An area centred ~70 km north of Kimba, which also lies about 7 km north of the Menninnie Dam lead-zinc-silver deposit, was taken up to explore for possible buried economic volcanic epithermal/hydrothermal Mesoproterozoic Fe-rich Cu-Au mineralisation or Fe-poor Au mineralisation, besides any significant buried stratabound epigenetic/metamorphic Ag, Pb and Zn mineralisation that might have formed within Palaeoproterozoic and Mesoproterozoic rocks. During May 2005, PIRSA had conducted a regional 2 km x 2 km ground gravity survey along the southern margin of the Gawler Ranges, including over EL 3535, where 119 gravity stations were read. Minotaur identified a positive gravity anomaly in these gravity data and, to better define it, decided to conduct a follow up detailed gravity survey. 235 additional stations were read for the company on a regular 400 m x 400 m grid during October 2005, and other detailed traverses with 250 m station intervals were also acquired to assist with modelling of the anomaly. That work revealed an isolated positive anomaly in the south-eastern corner of the tenement area, having a 5 mGal magnitude and 2D extent of 3.5 km x 4.5 km. It did not appear to be associated with any significant magnetic anomalies, although a relatively thin, magnetic NW-trending dolerite dyke is present. The gravity anomaly's isolated nature and lack of magnetic response, coupled with its proximity to exposed Gawler Range Volcanics, in Minotaur's view made it interesting as a target for potential IOCG-style mineralisation. During the first licence year, Minotaur performed 3D inversion modelling of the gravity anomaly to derive a probable source depth. A vertical exploratory drillhole carried to 400 m depth was deemed necessary to adequately test this target. This hole, NN06R001, was RC drilled in September 2006. It was not cased, and high groundwater flows of very saline water resulted in continual blockage of the hammer and caving of the hole walls, causing drilling to be abandoned at 211 m, much shallower than desired. The hole encountered schist and quartz+feldspar+biotite gneisses (?Palaeoproterozoic Hutchison Group) which are not sufficiently dense to account for the gravity anomaly, and so Minotaur decided that further drilling was warranted. Late in March 2007, a ground magnetic traverse was read over the main gravity anomaly on EL 3535. It consisted of a NE-trending line incorporating 301 stations and a base station, and was conducted in order to assist siting of a second drillhole into the gravity anomaly. Interpretation of the magnetic data showed a very well defined NW-trending Gairdner Dolerite dyke, plus other anomalies with very short wavelengths and moderate amplitudes that are broadly coincident with the regional positive gravity anomaly, but which probably reflect detrital maghemite and magnetite within surficial Quaternary sediments, rather than lithological variations within the basement. During June 2007, a second hole, NN07RD02, was drilled vertically at a site positioned 500 m south of NN06R001. It was RC precollar drilled to 133 m depth, at which point a high groundwater influx caused an earlier than anticipated need to switch over to diamond coring, which was subsequently carried to a total depth of 432.5 m. Basement in this hole was penetrated at 50 m depth, and found to comprise a highly deformed paragneiss which is intruded by pegmatite and minor porphyritic granitoid rock. Significant sulphide mineralisation and pervasive IOCG-type alteration appeared to be absent. The sequence probably represents a combination of pelite, psammopelite and psammite metasediments (?Palaeoproterozoic Hutchison Group) that have been metamorphosed to amphibolite facies during at least two major deformational episodes. Density measurements made on the drill core yielded an average SG of 2.75 g/cc that is significantly lower than the pre-drill models' assumed 2.9 g/cc (3D modelling) and 2.85 g/cc (2D modelling). Minotaur's revision of the geophysical data in view of the drilling results suggested that two basement units may be present, including a deeper denser body (gabbro intrusion) with a SG of 3.0 g/cc and likely depth extent of 1000–1500 m. During licence Year 3, after new joint venturer Menninnie Metals Pty Ltd (MMPL) began managing exploration on EL 3535 late in June 2008, that company contracted Search Exploration to acquire 114 line km of dipole-dipole ground IP data along dispersed partial grids of 43 traverses using 100 m and occasionally 50 m station intervals. The processed IP data pseudosections were later modelled by geophysicist Dave McInnes of Montana GIS, using Zonge's Smooth Model Inversion software to generate apparent resistivity and chargeability models which reflect the geometries and locations of IP anomaly sources. A number of valid chargeable features were identified in nine locations. Some of these features occur near the margins of a residual gravity low that it was thought might represent an alteration zone within or above a shallow felsic pluton. During September 2008, Haines Surveys on behalf of OZ Minerals Ltd collected more ground gravity readings from 444 stations, with the gravity data comprising three distinct sets: • regional infill readings taken at 400 m x 400 m station spacing in the north-east of the licence area; • infill data also collected there along nine established tracks using a 400 m station spacing; and • two other separate smaller grids where detailed data was acquired on a station spacing of 100 m x 100 m in an attempt to better understand the size and orientation of sparsely outcropping quartz vein systems. During licence Year 4, MMPL made plans to acquire an airborne EM and magnetic survey over selected soil geochemical and IP anomalies, but scheduling delays and logistical problems with the survey contractor meant that the programme was later revised to address just 29 of the IP anomalies. 10 reconnaissance soil samples were collected and sent for laboratory orientation analysis. They included 7 samples of float shed from an epithermal vein system in the Gawler Range Volcanics, and a stream sediment grab sample from further downslope. Two shallow hand-held auger samples of calcrete and of clayey soil were collected from above an IP chargeability anomaly in the north-eastern part of the tenement. Results were unremarkable. The 118 line km, helicopter-borne Gawler VTEM survey was acquired on 6/5/2010, during licence Year 5, along either north-south or east-west orientated flight lines, using a 41 m mean terrain clearance and variable, 1 km down to 200 m or closer line spacings. Following processing and interpretation of the AEM and magnetic data, 16 conductivity anomalies were recommended for moving loop ground EM profiling to confirm their validity. The airborne EM and the IP data were later integrated into a layered earth inversion model that would allow ranking of targets. 12 reconnaissance soil samples were collected and sent for laboratory analysis, and 566 field portable X ray fluorescence (FPXRF) spectrometric analyses of outcrop were taken. During the sixth licence year (the first year of renewed EL 4813), detailed soil sampling was done by MMPL over the Pipe Track IP anomaly and legally accessible parts of nearby EM conductors, and geological mapping and reconnaissance lag sampling along fencelines and station tracks was progressed. Additional epithermal veins, breccias and lag fields were located within the Gawler Range Volcanics, and preparation of samples for petrological and rock geochemical studies commenced. The AEM data were reprocessed to produce CDI (Conductivity Depth Inversion) sections, to enable the re-interpretation and re-ranking of modelled conductors, and follow-up ground EM and IP profiles were designed to help define drill targets. Exploratory RC drilling of 4 holes at the Tank Hill North and Pipe Track IP anomalies was planned.