Ancient Tectonic Histories Shape Subduction Dynamics Beneath Lesser Antilles

New research identifies a basalt-rich mantle transition zone, 330 kilometers thick, that alters the descent of oceanic plates into Earth's mantle.

A groundbreaking study reveals that ancient tectonic histories create compositional anomalies in oceanic plates, influencing their subduction behavior.
The mantle transition zone (MTZ), between 410 and 660 kilometers deep, acts as a gateway that can slow or stagnate sinking tectonic plates due to its basaltic composition.
Researchers identified an exceptionally thick MTZ—approximately 330 kilometers—beneath the Lesser Antilles, the thickest observed globally in this region.
Subducting oceanic slabs, around 100 kilometers thick, contain significant basaltic material that impacts their interaction with the mantle's layers.
The findings stem from the VoiLA project, which deployed 34 ocean-bottom seismometers to better understand subduction processes in the Atlantic region.