Figure 5. Development in Mg# in a combined section through the syn- and postbreakup basalts. The lava successions are placed on top of each other in accordance with their inferred relative age. It is possible that the lava flows from Site 989 are exactly coeval with the uppermost flows from Site 990, as detailed in the text. The two dikes are, for comparison, placed in the void between Sites 990 and 918.