Figure F21. Major element compositions vs. MgO of basalts from Holes 1156A and 1156B compared with Southeast Indian Ridge glasses from Segment B5. Only the average X-ray fluorescence (XRF) or ICP-AES analyses reported in Table T3, are plotted. XRF and ICP-AES data for splits of a single whole-rock powder are shown on all plots; two points represent each type of analysis for one sample.