Rupert Resources

Ikkari Discovery


Ikkari was discovered using systematic regional exploration that focused on geochemical sampling of bedrock/till interface through glacial till deposits of 5 to 40m thick. No outcrop is present, and topography is dominated by low-lying swamp areas. In the Ikkari area, a single anomalous base of till sample of 0.2ppm Au was followed up with infill sampling to a 50 x 25m grid, and a small cluster of anomalous samples up to 1ppm Au was identified. The first drill hole into this geochemical anomaly (hole 120038) was drilled in April 2020 and assayed 54m grading 1.5g/t Au from 25m, under 13m of glacial till cover material. Follow-up drill hole intercepts demonstrated very broad mineralised zones with a high-grade component over an initial strike length of >500m.

The Ikkari deposit occurs within rocks that have been regionally mapped as 2.05-2.15 Ga old Savukoski group greenschist-metamorphosed mafic-ultramafic volcanic rocks, part of the Central Lapland Greenstone Belt (CLGB). Gold mineralisation is largely confined to the structurally modified unconformity between Savukoski and Kumpu groups strata. The two units are complexly interleaved, the result of early low angle thrusting and folding and subsequent upright folding and shearing.

The mineralised zone is bounded to the north by a steeply N-dipping cataclastic zone and is closely associated with intercalations of Kumpu sediments within the Savukoski komatiite-dominated strata he mineralised zone is overprinted by a complex history of hydrothermal brecciation, the latest stages associated with a second phase of high-grade gold mineralisation.


Within the mineralised zone, sedimentary slivers are interleaved with komatiite-dominated strata and these are mantled by Fe-metasomatic halos, which enclose the bulk of the Au resource. The main mineralised zone is strongly altered and characterised by intense veining and foliation that frequently overprint original textures. An early phase of finely laminated, grey ankerite/dolomite veins is overprinted by stockwork-like irregular siderite ± quartz ± chlorite ± sulphide veins. These vein arrays are often deformed with shear-related boudinaging and in situ brecciation. Magnetite and/or haematite are common, in association with pyrite. Hydrothermal alteration commonly comprises quartz-dolomite-chlorite-magnetite (±haematite).

Gold is hosted by disseminated and vein-related pyrite, frequently occurring as ~1mm visible gold grains. Multi-phase breccias are well developed within the mineralised zone, with early silicified cataclastic phases overprinted by late, carbonate- iron-oxide- rich, hydrothermal breccias which display a subvertical control. All breccias frequently host disseminated pyrite, and are often associated with bonanza gold grades, particularly where magnetite or haematite is prevalent.  In the sedimentary lithologies, albite alteration is intense and pervasive, with pyrite-magnetite (± gold) hosted in veinlets in brittle fracture zones.


The independent and qualified person for the Mineral Resource Estimate as defined by NI43-101 is Brian Wolfe, Principal Consultant, International Resource Solutions Pty Ltd. These are mineral resources not mineral reserves as they do not have demonstrated economic viability. Results are presented in situ. Ounce (troy) = metric tonnes x grade / 31.103475. Calculations used metric units (meters, tonnes, g/t). Any discrepancies in the totals are due to rounding effects. The effective date of the 2022 Mineral Resource Estimate for Ikkari is 28 November 2022. The Mineral Resource Estimate at Ikkari is calculated using the multiple indicator kriging (MIK) method and is reported both within a designed open pit and as a potential underground operation outside that. The Mineral Resource Estimate at Ikkari is reported using a cutoff grade of 0.5g/t Au for mineralisation potentially mineable by open pit methods and 1.0g/t Au for mineralisation potentially extractable by underground methods. The potential open pit mine and cut off-grade is calculated using a gold price at $1650 per ounce, 5% mining dliution, 95% Au recovery. Open pit mining costs at $2.5/t, process costs at $11.3/t, other costs (includes co-disposal, water and closure) at $4.0/t and G&A including royalties and refining at $3.2/t. The calculated cutoff grade is rounded up to 0.5g/t for reporting. The underground cutoff grade is calculated at underground mining cost $21.8/t and underground mining dilution at 8% based on sub level caving. The calculated underground cutoff grade is rounded up to 1.0g/t as the resource is not constrained within mineable shapes.


Metallurgical test work indicates that Ikkari is non-refractory and can be recovered using conventional processing techniques. The PEA considered a new plant to process 3.5 Mt/a of run-of-mine (ROM) ore from the Ikkari open pit and underground at an average grade of 1.82 g/t Au (including processing low grade stockpiles towards the end of life of mine). The process considered comprises crushing and grinding to reduce the ROM material to a characteristic grind (P80) of 175 µm, and a gravity circuit to recover the native gold. The pyrite associated gold will be recovered by flotation and fed, with the re-pulped concentrate from Pahtavaara, into the leach circuit where lime and cyanide are added in the presence of air to extract the gold. The gold will be then recovered in an adsorption, desorption, and recovery (ADR) circuit. The leach tails will be treated to remove cyanide and filtered for co-disposal with waste rock. The liquor recovered from the filtration is treated prior to re-use.


Ikkari is located 30km from the town of Sodankylä by 40km tarmac road and a further 5km of well-maintained forestry gravel roads managed by Metsähallitus, the state-owned forestry company.

A 220 kilovolt (kV) power transformer substation is located 9 km from Ikkari that
can be used as a connection point to the national grid for a 110 kV power line to
the Ikkari minesite. A power surplus is envisaged in Lapland towards the end of
the decade, with a significant contribution expected from renewables.