Figure 5.03. 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 liquidus curve, a 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 solidus curve that gives the melting temperature for olivine as a function of composition. Areas that have the horizontal line pattern indicate temperatures and compositions for which two phases, olivine and liquid, are in equilibrium. Click on he "Show Phase %" button and mouseover the diagram for lever rule phase proportions. This diagram was drawn from data obtained in high temperature experiments by Bowen and Schairer (1935).

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