The subject Golf Bore prospect and its currently subeconomic gold occurrence are located in the north-eastern corner of the Jumbuck Project mineral exploration tenement package, which incorporates ~8000 square km of ground – approximately 2500...
The subject Golf Bore prospect and its currently subeconomic gold occurrence are located in the north-eastern corner of the Jumbuck Project mineral exploration tenement package, which incorporates ~8000 square km of ground – approximately 2500 square km of which is now part of a joint venture arrangement made by Trafford/Tyranna Resources with Kingsgate Consolidated, who own and operate the nearby Challenger gold mine. Golf Bore lies on the JV ground, within EL 4577 Sandstone. The buried Golf Bore gold occurrence was originally discovered by Dominion Mining/Resolute Resources through their calcrete sampling carried out in 1995-1996. By 1998 an inferred resource of 77,000 oz @ 3.3g/t Au had been defined through much RAB and RC drilling of the basement rocks, but the project was put on hold by Dominion, presumably due to activities at the Challenger mine taking precedence. When Southern Gold began its JV with Dominion in 2007, Golf Bore was the primary target, and over the following three years considerable further aircore and RC holes plus a single diamond hole were completed on it, besides the conduct of IP, CSAMT and ground magnetic surveys. Following a degree of success achieved in their appraisal drilling programme, it was stated by the JV partners: “the high grade gold intersections drilled by Southern Gold at Golf Bore are similar in grade and width to the exploration drill intersections of the M1 ore zone at the Challenger mine”. A final resource of 3,326,000 t @ 1 g/t Au, for 102,600 oz, was defined, and then no further work was done at the prospect, with the final opinion being that, in order to upgrade the indicated deposit size, much closer spaced drilling, to the point of being uneconomic, would be required due to the tight isoclinal nature of the host fold structures. The mineralisation at Golf Bore is associated with a large NE trending shear structure, and exists within a host rock of weakly foliated to strongly sheared biotite-quartz-feldspar gneiss. The mineralised body dips to the NW at ~ 45 degrees and was, prior to the current round of PACE - sponsored exploratory/appraisal drilling, defined along an 800 m strike length with mineralisation shown to be present down to a maximum depth of 100 m. A 2-5 m thick, low grade supergene blanket occurs consistently through the deposit from around 20 m depth below the surface. The underlying primary lodes have two lithologies – a pelitic quartz, biotite +/- amphibole gneiss with accessory pyrite, chlorite and garnet in parts, and a series of steeply dipping late stage pegmatites. There are slight variations in the geology from south to north, but these lithologies are present throughout. After it applied for and was granted subsidy funding for its planned drilling at Golf Bore, which was granted under the PACE Initiative Year 8 industry/government collaborative drilling programme as project DPY8-20, Trafford Resources undertook RC drilling there of 101 holes in two campaigns during August-September and December 2015, for a total penetration of 6133 m involving 79 vertical holes and 22 inclined holes. Prior to the 2015 drilling, the interpretation made from previous drilling results was that there were three confirmed zones of gold mineralisation present in the South, Central and North portions of the Golf Bore orebody, developed along an 800 m strike length. One of the DPY8-20 drilling objectives was to test more fully between these zones to investigate if the mineralisation could be connected. The 2015 drilling showed in part that gold mineralisation in the South zone occurs almost exclusively, with the exception of the 4 m @ 6.07 g/t Au intercept made in hole 15GBRC003, within the weathering transition horizon starting at the base of oxidation. The lithological host in the South is assumed to be gneiss, as pegmatite in the regolith contains quartz fragments. The gneiss in the regolith is generally composed entirely of grey sericitic clay. The average depth of gold intercepts here is 27-35 m. The 2015 drilling proved that gold mineralisation occurring in the regolith at Golf Bore may be connected between the South and Central zones, because hole 15GBRC085 intersected 3 m @ 7.66 g/t Au, including 1 m @ 16.5 g/t Au, within the 100 m wide gap that previously separated those orebody zones. Further drilling is required to map this area in more detail. The Central zone is where the most impressive drill intercepts have been obtained, and so it is likely to overlie the source of the mineralisation at Golf Bore. The geology is generally the same as in the South zone, but without the biotite-rich pegmatite, i.e. having a downwards soil to bedrock stratigraphic progression of a pallid zone, then lower saprolite down to the redox boundary, followed by reduced clays containing elevated gold, passing into fresh quartz/biotite/amphibole gneiss and pegmatite. Mineralisation is found within the transition units as well as the fresh rock. It is difficult to discern where gold is located based solely on visible geology in drill samples of both the regolith and the fresh rock. In the regolith it can begin at the redox boundary, or within the reduced grey clays which are believed to represent the gneiss. Similarly, in the fresh basement there are no clear informative signs – often there is pyrite associated with blue quartz, however, this can also be seen in barren zones so cannot be considered an identifying characteristic. Furthermore it cannot be said that mineralisation is restricted to lithological boundaries, in fact the opposite appears to be the case with intercepts often lying in the middle of thick gneiss zones. Overall in the Central zone, the average depth of gold intercepts is 36-44 m, which is deeper than in the South zone. In the Central zone, mineralisation appears to have been well defined by drilling to the east. However, it does not appear to be associated with pegmatite as in the South zone. This is likely due to the mineralisation being more primary in this area and therefore less likely to have migrated and be controlled by lithological boundaries. There is little evidence that mineralisation occurs in more than one main structure, which again is in opposition to that observed in the South; its lateral width in the regolith is ~100 m compared to ~130 m in parts in the South. This again can be explained by the probability that this zone is closer to the source than the observed, probably migrated, mineralisation in the South. The 2015 drilling indicates that mineralisation in the fresh bedrock is plunging to the north at approximately 30 degrees dip, which is the same dip as occurs at Challenger. The dip azimuth is towards 045, and this plunging shoot can be traced over a distance within a 30 m wide corridor. Defining the orientation of this bedrock structuring is potentially a vital part of unravelling the story of how gold mineralisation comes to be at Golf Bore, as it is the first indication of a traceable structure at depth akin to that found at Challenger. The shoot's grade and size is not of the same magnitude as in the Challenger main vein, however, the associated 800 m strike length of supergene mineralisation is almost double the length of that seen at Challenger. This may indicate that there is actually a series of similar structures underlying Golf Bore, of which this is merely the first that has been discovered. The 2015 drilling extended the known mineralisation in both the Central and North zones within the regolith, but it appears to be the case that grade diminishes considerably in the area between these zones. In the North zone, the 2015 drillholes showed that there is a change in the regolith profile whereby the pallid zone is not present in most of the holes along drill section 27a. In effect this merely moves the regolith closer to the surface, with a sequence comprising lower saprolite below the duricrust, and an extended saprock unit above fresh bedrock. On the north-western side of this orebody zone the saprolite almost disappears, although fresh bedrock still lies at around 30-35 m depth. The average depth here of gold intercepts is 49-55 m, which is deeper than in the South and Central zones. This may be due to the change in the regolith along strike, or more likely reflects the gentle northwards plunge of the orebody. At Golf Bore, the boundary of mineralisation in the regolith to the east has now been well defined by drilling the occurrence along its entire strike length. In the South zone, the western portion of the mineralisation appears to remain open in places, which might suggest that it is not a coherent orebody, but equally too, it may be that the more erratic distribution of mineralisation could arise from it being dispersed more widely along lithological contacts and fractures. In the Central and North zones, mineralisation is probably much more confined and coherent, and is readily traceable from drill section to drill section. Strategically, Trafford Resources thinks that the most important outcome of the subject 2015 PACE drilling project has been to affirm the previously inferred observation that the Golf Bore supergene gold mineralisation has an average lateral width of 100-120 m and a strike length of 800 m: the siting of so many additional drillholes has refined this shape and proved continuity of the wireframes. In consequence, the aggregate drilling results obtained to date have now proven enough in situ gold resources to define the economics of a minable deposit at Golf Bore, as well as defining suitable targets at depth for future diamond drilling aimed at resolving the primary lode distribution and ore controls within basement.