The Indian Plate Could Be Undergoing a Split Similar to East Africa’s Division
A new study proposes that the Indian Continental Plate may be undergoing a unique form of splitting, not vertically like East Africa, but horizontally as it converges with Eurasia. This unconventional process could create two layers, each approximately 100 kilometers (60 miles) thick.
Understanding the Himalayas and Tibetan Plateau: Seeking Clarity
Despite the Himalayas being the world’s mightiest mountain range, the distinctive feature lies behind the Tibetan Plateau. The driving force behind these geological formations is India’s northward movement at a rate of 1-2 millimeters/year (0.04-0.08 inches/year) colliding with Eurasia.
While this slow-motion collision over 60 million years explains the towering heights of the Himalayas, the precise mechanisms behind this process remain debatable.
Exploring Geological Theories: Delamination Unveiled
A new theory surfaced at the December American Geophysical Union conference, suggesting that the Indian Plate is “delaminating.” The upper part peels off to support Tibet in this scenario, while the denser lower section sinks into the mantle. This unexpected behavior challenges previous assumptions about continental plate dynamics.
Helium Clues and Geological Evidence: Unearthing Insights
The study draws evidence from helium analysis in Tibetan springs, particularly helium-3 concentrations. Helium-3, a rare isotope, suggests a mantle source.
By measuring the isotope ratio at 200 Tibetan springs, researchers identified a pattern indicating the proximity of the mantle to the surface in northern Tibet. The observed earthquake patterns further support the hypothesis that mantle intrusion occurs from the plateau’s eastern side.
Plausible Explanations: Tectonic Cake Layers and Plate Shape Dynamics
Considering the layered structure of tectonic plates, akin to a cake, where denser material forms the bottom layer, computer models support that something separates the lower part of the Indian Plate from the more viscous mantle material above.
The authors propose that the unique shape of the Indian Plate, thicker at its northernmost point and thinner at the sides, contributes to the delamination process. The center’s faster sinking, influenced by the plate’s shape, allows even modest pressures from the mantle to peel off the lower section.
While drilling to depths of up to 100 kilometers for direct confirmation is impractical, the study presents a compelling argument based on multiple lines of evidence, challenging previous notions about continental plate behavior.
Read the original article on IFL Science.
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