Is There a Global Carbonate Layer in the Oceanic Mantle?

Previous modeling of carbonate subduction by high-pressure experimentation has allowed to propose scenarios for bulk carbon return the mantle, but detailed transfer mechanisms have seldom been studied. We monitored carbonate–silicate reactions combining experiments and synchrotron-based X-ray diffraction. Carbonates break down at moderate pressure high temperature CO2 is trapped grain boundaries. Further isothermal compression yields melting, which may control continuous introduction, first in mantle wedge, next, away from wedge. Carbon presence discussed a variety magmatic contexts, under oceanic lithosphere (hotspots, petit spots, fossil ridges). suggest global carbon-rich layer that steadily fed processes. This can be source mechanical weakening lithosphere–asthenosphere boundary oceans. Therefore, carbon-induced melting key mechanism modern-style plate tectonics.