Frans ABEN

Project Summary :
Faults are complex systems consisting of zones of intense deformation (fault cores) and broad zones which accommodate almost no movement but are nonetheless heavily deformed (damage zones). The latter can have a large influence on the strength of the fault as it acts as a conduit for fluids. This depends on the balance between damaging and healing of the rocks ; if healing is dominant a fault strengthens quicker and permeability is inhibited, creating larger fluid pressures at depth. When damage formation is more dominant, the fluid system stays open but it can cause faster healing and a larger contribution of pressure solution processes to the fault movement as well. The rate of damage and healing can also have large effect on the strain localisation of a fault ; i.e. the difference between a single slip plane or a multi-branched fault system. To understand all these intertwined processes and effects, I’ll focus on two aspects during my experimentally focused PhD-project : (1) the creation of brittle damage in the damage zone and (2) the healing and sealing processes in damaged rocks.