Figure 6.06. Mg₂SiO₄-Fe₂SiO₄ equilibrium phase diagram. Phases at equilibrium for the chemical system Mg2SiO4-Fe2SiO4 are shown as a function of chemical composition (weight percent Fe₂SiO₄) and temperature. The orange area indicates temperatures and compositions for which a single phase, silicate liquid (magma), is present at equilibrium. The liquid only region is bounded by a single saturation curve for olivine (Ol). Olivine is a solid solution phase. The green area indicates temperatures and compositions for which a single phase, olivine, is present at equilibrium. The olivine only region is bounded by a single saturation curve for liquid (Liq). Areas that have the horizontal line pattern indicate temperatures and compositions for which two phases, olivine and liquid, are in equilibrium. Notice that the composition of olivine in equilibrium with an Mg₂SiO₄-Fe₂SiO₄ liquid is different for each temperature. Click on the "Coordinates" and "Show Phase %" buttons, then mouse over the pattern region to see the phase compositions and proportions (all in weight percent). The This diagram was drawn from data obtained in high temperature experiments by Bowen and Schairer (1935). Return to previous view