An Icy Superhighway Once Carried Glaciers From Namibia to Brazil

An Icy Superhighway Once Carried Glaciers From Namibia to Brazil

Namibia is famed for its deserts, including the world’s oldest, a vast expanse of undulating, scorched sand dunes occasionally visited by an ethereal fog. But around 300 million years ago, Namibia was frozen and located near the South Pole, smooshed against what is now South America within the emerging Pangea supercontinent.

There, it was a superhighway for fast-moving ice, as glacial fragments slipped away from a colossal ice cap in southern Africa, and carved signatures in the underlying rock as they sped into what is now Brazil. The two countries today are separated by roughly 3,500 miles of Atlantic Ocean. But a team of researchers reported last month in PLoS One that they had pieced together a picture of this ancient flow of ice between the two landmasses.

The key piece of evidence came in the form of lacerated Namibian hills formed long ago by the migration of glaciers and icy rivers. This study features some of the oldest descriptions of these ice-formed sculptures, and it is the first time they have been described in southern Africa.

“Trying to identify such ancient features in the geological record is a tremendous challenge,” said James Lea, a lecturer in glaciology at the University of Liverpool who was not involved in the study. But if the findings are confirmed by additional field work, he said, “their preservation represents a minor miracle, and provides a fascinating insight into the behavior of a largely lost ancient glacial landscape.”

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