Fig. 4: One-dimensional P-wave velocity-depth profiles.

a Profiles extracted from Segments 1, 2, 3-S, 4, 5 (see the legends) with predominantly magmatic accreted crust. b Profiles extracted from Segment 3-N with predominantly tectonically formed crust. The black dashed lines represent the velocity envelope for the oceanic crust aged 59–150 Myr in the Atlantic Ocean29. The grey shading represents the velocity envelope for the slow-spreading oceanic crust aged >7.5 Myr28. The black solid lines show the 7.2 km/s velocity.