The sedimentary rock of The Skillion was laid down in the Middle Triassic and was formed in an alluvial environment, possibly in a delta or river flood plain. Examination of the rock face will show bedding where silt has been deposited over eons. On the eastern base of The Skillion, note a distinct band of grey shale rock underlying the sandstone. Examine the rocks on the next platform north, here dimples cover a portion of the platform indicating that it may have been the floor of a shallow sea. There are ferruginous deposits on many of the rocks and in zones on the cliff face forming bands resistant to weathering. Look for joint lines crossing the platforms. Log onto www. geomaps .com.au tor details on all sites.