Failure modes in fluid saturated rocks: deformation processes and mode-switching

Abstract We consider the implications of adding a cap to yield surface for elastic–plastic and elastic–visco-plastic solids with coupling between deformation, fluid flow mineral reactions. For suitable combination (low) permeability strain rate, opening-mode veins can form in compression. Such behaviour is enhanced by dissolution simultaneous reactions negative ΔV. These are equivalents compaction bands rocks high permeability. Stylolite parallel considered as forming this way; such commonly laminated or ribbon-quartz associated intense gold mineralization. Axial plane melt segregations class also. The addition limits permissible stress states portrayed failure-mode diagram has breccia formation. Failure discontinuities that at require decrease pressure opposed extension joints an increase pressure; orientations interpreted reactivated early discontinuities. switching low pressure, which we call mode - , arises from competition deposition. This alternative fault-valve mechanism does not fault reactivation failure ‘seal’ linked seismicity reactivation. capped concept provides unifying self-consistent approach vein/breccia formation kinematics brittle visco-plastic rocks.