In situ X-ray diffraction measurements of the phase transformations in serpentine have been carried out using a multianvil high-pressure system combined with synchrotron radiation. Serpentine persisted upon compression to 28 GPa at a room temperature, while it became amorphous in a limited temperature interval of 200-400°C at pressures above 13 GPa. A rapid crystallization of high pressure phases then started at temperatures greater than about 400°C. These observations suggest that the amorphization of serpentine is an unlikely mechanism of deep-focus earthquakes associated with subduction of slabs, as the temperatures of these slabs are generally higher than those of the rapid crystallization regime.
