Hydrofracture dilatancy and the development of quartz-vein arrays in the Wattle Gully Fault Zone, Victoria

Hydrofracture dilatancy associated with faulting at high fluid pressures
has generated major quartz-vein systems in many reverse fault
zones which developed during regional deformation and low-grade
metamorphism in the Bendigo Trough, Victoria.

Within the Wattle Gully Fault Zone dilatancy has occurred both
within faults and in hydraulic fracture arrays adjacent to faults. The
overall geometry of quartz-vein arrays reflects development in a stress
regime in which the far-field ~r n axis was oriented approximately E-W,
and the far-field ~r~ axis was approximately vertical. Complex vein
geometries adjacent to many faults reflect the influence of various
factors including local stress reorientation, vein rotation and mechanical
anistropy of the wall rocks.