Yellowstone may be powered by a vanished tectonic plate, not a mantle plume

A new paper proposes that the Yellowstone hotspot - famous for its supervolcanic eruptions - may not be driven by a deep mantle plume after all. Instead, the researchers argue that the ancient Farallon plate, which subducted beneath North America over millions of years, is the real engine behind the volcanic activity.

The Farallon plate shaped much of the western continent as it dove under North America, building California and still powering the Cascade volcanoes through its remaining fragments. The new hypothesis suggests that stresses created by the plate’s disappearance opened pathways for molten rock to rise to the surface, producing the chain of massive eruptions visible across the Snake River Plain leading to Yellowstone’s calderas.

The idea challenges the conventional mantle-plume model, which explains most geological hotspots as columns of deep, buoyant rock convecting upward. Yellowstone has always been an odd case - hotspots typically punch through thin oceanic crust, not thick continental crust - making alternative explanations worth serious consideration.