Key Highlights

  • Eleven felsic-intrusion targets have been identified at the Sandstone gold project.
  • The targets are modelled on the Two Mile Hill and Bull Oak deposits.
  • All of the targets sit within the Two Mile Hill-Bull Oak corridor.
  • Reverse circulation drilling of the highest-priority, drill-ready targets was scheduled to start this month.

Brightstar Resources (ASX:BTR) has identified 11 targets at its Sandstone gold project in Western Australia that it believes could host gold in felsic intrusions similar to its Two Mile Hill-Shillington and Bull Oak deposits. All of the targets sit within the Two Mile Hill-Bull Oak corridor, and Reverse Circulation Drilling of the highest-priority, drill-ready targets was scheduled to start in November 2026.

Sandstone hosts a resource of 3.6 million ounces at 1.4 grams per tonne gold, and the two intrusion-hosted deposits account for about 1.8 million ounces, or roughly half of it. Finding another deposit of this style could therefore have a material effect on the project's scale.

Why intrusion-hosted gold appeals

Two Mile Hill-Shillington holds 24.6 million tonnes at 1.8 g/t for 1.45 million ounces, and Bull Oak 10.5 million tonnes at 1.0 g/t for 322,000 ounces. Both are open at depth. Recent intercepts include 305 metres at 1.33 g/t from 584 metres in hole TMHDD26003 at Two Mile Hill and 167 metres at 2.07 g/t from 104 metres at Bull Oak.

Wide, continuous mineralisation like this can support bulk mining, where width matters as much as grade. Both deposits share a similar setting, with felsic intrusive stocks emplaced into basalt and banded iron formation.

How the targets were chosen

A felsic intrusion is less dense than the surrounding mafic and ultramafic rocks, so it can appear as a gravity low. Brightstar has generally defined targets where a gravity low coincides with mapped or logged granitoid and gold anomalism in surface geochemistry or historical drilling. It also used magnetics, radiometrics, mapping and old workings. The company says historical exploration for this style has been limited and that it is applying a systematic screening approach across the belt.

The targets vary widely in maturity. Twin Shafts already has a small resource of 6,000 ounces at 0.9 g/t and a historical intercept of 4 metres at 7.74 g/t, and will be drilled beneath and south of that resource. Mt Klempt South has returned 9 metres at 2.70 g/t from 16 metres, while Workers Granite has 9 metres at 1.99 g/t from 22 metres. Welcome Granite and Iron Duke are also slated for RC drilling. Four others, Ammirati, Turley, Peanut and Freedom, need gravity work or reconnaissance first.

The historical results come from shallow rotary air blast and early RC drilling, so they are early indications rather than discoveries. A gravity low and a granitoid do not guarantee gold; most such targets will not become deposits.

Brightstar notes that several targets are also associated with significant historical Mining activity. Old workings can indicate gold at surface, but small historical mines rarely reveal the scale of a bulk intrusion-hosted system, so drilling is needed to determine whether broad, lower-grade mineralisation exists at depth.

Managing expectations

Managing director Alex Rovira said several targets were drill-ready and the company was fast-tracking testing ahead of a more substantial corridor-wide programme in 2027. A detailed ground gravity survey across the corridor is under way to refine and add targets, and Brightstar is planning a research study into the age and origin of the host intrusions.

Busy quarter ahead

Several other catalysts are due. Assays from three Two Mile Hill diamond holes are expected in November, about 6,500 metres of deep drilling continues in the Shirvington zone, and an updated Two Mile Hill resource and the Sandstone pre-feasibility study remain on track for this quarter.

Brightstar holds 5.2 million ounces of resources across its Goldfields and Sandstone regions and is targeting first gold from its Goldfields operations in the June quarter of 2027. The pre-feasibility study will be the more important near-term test of Sandstone's economics; the new targets offer longer-term growth optionality.