Velocity of compressional waves in limestones, marbles, and a single crystal of calcite to 20 kilobars

Velocity of compressional waves in Solenhofen limestone, Oak Hall Quarry limestone, Danby marble, Rutland white marble and a single crystal of calcite (along the c axis) are measured under hydrostatic condition to 20 kb. All measurements show the following characteristics: The velocity rises with increasing pressure to a maximum, falls to a minimum at 15.5±0.5 kb, and rises again with pressure. The measurements are reproducible during the course of lowering the pressure. The peculiar change of velocity at about 15.5 kb is associated with one of the calcite transitions discovered by Bridgman.