Metal outgassing from Ambrym and Yasur volcanoes, Vanuatu

This project will seek to understand why the volcanoes of the Vanuatu arc emit large fluxes of volatile metals to the atmosphere. Analysis of erupted rocks from Yasur and Ambrym volcanoes will be carried out in order to understand the partitioning of metals between silicate melt, sulphide phases and the exsolved volatile phase. These studies will be supplemented by a field campaign to capture volcanic gas and aerosol emissions, which will be characterised for their volatile metal content and speciation. In particular the project will focus on the role of magmatic chlorine in transporting metals in the exsolved volatile phase, and will compare natural data to experiments to constrain chlorine partitioning.

The student will undertake microanalysis of erupted, quenched rocks from Yasur and Ambrym volcanoes, Vanuatu, e.g. using scanning electron microscopy, electron probe and secondary ion mass spectrometry to quantify major, trace and volatile elements in whole rocks, glasses and sulphides. The student will undertake fieldwork in Vanuatu to acquire samples of volcanic gases and aerosols from the crater rim at Yasur and Ambrym volcanoes, and will analyse them for major anions and cations (including the volatile metals), as well as for sulphur isotopes. The student will use these observations to model metal partitioning between silicate melt, sulphide and aqueous fluid to understand the sensitivities of the magmatic system with respect to parameters such as fO2, pressure and aqueous fluid salinity and produce insights into metal processing by volcanoes and the mechanisms of metal enrichment.