TARGET: The aim was to test if analyses of soil air and subterranean gases sampled via drill holes could define zones of known and unknown mineralisation. EXPLORATION: Soil air carbon dioxide and oxygen measurements were assessed as a guide to oxidising sulphide at 5 sites within the Willyama Supergroup. RESULTS: The response from known mineralisation is relatively weak in the Cottage Dam area and at most other sites tested, to the south. None of the stronger CO/O2 responses were found to correlate with known mineralisation, but some results at Cottage Dam were encouraging. Rainfall immediately prior to the conduct of field tests influenced their results and made interpretation difficult.