Olivine/melt transition metal partitioning, melt composition, and melt structure - Influence of Al3+ for Si4+ substitution in the tetrahedral network of silicate melts

The influence on olivine/melt transition metal (Mn, Co, Ni) partitioning of Al3+ double left right arrow Si4+ substitution in the tetrahedral network of silicate melt structure has been examined at ambient pressure in the 1450-1550 degrees C temperature range. Experiments were conducted in the systems NaAlSiO4-Mg2SiO4-SiO2 and CaAl2Si2O8-Mg2SiO4-SiO2 with about 1 wt% each of MnO, CoO, and NiO added. These compositions were used to evaluate how, in silicate melts, Al3+ double left right arrow Si4+ substitution and ionization potential of charge-balancing cations affect activity-composition relations in silicate melts and mineral/melt partitioning.