Diablo Resources Limited (ASX: DBO | OTC: DBORF) has commenced a maiden drilling program at its high-priority Fair Dinkum Prospect in Utah, following the United States Government’s move to formally designate copper as a critical mineral for the first time.
The program marks a major step in advancing the Company’s 100%-owned Phoenix Copper Project, located ~70km southwest of Moab and along strike from the producing Lisbon Valley Copper Mine - one of the leading copper operations in the United States.
The Fair Dinkum Prospect sits along the same structural corridor as the Lone Wolf and Flying Diamond deposits and has returned highly encouraging rock sample results including peak grades of 2.76% Cu and 92 g/t Ag, averaging 1.12% Cu across the sampled outcrop. Seven of the 13 samples collected exceeded 1% Cu.
Drilling will also resume at the Philadelphia Prospect, where prior scout drilling intersected 10.5m @ 1.02% Cu, including 1.5m @ 3.99% Cu from shallow depths. Mineralisation remains open in all directions.
On-site drilling images show a track-mounted RC rig mobilised to enable low-disturbance drilling across multiple pads (see page 1 and 2 of the source document).
CEO, Lyle Thorne commented:
“The commencement of drilling at Fair Dinkum represents a major milestone advancing our U.S critical minerals strategy. With copper now formally added to the U.S Critical Minerals List, the importance of domestic copper projects has never been greater.
Our targets at both Fair Dinkum and Philadelphia lie within a proven copper district and have already delivered highly encouraging results. With mineralisation open in all directions and multiple drill pads permitted, we see strong potential to rapidly advance these targets. Together, these prospects outline a potential multi-kilometre mineralised system within a proven copper district.
Combined with ongoing sampling and mapping at our Star Range Silver-Antimony Project, Diablo is positioned to deliver significant newsflow and value creation as momentum continues to build across the U.S critical minerals sector.”
Strategic Context: Copper Added to U.S. Critical Minerals List
The U.S. Geological Survey’s Final 2025 Critical Minerals List has included copper for the first time, recognising its essential role in electrification, renewable energy, defence, infrastructure and national security.
In parallel, the U.S. Government has:
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Streamlined permitting through FAST-41, used for the Lisbon Valley Copper Mine expansion near Diablo’s project area.
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Announced US$355 million in new Department of Energy funding to boost domestic critical minerals exploration, production and processing.
This policy shift materially enhances the strategic value of copper discoveries in the United States - particularly within established mining districts such as Lisbon Valley.
Fair Dinkum Prospect: High-Grade Copper Along Proven Structural Trend
The Fair Dinkum Prospect is positioned 5km southeast of the Lone Wolf Deposit and 2km east of the Flying Diamond Deposit. The Company holds permit approval for up to 36 drill holes across 12 pads, targeting shallow-dipping mineralisation and step-out extensions.
Rock sampling results include:
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2.76% Cu and 92 g/t Ag (peak)
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1.12% Cu (average)
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All samples above 0.19% Cu
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7 out of 13 rock samples above 1% Cu
Cross-sections and planned drilling maps (page 4) show copper mineralisation aligned with the Flying Diamond Fault system, a structure known to host significant copper in the district.
Philadelphia Prospect: High-Grade Shallow Copper with Growth Potential
Located on historical copper workings dating to the early 1900s, Philadelphia is centred on a sub-vertical fault zone with strong copper enrichment.
Significant surface sampling included:
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6m @ 2.13% Cu (incl. 1m @ 7.16% Cu)
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3m @ 1.28% Cu
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10m @ 0.55% Cu
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Rock samples up to 45.7% Cu
Scout drilling returned:
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10.5m @ 1.02% Cu (incl. 1.5m @ 3.99% Cu)
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1.5m @ 1.33% Cu from 32m
Mineralisation remains open along strike and depth, with step-out drilling planned.
Next Steps
Diablo’s next phase of work includes:
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Completion of the current RC drilling program across both prospects
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Submission of samples for laboratory assay
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Geological model updates and interpretation of structural controls
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Ongoing evaluation of additional U.S. critical minerals opportunities
For further information
Lyle Thorne
Chief Executive Officer
Email: [email protected]
Contact details:
Jane Morgan: [email protected]
