Legacy Minerals Maps Three Untested Copper-Gold Drill Targets at Rockley
Key Takeaways
- The 2026 IP survey at Crystal Hill has defined three discrete, never-drilled chargeability targets — North-West, Central, and East — with peak readings ranging from 35mV/V to 45mV/V.
- The Central target is the highest priority, returning up to 45mV/V over an 800m NNW-trending strike length from approximately 100m depth, roughly 10 times above the 3mV/V background level.
- The Central target sits directly beneath previously reported rock chip assays of 9.3% Cu, 3.9g/t Au, and 415g/t Ag — a three-way convergence of geophysics, geochemistry, and structural setting.
- Rockley is located within the Ordovician Macquarie Arc, the same geological province hosting Cadia Valley (750Moz Au + 8.7Mt Cu) and less than 15km from the Bushranger Deposit, which has returned 920m at 0.3% Cu from 110m.
- No drill programme has been formally announced — drill testing remains subject to planning, landholder access, statutory approvals, and funding.
Three high-priority copper-gold targets emerge at Rockley
A recently completed induced polarisation (IP) survey at the Crystal Hill Prospect has defined three discrete chargeability targets at Legacy Minerals Holdings‘s 100%-owned Rockley Project (EL8926), located 25km west of Oberon, NSW, within the Lachlan Fold Belt. None of the three targets has ever been drill tested.
The standout result is the Central target, which returns peak chargeability of up to 45mV/V over an 800m strike length, modelled from approximately 100m depth and sitting directly beneath the Crystal Hill soil geochemistry anomaly. That puts the Central target roughly 10 times above the 3mV/V background chargeability level, a signal scale that demands attention.
Reinforcing the case further, nearby rock chip samples from Crystal Hill previously returned assays of up to 9.3% Cu, 3.9g/t Au, and 415g/t Ag (as reported in the ASX release of 14 October 2024). These are not new assay results — they are previously reported figures that now have a compelling geophysical target sitting directly beneath them.
Christopher Byrne, CEO and Managing Director
“It’s hard to ask for better drill targets than these three clear, untested copper targets at Rockley. The most compelling target sits directly beneath the copper, gold and silver anomaly we mapped during previous campaigns… This is the first time we have an extremely high-conviction geophysical response, up 45mV/V over an 800m strike length, coincident with highly anomalous surface geochemistry. This is ground that has never been drilled, and it lies in the same-aged volcanics that host the world-class Cadia-Ridgeway deposits.”
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Understanding IP surveys and what these results mean for investors
An induced polarisation (IP) survey is a geophysical technique that measures how strongly the ground retains an electrical charge after a current is passed through it. This property, called chargeability and measured in millivolts per volt (mV/V), is most commonly elevated in areas where disseminated sulphide minerals such as pyrite and chalcopyrite are present. In copper-gold porphyry exploration, that matters because sulphides are closely associated with mineralised systems.
The key caveat is important: chargeability alone is not diagnostic of mineralisation. Clay alteration, disseminated magnetite, and other lithological variation can also produce elevated responses — and several of those are plausible within the Ordovician sequence mapped at Rockley. Drill testing is required to determine the actual source of the anomalies.
What makes the Central target the highest priority is a three-way convergence: it has the largest modelled strike extent (~800m), the highest chargeability reading (up to 45mV/V), and direct coincidence with the surface soil geochemical anomaly. That combination meaningfully strengthens the exploration case compared with a geophysical response in isolation.
The table below summarises the three targets defined by the 2026 IP survey, as reported in Table 1 of the announcement:
| Target | Peak Chargeability | Modelled Depth | Strike / Size | Status |
|---|---|---|---|---|
| North-West | >40mV/V | ~200m | Discrete zone | Untested |
| Central | Up to 45mV/V | ~100m to ~200m | ~800m strike, NNW trend | Untested — highest priority |
| East | 35mV/V | ~200m | Discrete zone (resistive host) | Untested |
The resistivity data adds a further interpretive layer. The Central target sits within a conductive zone, consistent with sulphides in sericite-altered wall rock. The East target is the opposite: a chargeable zone within resistive ground, a pairing more typically associated with sulphides in silicified or quartz-veined rock. The North-West target sits near a modelled resistivity contact interpreted to reflect a schist-metabasalt boundary.
A world-class address: Rockley’s place in the Macquarie Arc
Rockley sits within the Ordovician Macquarie Arc, a geological province that hosts some of Australia’s most significant copper-gold deposits. For context only, these neighbouring systems include:
- Cadia Valley (Newmont): 750Moz Au + 8.7Mt Cu
- North Parkes (Evolution Mining): 5.2Moz Au + 4.4Mt Cu
- Cowal (Evolution Mining): a major gold system in the same arc
These figures represent peer deposits in the same geological province and are provided for regional context only. They are not analogous to the Rockley Project, and no Mineral Resource has been reported for Rockley.
Closer to home, Rockley is less than 15km from the Bushranger Deposit, where drilling has intersected 920m at 0.3% Cu from 110m, including 156m at 0.48% Cu.
In 2019, Kenex Pty Ltd, in conjunction with the Geological Survey of NSW, assessed the Rockley Project area as one of the most prospective areas for porphyry-related copper-gold mineralisation in the Rockley-Gulgong Volcanics. Key features identified at the Rockley Project include:
- Copper oxides (malachite, azurite) and sulphides (chalcopyrite) documented across an area of at least 3km²
- Pathfinder elements including Mo (28.5ppm), Sb (5,550ppm), As (1,845ppm), and Te (19ppm)
- Higher-grade copper zones associated with third-order faults of the Native Dog Fault, which may have potentially tapped a mineralised intrusion at depth
- Potassium highs in radiometric data coincident with an aeromagnetic high, suggestive of potassic alteration zones at depth consistent with a porphyry system
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What comes next for Legacy Minerals at Rockley
The company is currently integrating the 2D and 3D inversion models with its geological mapping, structural interpretation, and soil and rock chip geochemistry to refine and prioritise the three targets.
Drill testing of the three chargeability anomalies is under consideration and remains subject to drill planning, landholder access, statutory approvals, and funding. No drill programme has been formally announced.
Statutory approvals represent a critical gating item for any drill programme, and Legacy’s experience securing Mt Carrington drilling approvals for gold-copper exploration earlier in 2025 offers a practical reference point for the timeline considerations now facing the Rockley targets.
From a portfolio perspective, CEO Christopher Byrne noted that Rockley is being advanced alongside generative work at NiCo Young and the ongoing programmes at Mt Carrington, providing shareholders with what he described as “additional critical mineral and copper discovery exposure.”
Legacy Minerals has been applying a similar IP-led exploration approach across its portfolio, with ground geophysics at Mt Carrington also generating priority targets for follow-up drilling at the Battery and Mascotte prospects.
The broader significance of the current result is that Crystal Hill remains entirely undrilled at meaningful depth. The only historical drill holes at the prospect were shallow reconnaissance holes of less than 14m depth, completed more than 25 years ago. The three IP targets defined by the 2026 survey represent genuinely fresh ground at depth, with no prior drill testing to inform or constrain what lies beneath the surface anomalism.
Ready to Explore the Untested Copper-Gold Targets at Legacy Minerals’ Rockley Project?
The 2026 IP survey at Crystal Hill has defined three discrete, undrilled chargeability anomalies — including a standout Central target returning up to 45mV/V over an 800m strike length, sitting directly beneath high-grade surface assays of 9.3% Cu, 3.9g/t Au, and 415g/t Ag. With Rockley located within the same Macquarie Arc volcanics that host world-class deposits like Cadia Valley, the convergence of geophysics and geochemistry makes this one of the most compelling undrilled targets in Legacy Minerals’ portfolio.
To follow Legacy Minerals’ progress as it integrates 3D inversion models and advances drill planning at Rockley, visit the Legacy Minerals Holdings investor profile for the latest updates and project details.