Key Highlights

  • The 2,000 metre RC programme is under way at Mission Sill, part of Galileo's wholly owned Norseman project.
  • Two anomalous PGM zones are being tested, stretching along 1.4 kilometres and 2 kilometres of strike.
  • The programme will test a gabbro-ultramafic contact that has not been drilled before.
  • Mission Sill is an exploration prospect and no mineral resource has been reported there.

Galileo Mining (ASX:GAL) has started a 2,000-metre reverse circulation (RC) drilling programme at the Mission Sill prospect, part of its wholly owned Norseman project in Western Australia. The programme, announced on 9 November, is aimed at finding higher-grade platinum group metals (PGMs), copper and nickel around shallow sulphide mineralisation identified in earlier drilling. Norseman is a long-established mining centre at the southern end of Western Australia's Eastern Goldfields, and Galileo holds 100% of the project.

The company said the drilling will cover two anomalous PGM zones, one stretching along 1.4 kilometres of strike and the other along 2 kilometres. Strike length describes how far a mineralised trend continues along the ground surface. It shows the potential scale of a target, but it does not indicate grade or how far the mineralisation continues at depth.

The targets

As well as following up the known shallow sulphides, the programme will test a position on the gabbro-ultramafic contact that has not been drilled before. It will also test a bedrock target beneath an anomalous weathered zone at Mission Sill South. Contacts between gabbro and ultramafic rocks are a common focus for nickel-copper-PGM exploration, because metal-bearing sulphides in these systems can collect along such contacts.

Testing beneath a weathered zone is a routine step in Western Australian exploration. Drilling through the weathered profile into fresh rock is the way to check whether a primary source lies underneath.

Why it matters

PGMs, which include palladium and platinum, are used in vehicle catalytic converters, in industrial catalysts and in some hydrogen technologies. Copper and nickel are often found with them in mafic and ultramafic intrusions. A deposit containing several of these metals can be more valuable than one containing a single metal, although grade, metallurgy and scale ultimately decide whether a deposit can be mined economically.

For Galileo, the programme is a test of whether the broad PGM anomalism at Mission Sill contains zones of higher grade. RC drilling is relatively quick and inexpensive, which makes it suitable for testing several targets over a short campaign before deciding which areas deserve deeper or more detailed work. At 2,000 metres in total, however, the programme will give an early indication rather than a complete picture of either PGM zone.

Limitations

Mission Sill is an exploration prospect.

Anomalous zones and geological contacts identify places worth drilling, not proven mineralisation. Results from this programme may or may not confirm the higher grades the company is seeking. Any significant intercepts would need further drilling to establish continuity before a resource could be estimated. Widths reported from the new holes would need to be read carefully, as downhole widths often differ from true widths.

Next steps

Galileo said drilling itself is expected to take about two weeks. Assay results are expected about six weeks after the programme finishes, which suggests results could be reported around the turn of the year, depending on drilling progress and laboratory turnaround times. Once assays arrive, the company would be expected to use them to decide on follow-up work at Mission Sill and Mission Sill South.