Because deep carbon is stored for long periods in the lithospheric mantle, rift CO₂ flux depends on lithospheric processes that control melt and volatile transport. Data discussed in this paper indicate that advection of the root of thick Archaean lithosphere laterally to the base of the much thinner adjacent Proterozoic lithosphere creates a zone of highly concentrated deep carbon. This mode of deep-carbon extraction may increase CO₂ fluxes in some continental rifts, helping to control the production and location of carbonate-rich magmas.

The interaction between deformation of the lithosphere and the chemical evolution of migrating melts is incompletely understood. Here, we describe an approach in which we couple a large amount of precomputed phase diagrams with a lithospheric deformation code that includes a simple diking parameterization. The simulations are shown to give detailed, yet realistic, predictions that compare reasonably well with observations.

In view of the elevated upper-mantle temperatures within the Cape Verde hotspot regime, fracturing induced by magmatic injection is the most likely cause for the observed deep earthquakes.

The source of fluids that are released from subducting slabs is incompletely understood. The team here employs novel experiments to simulate the conditions in the lab and shows that the reaction of sediments from the subduction zone with peridotite is very similar to traces of fluids found in diamonds and kimberlite magmas.