Fig. 7: Excess volcanism from the T-G plume through time.

a The residual bathymetry in the South Atlantic was used to calculate the extrusive volume of the T-G plume through time, using the 800 m contour (the thin black contour line), which is the closest contour to the break in slope throughout RGR/WR. Profiles A-A’ through F-F’ for RGR and WR can be found in Supplementary Fig 5. b Total magmatic volume generated by the T-G plume uses the excess crustal volume estimations from Huang & Li⁵². The subdivisions (outlined in black in (a) and blue in (b)) are based on the age of WR volcanism in 10 Myr increments, using ages from the literature^6,7,10,20,21, and for RGR include our W, NE, and SE subdivisions. The thin line denotes areas with excess volume, and the thick red line down the middle marks the MAR. Maps were made in GMT⁷⁰.