Concerted exploration for possible stratiform Mount Gunson type or epithermal Olympic Dam type base metal deposits, on the south-eastern edge of the Stuart Shelf near Port Pirie, was begun by North Broken Hill Ltd in response to the public release by Western Mining Corp. of initial geological information about its recent giant orebody discovery on Roxby Downs Station. NBH targeted a large regional aeromagnetic high at Wandearah with detailed ground gravity and ground magnetic surveys, which disclosed a number of likely gravity and magnetic sources in the previously untested deep metasedimentary sequence of Adelaidean age. These inferred iron-rich anomalies were progressively diamond drilled by NBH in 15 stratigraphic/exploratory core holes totalling 6657.18 m. Widespread, disseminated low grade base metal sulphide, ilmenite - haematite - molybdenite and uranium oxide mineralisation was found over the south-western portion of a 25 km x 17 km area at many stratigraphic levels within a strongly block-faulted post - Pandurra Formation sequence, occurring typically within carbonate veins or the matrix quartzite of conglomeratic and fault-brecciated sediments, or in reduced graphitic-argillaceous shale facies proximal to redbed units and to isolated, altered acid-intermediate and trachybasalt interbeds of the Beda Volcanics. Examples of trace to minor chalcocite - chalcopyrite - pyrite - bearing intersections include 25.6 m of 0.16% Cu below 226.1 m depth in conglomerates in hole PP2, and 0.72% Cu over 7.25 m in hole PP5, the latter interval entraining 2.7 m @ 1.53% Cu below 297.8 m. Minor uranium mineralisation up to 250 ppm U was present in grey siltstones below the Sturt Tillite in drillhole PP3, and this hole also showed anomalous cobalt in zones of high copper assays, plus scattered gold values of about 0.3 g/t Au. Trace to minor galena and sphalerite were intersected near the base of the Tapley Hill Formation in drillhole PP4 and in several subsequent nearby holes. In the light of these results, Aquitaine Australia Minerals entered into a 40% joint venture with NBH in the second half of 1978. The programme of drilling is yielding encouraging results, both in terms of stratigraphic discoveries and in exploration model formulation, and will be continued.