Galileo Mining Uncovers Mineralised Outcrop at North Callisto, 2km from 17.5Mt Callisto Resource

Discovery of Surface Mineralisation Opens New Exploration Prospects at North Callisto

In its latest update, Galileo Mining reported the identification of mineralised fresh rock outcrop at surface at the North Callisto prospect, approximately 2 kilometres along strike from the Callisto resource. This milestone marks the first time mineralised outcrop has been found at surface within the Norseman project. Rock chip sampling over sporadic outcrop on a gently sloping sheetwash and clay plain revealed mineralisation extending about 40 metres along strike, with minimal additional outcrop nearby.

Samples yielded promising grades, with the highest at 1.87 g/t 3E (combined palladium, platinum, and gold), alongside other samples of 1.11 g/t and 0.85 g/t 3E. Unlike the Callisto resource, which was discovered 100 metres below surface via drilling, this surface mineralised outcrop at North Callisto suggests potential for new, shallower discoveries, broadening the company’s exploration opportunities within the project.

Geological Interpretation and Past Drilling Inform Drill Targeting

Geological analysis from resource drilling at Callisto indicates east-dipping stratigraphy at North Callisto, suggesting mineralisation may extend beneath and east of the surface outcrop where no drilling has yet occurred. This structural insight guides drill hole placement to test subsurface mineralisation. The geological team has defined a drill target area to explore these extensions.

Previous drilling near North Callisto returned encouraging but anomalous results, including 62 metres at 0.22 g/t 3E 140 metres north of the outcrop, and 100 metres at 0.19 g/t 3E 170 metres south. Combined with surface rock chip data, these results indicate a mineralised system warranting systematic drill testing. The proximity of anomalous drill intercepts to surface mineralisation confirms North Callisto as a credible exploration target for additional resource-scale mineralisation.

Diamond Drilling Beneath Callisto Reveals Multiple Mineralised Intrusions

Diamond drilling beneath the Callisto deposit earlier in 2026 intersected a separate intrusive rock unit containing platinum group metals, showing the Callisto intrusion is not unique within the project. This discovery increases the probability of additional mineralised intrusions within the 20-kilometre strike length surrounding Callisto. The secondary mineralised intrusion supports the company’s exploration strategy and justifies a staged program across multiple prospects.

The presence of multiple mineralised intrusions at depth, along with the recent surface discovery, creates a strong exploration case for the Norseman project. The company’s interpretation suggests significant potential for further discoveries along the 20-kilometre strike, especially where geological and structural conditions favor mineralisation. This multi-target strategy enables Galileo to systematically assess the broader prospectivity of its landholding.

Completion of Aircore Drilling at Mission Sill and South Callisto

Galileo Mining concluded an aircore drilling campaign at the Mission Sill and South Callisto prospects in late June 2026, totaling approximately 4,500 metres. This staged exploration extends beyond the core Callisto area, targeting geologically distinct prospects with varying mineralisation styles and structures.

Assay results are anticipated in August 2026, with laboratory demand causing extended turnaround times. These results will provide insights into the prospectivity of these satellite targets and their potential contribution to the company’s resource development plans. The drilling program’s completion highlights active exploration momentum during the June quarter.

Callisto Deposit and Its Similarity to Southern African Platinum Deposits

Discovered in 2022, the Callisto deposit is Australia’s first of its kind and is geologically analogous to the Platreef deposits in South Africa’s Bushveld Complex, a major precious and base metal resource. Callisto is estimated at 17.5 million tonnes grading 2.3 g/t palladium equivalent, including 1.04 g/t 4E (palladium, platinum, gold, and rhodium), 0.20% nickel, and 0.16% copper.

Callisto’s mineralogy suggests compatibility with conventional processing methods. Metallurgical testing indicates the mineralisation can be concentrated via standard crushing, milling, and flotation processes, widely used in platinum group metal recovery globally. The company’s assessment of Reasonable Prospects for Eventual Economic Extraction reflects confidence in the deposit’s commercial potential pending further development and feasibility studies.

Norseman Project Tenure and Regional Mineral Potential

Galileo Mining holds 100% ownership of the Norseman project, covering 255 square kilometres of mining, exploration, and prospecting licenses. The project includes the Callisto discovery and regional prospects like Jimberlana and Mission Sill, with potential for palladium, platinum, nickel, copper, cobalt, and rhodium mineralisation. Located in Western Australia, the project benefits from established mining infrastructure and a history of precious and base metal exploration.

Additionally, Galileo operates joint ventures with the Creasy Group over Fraser Range tenements prospective for nickel-copper sulphide deposits similar to the Nova mine. This diversified portfolio spans multiple commodities and geological settings, with a strategic focus on Western Australia’s supportive mining jurisdiction, infrastructure, and mineral endowment.

Planned Drilling and Prospecting at North Callisto

An initial aircore drilling program is planned to test mineralisation around the North Callisto outcrop, with drill planning underway. This structured approach aims to systematically evaluate subsurface extensions of the surface mineralised system. Follow-up prospecting and mapping will seek additional anomalous outcrop within the broader project, potentially expanding the pipeline of drill-ready targets.

Combining drill testing with surface prospecting represents a staged exploration strategy to optimize exploration capital and build a portfolio of defined targets. Discovering further anomalous outcrops could generate more drilling opportunities, extending exploration across multiple prospects and periods. This methodology aligns with industry best practices for early-stage projects with multiple targets.

Regional Geological and Infrastructure Context

The Norseman project is situated in a region with established mining infrastructure and a history of precious and base metal mining. The company’s update included a location map showing Norseman’s position relative to existing mines, resources, and infrastructure, relevant for potential future development by reducing capital and operational complexity.

The regional geology has supported significant precious and base metal deposits, with Callisto representing the first discovery of its mineralisation style in Australia. The Platreef analogue in South Africa underscores the resource potential of similar deposits in comparable settings. Norseman’s location within this prospective framework situates it amid a region with mining heritage and active exploration.

Metallurgical Processing and Metal Recovery Assumptions

Metallurgical test work to date suggests Callisto’s mineralisation is suitable for concentration via conventional crushing, milling, and flotation. Recovery assumptions used in metal equivalent calculations for Callisto are palladium 82%, platinum 78%, gold 79%, rhodium 63%, nickel 77%, and copper 94%. These reflect expected processing performance and were based on 12-month average metal prices as of 11 September 2023.

Utilizing established gravity and flotation methods is advantageous due to their widespread industry use and proven effectiveness. The company’s processing viability assessment marks progress toward potential commercialisation, although further metallurgical and engineering studies are needed to advance the project toward development.