[ Note - here is only Part 2 of an abstract comprised of three separately indexed parts ]. RAB/RC appraisal drilling on 13 historic gold prospects and soil sample anomalies on the Tarcoola Goldfield commenced in late 1992. In the succeeding year,...
[ Note - here is only Part 2 of an abstract comprised of three separately indexed parts ]. RAB/RC appraisal drilling on 13 historic gold prospects and soil sample anomalies on the Tarcoola Goldfield commenced in late 1992. In the succeeding year, 316 holes totalling 26,839 m were drilled, funded by new JV partner Grenfell Resources. Soil geochemical sampling along 50 m - spaced prospect traverses was also carried out. During 1992, computer-generated orebody plans and sections were drawn up for the Perseverance prospect resource, based on all of the subsurface data available for an envelope of mineralisation covering an area of approximately 400 m x 150 m and extending to 50 m depth. Snowden and Associates were commissioned to prepare a first pass global assessment of the Perseverance gold resource, to measured status. Using a 14 g/t Au top cut (normal kriging equivalent) and a nominal 0.6 g/t Au cutoff grade, the calculated resource was in the order of 800,000 t of approximately 2.0 g/t Au gold ore. This work was followed in November 1993 by a second pass, more specific ore resource calculation incorporating newer drilling results, which yielded a measured resource estimate of 975,000 t of 2.0 g/t Au [@ 0.5 g/t Au cutoff], including 500,000 t of 3.2 g/t Au [@ 1.0 g/t Au cutoff]. By March 1994, preliminary mine pit design studies and ore processing metallurgical testwork were underway for Perseverance, while an extensive programme of regional soil geochemical sampling (7121 samples), including calcrete, was being pursued elsewhere to define new RAB drilling targets. The JV were aiming to delineate a minimum measured gold resource of 100,000 oz for the Tarcoola district before deciding to proceed to a mining feasibility study. Subsequent RAB and RC drilling of twenty targets (via 972 holes for 21,137.5 m) provided some encouraging high order gold intercepts in a few instances (e.g. at the Tolmer Hill, Mulgathing and Wunderbar prospects). During 1996-1997, continuing drill-based evaluation of the Perseverance gold resource included an initial diamond drilling programme (6 holes for 2045.9 m) designed to provide detailed lithological and structural information about the principal ore zone. These drillholes also made a number of significant mineralised intercepts that were inferred to lie within the NNE-trending Perseverance Fault structure, in an area immediately north of the mapped resource envelope. Follow-up RC drilling (86 holes for 11,571 m) was, however, unable to establish continuity of the high grade material seen in the diamond drillcores, revealing instead only moderate gold grades from within a restricted zone. In 1998, further diamond drilling was carried out at Perseverance to obtain core samples for geotechnical and metallurgical evaluation (10 holes for 1000+ m), while ongoing RC drilling of Tarcoola Ridge geochemical and magnetic anomalies (45 holes for 4045 m) returned significant gold assay peaks from the School, United and Warburton prospects. Other new activities that commenced during 1998-1999 consisted of prospect-scale infill to regional calcrete sampling (8290 samples), ground magnetic (44.6 line km) and ground radiometric (3.1 line km) surveying, infrared spectral studies of drill samples, and petrological and zircon age dating determinations. As well, a preliminary open pit mine feasibility scoping study for the Perseverance prospect was performed by contractor Australian Mining Consultants, which concluded that mining of the 'bonanza' high grade zone there (23,000 t @ 17.6 g/t Au) was only marginally economic at the prevailing gold price. In early 2000, one RAB drillhole was put down on the Daly's Dream prospect, where very high gold values (147 g/t Au from the depth interval 29.1-31.1 m in MESA TD3) had earlier been reported from a quartz breccia, possibly representing an epithermal mineralising system. The Grenfell Resources hole failed to replicate this bonanza grade intercept, the best returned assay values being 10 m @ 0.23 ppm Au from 20-30 m depth, including 1 m @ 1.25 ppm Au. For new regional RAB/aircore drilling (76 holes for 2893.5 m) done elsewhere, though, and particularly for that done on robust calcrete gold anomalies, the outcomes were surprisingly far less successful, with drilling being largely unable to detect primary bedrock sources for such promising surface anomalies.
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