2020 | Halogens as tracers of magma evolution from the mantle source to the atmosphere
Halogens (F, Cl, Br, I) are important volatile components in magmas in addition to H2O, CO2 and S. Their extremely high chemical activity in melts and fluids leads to a significant influence that halo-gens impose on the properties of magmas, on magma degassing, on the extraction, transport and deposition of metals as well as on the chemistry of volcanic emissions and composition of atmos-phere. Since halogens can be inherited from different sources (mantle, crust, sediments, etc.) and by different processes (melting, assimilation, mixing) during magma genesis, their geochemical be-haviour can be used as a key indicator of genetic conditions and evolution of the magma. While chlorine (and partly fluorine) is routinely measured in different magmatic phases including volcanic gases, the data for other halogens is quite scarce, unsystematic and inconsistent. Thus, our under-standing on how halogen concentrations, speciation and ratios are linked to magmatic processes and conditions remains elusive. The main challenge is typically very low concentration of bromine and iodine in magmas requiring special sampling efforts and development of sensitive and reliable analytical methods. The major goal of this project is an understanding of halogen behaviour in magmatic systems from source to eruption and a development of sampling and analytical tools al-lowing for reconstruction of magmatic evolution. This will be achieved by joint efforts of a multidisci-plinary team combining field campaign(s), testing and application of sampling and analytical tools and modelling of halogen behaviour in magmas. In other words, we will combine petrological and volcanological methods, analytical chemistry and atmospheric remote sensing.