Figure F43. TiO2 vs. Mg# for basalts from all ODP drill sites on the Ontong Java Plateau (Mahoney et al., 1993; this volume). Data fields for the Kwaimbaita and Singgalo Formations of Malaita are shown for comparison (Tejada et al., in press). Data for Hole 1186A cover a similar range to those for Hole 1183A and fall within the field of the Kwaimbaita Formation. Mg# is calculated assuming 12% of the iron is Fe3+, which is equivalent to Fe2O3/(Fe2O3 + FeO) = 0.13, or Fe2O3/FeO = 0.15.

Figure F43. TiO₂ vs. Mg# for basalts from all ODP drill sites on the Ontong Java Plateau (Mahoney et al., 1993; this volume). Data fields for the Kwaimbaita and Singgalo Formations of Malaita are shown for comparison (Tejada et al., in press). Data for Hole 1186A cover a similar range to those for Hole 1183A and fall within the field of the Kwaimbaita Formation. Mg# is calculated assuming 12% of the iron is Fe³⁺, which is equivalent to Fe₂O₃/(Fe₂O₃ + FeO) = 0.13, or Fe₂O₃/FeO = 0.15.