Sulphur solubility in andesitic to basaltic melts: implications for Hekla volcano |
| |
| Authors: | Séverine Moune François Holtz Roman E Botcharnikov |
| |
| Institution: | 1.Institute für Mineralogie,Leibniz Universit?t Hannover,Hannover,Germany;2.Laboratoire Magmas et Volcans,Clermont-Ferrand,France |
| |
| Abstract: | The solubility of sulphur in sulphide-saturated, H2O-bearing basaltic–andesitic and basaltic melts from Hekla volcano (Iceland) has been determined experimentally at 1,050°C,
300 and 200 MPa, and redox conditions with oxygen fugacity (logfO2) between QFM−1.2 and QFM+1.1 (QFM is a quartz–fayalite–magnetite oxygen buffer) in the systems containing various amounts
of S and H2O. The S content of the H2O-rich glasses saturated with pyrrhotite decreases from 2,500 ppm in basalt to 1,500 ppm in basaltic andesite at the investigated
conditions. Furthermore, the reduction of water content in the melt at pyrrhotite saturation and fixed T, P and redox conditions
leads to a decrease in S concentration from 2,500 to 1,400 ppm for basaltic experiments (for H2O decrease from 7.8 to 1.4 wt%) and from 1,500 to 900 ppm (for H2O decrease from 6.7 to 1.7 wt%) for basaltic andesitic experiments. Our experimental data, combined with silicate melt inclusion
investigations and the available models on sulphide saturation in mafic magmas, indicate that the parental basaltic melts
of Hekla were not saturated with respect to sulphide. During magmatic differentiation, the S content in the residual melts
increased and might have reached sulphide saturation with 2,500 ppm dissolved S. With further magma crystallization, the S
concentration in the melt was controlled by the sulphide saturation of the magma, decreasing from ~2,500 to 900 ppm S. |
| |
| Keywords: | Sulphur Sulphide Saturation Hekla volcano Experiments |
| 本文献已被 SpringerLink 等数据库收录！ |
|
