(Table 1) Summary of densities and compressional-wave velocities at DSDP Hole 72-516F

Compressional-wave velocities were measured in 9 samples from the 18 m of igneous basement penetrated by drilling at Hole 516F. Wet-bulk densities range from 2.50 to 2.92 g/cm**3; compressional-wave velocities (measured at 0.4 kbar confining pressure) range from 4.29 to 6.32 km/s. Because of progressive alteration, compressional-wave velocities in deep-sea basalts tend to decrease with age; velocities in basalts from immediately beneath the sediment/basement contact are consistent with the proposed age (86 ± 4 Ma) of basement at the site. A very strong vertical velocity gradient of 0.126 km/s/m in the 18-m basement interval reflects a marked decrease in the degree of alteration with depth beneath the contact.