Mobility of carbon-rich melts in the upper mantle: a combined experimental and theoretical study of carbonatite melts densities

Basic data for this project

Description

Understanding the mechanisms of carbon transport and storage at depth is key to constrain the carbon fluxes between surficial and deep reservoirs, and hence the global carbon cycle. Carbonated melts are important hosts of carbon in the mantle, yet the physical properties that control their mobility and migration rates, such as the density and viscosity, are still poorly known at relevant conditions. This is particularly the case for the carbon-rich compositions, i.e. carbonate/carbonatites, produced by incipient melting of carbonated peridotites and eclogites. This project will capitalize on recent experimental progress using the synchrotron X-ray absorption method coupled with the Paris-Edinburgh press and advances on Molecular Dynamic simulations to determine the density of carbonatite melts at upper mantle conditions. The combined density datasets will be implemented in a continuous density model for carbon-rich melts that will find direct application to model the redistribution of carbon in magmatic processes over a broad range of crustal and mantle conditions. Specifically, the expected results will be applied to develop quantitative models for the extractions of carbonate/carbonatite melts from subducting slabs and its migration/ascent/emplacement through the mantle, ultimately leading to a new understanding of carbon mobility and recycling in the deep Earth.