Possible hydrothermally - deposited native mercury metal associated with the Mount John Fault zone, perhaps in a quartz splinter vein setting similar to that of the mercury occurrence previously found nearby at the Moro mine, plus elsewhere, economic Lower Cambrian stratiform base metal occurrences in the gossanous upper Parachilna Formation near its contact with the Wilkawillina Limestone, were the dual targets of exploration carried out in the area south-west of Italowie Gorge. Stream sediment and rock chip geochemical sampling, and reconnaissance 1:24,000 scale geological mapping, demonstrated the presence of several anomalous low order mercury values along the fault and in related diapiric sediments, while also confirming some high concentrations of syngenetic zinc in the Parachilna Formation (to 4000 ppm) and Wilkawillina Limestone (to 10,000 ppm), although without any elevated copper, lead, gold or antimony, which absence might suggest the lack of a hydrothermal influence on metallogenesis. A complex problem was identified with achieving accurate geochemical recovery of Hg at both the field and laboratory levels, so the observed mercury anomalism, although real, is still unquantified. The economic potential for base metals in Cambrian strata of the area studied was not regarded as encouraging, so it was decided to let the licence tenure lapse.