Sulfur in magmas is typically incorporated as reduced (sulfide) and oxidized (sulfate) species. Due to the change in valency, sulfur is incorporated differently into magma, leading to significant variations in solubility and isotopic fractionation. The X-ray absorption technique commonly determines the presence of sulfide and sulfate species in the melt. In this study, we investigated a series of mafic glasses synthesized under reduced conditions, where only sulfide species are anticipated to be present in the melt. The glasses were synthesized in a one-atmosphere gas mixing furnace using CO-CO2-SO2. X-ray Absorption Near Edge Structure (XANES) spectra were acquired at the LUCIA line of the SOLEIL synchrotron. The spectra obtained from these glasses revealed peaks corresponding exclusively to sulfide ionic species, yet the glasses exhibited significant isotopic fractionation against sulfide. Previous studies indicated that fractionation factors are influenced by melt and sulfide composition. To enhance our understanding of the potential causes of sulfur isotope fractionation, we examined subtle changes in the XANES spectra. Notably, variations in the relative peak size (height and area) of the peaks at 2472 and 2477 eV were observed among our samples. Our empirical investigation suggests a weak correlation between XANES peak characteristics and sulfur isotope fractionation systematics. Future detailed investigations are expected to clarify the significance of this correlation.
| Subject : | : | Poster |
| Topics | : | Magma, Melts and Volcanoes |
| Keywords | : | XENES ; Experiment ; High temperature |
| PDF version | : |  PDF version |
