High-grade hits from Astral Resources to support Mandilla resource update

• Astral’s infill drilling at Iris returned high-grade gold hits up to 37.9g/t
• Results likely to boost indicated resources in March 2026 update
• High-grade intersections found outside current pit designs

Special Report: Astral Resources is likely to enjoy a significant boost to higher confidence indicated resources when the next Mandilla resource update swings around after infill drilling delivered high-grade gold hits.

The 19-hole program totalling 2971m at the Iris deposit returned results such as:

• 4m grading 21.3g/t gold from a down-hole depth of 91m including 2m at 37.9g/t as well as 2m at 12.8g/t from 120m including 1m at 24.4g/t (MDRC983);
• 21m at 1.59g/t Au from 148m including 1m at 13.5g/t from 166m (MDRC980); and
• 3m at 2.17g/t Au from 45m, 5m at 5.73g/t from 99m and 15m at 1.22g/t from 110m (MDRC971).

Notably for Astral Resources (ASX:AAR), the very high-grades in MDRC983 are outside the pre-feasibility study pit designs, which indicates potential for additional high-grade feed for the proposed Mandilla process plant.

The two lines of drilling at Iris followed up successful infill drilling reported in December 2024 and increased the infilled area at a 40m by 20m drill spacing to 140m by 360m.

“This is the second phase of infill drilling at Iris, with the strong results likely to support a further increase in indicated mineral resources when we deliver our next update to the Mandilla resource estimate planned for the March quarter of 2026,” managing director Marc Ducler said.

“The higher-grade core of the deposit has again delivered strong results, including 23 metres at 1.00g/t Au from 156m and 21 metres at 1.59g/t Au from 148m.

“Additionally, MDRC983 returned two very high-grade intersections outside of the current pre-feasibility mine design, including 4 metres at 21.3g/t Au from 91m and 2 metres at 12.8g/t Au from 120m.

“These high-grade results will complement the next resource update at Iris, with further drilling to the south currently being planned.”

Mandilla project

The company’s flagship Mandilla project sits in the northern Widgiemooltha greenstone belt, about 70km south of Kalgoorlie, WA.

The area hosts world-class deposits such as the Golden Mile Super Pit, Gold Fields’ St Ives gold mine and Westgold Resources (ASX:WGX) Beta Hunt gold mine.

Mandilla is no slouch as it hosts a resource of 42Mt grading 1.1g/t, or 1.43Moz of contained gold, within the Theia, Iris, Eos and Hestia deposits. About 63% of the resource is in the indicated category that has enough geological certainty for mine planning.

Metallurgical testing undertaken on each of the main deposits has demonstrated high gravity recoverable gold, fast leach kinetics and exceptional overall gold recoveries of up to 99.5% with low reagent consumptions and coarse grinding.

A pre-feasibility study released in June 2025 envisioned a standalone project with seven open pit mines (four at Mandilla and three at Feysville) feeding a 2.75Mtpa processing facility to produce 95,000ozpa gold in the first 12 years.

Using a conservative Australian gold price of $4250/oz, this is expected to deliver net present value – a measure of a project’s profitability – of $1.4bn at an 8% discount rate.

AAR noted the latest drill results targeting the inferred higher grade “core” of the Iris deposit provided further confidence that this zone of mineralisation was likely to support conversion into the higher confidence indicated category.

At Hestia deposit, a 24-hole reverse circulation program carried out to sterilise the south waste rock landform location and test for an extension to an offset lode returned a best assay of 4m at 2.08g/t gold from 192m (MDRC998).

This was 40m south of the known extent of gold mineralisation at Hestia and is likely an extension of the main gold mineralised trend.

Holes drilled south of the known extent of Hestia mineralisation did not encounter significant mineralisation and the program is considered to have been successful in sterilising the proposed waste landform footprint to the south.

More from AAR: Astral unveils golden opportunity with Mandilla PFS

Current and upcoming activity

ARI is carrying out infill drilling at Theia deposit with a 99 hole program totalling about 10,000m around 20% complete.

It plans to conduct follow-up infill drilling south of hole MDRC983, which intersected high-grade mineralisation outside the PFS pit designs, as well as further drilling west of existing mineralisation at Hestia.

“Diamond drilling targeting high-grade shear-hosted gold mineralisation within and immediately adjacent to Theia is expected to commence early in the December quarter,” Ducler said.

“The RC rig currently at Mandilla will relocate to Feysville to complete a 47-hole/7,000-metre program at Kamperman and undertake further greenfields exploration across the broader tenement package.”

At the Spargoville project, the company is continuing RC drilling at Eagles Nest with 68 holes totalling 11,000m drilled across several targets.

Once this is completed, a 21-hole program totalling 2500m will begin on behalf of the JV with KOMIR to investigate lithium pegmatite targets identified from a previously completed geochemical survey across the JV tenure.

Ducler added the company was continuing to ramp up drilling efforts across its project portfolio along with a definitive feasibility study for Mandilla, where the preferred engineering partner is expected to be appointed in coming weeks on completion of the competitive tender.

This article was developed in collaboration with Astral Resources, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.