Unveiling the role of DHMS in deep-focused earthquakes: high-pressure dehydration dynamics of key mantle minerals

The mechanisms driving deep-focus earthquakes and fluid migration in subducting slabs remain poorly understood, with phase transitions and dehydration processes having a key role. In these contexts, Dense Hydrous Magnesium Silicates (DHMS) play crucial role in storing and transporting water in the mantle. Recent studies on the 23 Å phase, an important DHMS, revealed an unexpected single-crystal-to-single-crystal transformation during dehydration, prompting new experimental approaches. We propose to investigate by simultaneously X-ray diffraction and ultrasonic methods the dehydration behavior of the 23 Å phase and three other key minerals—Phase A, chondrodite, and Phase E—under high-pressure and high-temperature conditions at ID06-LVP beamline. We aim to gain insights into the structural and kinetic aspects of their dehydration processes to assess their role in large scale geological phenomena.