Australian scientists find evidence of ancient "Himalaya-like" mountain range

APD

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Australian scientists have found evidence of an ancient mountain range that they believe sustained an explosion of life on Earth 600 million years ago.

The scientists from Australian National University (ANU) in Canberra said the range was similar in scale to the Himalayas and spanned at least 2,500 kilometers across the top of Africa, from modern west Africa to northeast Brazil, which at that time were part of the supercontinent Gondwana.

They were helped in their project by a Brazilian researcher, Carlos Ganade de Araujo from the University of Sao Paolo, who recently collected valuable rock and mineral samples from this area in Africa.

Like the Himalayas, the mountain range eroded intensely because of its size and the sediment which washed into the oceans provided "the perfect nutrients for life to flourish," according to Professor Daniela Rubatto of the Research School of Earth Sciences at ANU.

"Scientists have speculated that such a large mountain range must have been feeding the oceans because of the way life thrived and ocean chemistry changed at this time, and finally we have found it," she said.

The discovery is the earliest evidence of Himalayan-scale mountains on Earth.

"Although the mountains have long since washed away, rocks from their roots told the story of the ancient mountain range's grandeur," said co-researcher at ANU Professor Joerg Hermann.

"The range was formed by two continents colliding. During this collision, rocks from the crust were pushed around 100 kilometers deep into the mantle, where the high temperatures and pressures formed new minerals."

As the mountains eroded, the roots came back up to the surface. Some of them were recently collected in Togo, Mali and northeast Brazil by Brazilian co-researcher Carlos Ganade de Araujo.

Dr Ganade de Araujo recognized the samples were unique and brought the rocks to ANU where, using world-leading equipment, the research team accurately identified that the rocks were of similar age, and had been formed at similar, great depths.

The research team involved specialists from a range of different areas of Earth Science sharing their knowledge, said Professor Rubatto.

"With everyone cooperating to study tiny crystals, we have managed to discover a huge mountain range," she said.

The research from the ANU team is published in science journal Nature Communications.