This SADME stratigraphic drillhole has intersected high grade Precambrian basement gneisses at 691.33 metres depth below a sequence of unmetamorphosed arenaceous and rudaceous sediments of the ?Cambrian Murnaroo Sandstone. Evidence from the clasts in conglomerates of the latter succession suggests that the hole is sited on a basement high which has been stripped of at least two former cover sequences, one volcanic in nature and one of quartzofeldspathic sediments, before deposition of the Murnaroo sandstones. Conglomerate clasts also indicate that much of the Murnaroo time sedimentation was of colloidal silica formed at localities close enough to the drillsite for partially lithified intraclasts to be incorporated in the conglomerates. The Murnaroo sedimentation is thought to have taken place in a desert environment with intermittent drainage.