Journal Highlights

A coupled deformation-devolatilisation model

Editor’s Highlight—

 

This paper considers the mechanisms by which dehydrating mineral reactions are coupled to deformation to induce mechanical instabilities. The authors develop an isothermal “porosity-softening” coupled deformation-devolatilisation model. This leads to instabilities in the form of regions of shear enhanced compaction with a wavelength dependent on the hydraulic diffusivity, constitutive parameters and reaction rates. They propose that the fluid pressure and localised deformation leads to stress enhancement in surrounding unaltered strong rock leading to the nucleation of seismic events at intermediate depths in subduction zones. This study has direct application to all devolatilising reactions in the mantle and crust of the Earth, particularly those in prograde shear zones in the mid-crust.