Fe in P-doped basaltic melts: A Mössbauer spectroscopy study

Abstract The addition of P to a basalt causes a change in the environment of Fe. At low P contents iron is located in the glass structure and the Fe 3+ /Fe 2+ ratio is about 80/20. Further addition of P causes a collapse of the glass structure related to a phase separation that triggers the crystallization of a more reduced iron-containing phosphate phase with a crystalline structure similar to that of stanfieldite, and Mossbauer parameters similar to those of the alluaudite group, together with the formation of a Fe 3+ -Fe 2+ disordered phase. Their presence increases the viscosity of the melt.