Exploration of an area of Neoproterozoic metasedimentary rocks bordering, and in part intruded by, Ordovician plutons of the Anabama felsic intrusive complex, has targeted possible analogues to the Blue Rose copper-gold skarn mineralisation...
Exploration of an area of Neoproterozoic metasedimentary rocks bordering, and in part intruded by, Ordovician plutons of the Anabama felsic intrusive complex, has targeted possible analogues to the Blue Rose copper-gold skarn mineralisation occurrence, which was discovered nearby by Giralia Resources early in 2002, on the northern margin of the main Anabama Granite pluton. The Blue Rose occurrence reported drillhole intercepts included a best interval of 28 m @ 1.41% Cu and 0.33 g/t Au hosted by a thick skarn-altered dolomite, which unit had been targeted by Giralia because of its noticeable low magnetic response within the pluton's contact metamorphic aureole. Later in the year, Adelaide Exploration took up a parcel of newly available ground which had formerly been explored by Dominion Mining, that had its western boundary located 11 km to the east of this discovery, because of the presence of similar demagnetised features evident in the regional aeromagnetic dataset, a few of which had already been tested by Dominion with lesser success (e.g. the Maldorky prospect). Work by Adelaide Exploration on the subject EL 2980 commenced during March-April 2007, with the drilling of 34 ?vertical open RAB holes along 6 traverses for a total penetration of 2507 m, to explore three selected prospects having interesting demagnetised character. Two drill traverses were completed at each of the Dark Horse, Alderman's and Eastern Dam prospects. The best results were obtained from Traverses 1 and 2 on the Dark Horse prospect, which lies closest to the Anabama pluton and to Blue Rose, viz. a maximum assay value of 6050 ppm Cu in hole ANA020 from 105-108 m depth, within an open-ended mineralised interval of 46 m @ 0.07% Cu plus zinc to 0.27% Zn; and additional element suite maxima of 27 ppb Au and 230 ppm U in hole ANA016, from the depth intervals 49-50 m and 50-51 m respectively. A broad zone of mildly anomalous copper and uranium was disclosed at Dark Horse, which appeared to be associated with a fault splay of the Darling Lineament showing increased depth of weathering and a geochemically anomalous saprolite. Less elevated and far less extensive copper and uranium values were also detected by the drilling done at the other two magnetic lows. During 2008, a trial Niton XRF spectrometric surface geochemical survey was undertaken across the copper-anomalous zone at Dark Horse prospect, when 1008 stations were read at 20 m spacings along 13 lines. The survey results proved inconclusive, yielding poorly coherent anomalies within the target zone. This insensitivity to the known basement mineralisation was attributed to the quite variable thickness of the cover and to the presence of transported sediments occupying broad drainage channelways within that cover. Following a subsequent 4-year hiatus in exploration activities on the renewed EL 3816, caused by the licensee's need to concentrate on priority work at its exploration acreage elsewhere in the state, it was decided in 2012 to perform follow-up surface (Field Portable) XRF surveying, this time at closer station spacing, over places on the target prospects that are known to have thinner cover. The FPXRF trial repeat attempt was made at some time before June 2012, and produced more positive results. So early during the following year, 29 east-west aligned transects were FPXRF sampled on Dark Horse, with 2583 readings taken at 25 m spacings, while separately, 51 north-south aligned transects were sampled on Eastern Dam prospect, with 2415 readings also taken at 25 m spacings. This time more apparently coherent anomalism was detected amongst the data for the 32 elements analysed, outlining five copper-rich anomalies at Dark Horse which correspond with interpreted structural junctions identified from magnetic imagery. The level of copper anomalism seen at Eastern Dam is more subdued but of similar character: it was surmised that the largely unknown depth of cover may be masking the basement response here. It was briefly reported by the licensee that during 2012 existing JV partner Peninsula Resources carried out office-based investigations to assess the potential of the subject licence area to host metasedimentary iron ore deposits associated with the Braemar Iron Formation. This study included some reprocessing of existing aeromagnetic data. Also during 2012, Adelaide Resources made some joint venture invitation overtures towards three other companies, but ultimately these efforts were unsuccessful. No other field work was performed on the again renewed licence, EL 4969, during 2013, 2014 or 2015, before the decision was eventually made to surrender this tenement.
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