Antipa Minerals Limited (ASX: AZY), with its joint venture partner, Rio Tinto Exploration Pty Limited has announced the intersection of significant widths of gold-copper±silver mineralisation including 146.7m at 1.36 g/t gold and 0.08% copper from 95.9m down hole, from the Citadel Joint Venture Project 2020 Exploration Programme in Western Australia’s highly prospective Paterson Province.
AZY reported that assay results were received for a further two of the 27 diamond and RC drill holes drilled at theCalibre deposit in the 2020 field season.
The JV partners said that significant widths of gold-copper±silver mineralisation were intersected, including substantial high-grade gold mineralisation outside the existing Calibre Mineral Resource boundaries.
Significant assay results include 146.7m at 1.36 g/t gold and 0.08% copper from 95.9m down hole including 101.0m at 1.81 g/t gold and 0.05% copper from 95.9m, also including; 35.70m at 2.08 g/t gold and 0.15% copper from 96.3m, including; 9.4m at 4.26 g/t gold and 0.11% copper from 187.6m, including; 0.9m at 19.30 g/t gold and 0.09% copper from 192.5m.
The results are currently outstanding for remaining four drill holes completed at Calibre and other regional greenfield targets.
The JV partners said that the Citadel Joint Venture Project 2020 Exploration Programme budget is now $12.6m with the completed Programme including additional drill holes testing regional targets.
Citadel joint venture project
The Citadel Joint Venture Project is a JV between Rio Tinto and Antipa, wherein Rio Tinto can fund up to $60 million of exploration expenditure to earn up to a 75% interest in the project.
The Citadel project area consists of approximately 1,300km2 of highly prospective but largely underexplored Proterozoic stratigraphy in the north of the Paterson Province in Western Australia.
Citadel project hosts the Calibre gold-copper-silver-tungsten deposit, the Magnum gold-copper-silver deposit, and several other smaller deposits and promising prospects like the Le Tigre and Rimfire.
Calibre is located 45km east of Rio Tinto’s Winu copper-gold-silver deposit within a similar geological setting. Calibre and Magnum contain a combined Mineral Resource of 1.6 million ounces of gold and 127,300 tonnes of copper.
Calibre represents a very large‐scale mineral system with material potential exploration upside under just 80m of cover, with a strike length of approximately 1.6km, up to 480m thick, and open in several directions.
2020 Exploration Programme
The JV partners had commenced Citadel 2020 Exploration Programme to test potential extensions and further define and improve ore body knowledge at the Calibre deposit as well as to test certain greenfield targets.
The Citadel 2020 Exploration Programme is operated and fully funded by Rio Tinto with a now budgeted cost of $12.6m, reflecting a recent revision in the estimated cost of the programme and the inclusion of additional RC and DD drill holes to test regional targets.
Greenfield exploration programme
The JV partners said that the 2020 Citadel Project greenfield exploration programme comprised both geophysical and drilling activities.
The 2020 greenfield exploration drill programme (outside of the drilling at the Calibre deposit) comprised seven RC holes for 2,100m at Rimfire plus one DD hole for 387m at Le Tigre. The company said that the assay results are pending.
New target identified
The JV partners said that the preliminary processing, and review of the 2020 Gradient Array Induced Polarisation (GAIP) Geophysical Survey results identified a high priority target, GAIP20‐01, now known as the Boxer target. The company said that the timing for drill testing of Citadel Project greenfield GAIP targets, including the Boxer target, remains subject to the receipt of the necessary approvals.
Calibre exploration programme
AZY said that the drilling for calendar 2020 has been completed for Calibre gold‐copper resource drill programme.
The company said that 10,510m (6,730m DD plus 3,780m RC) were drilled; two Calibre metallurgical drill holes were completed; and seven drill holes tested peripheral targets between 200m to 700m from the Calibre deposit.
The company said that assay results have now been received for 22 of the 27 holes drilled.
High-grade assays from further two holes
The JV partners said that the assays for a further two drill holes have been received of the 27 diamond core (DD) and reverse circulation (RC) drill holes completed at the Calibre deposit in 2020.
Significant results for this batch of assays include 146.7m at 1.36 g/t gold and 0.08% copper from 95.9m down hole in CALB0027, including: 101.0m at 1.81 g/t gold and 0.05% copper from 95.9m, also including; 35.7m at 2.08 g/t gold and 0.15% copper from 96.3m, including; 2.3m at 2.37 g/t gold and 0.68% copper from 99.7m, 1.0m at 5.18 g/t gold and 0.21% copper from 116.0m, 3.9m at 9.51 g/t gold and 0.25% copper from 120.0m, 3.2m at 3.11 g/t gold and 0.10% copper from 128.8m, 1.0m at 3.99 g/t gold and 0.08% copper from 136.0m, 6.0m at 2.93 g/t gold and 0.03% copper from 147.0m, including; 0.8m at 9.87 g/t gold and 0.05% copper from 147.0m, 3.0m at 2.58 g/t gold and 0.11% copper from 155.5m, 7.7m at 2.87 g/t gold and 0.30% copper from 173.1m, including; 1.0m at 2.52 g/t gold and 1.22% copper from 173.1m, 2.2m at 4.82 g/t gold and 0.25% copper from 174.1m, 1.8m at 4.30 g/t gold and 0.19% copper from 179.0m, 9.4m at 4.26 g/t gold and 0.11% copper from 187.6m, including; 0.9m at 19.30 g/t gold and 0.09% copper from 192.5m, 2.0m at 2.73 g/t gold and 0.04% copper from 221.0m, 1.0m at 1.97 g/t gold from 116.0m down hole in CALB0022, 1.0m at 1.07 g/t gold from 249.0m down hole in CALB0022, 4.0m at 1.73 g/t gold and 0.11% copper from 254.0m down hole in CALB0022, 0.8m at 8.10 g/t gold and 0.16% copper from 278.5m down hole in CALB0022, and 14.6m at 0.71 g/t gold and 0.06% copper from 287.3m down hole in CALB0022, including; 3.6m at 1.50 g/t gold and 0.19% copper from 294.3m.
AZY noted that the results of the 2020 drilling received to date include significant intersections of goldcopper± silver mineralisation, including several significant intersections outside the existing Calibre Mineral Resource envelope.
The company said that the available 2020 DD and RC drill hole assay results from Calibre confirm significant gold‐copper±silver mineralisation along a 550m strike and up to 370m below the northern sector of the current Mineral Resource; mineralisation now extends up to 570m below surface, up to 300m across strike and over a total strike length of approximately 1,500m; and the mineralisation is interpreted to be closed off to the north, with the existing northern limit of the Mineral Resource likely to remain materially unchanged.
Remaining Citadel 2020 exploration programme
The JV partners announced that the remaining Citadel 2020 Exploration Programme consists of the ongoing review of the Calibre drill results and broader Magnum Dome modelling to identify further priority target areas, especially for higher grade mineralisation; the ongoing review of GAIP results in conjunction with other data; planning for drill testing of greenfield targets (in 2021), including the high priority target Boxer target; and possible Calibre Mineral Resource update following receipt of all 2020 drill data including assay results.
Next steps
The JV partners announced that further work would include the ongoing review and interpretations of the 2019 data, historical data, and 2020 exploration data; planning and execution of follow‐up exploration activities to identify potential high‐grade mineralisation; ongoing modelling/interpretation of airborne gravity survey data; full geological interpretation including 3D modelling where data supports; and possible Calibre gold‐copper‐silver deposit Mineral Resource estimate update.