Unveiling Earth’s Secrets: How a ‘Ghost’ Plume Reshaped India’s Collision with Eurasia

Scientists have recently uncovered an ancient “ghost” magma plume beneath Oman. This plume lies trapped beneath a thick layer of Earth’s crust and the upper mantle, which means it doesn’t cause any volcanic eruptions on the surface. While it’s unclear whether this plume ever triggered an eruption, there’s evidence that it may have influenced the angle of the Indian tectonic plate during its historic collision with Eurasia millions of years ago.

The plume is located beneath the Salma Plateau, which rises about 6,600 feet. Dr. Simone Pilia, a geophysicist from King Fahd University, suggests that the plateau might have formed due to this plume. “A plume is hot material that wants to rise, so it’s creating subtle topography,” he explains. Though the uplift is minor, it’s still a sign that the plume is active.

Researchers used seismic waves to make this discovery. These sound waves travel through the Earth at different speeds depending on what material they encounter. Oman’s extensive network of seismic stations played a crucial role in their research, leading them to name the plume “Dani” after Dr. Pilia’s son.

This “ghost” plume is unique. It’s a type that doesn’t lead to volcanic activity, yet it still influences geological processes. Mantle plumes usually originate from deep within the Earth, but they often trigger eruptions when they reach the surface. In continental areas like Oman, however, the thicker crust prevents these plumes from causing eruptions.

Interestingly, many researchers assumed that if no volcanism is present, there are likely no plumes underneath continental plates. Dr. Pilia counters this idea: “Absence of evidence is not evidence of absence.” Just because we don’t see eruptions doesn’t mean a plume isn’t there.

The Dani plume provides new insights into how plumes can influence tectonic plate movements. The study’s findings reveal that the Indian plate’s trajectory changed between 40 and 25 million years ago, possibly due to shear stress from the plume. This connection hadn’t been clearly established before, demonstrating how plumes can impact plate tectonics.

Historical data indicates that the Salma Plateau is about 40 million years old, aligning with the timeline of the Indian-Eurasian plate collision. This collision dramatically reshaped the region, and researchers are just beginning to piece together how such plumes affect geological activity.

The Dani plume suggests there may be many other “ghost” plumes waiting to be discovered, especially in areas with thick crusts, such as Africa, which sits over a known low-shear-velocity province.

In summary, the discovery of the Dani plume opens a new chapter in our understanding of Earth’s geology. It underlines the complexity of our planet’s inner workings and hints at many more hidden phenomena beneath our feet.



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