The rich fossils at the “roof of the world” have revealed that this mountain range was formed much earlier than previously thought and was once located along a stormy coastline of a long-lost archipelago.
Researchers have discovered that the rocks of the Parahio Valley in the Spiti region of India contain traces of an ancient river delta dating back 500 million years, filled with fossils from shallow coastal areas and debris from a much younger mountain range.
This finding challenges the long-held belief that the initial accumulation of the Himalayas began only 50 million years ago.
“When you view the Himalayas, you often get the impression that everything happened during the Cenozoic era (around 50 million years ago), but in reality, the early formation of this mountain range occurred during the Cambrian period (542-488 million years ago) or even earlier,” said geologist Paul Myrow from the University of Colorado in Colorado Springs.
Myrow and his colleagues trekked up and down the steep slopes of the Parahio Valley, collecting the first complete geological “slices” of the area. Each slice consists of multiple layers of rock resembling a multi-layered cake that geologists study to reconstruct the region’s history.
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A 3D image captured by the Endeavour Space Shuttle in 2000. The Himalayas are considered to be much older than recent calculations suggest. (Photo: AP) |
They studied rock slices starting at an altitude of 4,200 meters and extending to over 4,500 meters above sea level. What they found was a “treasure” of extinct trilobite species, which helped date the rock samples. Trilobites are among the earliest known arthropods, related to crabs, centipedes, and spiders.
The researchers also found numerous traces of a shallow coastline that once existed along the northern border of India before colliding with the Eurasian plate, near the Tethys Sea, leading to the formation of present-day Himalayas.
T. An
