Astral (JO:ARLJ) Resources NL (ASX:AAR) is upbeat about broad gold results received from infill drilling at Iris deposit within the Mandilla Gold Project near Kalgoorlie in Western Australia,
The program at Iris — comprising three lines of drilling — was designed to infill a small 60-metre by 280-metre section of the deposit to a 40 x 20-metre drill spacing to improve the resource category to indicated.
Iris currently hosts a mineral resource estimate of 4.4 million tonnes at 0.8 g/t gold for 115,000 ounces of contained gold, of which 90% is in the inferred category.
Continuity of mineralisation
The 21-hole (3,702-metre) infill reverse circulation (RC) drill program successfully demonstrated continuity of mineralisation across the three drill lines, with 81% of holes drilled returning significant gold mineralisation.
Results from the program include 20 metres at 1.5 g/t gold and 28 metres at 1.5g/t, as well as a high-grade zone of 5 metres at 10.3 g/t that included 1 metre at 47.1 g/t.
Drill collar locations of recent and historical drilling on local area geology
Cross-sections through Iris illustrating drill trace, assay results and geological interpretation.
PFS on track for delivery
Astral Resources managing director Marc Ducler said: “These infill results from the Iris Deposit are very encouraging, supporting our plans to include Iris in the upcoming pre-feasibility study (PFS) for the Mandilla Project development, which remains on track for delivery in Q2 2025.
“The infill program was focused on the central section of the Iris Deposit, with assay results confirming a very successful infill test, delivering a significant number of drill intersections with gold grades above the MRE grade of 0.8 g/t gold.
“Following the success of these results, planning will commence to infill the remainder of Iris.”
Based on the success of this program, further drilling will be planned to infill the remainder of the Iris Deposit.
Astral announced a mineral resource estimate (MRE) in July 2023 for the Mandilla Gold Project of 37 million tonnes at 1.1 g/t of gold for 1.27 million ounces of contained gold.
Metallurgical testing undertaken on each of the main deposits at Mandilla – Theia, Iris, Eos and Hestia – has demonstrated high gravity recoverable gold, fast leach kinetics and exceptional overall gold recoveries.
A September 2023 Mandilla scoping study has a net present value (at an 8% discount rate) of $442 million — based on a standalone project comprising three open pit mines feeding a 2.5 million tonnes per annum processing facility, producing 80,000 to 100,000 ounces per year and incorporating a gold price of A$2,750.
This was based on Theia, Hestia and Eos, with no contribution included from the Iris Deposit, which hosts an MRE of 4.4 million tonnes at 0.8 g/t for 115,000 ounces of contained gold
Neither did the scoping study include any contribution from Astral’s nearby Feysville Project, which hosts a 196,000-ounce MRE.
Mandilla Gold Project on local area geology.
Exploration continues
Ducler added, “RC programs have also recently been completed at Eos, comprising 16 holes for 2,558 metres, and at Kamperman, comprising three holes for 360 metres. Assay results for both these programs are pending and will likely be reported in the new year.
“In addition, a four-hole/1,762-metre diamond drill program has also been completed at Theia, with assays also expected in the new year.”
The now completed extensional drill program at the Eos Deposit, comprising 16 holes for 2,558 metres, tested the extent of previously identified fresh rock gold mineralisation adjacent to the Eos palaeochannel at Mandilla.
Infill diamond drilling at the Theia Deposit at Mandilla has also been completed, with four holes for 1,762 metres drilled. Astral expects the drill core to be sampled and dispatched for assay prior to the Christmas break.
Further, a single line of in-fill RC drilling comprising three holes for 360 metres has been completed at the Kamperman Deposit at the company’s 100%-owned Feysville Gold Project, with assays pending.
Flood of results in the new year
“The drilling effort at Mandilla and Feysville is now winding down ahead of the Christmas break, with the diamond drill rig recently completing the geotechnical programs at both Eos and Hestia,” said Ducler.
“We expect to commence 2025 with a flood of assay results from these recently completed drill programs, with a new round of diamond drilling also scheduled to commence at Kamperman to test a number of targets to improve our understanding of the structural controls to gold mineralisation as well as collecting drill core for metallurgical and geotechnical testing.”