Foliation boudinage structures in the Mount Isa Cu system

Small-scale foliation boudinage structures occur in rocks that were sampled drill core from the Mount Isa Cu deposit, northwest Queensland. The necks of plunge gently to north and south as a result layer normal shortening parallel extension steeply west-dipping Urquhart Shale. Detailed petrographic analysis has identified an initial rim quartz dolomite, followed by infill replacement pyrrhotite minor chalcopyrite. Foliation formed after dolomitisation silicification shale. They most commonly unaltered Shale where anisotropy homogeneity provided shale layering is still intact. Infilling occurred during protracted silica-dolomite alteration, chalcopyrite mineralisation. paragenesis consistent with established main over period D4a through mineralisation D4b west-northwest–east-southeast sinistral-reverse shortening. timing current kinematic model for system.