The hidden geological foundation supporting the majestic Himalayas has proven to be different than previously believed, according to recent scientific findings.
The Earth's crust beneath the Himalayas and Tibetan Plateau has long been thought to double in thickness due to the collision between the Asian and Indian continents. However, a new study published in the Journal Tectonics on August 26 challenges this belief, revealing a piece of mantle sandwiched between the Asian and Indian crusts.
Led by researcher Sternai and his colleagues, the study simulates the collision on a computer and finds that the Indian tectonic plate slipped under the Eurasian plate, resulting in a mantle sandwich beneath the region. This discovery contradicts the century-old theory proposed by Swiss geologist Émile Argand, which suggested that all the material beneath the Himalayas comes from the crust alone.
Simone Pilia, a co-author of the study, states that the observations in the Himalayas are now more easily explained by the model with crust, mantle, and crust. Douwe van Hinsbergen, a professor of global tectonics, finds the results to be a "nice new finding" and an "elegant interpretation."
The mantle, much denser than the crust, doesn't liquefy at the same temperatures. As such, the rocks in the crust turn molten around 25 miles (40 km) deep due to extreme temperatures. The mantle sandwich in the simulation matches previous evidence that Arnaud's theory couldn't explain.
Adam Smith, a postdoctoral research associate, finds the results plausible and capable of explaining geological oddities in the Himalayas. Van Hinsbergen suggests that the results are not controversial, as one would expect a sandwich consisting of crust and mantle lithosphere of the upper plate (Tibet) and then the crust of the lower plate (Indian) in a continent-shoving event.
The researchers' comparison of their results with seismic data and direct rock information supports the mantle sandwich model. The study presents strong evidence for the model with crust, mantle, and crust beneath the Himalayas.
Tectonic forces squeezed Tibet so hard that its area shrank by almost 620 miles (1,000 kilometers). The crust is so light and buoyant that it behaves similarly to an iceberg, lifting up higher above Earth's surface the thicker it gets. This explains why the Himalayan mountains, which formed around 50 million years ago due to the collision between the Asian and Indian continents, are among the tallest in the world.
The study's findings contradicting Arnaud's 100-year-old theory is controversial due to its widespread adoption. However, the researchers believe that their findings provide a more accurate understanding of the Earth's structure beneath the Himalayas and could lead to new insights into the region's geological history.
Read also:
- Understanding Hemorrhagic Gastroenteritis: Key Facts
- Stopping Osteoporosis Treatment: Timeline Considerations
- Tobacco industry's suggested changes on a legislative modification are disregarded by health journalists
- Expanded Community Health Involvement by CK Birla Hospitals, Jaipur, Maintained Through Consistent Outreach Programs Across Rajasthan
