Abstract:
The properties of residual dolomite, sometimes termed wad, are variable and uncertain. It represents the insoluble
residue after dissolution of dolomite and is commonly found in the Neoarchaean Malmani Subgroup of the
Chuniespoort Group (South Africa). This study comprised triaxial tests, crumb tests, X-Ray diffraction and fluorescence
spectroscopy, foundation indicators, stereo-microscope imagery and permeability testing of the represented formations
outcropping in the northeastern portions of South Africa. Results concur that residual dolomite is not typically
dispersive, has low density that can be below that of water, mostly grades in the silt fraction, has high plasticity
indices with low to high liquid limits, and has hydraulic conductivities in the order of 1x10-6 m/s. This new knowledge
database contributes to our understanding of the flow through these systems and to how ingress scenario subsidences
and sinkholes can possibly occur.
