EARTHCODES: developing a novel open-source computing approach to evaluate the multi-process genesis of the sub-ridge mantle from multi-isotope data

The global radiogenic isotope dataset of mantle-derived mid-oceanic ridge basalts (MORB) shows large-scale variations, providing an invaluable record of the thermochemical history of Earth's mantle.

These variations are the conjugated, time-integrated product of secular crust-mantle fluxes, followed by thermodynamically variable melting.

Existing models of MORB source formation rarely investigate multiple of these processes at once and mainly focus on mantle enrichment through crustal recycling.

I propose to test whether source age, melting rate, and in particular secular mantle depletion through melt extraction can also explain the observed large-scale isotope variations.

I will develop Earthcodes, a user-friendly, open-source software to thoroughly interpret radiogenic isotope data in terms of precursor processes.

This in silico laboratory of the mantle-crust system will allow users to test geochemical hypotheses by investigating the effects of selected parameter variations on the resulting isotope systematics.

This new method will use the large existing open-source datasets and make geochemistry accessible to researchers without a laboratory (e.g. in low and middle income countries) or limited by accessibility (e.g. handicap, home office).

I will consolidate these datasets with the measurement of radiogenic Ce isotopes, a crucial tracer of mantle depletion, for a geographically representative selection of MORB samples. I am experienced with this under-used technique and will implement the protocols at Cardiff University.

I will use Earthcodes to constrain the magnitude and relative importance of each process in generating the source of modern MORB and associated isotope systematics.

I will work with geodynamicists at Cardiff University to evaluate existing 3D models of mantle convection against the new Earthcodes constraints on upper mantle geology. Findings will provide an improved estimate of the rate of Earth's mantle convection.