An area located 50 km north-northeast of Wudinna, and situated on the southern margin of the Gawler Ranges, has been explored for possible economic deposits of both Olympic Dam style epithermal copper-gold-uranium and Tanami style orogenic lode gold, and latterly also for possible Tertiary roll-front style sedimentary uranium mineralisation. It was postulated that the thick lava flows of the Mesoproterozoic upper Gawler Range Volcanics may have formed a seal for later generated, outwardly migrating mineralising fluids. On the regional aeromagnetic images, zones of demagnetisation evident along linear structures and flow fronts suggested that there has been considerable magnetite-destructive alteration occurring during escape of these fluids from the sealed system. It was believed that this setting has the potential to form large gold deposits due to the focussing of mineralising fluids over a long time span. After reviewing the available geological and geophysical data of previous explorers, Monax Mining acquired a detailed ground gravity survey during February 2006 over the eastern half of the licence. 209 stations were read on a 1 km x 1 km grid to augment existing PIRSA regional gravity data. The new data revealed some subtle variations in gravitational response across NW-SE and NE-SW oriented boundaries of lava flows, which were taken to reflect past dilational movements along conjugate basement structural features that would render these sites amenable to fluid flow and potential mineralisation. To further the search for potential IOCG targets in the deeper basement rocks, Monax flew a detailed airborne magnetic / radiometric survey across the entire tenement area during November 2006. In total 3563 line km of profiles were flown along 100 m spaced east-west lines with a sensor height of 50 m. The new magnetic data greatly improved the resolution of features noted earlier on regional TMI images. The most prominent magnetic features are north-east and north-west trending magnetic lows, which are interpreted to represent basement structures that may have controlled the Yardea Dacite flows. These structures are potentially conduits too for mineralising fluids that were associated with the emplacement of Hiltaba Suite granites and Gawler Range Volcanics. The majority of the outcropping geology on EL 3458 has been mapped by previous explorers as Yardea Dacite, however, a central zone containing the two main structures appears slightly less magnetic. It was interpreted that this zone may be hiding a different volcanic flow unit within the Gawler Range Volcanics, or else it is an artefact of the hydrothermal alteration and destruction of primary magnetite. Within the zone there is also a notable horseshoe-shaped magnetic feature, which is most likely an artefact of topography. The most intensely demagnetised structural zones also correspond to palaeodrainage patterns delineated by the new uranium channel airborne radiometric data. After Marmota Energy commenced operating the subject licence on 21/11/2007, that company commissioned the flying of an aerial EM survey (25 Hz TEMPEST) during June 2008 to try to better outline the channels of the palaeodrainage system indicated on the airborne radiometric data from the far eastern part of the licence area. In total 1745 line km of profiles were flown covering the entire licence area, along 400 m spaced east-west lines with a sensor height of 220 m. Some conductive sediments that are thought to belong to the Thurlga Palaeochannel were interpreted from the processed EM data, but their perceived prospectivity for hosting sedimentary uranium mineralisation appeared to be low by comparison with that of palaeochannels identified on Marmota's other project acreage in the Gawler region. For this reason, planned soil geochemical sampling and radon soil gas sniffer surveys over the EM anomalies did not eventuate. No further work was undertaken on EL 3458 during the fourth and fifth licence years, before the joint venturers decided to allow their tenure to lapse.