Open pit mines in the Yilgam Craton have unique hydrogeological characteristics resulting from a combination of geology, mineralisation and the complex and extended development of the regolith. The principal features of this geological relationship are: deep and complex multi-stage development of the weathering profile; steeply dipping rock layering; supergene enrichment; and mining across the regolith/rock interface.
These features result in large changes in permeability horizontally across rock layers; vertically through the weathering profile and along-strike in association with mineralisation and the mineralised Structure.