Astral Resources NL has increased its total Group Mineral Resource Estimate (MRE) to 1.76 million ounces (Moz) of gold following the integration of the Spargoville Gold Project into its portfolio.
The Spargoville MRE, restated under the same economic parameters as Astral's Mandilla Pre-Feasibility Study (PFS), stands at 3 million tonnes at 1.4 grams per tonne (g/t) gold for 139,000 ounces. This addition follows Astral's acquisition of Maximus Resources, with Spargoville located adjacent to the Mandilla Gold Project in Western Australia.
The inclusion of Spargoville complements existing MREs of 42 million tonnes at 1.1 g/t for 1.43Moz at Mandilla and 5 million tonnes at 1.2 g/t for 196,000 ounces at Feysville. The consolidated MRE for Astral now stands at 50 million tonnes at 1.1 g/t gold for 1.76Moz.
“With compulsory acquisition of the outstanding shares in Maximus having now been completed, we considered that it was important to set our own baseline for the recently acquired Mineral Resources at the Spargoville Gold Project, Astral Resources’ managing director Marc Ducler said.
“Astral’s standard approach when testing the Mineral Resources for reasonable prospects for economic extraction (RPEE) includes a first step of regularising the block model, which is the process of varying the size of the block model shapes to approximate the size of the earth moving machinery likely to be used in open pit mining.
“This serves to more accurately reflect the amount of dilution likely to be experienced during open pit mining and provides a good base for the subsequent optimisations used to identify the potentially economic portion of the mineralisation models.
“Today’s update reflects this process of regularisation as well as the application of the latest revenue and cost data for the pit optimisations derived from contractor quotes obtained for the upcoming Mandilla PFS. The downward revision in contained metal is mostly attributable to the impact of dilution resulting from increasing the block dimensions to 4mE x 5mN x 5mRL and application of the Astral economic constraints.”
Map illustrating the location of the Mandilla, Feysville and Spargoville Gold Projects.
Spargoville MRE details and methodology
The updated Spargoville MRE was compiled using a 0.39 g/t cut-off grade and constrained within A$3,500 per ounce gold price pit shells. Key changes from previous estimates by Maximus include the application of Astral's economic parameters and regularisation of block models to reflect a more realistic mining Selective Mining Unit (SMU).
This restatement resulted in a decrease from prior estimates of 6.9 million tonnes at 1.5 g/t for 335,000 ounces to 3 million tonnes at 1.4 g/t for 139,000 ounces.
“The due diligence conducted in the lead-up to the Maximus transaction involved an independent fatal flaws review of the mineralisation block models at Spargoville and an internal review of the economic assumptions and open pit optimisations to satisfy the RPEE aspects of the JORC 2012 code,” Ducler said.
“The due diligence identified that further technical work would be required on the then current Maximus MRE as reported to align it with Astral’s approach when reporting Mineral Resources.
“The fact that the work since undertaken by Astral has resulted in a reduction in the number of contained ounces of gold was anticipated by our team and was taken into account in determining an appropriate offer price.”
Exploration upside and development potential
Astral highlighted the discovery cost efficiency at Mandilla, which has delivered 1.43Moz at under A$18 per ounce. The new Spargoville ground is expected to unlock similar potential. A substantial reverse circulation (RC) drilling program is under consideration for the September 2025 quarter.
Spargoville incorporates several deposits:
- Wattle Dam Gold Project: 2.1Mt at 1.3g/t for 91,000oz
- Eagles Nest: 0.3Mt at 1.9g/t for 16,000oz
- Larkinville: 0.2Mt at 1.7g/t for 12,000oz
- Hilditch: 0.4Mt at 1.3g/t for 15,000oz
- 5B: 0.0Mt at 4.2g/t for 5,000oz (Inferred)
These deposits were not reinterpreted geologically but were regularised and optimised using updated cost models aligned with the Mandilla PFS.
Consolidated Mineral Resource Estimate (May 2025)
- Mandilla: 42Mt @ 1.1g/t for 1.43Moz
- Feysville: 5Mt @ 1.2g/t for 196koz
- Spargoville: 3Mt @ 1.4g/t for 139koz
- Group Total: 50Mt @ 1.1g/t for 1.76Moz
Resources are reported at a 0.39 g/t cut-off, constrained within optimised pit shells based on A$3,500/oz for Mandilla and Spargoville and A$2,500/oz for Feysville.
Strategic importance
Astral underscored the strategic importance of the Maximus acquisition, noting it not only boosts the company’s total MRE but also enhances development potential and exploration opportunities at Mandilla.
“The Maximus transaction was very important for Astral. Not only has it contributed a further 139koz of contained gold, increasing the Group MRE to a very healthy 1.76Moz, but it also provides the company with the necessary tenure footprint to develop the Theia deposit to its fullest potential as well as optimise the proposed site infrastructure layout – which were key drivers of the transaction,” Ducler said.
“Potentially significant operational efficiencies are also now likely to be achieved when the Mandilla Gold Project comes into production.
“The transaction also provides the company with additional highly prospective tenure adjacent to our Mandilla Project, which has already delivered 1.43 million ounces of gold discoveries at an average cost less than $18 per ounce. The new tenure includes previously untested areas immediately south of, and along strike from, the Hestia Deposit, where 2.4 Mt at 1.2 g/t for 91koz of contained gold are currently estimated.
“Astral considers the entirety of the new Maximums tenure to be highly prospective and is looking forward to completing our own targeting of the area prior to commencing future brownfields and greenfields exploration campaigns.
“This further underlines the strategic value of the acquisition to Astral, despite the revision to the published resource ounces announced today.
“Drilling is expected to commence on the new Spargoville tenure immediately south and north of the Hestia deposit at Mandilla in the current Quarter. A more substantial RC drill program is also under consideration for the September Quarter 2025.”