Prograde zircon growth in migmatites

Empirical studies of zircon in migmatites document features compatible with growth during heating at suprasolidus conditions. However, numerical modelling behaviour suggests that is expected to grow only cooling and melt crystallization. Here, phase equilibrium coupled mineral–melt Zr partitioning used an attempt reconcile the observations from predictions previous models anatectic systems. In general, equilibrium-based model includes does not allow prograde growth. melting metapelites temperatures just above wet solidus may limited because low solubility a source minor garnet ilmenite breakdown. Preservation this requires entrapment growing peritectic minerals subsequent further melting. Heating muscovite exhaustion unlikely progressive increase as well increasing compatibility residual mineral assemblage. The modelled residue metabasite decreases heating, but counteracts this; metabasites unlikely. Infiltration Zr-rich into migmatite open-system anatexis provides additional potential mechanism for high-temperature metamorphism.