A large area of the west-central Gawler Craton which is underlain by inferred gold-prone Archaean high grade metamorphosed rocks is being explored for Challenger style orogenic type lode gold that may have formed in the buried basement. The subject Ingomar tenement, which had occupied an isolated position on the far eastern side of the tenure region, has now been fully surrendered due to its perceived diminished prospectivity for such gold deposits. During Years 1, 2, 4 and 5 of the project, no work was done. The only reportable work took place during Year 3, when Ironclad Mining/Tyranna Resources undertook surface calcrete geochemical sampling plus a campaign of exploratory RC drilling for gold on EL 5526 Galaxy Tank, at a location ~ 56 km north-east of Challenger, besides conducting limited surface calcrete and soil sampling for nickel + copper on EL 4944 Garford Outstation East, at a location ~ 33 km north of Challenger. In April 2016, 32 inclined RC holes with a total penetration of 1706 m were drilled at the Golf Bore North prospect on a 50 m x 50 m hole spacing, following the collection from there in February and laboratory assaying of 98 calcrete and 9 soil samples. This sampling produced results which extended the continuity of surface gold anomalism from an historic 420 m to 500 m of strike length. Assaying of 1130 downhole drill cuttings samples yielded a series of single metre gold intercepts from the supergene zone, with a highlight of 5 m @ 3.2 g/t Au, including 1 m @ 7.2 g/t Au, reported from hole 16GNRC005. Minor disseminated pyrite was also recorded within the latest Golf Bore North holes, but appeared to have no direct relationship to the elevated gold. The bedrock geology recorded at Golf Bore North, by this first new drilling done there in 20 years, is the same Christie Gneiss that dominates at Golf Bore prospect, located 250 m to the south, but locally the rock has a more schistose texture, as was previously observed in drillholes put in to the south of Golf Bore. In consequence of the sparse and low grade gold mineralisation seen at Golf Bore North, no further drilling was recommended for there (to close up the resource definition hole coverage to 25 m spacing, as had been the original intent for the latest drilling). At the historic Thunderbolt Tank nickel-in-calcrete anomaly, Apollo Minerals undertook surface calcrete sampling on a 200 m x 200 m grid spacing (33 samples collected), which returned a highest result of 41 ppm Ni and 45 ppm Cu, giving no encouragement to proceed to drill there. Interest in this prospect had been raised by DSD's 2011 re-assaying of Dominion Mining's 1995 regional calcrete sampling pulps, that had produced maximum values of 480 ppm Ni and 380 ppm Cu. Apollo Minerals also detected elevated Ni, Cu and Au (23 ppb Au) in a surface lag sample that was collected at Thunderbolt Tank, so clearly something geologically unusual is present in the local bedrock. A programme of check soil sampling was undertaken in 2016 because it was known that historically, soil has been the second most commonly used sample medium in the project area. Orientation soil sampling was done at prospects where soils had to date not been assayed (Black Knight, Brickies North and South, Breakaway Bore, South Hilga and Thunderbolt Tank), and grid-based soil sampling was done on other prospects (Campfire Bore, Mainwood and Typhoon) using the most analytically effective size fraction where this has already been defined historically. The orientation soil sampling at each prospect involved taking samples of three separate size fractions (0.4 mm, 2.8 mm, 6.7 mm) from 3-5 sites known to have elevated gold-in-calcrete. From 9 such soil samples taken at Thunderbolt Tank, the partial leach gold assay results were all below detection limit, and the elevated values for nickel and copper as seen in calcrete were not echoed in the soil. A study of regolith materials recorded from the calcrete sampling and drilling was conducted by Ken Collison to identify patterns in the regolith, in an attempt to find a more reliable, wholly useful method of detecting underlying mineralisation in the greater Challenger region, where the presence of massive pedogenic calcrete is patchy, and reliance on testing its gold signal alone can result in broad, false or missed anomalies. It was evident from the sample metadata and results of recent calcrete sampling work that samples associated with topographical lows generally consisted of poorly formed calcrete and were low in gold. Furthermore, according to Dominion's historic exploration reports, all of the initial calcrete samples that had been taken pre-discovery from Challenger which had returned elevated gold were described as “massive” and occurred within the first metre from surface. The main conclusion to be drawn from this was thought to be that the presence of well-formed calcrete close to surface increases the chances of making a gold discovery in this type of regolith terrain. It does not, however, preclude areas of poor calcrete formation from being prospective for gold. It was recommended that in the subject area the empirical relationship of elevated topography to gold deposits must be investigated in further detail. It is on record that the Challenger discovery was located on a slight topographic rise, and the Campfire Bore, Mainwood, Golf Bore and Typhoon prospects also occur coincident with this feature. It was suggested that the lode finds and elevated gold at these sites may be due to well formed calcrete forming where the underlying geology is more conducive to gold formation (e.g. related to higher silica content and thus fresh rock existing close to surface), or it may just be that these prospects were easier to find because of the type of calcrete formation. In this latter instance, it is clear that a more effective surface geochemical sampling method must be distinguished which will delineate gold prospects located in topographic lows and in areas of poorly formed calcrete.