Koba Resources Uncovers Significant Uranium Mineralisation at Mt John Prospect

Exploration Breakthrough at Mt John

Koba Resources Limited (ASX: KOB) has announced significant uranium mineralisation results from the first phase of drilling at its Mt John Prospect, part of the broader Yarramba Uranium Project in South Australia. The initial drilling program focused on the MJ3B target, one of eight high-priority targets identified along a 15-kilometre stretch of the Yarramba Palaeochannel, a geological feature known to host substantial uranium deposits.

The maiden drilling campaign comprised 11 holes totaling 1,290 metres, with notable intercepts including 1.0 metre at 397ppm equivalent U3O8 from 104.4 metres, alongside other promising grades such as 0.7 metres at 282ppm and 0.8 metres at 246ppm eU3O8. These results confirm the presence of significant mineralisation extending over 600 metres of strike at MJ3B, which remains open in all directions, indicating strong potential for resource expansion.

Strategic Next Steps and Broader Prospectivity

Encouraged by these findings, Koba plans to resume drilling in early February with a further 20 holes aimed at both extending the mineralisation at MJ3B and commencing exploration of the seven other targets within the Mt John Prospect. This approach reflects a methodical strategy to systematically unlock the full potential of the Yarramba Palaeochannel, which is already known to host over 50 million pounds of U3O8, including deposits such as Honeymoon, Jason, and Saffron.

Complementing the drilling program, Koba completed a passive seismic survey across the entire Mt John Prospect in December 2024. This low-cost geophysical technique, successfully applied in nearby uranium projects, is expected to provide refined subsurface imaging to better target future drill holes. Processed data from this survey is anticipated in February, potentially accelerating discovery efforts and improving drilling efficiency.

Context Within a World-Class Uranium District

The Yarramba Project sits within the Frome Embayment, a globally recognised uranium province hosting multiple significant deposits and operating mines. Koba’s Mt John Prospect lies just 4 kilometres north of the 10.7 million pound Jason Deposit, underscoring the district’s rich endowment. The project’s extensive tenure of 5,000 square kilometres includes over 250 kilometres of palaeochannels, many of which remain underexplored, positioning Koba well for further discoveries.

Beyond Mt John, Koba’s 2024 exploration program has already yielded high-grade uranium intersections at other prospects such as Berber, Chivas, and Oban, reinforcing the company’s growing footprint in the region. The upcoming drilling phases at Mt John and these prospects will be critical in defining the scale and grade continuity of mineralisation, essential for advancing towards resource estimation and potential development.

Technological and Operational Considerations

Koba’s use of downhole gamma logging to estimate equivalent U3O8 grades provides rapid and reliable data, although the company notes that no disequilibrium corrections have yet been applied. The vertical drilling orientation aligns well with the flat-lying sedimentary host rocks, supporting confidence in the reported mineralised widths. What's more, the integration of passive seismic data represents a forward-thinking approach to cost-effective exploration in a challenging geological setting.

Managing Director Ben Vallerine emphasised the encouraging nature of the initial results and the company’s commitment to expanding its understanding of the Mt John Prospect. He highlighted the potential for discovering thicker and higher-grade zones as drilling progresses, signaling a positive outlook for Koba’s uranium exploration ambitions.