Exploration carried out over two adjacent areas located 50 to 70 km south-west and south of Wudinna was progressed under the terms of two separate joint venture agreements made by the licensee in October 2006, firstly with GE Resources (a...
Exploration carried out over two adjacent areas located 50 to 70 km south-west and south of Wudinna was progressed under the terms of two separate joint venture agreements made by the licensee in October 2006, firstly with GE Resources (a subsidiary company of Uranium Equities) to look for sedimentary uranium mineralisation, and secondly with the Silver Swan Group to look for all other minerals, particularly IOCG base metal deposits and lode gold. Following a review of the available exploration data commissioned from consultant Ian Garsed, it was decided by InterMet Resources to focus most effort primarily on the potential for finding palaeochannel-hosted and unconformity-related uranium, based on past reports of subeconomic drilhole uranium intercepts made by Carpentaria Exploration Co. upstream within the Yaninee Palaeochannel, which crosses the subject licences. Carbonaceous Tertiary palaeochannel fill occurs quite extensively across both ELs, and in view of the occurrence of numerous Hiltaba plutons in the region, any well-developed palaeochannel reaches must be regarded as highly prospective for finding roll-front uranium mineralisation. During February-March 2007 Haines Surveys acquired a gravity survey for Uranium Equities, with 892 stations read along 37 east-west lines forming a 1 km x 1 km grid across both licences. Access to the central part of the tenements, and into areas fringing their western and southern boundaries, proved too difficult owing to impenetrable thick scrubby vegetation and the inability to gain permission to venture off-road into conservation reserves. The Silver Swan Group requested infill gravity coverage (433 plus 114 stations) to 200 m x 200 m station spacing over two areas on EL 3462, to help delineate possible basement drill targets. Overall this survey was able to define six new residual gravity anomalies and two new palaeochannels. During May 2007 Uranium Equities drilled and wireline geophysically logged 43 vertical rotary mud holes at 1 km intervals along seven traverses to investigate palaeochannel sediments on both licences, for a total penetration of 2637 m. The drilling confirmed the presence of the two prognosed palaeochannels and discovered another palaeochannel in the western licence sector. Anomalous total-count gamma responses (up to 3-4 times background) were encountered in drillholes that terminated within relatively unweathered Hiltaba Suite granitic basement, thus confirming the presence of a suitable source rock. All three palaeochannels display up to 90 m thickness of channel fill, with sand-dominated and lignitic sequences up to 20-30 m thick being present both above and below a regionally extensive braided fluvial prelutitic sedimentary sequence. Some total-count gamma ray log anomalism was detected at the boundaries between these various sequences, in addition to at the contacts between oxidised and reduced facies within them. During August 2007 the Silver Swan Group completed a 3 vertical hole HQ/NQ2 diamond drilling programme totalling 919.1 m (including 131 m of rotary mud precollars in 2 holes) on EL 3462 to test two selected gravity anomalies, which geophysical models had suggested showed the best IOCG potential with regard to body densities and inferred structural controls. Drillhole A1-DDH1 reached a total depth of 341.8 m, penetrating two modelled gravity bodies. The dominant lithology encountered was a compositionally and grain size variable granodiorite, displaying intermittent quartz/feldspar veining and a weak to moderately strong magnetic response. Initial interpretation suggested that this undeformed granodiorite may be related to the Palaeoproterozoic St Peter Suite (1620- 1630 Ma). A less common weathered rhyolite was taken to represent Archaean basement known to be present in the area. The layered/banded nature of this rhyolite contrasts markedly against the fabric of the granodiorite. The presence of granite dykes within the rhyolite suggested that the granodiorite has intruded into the older rhyolite. Drillhole A1-DDH2, which reached a TD of 330.4 m, was intended to test the large gravity source body also present at the A1-DDH1 site, as well as a second smaller, shallower and denser gravity body. The precollar rotary mud drilling passed through a palaeochannel at 33 m depth, indicated by cuttings of medium to coarse grained, sub-rounded to rounded sands with partial iron staining. Grey/green lignitic clays were also seen between 47-52 m depth. The dominant basement lithology at the A1-DDH2 location was an undeformed medium to fine grained dolerite, intruded in part by porphyry and microgranite. The characteristics of the porphyry and pegmatitic rocks (mineralogy, iron staining, alteration) show some similarities, so the two may be associated. Zones of mixing between the dolerite and microgranite may also indicate that these intrusions were emplaced penecontemporaneously. The association of the magmatic mixing, fractured nature of the dolerite in drill core, and the presence of chlorite/sericite alteration would suggest that if a synemplacement relationship exists, the microgranite would be late stage. Drillhole A2-DDH2 targeted a second gravity anomaly linked to a north-west trending linear magnetic feature with a possible jog/dilational aspect. The hole reached a TD of 246.9 m, well into the gravity source body modelled to lie at 180 m depth. The dominant basement lithology is a coarse grained, undeformed phenocrystic granite. Equigranular (phenocrysts of K-spar absent), porphyritic and quartz-rich bands are also present, but these appear to be compositional and grain size variations rather than distinct lithological changes. Variations within the granite cease below 156 m depth, with the lithology to the end of hole consistently being phenocrystic granite. This granite has been interpreted as Mesoproterozoic Hiltaba Suite. Some intervals of the cored granite show moderate fracturing, with chlorite developed along fracture surfaces. Such surfaces also show some haematite staining in places. Distinctive quartz-feldspar-fluorite-?muscovite veining was visible in the porphyritic and quartz-rich granitic facies. It was found from taking petrophysical measurements of the drill cores that the modelled average basement anomaly source densities were far too high. The only mineralisation observed was limited to small accumulations of pyrite in isolated brecciated zones and in rare quartz-feldspar veins, or to finely disseminated pyrite and chalcopyrite (<1%). No significant downhole sample geochemical results were reported. No other field work was undertaken by the joint venturers during the rest of the licences' 5-year concurrent first terms, and tenure was eventually allowed to lapse.
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