(inset) Three models (dashed lines) with different, fixed lid velocities that fit the mean stacked SRF (Fig. 2). These models are tied back to the modified version of IASP91 (solid black line) at depth. (main) Predicted Rayleigh wave phase velocity dispersion curves (dashed lines) from the three models in the inset compared to phase velocity data for the central and southern Kaapvaal Craton (Li & Burke 2006; black line).