At the Elkford occurrence, a 0.5 metre thick phosphorite bed and a 0.4 metre thick phosphatic sandstone bed occur within the Permian Ross Creek Formation (Ishbel Group). This phosphate is underlain by conglomerate and limestone of the Telford Formation. Overlying the phosphate are siltstone and argillite of undetermined thickness. The phosphorite is pelletal and contains 5.93 per cent P2O5 (Open File 1987-16). Gangue minerals include calcite and quartz.