American West Metals has hit thick zones of visual copper, zinc and molybdenum mineralisation from three new diamond holes at its wholly-owned West Desert project in Utah, pushing the mineralisation beyond the deposit's existing footprint.
The ongoing diamond campaign has now completed seven holes specifically designed to test extensions to the existing resource, with the latest three probing west, north and east.
The standout hole stepped out 350m west of the deposit and reached 830m in depth, cutting into five zones of magnetite-rich carbonate replacement deposit (CRD) skarn totalling more than 149m. Skarn forms where hot mineralising fluids from an intrusion alter surrounding rocks.
A combined 140m carried visual copper and zinc sulphides, while a further 219m contained strong visual molybdenite with lesser copper sulphides in skarn and altered porphyry - intrusive rock associated with the wider mineralising system. American West says chalcocite with magnetite points to multiple mineralising events, while molybdenite-bearing veins suggest a later event.
The western hit has nearby pedigree. Historical drilling previously returned up to 20 per cent zinc, 1.4 per cent copper and 470 grams per tonne indium. American West believes the old timers hole clipped deep zone-style CRD mineralisation, with the latest work now indicating the mineralisation thickens northwards towards the porphyry contact. Additionally, management says the presence of arsenopyrite and pyrite in the new western hole has highlighted the potential for gold, interpreting the multiple mineralising events as encouraging for large deposits.
Almost 1km north of West Desert, drilling opened another front with the first visual copper identified, including a combined 11m of malachite copper oxide. To the east, visual zinc and molybdenite extended the search 370m beyond earlier drilling that returned more than 108m at 25g/t indium.
American West says mineralisation can now be traced for almost 2km along the east-west magnetic feature and porphyry-sediment contact, within a broader 4km magnetic trend. It compares the visual sulphides with those typical of very large regional systems, including Utah’s Bingham Canyon copper-molybdenum mine. Assays are required to determine grades and metal content.
American West Metals managing director Dave O’Neill said: “These latest exploration drill results have materially increased our confidence in the scale and potential of the mineral system. We believe West Desert is continuing to emerge as a significant and highly prospective critical minerals system, with considerable scope for further expansion.”
American West is already chasing the next piece of the puzzle, with the rods turning around the clock on an eighth hole and follow-up drilling chasing the new western mineralisation. Assays are expected within four to six weeks, subject to laboratory turnaround times.
Further work will test recent discoveries and high-priority geophysical targets, including a magnetic anomaly on the interpreted northern porphyry-sediment contact that earlier drilling couldn't reach because of drill pad constraints. New pads are being permitted to get at the untouched target.
The company is also pushing on with resource modelling using recent and historical drilling and plans metallurgical and mineralogical work to refine the processing flowsheet. The old data still leaves plenty to chase, with only about 35 per cent of historical samples assayed for indium and gallium, while molybdenum was barely tested.
West Desert already hosts a JORC resource of 33.7 million tonnes at 3.83 per cent zinc, 0.15 per cent copper and 9.08g/t silver, containing 1.29Mt of zinc, 49,000 tonnes of copper and 9.8 million ounces of silver. A separate JORC inferred resource contains 23.8 million ounces of indium and 118,761 ounces of gold.
West Desert is also well placed in Washington’s push for a domestic critical minerals supply, regularly engaging with US Government agencies and other parties on critical-metals partnerships, supply and production. The US relied entirely on imported indium in 2025, a position made considerably worse when China, which controls most of the global supply, imposed export restrictions last year. Indium is used in semiconductors, while molybdenum goes into aerospace, defence and energy alloys.
With a substantial resource already in the bag, the latest drilling is all about testing for scale. The step-outs west, north and east suggest the known deposit may be only one piece of a much bigger critical-metals system, but assays due in coming weeks will determine whether the grades match the impressive visual widths.
Is your ASX-listed company doing something interesting? Contact: matt.birney@businessnews.com.au
