During Year 7 of reporting, exploration work included two 1 km soil geochemical traverses, field inspection of Neogene palaeochannels and land access negotiations with landowners. Previous exploration in the region has recognised the correlation...
During Year 7 of reporting, exploration work included two 1 km soil geochemical traverses, field inspection of Neogene palaeochannels and land access negotiations with landowners. Previous exploration in the region has recognised the correlation between “lode” horizon lithologies, high gravity response and low magnetic response of Willyama Supergroup rocks as zones with higher potential for mineralisation. Two gravity highs on EL 3521 Bonython Hill were tested for soil geochemical (22) anomalism with two 1 km lines with 100 m spaced stations using Minotaur’s portable XRF device. Neogene palaeochannels have been interpreted and recognised by PIRSA geologist to traverse parts of EL 3521, they flow southeast and southward from a radiogenic hinterland that includes “Radium Hill”. The palaeochannels appear to have sufficient width and thickness, based on field observations, to host a concealed roll-front uranium deposit of economic dimensions. During Year 8 of reporting, exploration work was limited to drill travers planning and the imaging of various channels from previously collected TEMPEST AEM data. The re-processing of the AEM allowed for a more confident interpretation of the palaeochannels and to further refine the positioning of proposed drilling to test the palaeochannels for uranium mineralisation. During Year 9 of reporting, exploration work focused on the drilling of aircore holes to test palaeochannels for roll-front uranium mineralisation. Thirty-one vertical aircore holes (RR00001 – RR00031) were drilled for 770 m by Toro Energy Ltd, with 130 samples collected for multi-element geochemical analysis and each hole radiometrically logged. There is no evidence of uranium mineralisation present in the Tertiary palaeochannel lithologies within EL 3521. Toro Energy Ltd has therefore decided that no further investigation is required for uranium mineralisation within the tenement. During Year 10 of reporting, exploration work included ground and aerial geophysical surveys. A helicopter-borne magnetic survey was flown between 12th – 18th April 2010 over Minotaur’s Mutooroo Project, with a total 3497.5 line-km of magnetic data collected on a 50 m line spacing, with 240 line-km flown over EL 3521. The purpose of the survey was to further refine the magnetite-bearing stratigraphy to assist with drill hole targeting. A ground magnetic survey was conducted “in-house” by Minotaur across Dey Hill, with data collected from 8, 1.6 km long traverses, spaced at 100 m intervals. The ground magnetic survey was conducted to assess the potential for magnetite in the area. The ground magnetic data has enhanced the resolution of the magnetic data over the area, resolving the magnetic high seen in the regional data set into a series of discontinuous magnetic highs up to 500m long. During Year 11 of reporting, on renewed EL 4745, exploration was focused around the Maldorky bore region. Two inclined RC holes were drilled for 460 m (11RCBH05 – 11RCBH06), targeting the magnetic portion of the Braemar ironstone facies. Drillhole 11RCBH05 intersected magnetite-bearing sediments with a mineralised interval from 40 – 175 m for 135m @ Av. 12.07% DTR and 13.34% Fe (Head), while drillhole 11RCB06 intersected magnetite-bearing sediments with a mineralised interval from 155 – 230 m for 75 m @ Av 15.55% DTR and 17.5% Fe (Head). Re-modelling of heli-magnetic data from the previous reporting period indicates that drillhole 11RCDH05 effectively tested the modelled magnetic body, whereas drillhole 11RCBH06 was drilled almost parallel to the modelled dip of the magnetic body. Lithological variation and lift of 11RCBH06 indicate that the drillhole drilled slightly across the magnetic stratigraphy. During Year 12 of reporting, exploration work consisted of regional geochemical surveys (rock chip (8) and soil (267)) and ground EM surveying. A total of 14 line-km of moving-loop ground EM surveying was completed in 6 lines over five targets. The ground EM successfully delineated conductive features at the Mingary Mine and PTBA-3 targets. Rock chip sampling at Mingary Mine indicates highly anomalous Au, Ag, Cu and Pb from tectonised quartz vein to quartzite (i.e., samples 124302 – 1.64 ppm Au, 865 ppm Cu, 124338 – 0.12 ppm Au, 1.78 ppm Ag, 196 ppm Cu and 124339 – 1.2 ppm Au, 0.95 ppm Ag, 1580 ppm Cu) and gossanous Fe stones (i.e., sample 124301 – 0.54 ppm Au, 8.5 ppm Ag, 2.1% Pb, 605 ppm Zn). Rock chip sampling in the Open Dam region revealed highly anomalous results at the Open Dam gossan (2.81 ppm Au, 7.63% Cu, 228 ppm Ag, 1.1% Mn, 502 ppm Zn), and sample sites 124345 (0.8 ppm Au, 3.87 ppm Ag, 784 ppm As, 3440 ppm Cu, 606 ppm Zn, 50.3 ppm U and REE’s) and 124346 (i.e., 1.1 ppm Au, 4.5 ppm Ag, 6430 ppm As, 6920 ppm Cu, 516 ppm Pb and 2140 ppm Zn ) with follow up rock chip and soil sampling recommended at these locations. Regional soil sampling on 300m x 300m grid at Mingary Mine indicated limited dispersion of elements from the geochemically anomalous line-of-load outcrops. Au-in-soil anomalies were detected at three prospects i.e., Ariel, Bol’dor and Atlas away from Mingary Mine outcrops. Infill soil sampling was undertaken on 50m x 50m grid at these prospects. Only Ariel prospect was confirmed by infill sampling with the original results from Bol’dor and Atlas prospect interpreted as spurious. Elements Th, Te, and W complimented the Au-in-soil anomalies in both the regional and infill sampling. Soil sampling was undertaken at the Open Dam gossan site with Cd and Au indicating that potentially mineralised basement may continue to the SW under shallow cover. Further soil sampling is recommended. During Year 13 of reporting, exploration work included a three-hole drilling program to test beneath historical workings and associated EM anomalies. Three inclined RC holes for 491 m (14RCBH07 – 14RCBH09) were drilled in April 2014, with the drilling Mingary Mine prospect successfully tested ground EM conductors and sampled the Mingary Mine line-of-lode quartzite unit under historical workings and drilling with significant Au-Cu-Ag±Zn mineralisation intersected in drillholes 14RCBH07 and 14RCBH09 including 16 m @ 1.07 g/t Au, 5.22 g/t Ag and 0.26% ppm Cu from 80m in hole 14RCBH07 and 40 m @ 0.60 g/t Au, 1.21 g/t Ag and 0.395% Cu from 92 m in hole 14RCBH09. A 1m sulphide bearing interval was intersected in drillhole 14RCBH08 which is interpreted to represent the weak EM conductor. No significant results were returned from this interval or the entire drillhole. Four RC chips were collected from drillholes 14RCBH07 & 14RCBH09 for reflected and transmitted light petrology.