Patronus Resources Ltd (ASX:PTN) has defined a maiden JORC 2012 Exploration Target for its 100%-owned Merlin Prospect, part of the Cardinia Gold Project in Western Australia. The target is estimated at 1.0 to 4.0 million tonnes grading between 1.5 and 4.0 grams per tonne (g/t) gold, for a contained range of 50,000 to 500,000 ounces.
Situated just 400 metres north of the 138,000-ounce Mertondale 3–4/North Resource, Merlin lies within the 12-kilometre-long Mertondale East Shear Zone. The results further support Patronus’s strategy of targeting high-grade resource growth within a regionally significant and mineralised corridor.
Location overview of the Mertondale and Cardinia East Resources at the Cardinia Gold Project, Leonora.
The Merlin Prospect has delivered several significant assay results from recent RC drilling, including:
- 24 metres at 1.16 g/t gold from 61 metres (MT25RC008)
- 10 metres at 2.10 g/t gold from 94 metres (MT25RC007)
- 10 metres at 1.24 g/t gold from 76 metres (MT25RC006)
These results complement historical high-grade intercepts such as 15 metres at 5.23 g/t gold and 2 metres at 17.46 g/t gold. Mineralisation is associated with felsic porphyry intrusions and remains open along strike and down dip, with evidence of mineralised continuity over 1 kilometre north of current drilling.
“Merlin is shaping up as a pivotal discovery to support our strategy of targeting high-grade Resource ounces within the Mertondale Project area. The scale of this Exploration Target, supported by recent high- grade and shallow gold intercepts, reinforces our belief that the Mertondale East Shear Zone has the potential to emerge as a multi-kilometre mineralised system with district-scale potential,” Patronus Resources managing director, John Ingram, said.
“These results are exactly what we are targeting — broad, near-surface gold in a highly continuous shear system. With the mineralisation remaining open in all directions, Merlin presents a compelling opportunity to rapidly build ounces close to existing resources.”
High-grade gold intercepts
Recent Reverse Circulation (RC) drilling at Merlin, returned multiple noteworthy intercepts, including:
- MT25RC006: 10 metres at 1.24 g/t gold from 76 metres
- MT25RC007: 10 metres at 2.10 g/t gold from 94 metres
- MT25RC008: 24 metres at 1.16 g/t gold from 61 metres
These results add to a suite of previously reported significant historical intercepts from verified drilling programs, also noted in the June 18, 2025, ASX release:
- NMAC433: 15 metres at 5.23 g/t gold from 30 metres
- NMAC1290: 7 metres at 3.92 g/t gold from 21 metres
- NMAC1288: 10 metres at 2.86 g/t gold from 35 metres
- NMAC1208: 2 metres at 17.46 g/t gold from 4 metres
- MPD412: 2 metres at 12.91 g/t gold from 97 metres
Plan map showing the significant down hole intercepts at Merlin Exploration Target. Verified historical intercepts are labelled in white, with more recent intercepts in yellow. Note that significant assays in MT25RC005 are located 400m north of the Mertondale 3-4/Nth resource (138,000 ounces) situated within the Mertondale East shear trend. Additionally, the Quicksilver resource (42,000 ounces) is located less than 700m to the west along the Mertondale West shear trend. Previous intercepts reported in PTN ASX Announcements 17th Feb 2025 and 18th June 2025.
Long Section looking west at the Merlin Exploration Target showing recent (yellow label) and previous (white label) drilling and results as gram m intercepts down hole. The section also highlights the potential further north along strike of Merlin as well as the close proximity to the Mertondale 3-4/North Resource, 400m to the south. See ASX Announcement on Feb 17 2025 and June 18, 2025 for hole details.
Geological interpretation highlights the presence of felsic porphyry intrusions along the Mertondale East Shear Zone, which are often associated with higher-grade mineralisation. This is consistent with patterns observed at the Mertondale 3-4 pit, last mined by Navigator Resources in the early 1990s. Logging at Merlin confirms a similar porphyry unit across 100 metre-spaced drill sections, closely linked with the broader gold mineralisation zones.
The gold mineralisation at Merlin is interpreted to plunge approximately 15 degrees to the north, a structural trend mirrored by other nearby deposits including Merton’s Reward, Mertondale 3-4 and Mertondale 5. Anomalous gold continues for more than one kilometre along the shear zone to the north, reinforcing the area’s potential to host further high-grade mineralised shoots.
Read more: Patronus Resources uncovers high-grade gold shoot at Merlin, expanding Mertondale East trend
Exploration Target modelling and methodology
The Exploration Target is based on detailed geological interpretation, incorporating 42 drill holes across a 1.4-kilometre strike length.
Modelling used Leapfrog Geo software and a conservative approach to width and grade estimation. A density of 2.4 grams per cubic centimetre was applied, consistent with oxide/transitional material from nearby deposits.
While the target is conceptual, it aligns geologically with the adjacent Mertondale 3–4 Resource, where felsic intrusions and structural controls are key features. Further infill and step-out drilling is planned to refine the model.
Next steps: metallurgical test work and drilling
Patronus will initiate metallurgical test work and RC drilling in Q3 calendar year 2025 to extend known mineralisation at Merlin and assess targets to the north and south. Historical drillholes to the north, including 1 metre at 26.9 g/t gold from 50 metres and 5 metres at 1.74 g/t gold from 36 metres suggest further potential along the shear corridor.
The program will also target extensions south of Merton’s Reward, further evaluating the 12-kilometre Mertondale East trend, which remains underexplored.