Elastic Characteristics of Serpentinite Dehydration at High Pressure and its Significance

Abstract

[1] To understand the elastic characteristics during serpentinite dehydration, the ultrasonic velocities of the serpentinite from Shuanggoujie, Yunnan Province, southwest China, were measured at the pressure 1.0GPa and high temperature by the pulse transmission method. During the measurement of the ultrasonic velocity, the waveforms were observed. The ultrasonic velocities of the serpentinite decreased sharply with the increasing temperature as it is higher than 640 °C. At the temperature higher than 700 °C, the experimental sample exploded in the chamber. It was discovered that the amplitude of the ultrasonic wave recorded as the ultrasonic velocity began to decrease was smaller than that before the sample exploded. Comparing the present experiment with the previous experiments, we suggested that the drop of the ultrasonic velocity and the increase of its amplitude are associated with the dehydration of the serpentine in the rock. The phenomenon of the amplitude's increase can not be explained exactly at present. The new discovery of this study may provide a clue for elucidating and predicting distractive changes of the Earth's interior.