Aureka Limited has boosted its global JORC gold resource by 26% to 455,000 ounces, driven by a 30% increase at its flagship Irvine Gold Project in Victoria’s Stawell Corridor. The upgrade reflects enhanced geological modelling and successful diamond drilling since early 2025.
- Global JORC resource rises 26% to 455koz gold
- Irvine Project inferred resource grows 30% to 398koz
- Gold grade at Irvine improves to 2.59g/t
- Exploration targets expanded with ongoing drilling
- Resource remains classified as inferred due to data gaps
Significant Resource Upgrade at Irvine Gold Project
Aureka Limited (ASX:AKA) has announced a 26% uplift in its global JORC-compliant gold resource to 455,000 ounces, primarily driven by a 30% increase at its Irvine Gold Project in the Stawell Corridor. The inferred resource at Irvine now stands at 398,000 ounces, up from 304,000 ounces at the start of 2025, with an improved average grade of 2.59 grams per tonne (g/t) gold, reflecting both higher tonnage and better grade.
This resource growth follows just under 5,000 metres of diamond drilling across eight holes since January 2025, which successfully targeted the Resolution Lode, the project’s main mineralised zone. The drilling has delivered high-grade intercepts, including visible gold, underpinning the revised estimate.
Enhanced Geological Understanding Drives Upgrade
The upgrade is attributed to an improved geological model incorporating new structural interpretations, notably the redefinition of the Tenacity Fault as a moderately west-dipping structure rather than vertical. This refined domaining, combined with additional drilling data, has allowed Aureka to delineate 11 mineralised domains within the Resolution Zone, with the Resolution Fault and Tenacity Fault zones being the most significant.
The Resolution Lode resource now totals 4.11 million tonnes at 2.71 g/t gold for 358,000 ounces, split between open pit (43%) and underground (57%) mineralisation. This represents a 28% increase in tonnage and a 6% increase in grade compared to the previous estimate. The Adventure Lode resource remains unchanged from the 2021 maiden resource.
Exploration Targets Expanded with Ongoing Drilling
Beyond the resource upgrade, Aureka has defined advanced and conceptual exploration targets at Irvine, ranging from 57,000 to 130,000 ounces and 151,000 to 348,000 ounces respectively. These targets are based on geological and geophysical data, including recent high-resolution drone magnetic surveys, and remain conceptual with low geological confidence.
Diamond drilling continues at Irvine to test extensions of the Resolution Lode and new targets such as the North Resolution anomaly. Concurrently, infill drilling at the St Arnaud Comstock Gold and Silver Project aims to upgrade resources from inferred status and support near-term production options.
Resource Classification and Metallurgical Status
The entire updated resource remains classified as inferred due to wide drill spacing, reliance on air core drilling in upper zones, and suboptimal drill angles. Metallurgical testing has not yet been conducted; cost and recovery assumptions are benchmarked against the nearby Stawell Gold Mine, which achieves 80-90% gold recovery using conventional processing.
Aureka’s Managing Director James Gurry highlighted the importance of the resource growth and the company’s goal of reaching a 1 million ounce resource within three years, supported by Exploration Manager Jozef Story’s leadership and incentives.
Technical Rigor and Independent Oversight
The updated JORC resource estimate was compiled by John Collier of Conarco Consulting, a geologist with extensive experience in Victorian goldfields and major Australian deposits. The estimation employed ordinary kriging and inverse distance weighting, with careful top-cutting of high-grade outliers and validation steps to ensure volume and grade integrity.
Quality assurance protocols included certified reference materials, blanks, and duplicate samples, with no significant analytical bias detected. Density measurements informed tonnage calculations, though further data collection is recommended to improve confidence.
Bottom Line?
Aureka’s substantial resource upgrade at Irvine signals growing confidence in the Stawell Corridor’s potential, but inferred classification and pending metallurgical data mean cautious optimism remains until further drilling and testing refine the project’s economics.
Questions in the middle?
- Will ongoing drilling convert inferred resources to higher confidence categories?
- How will metallurgical test results impact recovery assumptions and project economics?
- Can Aureka successfully expand the exploration targets into defined resources within the next drilling campaigns?