Mandilla Gold Project
Flagship Project
Astral Resources 100%
Mandilla is situated in the northern Widgiemooltha greenstone belt, approximately 70 kilometres south of the significant mining centre of Kalgoorlie, Western Australia (Figure 1). Mandilla is covered by existing Mining Leases which are not subject to any third‐party royalties other than the standard WA Government gold royalty. Mandilla includes the Theia, Iris, Eos and Hestia deposits.
Gold mineralisation at Theia and Iris is comprised of structurally controlled quartz vein arrays and hydrothermal alteration close to the western margin of the Emu Rocks Granite and locally in contact with sediments of the Spargoville Group. Significant NW to WNW-trending structures along the western flank of the project are interpreted from aeromagnetic data to cut through the granitic intrusion. These structures are considered important in localising gold mineralisation at Theia, which now has a mineralised footprint extending over a strike length of more than 1.6km.
A second sub-parallel structure hosts gold mineralisation at the Iris deposit. The mineralised footprint at Iris extends over a strike length of approximately 600 metres, combining with Theia to form a mineralised zone extending over a strike length of more than 2.2 kilometres.
At Eos, located further to the south-east, a relatively shallow high-grade mineralised palaeochannel deposit has been identified and which extends over a length of approximately 600 metres. A primary gold source is also present with further drilling required to determine both the nature and structural controls on mineralisation and its extent. Mineralisation delineated over approximately 800 metres of strike at the Hestia deposit, located approximately 500 metres west of Theia, is associated with a shear zone adjacent to a mafic/sediment contact, interpreted to be part of the major north-south trending group of thrust faults known as the Spargoville Shear Corridor.
Scoping Study
The Mandilla Scoping Study (Study) (published September 2023) confirmed the potential for Astral’s flagship Mandilla Gold Project to become a highly profitable standalone gold operation. Mandilla is situated in the premier Goldfields region of Western Australia and is firmly established as one of the best free-milling, open pit Resources in this district in both scale and quality of project.
The Study outlined compelling financial metrics for a Mandilla development, with projected free cash-flows of approximately $740 million over a life-of-mine of 11 years and a payback period of less than a year for total pre-production capital expenditure of approximately $191 million.
The Study financials were modelled using a gold price assumption of A$2,750 per ounce, which is significantly lower than the spot price has been for the past six months and used a five-stage open pit design based on a A$2,100 per ounce pit optimisation. This further highlights the potential upside for a Mandilla development.
Astral continues to advance exploration and resource definition efforts at Mandilla, as well as at the Company’s nearby Feysville Gold Project, while simultaneously progressing pre-feasibility studies as it seeks to deliver on its strategy of building another quality Western Australian mining operation.
Mineral Resource Estimate (JORC 2012)
On 20 July 2023, the Company announced an updated JORC 2012 Mineral Resource Estimate (MRE) of 37Mt at 1.1g/t Au for 1.27Moz of contained gold, encompassing the Theia, Iris, Eos and Hestia deposits. The MRE was prepared by independent consultants Cube Consulting in accordance with the JORC Code (2012 Edition).
The locations of the optimised pit shells based on a gold price of AUD$2,500 per ounce are set out in plan view in Figure 2 below.
Table 1 – Mandilla Mineral Resource Estimate (July 2023)
| Mineral Resource Estimate for the Mandilla Gold Project (Cut-Off Grade >0.39g/t Au) | |||
| Classification | Tonnes (Mt) | Grade (g/t Au) | Au Metal (koz) |
| Indicated | 21 | 1.1 | 694 |
| Inferred | 17 | 1.1 | 571 |
| Total | 37 | 1.1 | 1,265 |
| The preceding statement of Mineral Resources conforms to the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code) 2012 Edition. All tonnages reported are dry metric tonnes. Minor discrepancies may occur due to rounding to appropriate significant figures. | |||
Table 2 – MRE (July 2023) by source
| Deposit | Classification | Tonnes (Mt) | Grade (g/t Au) | Au Metal (koz) |
| Theia | Indicated | 17 | 1.1 | 573 |
| Inferred | 12 | 1.1 | 447 | |
| Total | 29 | 1.1 | 1,021 | |
| Iris | Indicated | 0.4 | 0.8 | 11 |
| Inferred | 4.0 | 0.8 | 103 | |
| Total | 4.4 | 0.8 | 115 | |
| Eos | Indicated | 0.6 | 1.6 | 29 |
| Inferred | 0.5 | 1.3 | 19 | |
| Total | 1.0 | 1.5 | 48 | |
| Hestia | Indicated | 2.7 | 0.9 | 78 |
| Inferred | 0.2 | 0.8 | 4 | |
| Total | 2.9 | 0.9 | 82 | |
| Total | 37 | 1.1 | 1,265 | |
| All tonnages reported are dry metric tonnes. Minor discrepancies may occur due to rounding to appropriate significant figures. | ||||
Table 3 – MRE (July 2023) by cut-off grade
| Cut-off grade (g/t Au) | Tonnes (Mt) | Grade (g/t) | Au Metal (koz) |
| 0.30 | 43 | 1.0 | 1,332 |
| 0.35 | 40 | 1.0 | 1,298 |
| 0.39 | 37 | 1.1 | 1,265 |
| 0.40 | 37 | 1.1 | 1,258 |
| 0.45 | 34 | 1.1 | 1,215 |
| 0.50 | 31 | 1.2 | 1,171 |
| All tonnages reported are dry metric tonnes. Minor discrepancies may occur due to rounding to appropriate significant figures. | |||
Theia Deposit
Theia is the cornerstone deposit at Mandilla, representing approximately 81% of the reported MRE. The total MRE at Theia is 29Mt at 1.1g/t Au for 1.02Moz of contained gold.
Figure 3 below shows the Mineral Resource for Theia within the optimised pit shell in cross-section.
Iris Deposit
The Iris Deposit hosts a MRE of 4.4Mt at 0.8g/t Au for 115koz of contained gold.
Eos Deposit
The Eos Deposit hosts a paleochannel deposit MRE of 0.8Mt at 1.6g/t Au for 41koz of contained gold. Additionally,a maiden Inferred MRE of 0.2Mt at 1.0g/t Au for 7koz of contained gold was reported in the July 2023 MRE.
Section 4, as illustrated in Figure 4 below, shows a cross-section view of both the Eos paleochannel and the new fresh rock MRE.
Hestia Deposit
A maiden Mineral Resource was first declared at Hestia in December 2022. Mineralisation was identified over one kilometre of strike length; however, at that stage the drill density was considered too sparse to support resource estimation over the entire strike length.
As part of the July 2023 MRE Update, Astral reported an MRE of 2.9Mt at 0.9g/t Au for 82koz of contained gold. This represented a 583% increase in resources and a 12% increase in grade. Pleasingly, 95% of the MRE at Hestia is in the higher confidence Indicated category.
Section 5, as illustrated in Figure 5 below, shows a longitudinal projection of Hestia as previously reported on 6 December 2022.
