The south-western fringe of the Murray Basin was explored by the licensee for pointers to possible blind base metal sulphide orebodies lying within the Cambrian basement concealed under extensive, thick porous sediment cover, by performing geochemical soil sampling and analysis for detecting low level mercury emissions (the so-called 'mercury halo' phenomenon). Research into and development of a local application of this new exploration technique were carried out in association with AMDEL, to determine how to allow the reliable determination of mercury concentrations as low as one part per billion (1 ppb). Geochemical orientation exercises and reconnaissance sampling resulted in the collection of 7746 soil samples. Analytical results varied from 1 to 485 ppb Hg, with most being in the 5-80 ppb Hg range. 50 anomalous areas having > 100 ppb Hg were followed up by obtaining 663 further check samples, in order firstly to validate the initial high analysis, and then to extend laterally the soil sampling coverage across a true mercury anomaly, via a small grid pattern of samples. This follow-up sampling work was less than 25% complete at the time of expiry of the licence. It was found that the analyses of the follow-up samples did not always correlate closely with the original anomalous values, and in some cases the anomaly seemed to disappear. Also, the type of soil material sampled, or perhaps the position of the material within the soil profile, had a marked effect on the results. However, a number of mercury-anomalous zones were able to be detected ( these being zones which have apparently 'constant' high values obtained in the follow-up sampling, taken from sampling locations within a short distance of the original high). So far, two definite mercury-anomalous zones have been delineated in the area situated north of the Dukes Highway between Keith and Bordertown (designated the Senior anomaly and the Cannawigarra anomaly), while other anomalous zones have tentatively been identified to the north of Naracoorte. Other exploratory work recently done at the Senior anomaly has included field trials of gold and silver sampling probes, in an effort to identify a mercury measurement method which is not influenced by the type of soil present, plus drilling of 19 deep auger holes each to 82 feet depth to assess whether the surface geochemical anomaly intensifies or shifts laterally at depth (314 downhole samples taken for analysis - still in progress), and lastly, the conduct of a ground magnetic survey there, which revealed subdued magnetic relief.