Discovery of Ancient 'Ghost' Magma Plume in Oman Alters Tectonic Theory

Recent research has unveiled the existence of an ancient 'ghost' magma plume located beneath the Salma Plateau in Oman, which is believed to have significantly influenced the trajectory of the Indian tectonic plate between 25 million and 40 million years ago. This discovery, detailed in a study published on June 6, 2025, in the journal *Earth and Planetary Science Letters*, sheds light on the complex dynamics of tectonic movements and geological formations.

The study was led by Dr. Simone Pilia, a geophysicist and assistant professor at King Fahd University of Petroleum and Minerals in Saudi Arabia. Pilia and his team utilized seismic wave data to identify the Dani plume, named after his son, which resides beneath a thick crust and upper mantle layer, thereby preventing any surface volcanic activity typical of other mantle plumes. "A plume is hot material that wants to rise, rise, rise — so it's underneath and it's pushing up, creating topography," Pilia explained, indicating that the Salma Plateau’s formation may be attributed to this plume's activity.

Historically, mantle plumes have been associated with volcanic eruptions, particularly in oceanic plates. However, the Dani plume represents a new classification termed 'amagmatic ghost plume,' highlighting the possibility that such plumes can exist beneath continental crusts without resulting in volcanic activity. This finding challenges previous assumptions in the geological community that the absence of surface volcanism indicated the absence of a plume.

According to the study, the Salma Plateau, approximately 40 million years old, aligns chronologically with the collision between the Indian and Eurasian tectonic plates. Pilia's team reconstructed the trajectory of the Indian plate, revealing that the plume's influence altered its direction during the pivotal collision period. "We demonstrated that the shear stress produced by the plume was the reason for the change in azimuth [angle] of the Indian plate," Pilia noted, suggesting a direct correlation between the plume's presence and tectonic plate dynamics.

The implications of this research extend beyond Oman. The study encourages a reevaluation of current geological models, particularly regarding regions with thick continental crusts, such as Africa, where similar ghost plumes may exist undetected. This revelation could lead to a deeper understanding of tectonic processes and the historical geology of the Earth.

Pilia emphasized the need for further investigation, stating, "What we strongly believe is that there are many other ghost plumes that we don't know of." The findings not only contribute to the understanding of geological phenomena but also invite a broader discussion on the effects of such plumes on tectonic movements worldwide.

As seismic technology continues to advance, the potential for discovering additional ghost plumes may reshape the landscape of geological science, providing insights into the underlying mechanisms that have shaped our planet over millions of years. This research underscores the complexity of Earth's interior and highlights the interconnectedness of geological processes, which remain a vital area of study for both scientists and policymakers alike.