An area covering ground adjacent to the southern boundary of current EL 3056 (formerly EL 2483), on which licence the newly discovered (in November 2001) Prominent Hill IOCG deposit is situated, is being explored for similar style buried epithermal/hydrothermal copper-gold mineralisation hosted by Proterozoic basement rocks. Open file airborne magnetic survey data for the region clearly show the highly magnetic lithologies of the Mount Woods Inlier. The Minotaur Resources - BHP Billiton JV's very large Prominent Hill deposit is located immediately south of the southern margin of this highly magnetic terrain, within a distinctive subsurface featural domain characterised by more subtle but complex magnetic responses. This domain extends into the north-western part of the subject EL 2901. During the first licence year, EL 2901 joint venturers Adelaide Exploration Limited and Perilya Freehold Mining Limited carried out a ground gravity survey and an airborne magnetic/DEM survey covering a 150 square km area in the north-west of the tenement, 8 km away from Prominent Hill. The gravity survey conducted during April 2002 comprised 2368 stations read on a regular 400 m x 200 m grid. It defined a northeast-southwest trending ridge of elevated response. Within this ridge there are several subtle residual gravity anomalies, one of which is broadly coincident with the Gemini magnetic anomaly. The high resolution airborne survey was flown during April 2002 over the same ground along north-south lines 100 m apart using a mean sensor height of 40 m above the ground surface, for 1664 line km of detailed data acquisition. These data further defined a 3 km x 2 km oval cluster of three discrete magnetic anomalies termed Gemini A, B and C. This Gemini prospect, which lies as close as 7 km to Prominent Hill, was recognised by the data interpreters as the most promising geophysical feature identified in the surveyed area. Modelling of the anomalies by 3D inversion and forward modelling suggested that depths to the tops of magnetic source bodies are between 200 m and 300 m below the surface. Interpretive sections for the geological setting of Prominent Hill, released by Minotaur Resources and available on that company’s website, showed a relatively unmetamorphosed volcano-sedimentary sequence and mineralised breccia complex occurring south of, and in fault contact with, a ‘magnetic complex’. On the basis of this sectional model, the EL 2901 partners thought that it was reasonable to conclude that the distinctive, more subtle, domain recognisable in their new aeromagnetic data reflects the above mentioned package of rocks which hosts the Prominent Hill deposit. They felt that it was quite feasible to assume that this more restricted domain represents rocks of Gawler Range Volcanics (Hiltaba) age rather than the high metamorphic grade Palaeoproterozoic metasediments of the Mount Woods Inlier. During licence Year 2, no exploration took place on EL 2901. The JV partners submitted a proposal to PIRSA for the grant of PACE Initiative Year 1 collaborative drilling project subsidy funds to help with the cost of drilling the Gemini prospect, and the application was successful. PACE Project DPY1-13 was funded to the tune of $27,000 by the SA Government to allow for drill testing of the Gemini A and Gemini B targets. During licence Year 3, three vertical RC drillholes totalling 910 m were completed during October-November 2004, with the two last holes successfully penetrating into basement rocks consisting of weathered but recognisable Gawler Range volcanic lithotypes (vesicular basalt, rhyolite and dacite). Accessory titanomagnetite in basaltic rocks in the basement was thought to account for the magnetic anomalies at Gemini, and the presence of mafic volcanic rocks could explain the subtle semi-coincident gravity feature. No economic mineralisation was encountered, but weak hydrothermal alteration of probable IOCG association was noted [see drilling project final report, held separately in Env 11031]. A petrological consultant's examination of four basement drill cuttings samples from PACE hole GEMRC2 observed that the hydrothermal alteration had destroyed the magnetic mineral phases, and therefore it was suggested that areas of “magnetite destruction” might constitute more prospective targets that those magnetic anomalies so far tested. During licence Years 4 and 5, no exploration took place on EL 2901. This was due to a long negotiation process that occurred between Adelaide Exploration Limited and Minex (SA) Pty Ltd to effect the purchase and transfer of the licence. The sale was completed late in 2006, and Oxiana Limited assumed management of the exploration programme going forward.