Galileo Mining has lined up two drilling programs at its Norseman project, targeting an untested extension near Callisto and shallow sulphide mineralisation at Mission Sill. The programs will test encouraging but still preliminary exploration indicators, with results yet to come.
- 5,000m North Callisto aircore campaign due to start in late September
- RC drilling at Mission Sill scheduled for November
- North Callisto rock chips returned up to 1.87 g/t 3E
- Mission Sill targets two PGM anomalous zones extending 1.4km and 2km
- No new resource, assay results or economic guidance reported
North Callisto aircore drilling targets untested ground
Galileo Mining Ltd (ASX:GAL) is preparing a 5,000-metre aircore campaign at its 100%-owned Norseman project in Western Australia, with drilling scheduled to begin in the last week of September. The first focus is North Callisto, about 2 kilometres north of the Callisto resource, where rock-chip sampling returned up to 1.87 g/t 3E, comprising palladium, platinum and gold.
The target has a useful geological complication: nearby drilling has already returned broad, anomalous intersections, including 62 metres at 0.22 g/t 3E to the north and 100 metres at 0.19 g/t 3E to the south. Galileo says the local stratigraphy dips east, raising the possibility that mineralisation sits beneath and east of the outcrop, in ground that has not yet been drilled. Additional aircore holes are planned farther north along the prospective Callisto geological contact zone.
Mission Sill RC program moves from anomalies to sulphides
A reverse-circulation contract has also been signed for a November program at Mission Sill. The campaign will follow up mineralisation identified across multiple drill lines and concentrate on two PGM anomalous zones: Zone A, extending over 1.4 kilometres, and Zone B, extending over 2 kilometres.
Limited RC drilling in December 2025 established shallow sulphide mineralisation on sections within both zones. Galileo plans to drill down-dip and along strike, including areas where hole NRC516 finished in mineralisation. That design is intended to test whether the shallow indicators continue through the broader anomalous trends, although the announcement does not provide new assays from the planned work.
Callisto resource remains the exploration anchor
The drilling is being planned around the existing Callisto deposit, where Galileo reported a 2023 mineral resource of 17.5 million tonnes at 1.04 g/t 4E, alongside 0.20% nickel and 0.16% copper. The company describes Callisto as a Platreef-style palladium, platinum, nickel, copper, cobalt and rhodium system, but the new programs are exploration campaigns rather than an updated resource or economic study.
That distinction matters. The historical intersections, rock-chip grades and sulphide observations establish targets; they do not yet demonstrate a new mineral resource or confirm that the mineralisation can be economically extracted. The next meaningful evidence will come from drilling completion, assay results and any subsequent changes to the geological model at North Callisto and Mission Sill.
Bottom Line?
Galileo has converted two prospective Norseman targets into defined work programs, but the investment case still depends on whether drilling turns broad anomalies into coherent, economic mineralisation.
Questions in the middle?
- Will North Callisto drilling confirm mineralisation beneath and east of the outcrop?
- Do the Mission Sill sulphide indicators continue along the full Zone A and Zone B trends?
- How quickly will drilling results support any revised resource or development assessment at Norseman?