Drilling Update: Mandalay Resources at Costerfield
Mandalay Resources Corporation (“Mandalay” or the “Company”) has issued a fresh update on drilling at its Costerfield operation in Victoria, Australia. Recent results point to continued high-grade gold and antimony production, and they also support stepping down to test deeper targets that could expand the operation over time.
Highlights from Recent Drilling
The latest campaign centered on the Shepherd and Kendall vein systems. A mix of extension and infill drilling has tightened confidence in the resource and added detail to the mineralized trends. Notable intercepts include:
- 751.7 g/t gold and 1.8% antimony over 0.22m in PD142
- 291.3 g/t gold over 1.26m in PD175
- 547.3 g/t gold over 0.86m in KD907
- 107.0 g/t gold over 0.55m in PD114
- 33.4 g/t gold and 31.4% antimony over 1.00m in BC399
South of the current workings, beneath the Cuffley mine, step-out holes have returned strong grades at depth, pointing to additional high-grade shoots that may be open:
- 550.0 g/t gold over 0.15m in AD213
- 58.4 g/t gold and 17.6% antimony over 0.77m in AD203
To the north of the Cuffley deposit, drilling also indicates room to grow the system. Intercepts include:
- 17.1 g/t gold and 0.3% antimony over 1.20m in CB001
- 4.0 g/t gold and 20.2% antimony over 0.45m in TP021
Taken together, these results support ongoing growth on both flanks of the mine, which in turn strengthens the case for a longer life at Costerfield.
Priorities for 2024 Exploration
In 2024, Mandalay’s near-mine exploration will zero in on targets that connect to existing infrastructure, allowing the Company to pursue high-grade opportunities with shorter development timelines. The focus remains on extending the Shepherd and Youle vein systems, both of which have underpinned strong production in recent years.
At Shepherd, drilling has concentrated on defining the westernmost vein (630) and mapping parallel structures to the east and west, broadening the footprint of mineralization. Selected intercepts are:
- 7.4 g/t gold and 49.1% antimony over 0.44m in PD147
- 18.3 g/t gold and 26.2% antimony over 2.02m in PD190
- 15.1 g/t gold and 22.2% antimony over 1.26m in PD211
- 26.7 g/t gold and 22.1% antimony over 0.31m in SQ040B1
- 108.0 g/t gold and 29.1% antimony over 0.58m in PD151
- 26.4 g/t gold and 36.7% antimony over 0.21m in PD210
These results reinforce the antimony-rich character of the 630 vein in the southern Shepherd area, as flagged in Mandalay’s 2023 exploration update. The consistency of antimony here supports long-term production planning for this part of the mine.
In the Kendall area, follow-up work on the “580” vein—previously identified—has upgraded confidence and grade with the following intercepts:
- 82.6 g/t gold and 45.0% antimony over 0.20m in BC394
- 54.7 g/t gold and 63.5% antimony over 0.60m in BC395
- 38.0 g/t gold and 35.7% antimony over 1.00m in BC399
This area sits close to existing development, so it can be accessed with limited capital. The next phase of drilling will step out within the Kendall vein set, with a particular eye toward the boundary of the Whitelaw Fault footwall.
Cuffley: Depth Potential and Northern Step-outs
Late in 2023, drilling cut high-grade mineralization beneath the known Cuffley resource in a previously untested zone. Drillhole AD200, about 150m south of the current Cuffley resource boundary, returned encouraging results. Follow-up holes in all directions around AD200 have confirmed mineralized structures. In total, 14 holes covering 7,006m have been completed here, including these key intercepts:
- 58.4 g/t gold and 17.6% antimony over 0.77m in AD203
- 550.0 g/t gold over 0.15m in AD213
These outcomes suggest the Cuffley deposit extends farther south and may host additional high-grade shoots along the structure—an important opening for future definition drilling and potential resource growth.
North of Cuffley, Mandalay has also logged positive hits. Drillhole TP021 intersected 4.0 g/t gold and 20.2% antimony over 0.45m. In the Cuffley–Brunswick Gap program, drillhole CB001 returned 17.1 g/t gold and 0.3% antimony over 1.20m, roughly 80m north of the current Cuffley resource boundary. These intercepts imply the system may strengthen to the north after crossing the Rattler Fault.
Forward Exploration Strategy
Building on these results, Mandalay will concentrate near-mine drilling in the Cuffley Deeps area. Work will continue along the northern continuation of the Cuffley system and into the Brunswick North extension, approximately 300m east of the central corridor. In parallel, regional drilling will test depth extensions at satellite deposits such as Robinsons and True Blue and evaluate targets to the north of the field.
Sampling, Assaying, and QA/QC
All diamond drill core was logged and analyzed by On Site Laboratory Services (OSLS) in Bendigo, Victoria. Gold was assayed by fire assay, and antimony by Atomic Absorption Spectroscopy (AAS). Where coarse visible gold was present, screen fire assays were used to improve accuracy. Quality assurance and quality control protocols included submitting reference materials and blanks with drill and face samples. For further detail on drilling, sampling, and assaying procedures, see Mandalay’s technical report on the Costerfield operation, available on SEDAR.
Qualified Person
Chris Davis, Vice President of Operational Geology and Exploration at Mandalay, is the Qualified Person as defined by NI 43-101. He is a Chartered Professional of the Australasian Institute of Mining and Metallurgy (MAusIMM CP(Geo)) and a Member of the Australian Institute of Geoscientists (MAIG). Mr. Davis has reviewed and approved the technical information in this release.
About Mandalay Resources
Mandalay Resources Corporation is a Canadian resource company with producing assets in Australia (the Costerfield gold–antimony mine) and Sweden (the Björkdal gold mine). The Company’s strategy is to increase production while lowering costs to generate robust cash flow, with a commitment to safe, environmentally responsible operations and strong engagement with employees and local communities.
At Costerfield, the Company’s key objectives are to continue mining the high-grade Youle vein and ramp up production from the deeper Shepherd veins. These sources are expected to feed the processing plant and support ongoing Mineral Reserve additions. At Björkdal, Mandalay aims to maximize profitability by focusing on the Aurora zone and other high-grade areas over the coming years.
Frequently Asked Questions
What are the standout results from the latest drilling?
High-grade intercepts were returned across several areas, including 751.7 g/t gold and 1.8% antimony over 0.22m (PD142), 547.3 g/t gold over 0.86m (KD907), and 33.4 g/t gold with 31.4% antimony over 1.00m (BC399). At depth beneath Cuffley, 550.0 g/t gold over 0.15m (AD213) and 58.4 g/t gold with 17.6% antimony over 0.77m (AD203) were also reported.
Which vein systems are the main focus in 2024?
Mandalay is prioritizing near-mine targets, especially extensions of the Shepherd and Youle vein systems. Within Shepherd, the antimony-rich 630 vein and its parallel structures are key, while at Kendall the “580” vein is being extended where access is already in place.
What do the results mean for the Cuffley deposit?
Drilling late in 2023 identified mineralization below the current resource footprint. Follow-up work—14 holes totaling 7,006m—suggests the system continues south with potential for new high-grade shoots. North of Cuffley, intercepts near the Rattler Fault indicate mineralization may strengthen in that direction too.
How were the samples analyzed and quality controlled?
Drill core was logged and assayed by OSLS in Bendigo. Gold was analyzed by fire assay, antimony by AAS, and screen fire assays were used when coarse visible gold was present. QA/QC included reference materials and blanks submitted with drill and face samples.
Who verified the technical information in this update?
Chris Davis, Mandalay’s Vice President of Operational Geology and Exploration, is the NI 43-101 Qualified Person. He reviewed and approved the technical details disclosed in this release.
