Diablo Resources (ASX: DBO) has completed a reverse circulation (RC) drilling program at its 100%-owned Phoenix Copper Project in southeast Utah, with assays pending from 10 holes drilled across the Fair Dinkum and Philadelphia target areas.
A track-mounted RC rig drilled 10 holes for 906 m, with samples submitted to the laboratory.
At Fair Dinkum, the company completed 8 holes for 722 m targeting the Flying Diamond Fault zone, which Diablo considers a key structure associated with copper mineralisation in the broader district. The target sits about 5 km southeast of the Lone Wolf deposit and around 2 km east of the Flying Diamond deposit.
Diablo previously reported surface grab sampling at Fair Dinkum returning peak results of 2.76% copper and 92 g/t silver, with an average copper grade of 1.12% (minimum 0.19% Cu) and 7 of 13 samples above 1% Cu.
At the Philadelphia Prospect, Diablo drilled 2 holes for 184 m to test strike and depth extensions of a copper mineralised zone associated with historical workings and a sub-vertical fault system. The latest work followed earlier wide-spaced drilling that returned 10.5 m at 1.02% Cu including 1.5 m at 3.99% Cu from 36.5 m in hole PHIL 25-107, while earlier surface sampling included 6 m at 2.13% Cu (including 1 m at 7.16% Cu) and rock samples up to 45.7% Cu.
“The company has had an active and rewarding 2025, with exploration firmly focused on advancing prospects within our portfolio to take full advantage of the current US administrations drive to secure domestic critical minerals supply. This approach returned exciting results at our two key projects delivering priority targets to progress in 2026," CEO, Lyle Thorne said.
"At our Phoenix Copper Project, early surface geochemical sampling and mapping provided strong encouragement to drill high grade outcropping copper targets at several areas, including Fair Dinkum and Philadelphia, where geological similarities to known copper deposits are compelling. We completed our maiden drill program at Phoenix in August, returning shallow high-grade copper intercepts from wide-spaced drilling at Philadelphia. This gave us sound momentum to undertake a second program, recently completed, at both Philadelphia and our priority Fair Dinkum Target located along strike from known copper deposits, with assays results awaited."
Star Range silver–antimony sampling expands as targets take shape
Meanwhile at the Star Range Silver–Antimony Project in Beaver County, Utah, Diablo has expanded its surface sampling, with 65 reconnaissance rock samples now at the laboratory.
Earlier work confirmed multiple high-grade vein-breccia systems, with peak results reported at 3,043 g/t silver and 0.7% antimony, supported by historical results up to 8,760 g/t silver with >1% antimony.
"Our ongoing review of other opportunities in the US critical minerals space led to the acquisition of the Star Range Silver-Antimony Project during the year. Defined by numerous old workings, outcropping silver-antimony mineralisation and a rich mining history, the project has already delivered high grade results from several prospect areas. On ground exploration also led to a meaningful expansion of tenure covering mineralised outcrop and extensions to known mineralised trends,' Thorne said.
"Results from the recent geophysical and geochemical programs are pending with an anticipation of further delineating exciting targets for follow-up. We plan to quickly outline drill targets and get the drill bit turning in 2026.
"We also listed on the US OTC market this year which allows U.S. investors to better appreciate the value of our near-mine, high-quality exploration assets. In line with this strategy, we also appointed a US-based Non-Executive Director to strengthen our domestic presence, positioning the company to explore additional promising US opportunities, including potential acquisitions, mergers, joint ventures, and other strategic corporate initiatives.
"All of our efforts in 2025 have provided a strong foundation for ongoing exploration success at both projects into 2026. Our highly experienced US-based team provide a definitive in- country advantage for effective completion of well-planned exploration programs, and is committed to deliver shareholder value through continued systematic, focused and efficient exploration."
Diablo recently completed a second Phoenix drill program at both Philadelphia and Fair Dinkum and was awaiting assays, while geophysical and geochemical results at Star Range were also pending as it moves to outline drill targets for 2026.