The Ridge Hill Shelf is a landform that forms part of the foothills of the Darling Scarp, a low escarpment that runs parallel with the west coast in southwest Western Australia.
The action of coastal forces produced sand dunes that subsequently lithified into eolianite, and eroded the ironstone of the scarp, resulting in an iron-rich sandstone with a laterite cap.
The iron gives the sandstone a dull purple-brown colour; depending on the extent of iron-enrichment, the sandstone may appear predominantly yellow, predominantly purple-brown, or a mottled combination of the two.
It is largely vegetated by a forest of Eucalyptus marginata (jarrah) and Corymbia calophylla (marri), with an understorey of Banksia, Casuarina fraseriana and Xylomelum occidentale (woody pear).
[1][2] Some publications identify the Ridge Hill Shelf with the foothills of the scarp, but this is incorrect.