are today, the researchers said.

"Explorers that set foot on the moon for the first time were confronted with many unknowns and challenges -- the same holds true for the Gamburtsevs, in my view," Ferraccioli said.

"Unravelling the mystery of how the mountains formed by analysing the new data and putting together bits and pieces of a billion-year history of the region was really exciting."

The new geophysical images and models will help guide future research on geological evolution and mountain-building in this remote region for years to come, he added.

PTI


First Published: Monday, November 21, 2011, 21:53


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