At the Forsyth Creek South occurrence, a 1 metre thick siltstone bed containing phosphate nodules 3 to 6 centimetres in diameter, overlies a 15 metres thick chert horizon. Below the chert are 2 metres of phosphatic chert averaging 1.2 per cent P2O5. In the lower part of the section phosphate is in the form of ovoid nodules. Nodules in the upper phosphatic horizon (above the chert) contain in excess of 25.8 per cent P2O5 (Open File 1987-16). The stratigraphic section is part of the Permian Ranger Canyon Formation (Ishbel Group). Overlying this section are reddish brown weathering siltstone of the Triassic Sulphur Mountain Formation (Spray River Group).