Scientists have discovered a 900-mile-long conduit in the Earth’s mantle, beneath the Earth’s crust, that carries volcanic material from the Galápagos Islands to Panama in Central America.
An interdisciplinary team led by the Woods Hole Oceanographic Institute discovered “anomalous geochemical compositions beneath Panama” that trace back to the Galápagos plume, a column of molten rock that rises from deep within the Earth.
The team used helium isotopes and other data from fluids and rocks that showed the volcanic materials present in Panama come from the Galápagos Islands, located more than 900 miles off the coast of Ecuador. .
“Lateral transport of plume material represents an understudied mechanism that disperses enriched geochemical signatures in mantle domains away from plumes,” said David Bekaert, postdoctoral researcher at the institute and lead author of the study. published in Proceedings of the National Academy of Sciences.
“We can compare volcanic systems to the body of a living organism; when the body bleeds, it’s a bit like magma coming out of the Earth. And you can measure the composition of that magma, just like you can measure a blood type.
“In this study, we measured an unexpected volcanic gas composition, much like when a human has a rare blood type. In the case of the Earth, we then try to explain where it came from in terms of deep geological processes.
The team of experts demonstrated that hot elements from the Earth’s deep interior move “laterally through the shallow mantle, like the wind blowing across the Earth’s surface”.
In addition to chemical observations, the researchers used geophysical imagery from deep within the Earth to determine the source and direction of what they called the “mantle wind.”
It is usually not easy for mantle materials to pass through subduction zones because the edge of the tectonic plate, called the “slab”, acts as a barrier. But the area under Panama is unusual in this regard, as it appears to have a “slab window” that allows this mantle wind to blow through, the scientists said.
“Exotic volcanic chemical characteristics have already been documented in Central America,” Bekaert said. “We use these chemical characteristics as indicators of major geological processes. In this case, our findings help explain why plume-derived volcanic materials appear in central Panama, even though there are no active volcanoes there.
“Overall, this study tells us that, even after billions of years of evolution, our planet remains a dynamic system marked by large-scale movements of solid material, miles below our feet,” concludes the report.
Edited by Matthew B. Hall and Kristen Butler