In December 2005 Mithril Resources completed five RC percussion drillholes totalling 682 m on three 100 m - spaced traverses, as one of the approved PACE Initiative Year 2 subsidised drilling projects. This drilling was intended to test a surface TEM conductor that was seen to coincide with chalcophile element geochemical anomalism and the development of supergene nickel enrichment in the weathering profile, over a portion of the Harris Greenstone Domain known as the Mullina Well prospect, which is located approximately 15 km south-east of Tarcoola. All of the drillholes intersected a buried intrusive igneous bedrock sequence consisting of ultramafic rock types, which are interpreted to be komatiites, that have sheared contacts with older gneissic rock types. Sulphides (dominantly pyrite) were commonly identified in the ultramafic rocks, but only in amounts of less than 2%. Two 8 m thick intervals grading over 0.5% Ni were intersected in weathered ultramafic rocks. One drillhole (THRC069) intersected stringers of sulphide mineralisation containing up to 15% pyrite, which graded 0.44 g/t Au, below 100 m depth over a 2 m interval within gneiss close to the sheared contact with ultramafic (komatiitic) rocks. It is probable that this weakly conductive pyritic horizon is the source of the surface conductor, although downhole EM logging performed in this hole and two others failed to detect any significant off-hole conductive bodies in fresh bedrock. However, the presence of anomalous platinum and palladium in the regolith may be reflecting the presence of low grade disseminated magmatic sulphides.