LIMELIGHT · The contribution of magma-carbonate interactions in the upper crust to volcanic CO2 emissions: quantitative constraints from experimental petrology, isotope geochemistry and thermal modelling

Mt. Etna and Popocatépetl, the most important subaerial sources of volcanic CO2 show evidence of interactions with the carbonate rocks forming their sedimentary basement. The present project aims at quantifying the contribution of magma-carbonate interactions in the upper continental crust to massive CO2 production in these volcanic areas. Carbonate assimilation will be investigated by hydrothermal experiments and thermal modelling. The experiments will be performed at magmatic conditions (pressures, temperatures and water contents). The comparison between experimental results and existing data on natural volcanic rocks will allow to assess the degree of magma-carbonate interaction and the ensuing CO2 production. Furthermore, CO2 degassing mechanisms will be experimentally investigated by studying the carbon isotopic fractionation between the magma and the fluid phase, with the final goal of interpreting the isotopic signature of volcanic gases. In conclusion, by this study we intend to define a petrological and geochemical tool to characterize carbonate assimilation occurring at a given volcanic centre to finally quantify its CO2 emissions. By the proposed project the applicant seeks a competence diversification in the volcanological, petrological, geochemical and experimental fields. The demanded host organisation is at the forefront of experimental petrology, thermodynamic and volcanic degassing modelling and therefore represents the most appropriate one to the project and to the applicant’s individual needs. Via the training, the candidate intends not only to attain a high-level of expertise with both experimental and analytical instruments, but also to definitely broaden her methodological approach to volcanology, by increasing her physical and chemical knowledge of volcanological processes. These competencies are necessary for the applicant to reach a position of professional maturity and independence in her research domain and to promote her research career.