Exploration of a long-held tenement package in the northern Gawler Craton was directed primarily at gold and also at platinum group metals, in specific work programmes executed under separate early joint venture arrangements made with Gawler Gold and Minerals Exploration NL (GGME) by licensee Minotaur Exploration. Over the period 1997 to 2000 GGME investigated closely the platinoid metal potential of the Wirrida Mafic Complex, which lies in the centre of the Wirrida licence area. Prior exploratory drilling done here, by the South Australian Department of Mines and Energy as part of the SA Steel and Energy Project, had tested the magnetic highs on the complex with 21 RC holes, 9 of which recorded anomalous platinum up to 17.5 ppb from weathered bedrock. Mineralogical studies of samples from those holes suggested that this drilling had penetrated the upper portion of a differentiated mafic intrusion in which primary sulphides are present. GGME re-analysed 63 bottomhole samples from all of the MESA Wirrida Complex drillholes, and these returned maximum assay values of 0.6 ppb Pt, 0.4 ppb Pd and 1.6 ppb Au. In May 1997 the Commonwealth Hill Project consortium acquired 8000 line km of aeromagnetic / radiometric / DEM data in an aerial survey flown over the EL 1900/EL 2441 area on E-W lines at 100m line spacing and 60m sensor height, partly to help with basement structural interpretation and selection of new drillsites on the Wirrida intrusion. In addition, 818 existing calcrete sample pulps, 149 new soil samples and 2140 new auger samples of calcrete were submitted by GGME for mobile metal ion (MMI) analysis for a suite of trace metals, including platinum. 24 of the auger samples returned anomalous platinum values ranging from 0.9-1.6 ppb Pt, mostly from sites over the interpreted basal part of the intrusion. From this work 11 drillable prospects (the Focus series) were identified, with near-surface precious and base metal geochemical anomalies occurring at Focus 3 & 4 over the south-western and northern contact zones, over country rock gneisses (Focus 1, 2, 5-8 and 11), and over mafic rocks (Focus 9 & 10). Subsequent RC and aircore drilling carried out by GGME over these Wirrida JV targets (82 RC holes for a total penetration of 5398 m, plus 202 shallow AC/RAB holes for a total of 4970 m) showed that the bedrock consists of differentiated mafic rocks (olivine-deficient gabbro/norite to diorite), with the most mafic portion existing in the central part of the igneous complex; no ultramafic rocks were encountered. The RC holes were drilled at 400 m intervals along previous auger traverses, to investigate firstly the Focus prospect platinum anomalies and then to profile the basal section of the northern and north-western parts of the intrusion. The aircore drillholes tested similar targets along the southern and western contact zones, with additional coverage of an interpreted alteration zone within the complex, and of platinum anomalies associated with interpreted small mafic bodies lying distal to the main intrusion. No significant platinum or palladium values were reported from analyses of 908 RC and 1124 aircore downhole samples, and trace sulphides only were seen. Gold values of between 16 and 45 ppb Au were returned from weathered saprock in only two holes, 97RC030 and 97RC063. It was concluded that the most prospective ground lay along the basal section of intrusive igneous rocks on the south-western flank of the complex, where a wide NW-trending sheared contact zone abuts Archaean basement that dips only moderately northwards. Here aircore drillhole 98AC008 had intersected weak platinum mineralisation (up to 60 ppb Pt) over a 10m wide interval of saprolite. Immediately east of this contact zone, extensive sericite-chlorite hydrothermal alteration of the intrusion was recognised from mineralogical studies of drillhole samples. A follow-up programme of ground magnetic surveys and 4 RC drillholes for 462 m was completed in November 1998 to address this prospect, but analyses of 93 downhole samples failed to encounter significant gold, platinum or palladium values either within the saprolite or in the underlying mafic bedrock, while only weakly anomalous base metals are present. Contemporaneous gold exploration of the subject tenement area did not advance markedly during the tenure period, owing to company emphasis on evaluating several competing, better-looking gold prospects in the adjoining tenement areas that had related joint venturer interests. In particular, no new field work was done on the EL 2441 area during the period 1999-2002 after GGME ceased its dual JV participation, owing to Minotaur's inability to attract further joint venture partners to fund exploration. However, in September 2002 the licensee flew a further 2724 line km of aeromagnetic survey coverage over ELs 2441 and 2595 at 50 m line spacing and 20 m sensor height, to provide improved basement structural data for modelling revised gold drilling targets. This stratagem enticed the Gawler joint venture's second operator Redport to look into EL 2441, and subsequently it tested seven of the upgraded aeromagnetic anomalies for Challenger-type metamorphic/hydrothermal gold mineralisation, via 15 vertical RAB/aircore drillholes totalling 652.5 m. Redport had noted a strong bias to past gold exploration target selection at Commonwealth Hill, with most of Minotaur?s prospects located within areas of slightly elevated topography, where the reconnaissance calcrete/silcrete sampling medium is better developed. After completing mapping of the distribution of transported versus residual regolith across the project area, Redport was able to prioritise targets in areas where it felt that the past calcrete geochemical prospecting, even where carried out down to 50 m sample spacing, would have been of limited effectiveness. In September 2002 this approach resulted in the discovery by drilling of a hitherto unknown gold occurrence at the Target 14 aeromagnetic anomaly, situated approximately 11 km south of the major Comet gold prospect on EL 2595. Redport's aircore holes RED 15 & 16 which were drilled 100 m apart encountered bedrock gold values of between 62-92 ppb Au from the depth interval 32-42 m within a finely layered biotite-quartz schist. The find is regarded as important because it lies in an area of sand dunes and small salt lakes where calcrete sampling for gold would probably have been ineffective at detecting the bedrock gold. Redport estimates that this situation may apply to more than half of the Commonwealth Hill Project area, because major shear zones such as the one disclosed at Target 14 tend to form topographic lows and eventually become covered by transported regolith materials.