VARIATION OF ELASTIC WAVE VELOCITIES IN BASIC IGNEOUS ROCKS WITH PRESSURE AND TEMPERATURE

Abstract

The dilatational and rotational wave velocities have been measured as functions of pressure and temperature for three gabbros, two basalts and a dunite. The pressure range was 200–6,000 bars. The temperature range was 25° to 300°C. and 400°C. for one sample. The maximum pressure is equivalent to 23 km of depth and the highest temperature is believed to correspond to 25 km. The data indicate a tendency for the velocity to reach a maximum somewhere between 10 and 20 km and then decrease slightly.