Mantle convection and Earth's isotopic heterogeneity

Last updated: August 2026

About

Oceanic basalts record a broad spectrum of radiogenic isotope compositions. This spectrum reflects the creation of chemical contrasts by melting, crust formation, alteration, and recycling, followed by stretching, folding, mixing, and sampling during mantle convection. Apparent isotope end-members can therefore be the observable result of a continuous and evolving compositional field.

This project will investigate how whole-mantle convection transforms chemical heterogeneity and how volcanic systems sample it. It will connect statistical descriptions of mantle stirring with subduction recycling, melting, plume entrainment, and melt mixing.

Research questions

• How do the wavelength, amplitude, and longevity of isotopic heterogeneity evolve during mantle convection?
• How do mid-ocean ridges, subduction zones, and plumes filter this spectrum before it reaches the surface?
• Under what conditions do distinct apparent isotope end-members emerge from continuous heterogeneity?

Methods and data

Projects can combine numerical mantle stirring, statistical models, isotope datasets, subduction-recycling models, and melting calculations.

Possible projects

Possible directions include modelling a particular isotope system, testing the effect of subduction recycling, or comparing simulated isotope distributions with ocean-island and ridge-basalt datasets.

Essential background

Useful preparation includes geochemistry, geodynamics, physics, mathematics, programming, or data analysis.