Two separate licence areas located within the greater Waukaringa region north of Yunta in the Adelaide Fold Belt were taken up to explore for possible economic buried gold (both primary and secondary mineral occurrences), and also for any economic...
Two separate licence areas located within the greater Waukaringa region north of Yunta in the Adelaide Fold Belt were taken up to explore for possible economic buried gold (both primary and secondary mineral occurrences), and also for any economic metamorphic and hydrothermally altered stratabound/stratiform iron ore. No field work was performed during the first licence year of both tenements, while access negotiations were being conducted with an Aboriginal Native Title claimant group. Verbal permission was obtained to permit planned reconnaissance non - ground disturbing exploration activities to occur, but no written agreement was given that would help to guide more progressive investigations. Therefore the only travel allowed within the licences had to be done along existing tracks, with no deviations onto adjoining ground. Initial on-ground work, that commenced early in 2014, was directed at assessing the iron ore potential of interpreted Adelaidean Holowilena Ironstone strata, via the conduct of ground magnetic surveys over >20 km strike length of aeromagnetic anomalies (for a total 39 line km of magnetometer readings made along 116 lines spaced 25 m apart), accompanied by geological inspection and limited grab rock chip sampling of outcrops. The assay results and petrological examination of the outcropping material suggested that it was mainly hematite-rich, containing >40% Fe. Geochemical analyses of 561 soil samples were obtained using a portable hand-held Innov-X XRF spectrochemical instrument, which allowed the licensee to prospect for gold anomalies by using soil arsenic concentration as a vectoring agent. No significant As anomalism was found, although coherent weak trends were seen of arsenic values at 2-3x background. A few high arsenic results were returned from samples of gossans and historic gold mine spoils. During the third year of tenure, the licensee carried out desktop studies of past explorers' surface and downhole sampling geochemical results, looking for clues to gold distribution within the cover and shallow bedrock, and he collected 25 selected rock chip samples of outcropping quartz veins to assay for gold. The best value of 68 g/t Au was returned from sampling mine spoil at the Royal Charlie prospect, where elevated gold in a dolomitic unit outcrop was seen to extend for ~200 m between two previous RC drillholes that had been reported to contain minor levels of gold. In other work, Hutchens plotted conductivity depth images for 6 lines of airborne EM survey data from the 2010 Geoscience Australia Frome Embayment survey, that had been flown over what was now the eastern side of EL 5190. These AEM data were compared with the ground magnetic data previously read over the Roadside prospect, and 2.5 line km of follow-up ground EM surveying was done along 8 lines spaced 80 m apart. The results showed a weak east-west trending conductive zone at 641720mN that coincides with local mining activity at its eastern end. Some trial micro-EM surveying (i.e. metal detecting) was performed at the alluvial Osbourne Park/Johnson’s Gully prospect. A single nugget of gold was located weighing ~0.27 g, along with many small iron pieces. The deliberate specimen find showed that gold nuggets can still be sourced from sites of historic alluvial working. During the fourth year of tenure, in a return to exploring for iron ore, the licensee collected a further 120 line km of ground magnetic data and modelled the resultant defined anomalies for buried source geometry and magnetisation strength. Portable XRF spectrochemical readings were made on 14 grab samples of apparently more magnetite-rich Holowilena Ironstone found on EL 5191, and the richest 4 samples were examined mineralogically in thin section. Subsequent to completing this work, Hutchens sold EL 5191 to Olary Magnetite Pty Ltd. An application to fully surrender EL 5190 was submitted in May 2017. During the fifth year of tenure, no work was completed on EL 5191.
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