Patronus Resources Ltd has confirmed the continuation of high-grade gold mineralisation at depth through recent diamond drilling at the Koi Exploration Target, part of its wholly owned Cardinia Gold Project in Western Australia’s Leonora region.
Four diamond drill holes totalling 1,283 metres were completed, with significant results including 6 metres at 2.78 grams per tonne (g/t) gold from 270 metres in MT25DD001. This intercept lies 75 metres north of a standout 2024 result—12.82 metres at 3.28g/t gold from MT24DD010—and extends the high-grade north-plunging shoot to 180 metres in strike. The shoot remains open along strike and down-plunge, reinforcing the potential for resource expansion beneath the existing Mertondale 3-4 pit.
The latest results support the conceptual Koi Exploration Target, which ranges from 3.2 to 6.4 million tonnes at 1.5 to 4.0g/t gold for a potential 150,000 to 800,000 ounces.
Location of Patronus’s 1Moz Cardinia Gold Project in the Leonora area.
"More great results have been returned from the Koi Exploration Target at our fully permitted Mertondale Project, which confirm a down-plunge step-out of mineralisation 75m to the north of previously reported MT24DD010. These results confirm a total current strike length of 180m of multiple intercepts grading above 5 gram metres in this shallowly north-plunging shoot and demonstrate strong upside for Resource growth below the Mertondale 3-4 pit. We look forward to building on these results and our recent success in the Northern Territory, with further positive news flow expected from both projects," Patronus Resources managing director, John Ingram, said.
“The Koi target remains open along strike to the north and down-dip, with these targets to be drilled in the next quarter."
Overview of the Mertondale Gold Project area, showing individual Resources with the major shear corridors and the Koi Exploration Target area against drilling.
Targeted step-out drilling validates structural model
The recent drilling campaign aimed to test mineralisation continuity along a shallow north-plunging trend identified in 2024. MT25DD001 successfully intersected mineralisation in silicified and brecciated basalt, with visible gold logged and sulphides such as pyrite present. The downhole interval also included 1 metre at 6.21g/t gold from 272 metres.
Further validation came from MT25DD002, drilled up-plunge from MT24DD010, which intersected previously identified mineralised zones, including 1.45 metres at 2.56g/t gold. The continuity of mineralisation within the Mertondale East Shear Zone supports the structural model, with potential for extensions at depth and laterally.
Overview of Mertondale East Shear Zone trend showing max gold in drill-hole with 2025 Pit Optimisation outlines against RTP magnetics. Recent drill intercepts relating to this announcement are shown in red. Recently drilled significant intercepts are highlighted and the Exploration Target outline is shown as a pale yellow polygon. The Exploration Target does not overlap with the recently reported Inferred MRE boundaries. Anomalism continues north along the shear zone beyond the interpreted Target boundary, as highlighted by the two historical AC intercepts. The Mertondale East corridor is considered open in all directions.
Exploration Target underscores growth potential
The Koi Exploration Target lies north of the current Mertondale 3-4 Mineral Resource Estimate of 4.4 million tonnes at 1.7g/t for 241,000 ounces of gold. The target area does not overlap with the existing resource and reflects a discrete, high-grade trend within the broader shear corridor.
Recent drilling demonstrates favourable structural and geological controls, with mineralisation associated with shear-related quartz-sulphide veining and brecciation. These findings enhance the broader Mertondale exploration narrative and confirm the corridor remains open in all directions.
Long Section looking west showing the Koi Exploration Target (see PTN ASX 17 Feb 2025) outline against the current MRE areas, mined areas and recent significant intercepts. Recent drill results are shown in red. MT25DD001 is located 75m down plunge along one of the interpreted high-grade shoots.
Upcoming exploration and assay results
Patronus plans to undertake additional diamond drilling at Koi in the September 2025 quarter to further refine the geometry and grade continuity of the mineralised shoot. The aim is to advance the Exploration Target toward resource classification.
In parallel, reverse circulation (RC) drilling has been completed at the Merlin prospect, located directly north of Koi. Assays are pending and are expected to provide further insight into the continuity of mineralisation within the northern Mertondale region.
With a strengthened balance sheet and recently upgraded Mertondale resource base, Patronus continues to advance its exploration pipeline in the Leonora district and its broader portfolio in the Northern Territory.