By studying geochemical compositions beneath Panama, Woods Hole Oceanographic Institution (WHOI) scientists have been able to track large-scale movements in Earth’s deep interior. They were able to show that the volcanic material is sourced from the Galapagos plume, over 1500 km away.
“The lateral transport of plume material represents an understudied mechanism that scatters enriched geochemical signatures in mantle domains far from plumes,” said David Bekaert, lead author of the paper.
The team showed that hot material originating from Earth’s deep interior travels laterally through the shallow mantle, similar to wind blowing at Earth’s surface. Chemical observations were combined with geophysical imaging of Earth’s deep interior to locate the source and direction of the so-called ‘mantle wind’.
Usually, material cannot easily pass through a subduction zone, where the edge of a tectonic plate, called a ‘slab’, acts as a barrier. However, the region beneath Panama is unusual because there appears to be a ‘slab window’ that allow this mantle wind to blow through.
It is well established that rising plumes of superheated rock in Earth’s mantle are the main channels for transporting geochemically enriched material deep underground, but the extent to which lateral flow processes disperse mantle material far from vertical plumes, remains widely unknown. The discovery of lateral transport of deep, exotic material across the Earth’s interior could have far-reaching implications for scientists understanding of the chemical evolution of our planet over geological time.
https://phys.org/news/2021-11-mantle-slab-window-beneath-panama.html