Fig. 2. Fe³⁺/∑Fe values of Cenozoic intraplate basalts from EC.

Wet chemistry Fe³⁺/∑Fe values versus MBS Fe³⁺/∑Fe values (A), olivine δ¹⁸O (B), olivine V/Sc (C), and MgO (D). Wet chemistry and MBS Fe³⁺/∑Fe values are reported in tables S1 and S3, respectively. The triangle represents the U.S. Geological Survey basalt standard BCR-2. Error bars in (A) reflect ±10% error for wet chemistry Fe³⁺/∑Fe values and 1 SD for MBS Fe³⁺/∑Fe values. Olivine δ¹⁸O and V/Sc data are reported in table S4. Data points represent the average of analyzed olivine grains from individual EC basalts. A histogram plot of all analyzed olivine δ¹⁸O (n = 198) and a plot of δ¹⁸O versus V/Sc for all analyzed olivine grains are shown in fig. S4. Error bars in (B) and (C) represent 2 SE for olivine δ¹⁸O and V/Sc of individual samples. Samples with LOI > 3 wt % are shown in red dashed.