Unaweep Canyon in the Rocky Mountains includes a deep gorge with ancient landscapes and sediments. The inset image is of a "dropstone" from an ancient glacier.
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Image Courtesy of Gerilyn Soreghan

Cold and Ice, and Heat, Episodically Gripped Tropical Regions 300 Million Years Ago
News story originally written on July 31, 2008

For a long time scientists have thought that the tropics stayed warm when much of the Earth was covered with glaciers 300 million years ago. But scientists have learned this wasn't the case. In fact, the tropics experienced cold temperatures at that time.

Scientists found evidence for this in an ancient glacial landscape in the Rocky Mountains of western Colorado. Three hundred million years ago, the region was part of the tropics when the continents were part of the supercontinent Pangaea.

The ancient tropical glaciers were very close to the ocean, so the toes of the glaciers were probably less than 500 meters (1,640 feet) above sea level. This is much lower than the tropical glaciers on Earth during more recent glacial times.

This study shows that the Earth contains great amounts of information about its past climates, and discovering this type of information may help us understand and predict modern climate change."

Last modified October 2, 2008 by Becca Hatheway.

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