Three contiguous licences located at the south-western end of the Nackara Arc structural province have continued to be explored for possible economic buried diamond mineral occurrences in the cover and bedrock that may exist in association with...
Three contiguous licences located at the south-western end of the Nackara Arc structural province have continued to be explored for possible economic buried diamond mineral occurrences in the cover and bedrock that may exist in association with formerly extrusive to sub-volcanic bodies of kimberlite. Work completed on ELs 2977, 3225 and 3434 by Flinders Diamonds Limited (FDL) during 2005, which was Year 1 of the JV project joint reporting period, comprised: • Reprocessing and evaluation of existing (open file) aeromagnetic data • High definition helimag surveying (5361 line km flown during July 2005 at 100 m N-S flight line spacing and 25 m ground clearance) • Ground magnetic surveying over 76 selected aeromagnetic (and helimag) targets • Follow up trenching of selected ground magnetic targets (18 trenches excavated) • Geochemical and microdiamond analysis of 14 kimberlite samples. Eight new kimberlites were discovered within the tenements. Positive microdiamond results were reported from two of them, in 20 kg bulk samples examined from the H49-T2 (3) and 134a-T1 (1) kimberlites. These discoveries represented the first confirmed identification of primary (i.e. basement rock) - sourced diamonds in the Nackara area. The use of newly available high definition helimagnetic airborne surveying provided a large number of new kimberlite dyke, sill and pipe targets that it was intended would be tested by follow-up ground magnetic surveying and trenching. FDL also planned to undertake a test program of bulk sampling in 2006 that would test for macrodiamonds in the Fra149a-T2 kimberlite and also provide a gauge of the reliability of microdiamond analysis of a 20 kg sample to selectively identify potentially diamondiferous kimberlites, in place of having to do traditional bulk sampling all new kimberlites discovered. During 2006 and 2007, Years 2 and 3 of the project, the same kind of exploration work programme was continued by FDL, owing to its initial success as described above. A second high resolution helimagnetic survey totalling 17,103 line km, using the same acquisition equipment and parameters, was flown over the majority of the Nackara Project area during April and May 2006. Work continued in the interpretation of these new geophysical data, and it led to the identification of numerous magnetic anomalies which might represent kimberlite dykes and pipes. These magnetic targets, generally N-S orientated dipolar anomalies, were later tightly confined by ground magnetic surveying and then tested by either consteaning or auger drilling. A total of 270 ground magnetic grids were surveyed, totalling approximately 620 line km of profiling. 126 trenches/auger holes subsequently tested 71 targets, of which 30 were shown to arise from previously unknown kimberlite bodies (dykes, sills, blows and pipe diatremes). Microdiamond analysis was performed on a 20 kg sample of each kimberlite, but only two samples were confirmed as diamondiferous. One kimberlite pipe/fissure, the Monks Hill kimberlite, showed some diamond potential, having microdiamond counts of up to 110 grains per 20 kg sample. Consequently, bulk sampling was undertaken at Monks Hill in March 2007; no macrodiamonds were recovered. Bulk sampling of the previously discovered Pandappa K4 body, which was undertaken in mid-2006, also failed to yield macrodiamonds. Loam/drainage sampling was trialled over 17 other ground magnetic targets. Each loam sample equated to ~15 kg of sediment, sieved to obtain a minus 1.6 mm grainsize fraction. The results were inconclusive, as all of the samples lacked kimberlite indicator minerals. However, these anomalies were subsequently proved to be caused by mafic igneous intrusive rocks that are not kimberlites. Aircore drilling of 2 holes for 122 m were drilled with drill samples collected for petrology, geochemistry and diamond and indicator mineral examination. This drilling program included holes on the Franklyn target (EL 2977). Two holes (FR06AC015 & FR06AC016) were drilled on the ‘Magnetic Anomaly WO23’ north of the Franklyn Gravity Anomalies. Both holes intersected a series of igneous body of 5 and 7 m thick at between 4 and 11 m below the surface. During 2008, Year 4 of the project, as with 2005 exploration activities, the current exploration strategy has been modified since early 2004 from traditional KIM sampling techniques to the use of aeromagnetic and ground magnetic surveying as the main targeting method. Late in 2007, FDL flew a third helimagnetic survey, again along 100 m spaced flight lines, which covered the northern part of the Simonec Parties' JV project ground plus other adjacent ground held by the Filsell brothers and Colonial Copper. Some infill 50 m line spaced data were acquired over the Paratoo and Mount Grainger licences held by the Filsell brothers [this data subset is reported separately]. Both kimberlite dyke and pipe targets were selected for follow up ground magnetics, with selected targets tested by trenching. A single ground magnetic survey was completed in the reporting period with lines spaced 10, 30 and 40 m apart. To further trial the applicability of the chosen kimberlite prospecting method, orientation loam geochemical sampling was conducted over three previously discovered kimberlites during Year 4 of the project, 25 kg samples were collected and they all returned a strong positive result denoted by number of kimberlite indicator mineral (KIM) grain counts, the grain size distribution and the grains' morphology. Another 62 loam samples were collected to test targets generated from the newer helimag data. Five of these samples returned a positive KIM result. One sample, PU-23, contained a high Mg olivine. These five samples came from sites in close proximity in the east of EL 3225. 337 selected loam heavy mineral grains were sent off for electron microprobing to determine their chemistry for confirming their apparent KIM status, and also to determine potential diamond stability/preservation facies. Four large, 250 kg loam composite bulk samples were collected from separate 1 square km grids set out over the large Beatrice prospect aeromagnetic anomaly located on EL 3225. The objective of this was to confirm KIM anomalies previously reported in that area, and to vector towards a possible kimberlite source. In conjunction with loam sampling,100 g sub-samples of all of the loam samples collected during 2008 were laboratory assayed for gold, base metals and a suite of trace elements including rare earths. There was no obvious correlation between KIM-positive samples and chemical anomalies in elements such as Nb and REEs. During Year 5 of the project, the exploration work carried out by Flinders Mines included the completion of ground magnetic surveys over selected helimagnetic targets, local-scale regolith-landform mapping in the vicinity of the Pitcairn-Mafeking area within the Nackara-Bendigo tenements. The trenching of potential KIM trap sites generated from the regolith-landform mapping was undertaken, followed by mineral geochemistry of grains selected for KIM confirmation. In 2009, Flinders Mines used regolith mapping in conjunction with shallow trenching to obtain and sample palaeo-alluvial gravels for KIMs. Previous geophysical data has also been utilised to interpret KIM results. Ground based magnetic surveys were also conducted in October-November 2009 over targets generated from positive trenching results, with a total of 60 surveys undertaken. The regolith mapping fieldwork demonstrated the dominance of transported cover in the low-lying alluvial systems; however, the thickness of transported cover is often overestimated. In the northern Beatrice study area, within the mapped aeolian sediments the transported cover is less than 1 m. Often weathered bedrock can be seen exposed within the sandy sediments. the fieldwork, by trenching in areas of unknown depth of transported cover, as well as providing KIM samples for HMS analysis. A total of 35 trench samples were collected from the 35 costeans located across the Beatrice study area, of these 33 samples, weighing approximately 25 kg, were sent to Diatech for heavy mineral analysis, processing and observation including probe work. From these samples, 15 tested positive for DIMs, however only 6 samples contained significant numbers of key minerals. During Year 6 of the project, no filed work was conducted however microdiamond/heavy mineral re-analysis of 2 samples from the Monks Hill anomaly within EL 4638 (2006 trenching program) was undertaken. Some doubt surrounds the initial results of the sampling completed in 2006/2007 because the samples were sent to a laboratory in Canada, where there was an opportunity for contamination. One of the samples came back positive for 1 microdiamond, the other was negative. The observed concentrated samples came back with abundant heavy mineral indicator grains, returning a range of kimberlitic indicators. During Year 7 of the project, Flinders Mines withdrew from the JV in July 2011 with exploration responsibility returned to J. Simnovec, the principal investor in Amona Mining & Exploration Pty. Ltd. and Novec Pty Ltd. Since the resumption of management by Amona and Novec the release of information and material from the new Flinders Mines management has been hindered by their unfamiliarity with the project on account of staff losses. Simnovec initiated an assessment of the Gold prospectivity of the area in response to the appreciable rise of bullion value during the last two years. Several historical prospect localities were field visited and spot sampling undertaken. Geoscientific data has been summarised on regional and prospect scales. This work is ongoing. Exploration activities undertaken in the reporting period included two field inspections. The first was aimed at collecting confirmatory analytical; data with grab samples being assayed to verify the gold tenor reported by previous investigators. It was undertaken by J Simnovec and G Ferris of Intermet Resources Limited. The second was in relation to planning potential investor visits and re-establish communications with local landholders. It was undertaken by J. Simnovec and JL Curtis. Samples collected by G. Ferris (Intermet Resources) during an inspection of the Golden Point Prospect were gold anomalous, typically assaying up to 3.2 g/t Au, with an exceptional 18.6 g/t Au. Ten rock samples from five locations collected by G. Ferris (Intermet Resources) during an inspection of the Hill Grange Prospect, one was from Hill Grange North and four from the south. Eight were gold anomalous, five strongly so, with a maximum of 1.3 g/t Au. Year 8 and 9 of the project were jointly reported, covering the period from 1st January 2012 to 31st December 2013. Exploration work during the period was limited due to corporate issues. In September 2013 Yumei Mining Australia Pty. Ltd. entered into an exploration funding agreement for a joint venture covering EL 5020 Pandappa. J. Simnovec remained as project manager. In April 2013 Datong ‘Group’ of South Australia entered into an acquisition sales agreement with respect to J Simnovec ‘Group’ assets, ELs 4294 Mafeking & EL 4638 Bendigo and the ML’s covering the Mt. Grainger Gold Mine and related on-site assets. This agreement called for settlement in August 2013 but as of December 2013 this had not occurred. During the period 4 technical visits were made to EL 5020 and EL 4294, 2 were undertaken with Chinese delegations to facilitate investment negotiations and another with a Chinese consultant geologist unaccompanied by a geo-technically skilled translator. Upon the agreement with Yumei Mining a soil geochemistry survey was initiated over the Cox’s Sandstone and the Golden Point Prospect line of workings on EL 5020. The survey covered 2.4 km of strike using a sample spacing of 25 m along E-W lines 150 m long and 50 m apart. A total of 300 soil samples were acquired. The results of the orientation soil survey were disappointing, as the detection of gold in relation to the working and spoil heaps was not effective and was also not able to demonstrate the normal correlation between Au, As and Sb as was expected. It is believed that a high proportion of aeolian desert sourced dust (loess) is significantly diluting soils and suppressing the geochemical signatures of mineralisation in the Nackara Region of SA. It was hoped that it can be overcome by utilising MMI technology in future surveys. Appraisals were completed on the diamond exploration data from the Flinders Mines era and the company believe that the area has yet to be exhausted and that further exploration in conjunction with new generation aeromagnetic imagery to identify potentially fertile kimberlite. During Year 10 of the project, exploration activities have continued to be limited due to continuing corporate issues. The Datong default has precluded in-field exploration work but planning for on-going work was undertaken during the previous reporting period in anticipation of the clear return of the exploration areas and Mt Grainger Mine to J Simnovec ‘Group’ control which was achieved on the 15/01/2015. Regrettably DMITRE (now DSD) expenditure commitments have not been honoured by the failure of this intending purchaser to follow through. Alternate potential investors to fund the proposed work programmes were identified but ultimately declined to proceed. Exploration activities resumed on Pandappa EL 5020. Only Planning has been possible however with respect to ELs 4294 Mafeking (Nackara) & 4638 Bendigo. Soil analytical trials were undertaken at Gold Point on EL 5020, with surveys replicating the proportions of the orientation survey completed in the previous reporting period, with the survey 2.4 km of strike using a sample spacing of 25 m along E-W lines 150 m long and 50 m apart. Both XRF and Mobil Metal Ion (MMI) analysis were completed on new material from the sample sites. The survey demonstrated MMI technology has higher sensitivity and contrast to standard MS and XRF soil sample analysis procedures. It also demonstrated that at Golden Point Au has a strong spatial association with enhanced Cu & Ag (MMI & XRF). A less well-defined association with As is also present. The survey also identified a weak enrichment of Pb, Zn, Ni and Co in the footwall of the Cox’s Sandstone. During Year 11 of the project, the Yumei Mining JV over EL 5020 came to an end during the reporting period as of 22nd May2015. Exploration efforts were again limited by corporate and funding issues, with only planning possible on all exploration licenses. During the life of the now failed Daytong buyout the subject of gold assay discrepancies between bulk and small 2-5 kg samples at Mt Grainger became a subject of considerable interest. This issue of can see/recover but no assay gold has been long known to occur at Mt Grainger and regionally elsewhere, but never resolved. After an in-depth literature study, a technical programme to identify the specific impediment factors was developed, so that an appropriate viable laboratory methodology could be devised for the J. Simnovec Group. The assessment throws into question the reliability all laboratory gold assays of oxidised materials across the Nackara region and perhaps more widely in SA. Until it is resolved rock chip samples, drilling programmes and consequent down-stream assessment of gold mineralisation will not meet expected QA-QC for JORC reporting of results. The conclusion was drawn that a 'once and for all' technical resolution of the matter needed to be identified and converted to a viable lab assay protocol before ongoing field exploration could meaningfully be justified. It was requested that a programme be drawn up that would provide for the primary demonstration test and provide adequate material for the subsequent research effort. The approval process time became significantly extended during this period, and with the degrading mining industry resulting in the closing of laboratory services research institutes, and the loss of experienced personnel have limited progressing the issue. During Year 12 of the project, to 19th October 2016, no field work was carried out across all 3 tenements. No technical report was submitted for the respective expiry/full surrender of the tenements.