Comparison of travel-time and amplitude data from two Oblique Seismic Experi  ments located on 110 m.y. old oceanic crust in the western Atlantic and northwestern Pacific Oceans shows that compressional velocities within layer 2 are, within experimental error, identical at the two sites. This result implies that, at Oblique Seismic Experiments In an Oblique Seismic Experiment (OSE), shots generated near the sea surface are received as direct or 'oblique' rays by a borehole seismo- meter clamped into the igneous crust (Stephen et al., 1980). Fortuitously, two OSE's were least for 110 m.y. old crust, the velocity struc- performed in which experimental parameters were ture in layer 2, where extrusive lavas grade down- nearly identical. Figure 1 shows the locations ward into a sheeted dike complex, is independent of the spreading rate at which the crust was created.