Squeezing water (and carbon) from a stone: volatile-enriched magmatism at mid-ocean ridges
IPGP - Îlot Cuvier
Séminaires Géosciences Marines
University of Oxford
Water and carbon are present in the mantle beneath mid-ocean ridges at the low level of 100 ppm. Melting experiments show that the mantle solidus is drastically lowered by volatiles, even in such low concentrations. Should we then expect that water and CO2 have important consequences for melting and melt transport? In this talk I review new theory and models that address this question. A key finding is that volatiles can cause channelisation of melt transport a depths of 60-80 km, the transition from hydrous to silicate dominant melting. This has implications for the rate of melt transport, as well as for its trace-element signature. Time permitting, I outline a hypothesis and some early results regarding the coupling of the solid Earth and the climate system via mantle volatile emissions.