- University of Chinese Academy of Sciences, BEIJING, China (duojunwang@ucas.ac.cn)
The water liberated from the breakdown of hydrous minerals while sinking in subduction zones may be transported into the overlying mantle wedge and may subsequently trigger magmatism and induce magnetotelluric (MT) anomalies above the subduction zone.Geophysical observations such as MT reveal that the electrical conductivity in subduction zone is up to 1 S/m. In contrast, the electrical conductivity of some hydrous mineral before dehydration remains very low which cannot explain the high electrical conductivity. Therefore, the dehydration effect on the electrical conductivity of hydrous minerals need to be determined.Electrical conductivity of several typical hydrous minerals before and after dehydration has been investigated. We observed significantly enhanced conductivities when most of hydrous minerals were heated to temperatures beyond their thermodynamic stability fields. The increase in conductivity are interpreted as several dehydration models. The increased electrical conductivity due to dehydration may responsible for the high-conductivity anomalies observed in subduction zones.
How to cite: Wang, D., Shen, K., and Zhang, Z.: Electrical conductivity of hydrous minerals during dehydration and geophysical implications, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3942, https://doi.org/10.5194/egusphere-egu25-3942, 2025.