• Site-specific microstructural features of a shear zone are determining factors for macroscopic flow and transport properties. Conservative solute transport is governed by the effective porosity of the composite system of flow channels. Particle and gas migration are determined by the pore-size distribution in the shear zone. Experimental evidence for preferential gas flow is provided by visualisation experiments on both the field scale and on the laboratory scale.

     
  • The strong impact of the permeability-porosity relationship on hydrodynamic dispersion of solutes has been shown experimentally and by numerical simulations. This relationship is a site-specific property of shear zones, which may be determined by micro-structural analyses.

     
  • The use of complementary tracers is recommended to improve understanding of mass transfer parameters in a multiple porosity structure such as the GAM shear zone.

 

Gas Migration in Shear Zones (GAM)