Figure F22. Major element variations vs. MgO for basalts from Holes 1160A and 1160B compared with Segments A2 and A3 axis lavas. All whole-rock analyses are X-ray fluorescence (XRF) results, except for Sample 187-1160B-2R-1, 17-20 cm. Glass analyses are by ICP-AES. Only the averages of XRF or ICP-AES analyses reported in Table T4 are plotted. PRT = propagating rift tip lavas.