Astral Resources Hits 1.54g/t Average as Theia Drill Results Beat MRE Grade Again
Key Takeaways
- All four batches of Theia Stage 1 RC in-fill assays have exceeded the Stage 1 MRE grade of 1.1g/t Au, with the latest 41-hole batch returning a weighted average of 1.54g/t Au.
- Theia Deeps hole AMRCD374 delivered 426.5 gram x metres of mineralisation across 318.9m — including 1m at 219g/t Au from 25m — despite being terminated early due to deviation.
- The Stage 1 in-fill program is 225 holes (22,705m) complete of a 431-hole (44,400m) program, with the tighter 12.5m x 12.5m grid designed to convert resources to the Measured category ahead of the DFS.
- Assays are pending on AMRCD424 (Theia Deeps), with core logging already showing quartz veining and visible gold extending beneath the base of the Resource shell.
- The Mandilla DFS is forecast for completion in the March Quarter 2027, underpinned by a 2.07Moz group resource and a PFS base case NPV8 of $1.4 billion at A$4,250/oz gold.
High-grade results keep flowing at Theia as Astral advances toward DFS
Astral Resources (ASX: AAR) has released assay results for the next 41 holes (4,456m) of its ongoing Reverse Circulation (RC) in-fill drill program at the Theia Deposit, part of the 100%-owned Mandilla Gold Project located 70km south of Kalgoorlie, Western Australia. The latest batch returned a weighted average grade of 1.54g/t Au, well above the Stage 1 Mineral Resource Estimate (MRE) grade of 1.1g/t Au, continuing a trend of results that are meeting or exceeding expectations across the program.
The program is designed to convert Stage 1 Mineral Resources to the Measured category, a key de-risking milestone on the path to the Mandilla Definitive Feasibility Study (DFS) and project financing.
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Standout intercepts from the latest 41-hole batch
Stage 1 RC in-fill highlights
The following are the best results from the latest batch. All intercepts are downhole lengths; true widths have not been stated.
- 7m at 10.4g/t Au from 133m, including 1m at 53.0g/t Au from 133m and 1m at 17.8g/t Au from 139m (AMRC446)
- 13m at 5.00g/t Au from 36m, including 1m at 36.8g/t Au from 41m and 1m at 19.0g/t Au from 46m (AMRC431)
- 4m at 13.5g/t Au from 106m, including 1m at 45.7g/t Au from 107m (AMRC410)
- 11m at 4.00g/t Au from 34m, including 1m at 24.6g/t Au from 42m and 1m at 24.7g/t Au from 107m (AMRC444)
- 1m at 43.0g/t Au from 15m (AMRC433)
- 15m at 2.05g/t Au from 57m, including 1m at 14.4g/t Au from 69m (AMRC415)
Drill hole AMRCD374 — Theia Deeps highlights
AMRCD374 was an RC hole with a diamond tail, collared inside the Stage 1 pit footprint as part of the Theia Deeps program. The hole was terminated early at 318.9m, well before its intended target depth, due to excessive deviation. Despite not completing its planned program, it returned exceptional results:
The Theia Deeps program has been progressively extending the known mineralisation envelope below the Stage 1 pit shell, with earlier holes confirming high-grade gold continuity at depth before the current expanded 11,000m campaign was approved.
- 1m at 219g/t Au from 25m
- 3m at 15.4g/t Au from 141m, including 0.3m at 122g/t Au from 143.01m
- 13m at 2.29g/t Au from 62m, including 1m at 21.8g/t Au from 74m
- 3.35m at 5.86g/t Au from 229m, including 0.3m at 60.4g/t Au from 232.05m
Across its 319m length, AMRCD374 delivered a cumulative result of 426.5 gram x metres of mineralisation. Gram x metres is defined as the length of a reported intersection multiplied by its grade, and is used to express the overall gold content of a drill hole in a single comparable figure.
Assays are pending for AMRCD424, the third hole drilled from the same pad. Logging of the diamond core shows quartz veining and visible gold consistent with the MRE, and extending beneath the base of the Resource shell.
What is RC in-fill drilling and why does it matter for investors?
Reverse Circulation (RC) drilling is a method that forces air down the outside of the drill rod and back up the inside, bringing rock chips to the surface. Geologists collect and sample these chips at 1m intervals, giving a detailed picture of the rock and its gold content along the full length of each hole.
“In-fill” drilling refers to drilling additional holes between existing drill holes to reduce the grid spacing. At Theia, the program is tightening that spacing from 40m x 40m down to 12.5m x 12.5m, which increases confidence in both the grade and the continuity of the orebody.
That confidence matters because of how gold resources are classified under the JORC Code (the industry standard for reporting mineral resources in Australia). Resources move from Inferred (lowest confidence) to Indicated to Measured (highest confidence). Achieving that upgrade is a key de-risking milestone for the DFS and project financing.
Astral’s in-fill program is specifically designed to convert Stage 1 Mineral Resources to the Measured category.
Consistent results validate the Theia model — and the Mandilla development case
Results consistently beating the MRE grade
The weighted average grade from this latest batch sits at 1.54g/t Au, but it is the consistency across all previous batches that is particularly telling for investors. Every batch to date has come in above the Stage 1 MRE grade of 1.1g/t Au:
- 1.93g/t Au (announced 2 December 2025)
- 1.41g/t Au (announced 9 July 2026)
- 1.24g/t Au (announced 23 July 2026)
- 1.54g/t Au (this announcement, 8 September 2026)
The company states this pattern validates both the geological interpretation and the existing Mineral Resource model for Theia.
Marc Ducler, Managing Director, Astral Resources
“The average weighted grade of 1.54g/t Au across this latest batch of assays gives us further confidence that the current program is not only delivering on but exceeding expectations.”
The Theia and Mandilla project context
Theia hosts a Mineral Resource of 41.0Mt at 1.1g/t Au for 1.4Moz of contained gold, and contributes approximately 75% (1.1Moz) of the 1.48Moz total production case outlined in the Mandilla Pre-Feasibility Study (PFS). The Stage 1 open pit encompasses 4.2Mt at 1.1g/t Au for 146,000 ounces over the first 21 months of the project, at a strip ratio of 4:1.
At the group level, the consolidated Mineral Resource stands at 61.6Mt at 1.0g/t Au for 2.07Moz across Mandilla, Feysville, and Spargoville. The Mandilla PFS (June 2025) reported a base case NPV8 of $1.4 billion (at A$4,250/oz gold), rising to $2.7 billion at A$6,000/oz. These are PFS-level estimates based on the assumptions contained in the original June 2025 announcement and should be read as such, not as forecasts of future financial outcomes. The Mandilla DFS is forecast for completion in the March Quarter 2027.
| Metric | Theia Stage 1 Pit | Theia Deposit | Mandilla MRE | Group Total MRE |
|---|---|---|---|---|
| Tonnage | 4.2Mt | 41.0Mt | 53.5Mt | 61.6Mt |
| Grade | 1.1g/t Au | 1.1g/t Au | 1.0g/t Au | 1.0g/t Au |
| Contained Gold | 146,000oz | 1.4Moz | 1.74Moz | 2.07Moz |
| Notes | First 21 months; 4:1 strip ratio | ~75% of PFS production case | Mandilla deposits only | Mandilla + Feysville + Spargoville |
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What comes next — two rigs turning, more assays on the way
With two drill rigs currently operating at Theia, the program pipeline ahead remains substantial. Key milestones and current status are as follows:
- Stage 1 RC in-fill program: 225 holes / 22,705m completed of a 431-hole (44,400m) program; 206 holes / approximately 21,248m planned to complete
- Theia Deeps diamond program: 14 of 21 holes in the expanded 11,000m program completed; assays pending for 5 holes / 3,041m
- AMRCD424 (Theia Deeps, same pad as AMRCD374): Drilling complete, assays pending; logging shows quartz veining and visible gold extending beneath the Resource shell
- Heritage surveys at Kamperman (Feysville) and the Spiders complex (Spargoville): Completed; preliminary reports pending — once received, exploration programs will recommence at both areas
- Mandilla DFS: Forecast for completion during the March Quarter 2027
- Think Big early mining opportunity (Feysville): Could produce cash flow during the June Quarter 2027
The Think Big early mining opportunity at Feysville has received drill permit approval, positioning it as a potential source of project cash flow ahead of the main Mandilla development ramp-up.
Each batch of assays adds another layer of confidence to the geological model underpinning the DFS. With the program tracking consistently above the MRE grade and the drilling grid progressively tightening toward Measured classification, the systematic de-risking of the Mandilla development pathway continues to advance.
Ready to Dig Deeper Into Astral Resources’ Mandilla Gold Project?
The Theia Deposit’s in-fill drill program continues to deliver weighted average grades consistently above the Stage 1 Mineral Resource Estimate, reinforcing the geological model ahead of the Mandilla Definitive Feasibility Study, forecast for completion in the March Quarter 2027. With a consolidated group Resource of 2.07Moz and a PFS base case NPV8 of $1.4 billion, the systematic de-risking of this 100%-owned Western Australian gold project is well underway.
Explore the full project background, drilling updates, and investment case by visiting the Astral Resources (ASX: AAR) profile on Discovery Alert, where subscribers receive real-time notifications on high-impact discoveries like this one.