Compressional wave velocities as a function of pressure have been measured in pressure-amorphized anorthite to 14 GPa at room temperature. A weighted linear fit to the data gives a zero-pressure value of Vp=6.35¿0.12 km s-1, with a slope of 0.154¿0.016 km s-1 GPa-1. It is shown that these compressional wave velocities compare well with bulk sound speeds inferred from shock-wave experiments on anorthite above the phase transition at 30 GPa, assuming a value of Poisson's ratio in the range of 0.15 to 0.20. All crystalline assemblages which have been suggested as high-pressure phases of anorthite are shown to possess zero-pressure bulk sound speeds in the range 6.9 km s-1 to 8.1 km s-1, well above the evalue of 5 km s-1 extrapolated from the shock-wave data. It is therefore proposed that the shock Hugoniot of anorthite above 30 GPa represents the properties of the pressure-amorphized phase, rather than those of the equilibrium high-pressure phases. ¿ American Geophysical Union 1993