At the Weigert Creek West showing, a 2 metre thick phosphatic horizon occurs within a shale-sandstone sequence of the Permian Johnson Canyon Formation (Ishbel Group). This phosphate horizon is comprised of pellets, phosphate cement and rare intraclasts or nodules. It averages 14.25 per cent P2O5 over 2 metres (Open File 1987-16). The sequence forms the westerly limb of what appears to be an anticlinal structure.