Iltani Resources has intercepted significant lead, zinc, and copper sulphides over a 1,230m strike at its Union Jack Prospect in Northern Queensland, validating geophysical VTEM targets and setting the stage for expanded exploration within the Herberton Project.
- Three RC drill holes confirm widespread sulphide mineralisation
- Up to 35% sulphides intersected in VTEM anomaly-aligned hole
- Queensland Government funding supported VTEM geophysical survey
- Downhole EM surveys planned to refine mineralisation geometry
- Union Jack positioned as potential satellite deposit to Orient Project
Drilling Uncovers Extensive Sulphide Zones at Union Jack
Iltani Resources (ASX:ILT) has delivered a promising exploration update from its Union Jack Prospect, part of the broader Herberton Project in Northern Queensland. The company completed three reverse circulation (RC) drill holes targeting previously untested areas, successfully intercepting lead, zinc, and copper sulphide mineralisation over a 1,230-metre distance. This marks the first-ever drilling at Union Jack, where historical workings had indicated mineralisation but lacked rigorous follow-up.
In particular, drill hole UJRC0002 stood out by intersecting nine metres of sulphide mineralisation with up to 35% sulphide content from 165m to 174m, precisely coinciding with a VTEM (Versatile Time Domain Electromagnetic) anomaly modelled from a 2025 airborne survey. This alignment validates the effectiveness of Iltani's geophysical targeting approach, which had been supported by $230,375 in funding through the Queensland Government’s Collaborative Exploration Initiative (CEI) Scheme.
Geophysical Surveys and Historical Workings Guide Drilling
The Union Jack drilling campaign was designed to test both the historical workings and multiple VTEM anomalies identified in the area. UJRC0001 targeted beneath the old workings, intersecting a three-metre zone with up to 15% sulphides, while UJRC0003, drilled 1,230 metres away, intercepted 13 metres of sulphide mineralisation at shallow depths (6m to 19m) with up to 25% sulphides. The latter hole also revealed a secondary VTEM plate that may warrant future drill testing.
The mineralisation occurs as disseminated sulphides within propylitically altered porphyritic quartz eye rhyolites, with pyrite, galena, sphalerite, and chalcopyrite identified visually. However, the company cautions that visual estimates are provisional, pending laboratory assay results expected within one to two months.
Next Steps Include Downhole EM Surveys and Expanded Targeting
Following drilling, Iltani has installed polypipe casing in the two VTEM-targeted holes (UJRC0002 and UJRC0003) to facilitate planned downhole electromagnetic (DHEM) surveys later this year. These surveys aim to provide higher-resolution data on the geometry and extent of sulphide mineralisation, which could inform follow-up drilling and resource modelling.
Additionally, the company plans more detailed surface mapping and sampling to identify any surface expressions linked to the mineralisation and will reassess the numerous VTEM anomalies across the Union Jack area and the wider Herberton Project to prioritise future drill targets. This approach aligns with Iltani’s strategy to define satellite high-grade base metal-silver-indium deposits within trucking distance of its flagship Orient Silver-Indium Project, potentially adding value through shared processing infrastructure.
Union Jack’s promising initial results complement Iltani’s ongoing work at Orient, which holds a JORC-compliant mineral resource of 62.5 million tonnes at 81.5 g/t silver equivalent, including significant indium, lead, and zinc credits. The confirmation of sulphide mineralisation at Union Jack adds a new dimension to the Herberton Project’s exploration potential, with assay results and further geophysical data awaited to clarify the economic significance.
Bottom Line?
Assay results and downhole EM surveys will be pivotal in determining whether Union Jack can evolve into a valuable satellite deposit complementing Iltani’s Orient Project.
Questions in the middle?
- Will assay results confirm economically viable grades at Union Jack?
- How will downhole EM surveys refine the understanding of mineralisation geometry?
- Which VTEM anomalies beyond Union Jack will become priority drill targets?