The Yarri Project extends over more than 100km strike of prime gold exploration terrain that straddles the Keith-Kilkenny Tectonic Zone (KKTZ) and the Laverton Tectonic Zone (LTZ), both craton-scale structural features known to control gold mineralisation in this part of the Eastern Goldfields.
Hobbes Gold and REO Project
The Hobbes licence E31/1117 (Solstice 80%) covers a portion of the Edjudina Greenstone Belt, Pig Well Graben and north-northwest trending KKTZ within the Kurnalpi Terrane of the Archaean Eastern Goldfields Province. It is well situated close to established mining and haul road infrastructure approximately 5km southwest of the Porphyry Mining Centre. Northern Star operates open-pit and underground gold mines at Porphyry and is hauling material to its Carosue Dam operations.
In March 2023 Solstice reported a maiden pit-constrained Mineral Resource Estimate (MRE) at the Hobbes gold deposit comprising 4.6Mt at 1.2g/t Au for 177,000 ounces of gold. High level economic criteria were applied to the resource which was reported at a 0.6g/t Au cut-off and constrained within an A$2,500/oz optimised pit shell.
The Hobbes MRE delivered a solid foundation for further resource growth through exploration on the Hobbes licence and elsewhere in Solstice’s surrounding tenure.
Hobbes mineralisation is located under 30-40m of transported cover and was discovered and delineated by a combination of aircore then RC and DD drilling. Significant intercepts (minimum 2m >0.5g/t gold) of supergene mineralisation include:
- 19.8m @ 1.13g/t gold from 59.2m (HOBDD0004)
- 12m @ 1.21g/t gold from 57m (HOBRCDD0027)
- 13m @ 1.34/t gold from 58m (HOBRC0037)
- 17m @ 1.18g/t gold from 56m (HOBRC0032)
- 20m @ 1.55g/t gold from 53m (HOBRC0038)
- 10m @ 4.18g/t gold from 78m (HOBDD0002)
Geological modelling suggests that primary gold mineralisation is controlled by stacked WSW dipping NNW-striking zones in a fault block immediately south of the North Boundary Fault. There is potential for the North Boundary Fault to deliver new mineralisation across sequence, and for other ‘lookalike’ NE-striking faults to control new mineralised positions elsewhere on the Hobbes Licence and adjoining Solstice tenure. Significant intercepts of primary mineralisation from interpreted steeply dipping zones beneath the supergene blanket include:
- 27m @ 2.67g/t gold from 113m (including 20m @ 3.25g/t gold from 120m); 4.80m @ 3.19g/t gold from 150m and 7.20m @ 1.30g/t gold from 190.8m (HOBRCDD0003)
- 13m @ 4.04g/t gold from 96m (HOBRC0030)
- 8m @ 2.05g/t gold from 110m and 8m @ 2.32g/t gold from187m (HOBRC0033)
- 31m @ 1.71g/t gold from 118m (HOBDD0002)
- 11m @ 4.47g/t gold from 264m and 4.30m @ 3.38g/t gold from 395m (HOBRCDD0027)
In June 2023 the Company completed an aircore drill program testing an array of ‘lookalike’ structural targets. This program identified new gold anomalism as well as promising rare earth oxide mineralisation at the Leviathan Prospect.
The Leviathan Prospect is centred around a highly anomalous end-of-hole (EOH) result of 0.97% rare earth oxides + Yttrium (TREOY) in a 2023 aircore hole LVNAC0152. Rare earth oxides are associated with bastnaesite in a prominent strongly magnetic syenitic intrusion over 1km in diameter located in the south of the tenement. Follow-up drillholes intersected fresh syenitic and felsic porphyry intrusive rock types, and typically only penetrated a couple of metres below the transported cover profile. Despite the limited depth penetration, the drilling successfully confirmed a large area of highly anomalous TREOY values at or around EOH, including new spot results to 0.72% TREOY.
Statesman Well Prospect
At the Lake View licence (E31/1225), Solstice has undertaken compilation of historical exploration information and has identified significant drill results at the Statesman Well prospect. The prospect appears to have been first drilled by Tyson Resources Limited (Tyson) between 1986 and 1990. During 2012, Saracen Gold Mines Pty Ltd completed 24 RC holes (SWRC001–SWRC024) for 1,740m of drilling and reported that anomalous gold mineralisation was intersected in all the holes, with a peak individual sample result of 7.18 g/t Au (14–15 m) in SWRC022. Some of the more encouraging results from the drilling included:
- SWRC004 5m @ 1.25g/t Au from 21m
- SWRC010 7m @ 1.32g/t Au from 31m
- SWRC018 10m @ 1.63g/t Au from 58m
The gold mineralisation at Statesmen Well prospect occurs for at least 900m along strike and is open to the north and south.
The Bluetooth Prospect is located within E39/1914 and is associated with a mylonitic shear zone defined by tectonic cherts and quartz veins within a sequence of felsic metasedimentary schists, graphitic and sulphidic shales. Historical drilling, including 14 RC holes and 74 RAB holes, on nominal 100m line spacing, has defined a north-south mineralised zone interpreted by previous operators as dipping shallowly to the east, over a strike length of >800m. Better RC intercepts (using a 0.5g/t cut off) include:
- CBP001 8m @ 1.66g/t Au from 0m
- CBP007 4m @ 3.66g/t Au from 42m
- CBP008 15m @ 0.95g/t Au from 61m
- CBR014 2m @ 5.07g/t Au from 47m
- CBR022 12m @ 1.31g/t Au from 25m
The Bunjarra Licence is located approximately 70km northwest of Hobbes, and 50km southeast of Saturn Metals’ (ASX: STN) 1.84Moz Apollo Hill gold deposit. The Licence has promising structural settings, indications of gold mineralisation in on-strike positions, and is covered by a blanket of shallow transported alluvial material that has limited the effectiveness of previous exploration.
Yarri Regional Lithium Exploration
The Company has instigated and continues to undertake systematic ground truthing of areas of the Yarri tenement group considered to have potential for LCT pegmatite development. Prospecting during the year has located areas of previously un-mapped pegmatite on tenure. While this has shown that pegmatites sampled to date have low pathfinder chemistry, the field work demonstrates that new and potentially LCT mineralised pegmatite intrusions may exist elsewhere in the tenement group. Lithium exploration work is ongoing, and additional ground may be acquired in the Yarri area to compliment the current portfolio.