Researchers mapping deep underground structures have discovered two massive tears in a tectonic plate beneath Iran.
The findings, detailed in a study published in Nature Geoscience on November 4, 2026, capture a crucial transitional phase in Earth’s history as an ancient ocean vanished and continents collided. The international research effort included participants from China, France, and Iran.
The imaging revealed a stark contrast between two regions. In the Makran area of southeastern Iran, an oceanic slab continues to descend into the mantle to depths of at least 450 kilometers beneath the Eurasian plate.
Further west in the Zagros collision zone, where the Arabian plate meets the Eurasian plate, the descending continental slab reaches no deeper than 300 kilometers.
This depth discrepancy stems from a difference in rock density. Oceanic crust consists largely of denser rocks that sink smoothly into the mantle during subduction, while continental crust is less dense and resists downward movement.
The underlying phenomenon traces back to the ancient Neo-Tethys Ocean, which once separated the Arabian and Eurasian plates. Over millions of years of subduction, the ocean floor was consumed into the Earth’s mantle until the water body shrank and disappeared entirely.
As continental material enters the subduction zone, the opposing forces cause portions of the sinking plate to detach and tear. The study identifies a primary tear linked to the transition from oceanic subduction to continental collision, alongside a second tear near the intersection of the Makran trench and a transform boundary.
The authors emphasize that the study does not predict imminent earthquakes or volcanic eruptions. Instead, its primary value lies in uncovering the profound mechanisms governing the evolution of the Earth’s crust over time.
