Koba Resources Discovers High-Grade Uranium at Yarramba Project

Koba Resources Ltd Yarramba Uranium Discovery Shows Significant High-Grade Results

Koba Resources Ltd (ASX:KOB) has announced the discovery of a significant new high-grade uranium prospect at its Yarramba Uranium Project in South Australia. The company's step-out exploratory drilling program has delivered multiple intercepts exceeding 1,000ppm eU3O8, highlighting the Koba Resources Ltd Yarramba uranium discovery's continued exploration success and expanding potential.

The newly identified Delord Prospect has yielded impressive uranium intercepts during Koba's September 2025 drilling campaign. These results demonstrate the project's growing significance within Australia's uranium sector at a time when nuclear energy is gaining renewed global attention.

High-Grade Results from New Delord Prospect

The Koba Resources Ltd Yarramba uranium discovery has yielded impressive uranium intercepts during the company's recent drilling campaign, including:

• 1.07m @ 693ppm eU3O8 from 88.4m, including 0.53m @ 1,045ppm eU3O8
• 1.52m @ 482ppm eU3O8 from 86.5m, including 0.52m @ 1,071ppm eU3O8

These high-grade results were obtained during an 18-hole step-out exploration program totalling 1,818 meters. The campaign has successfully demonstrated significant uranium mineralisation in the previously underexplored 1.5km corridor between the Oban Deposit and Berber Prospect.

"We are very pleased to have discovered another high-grade prospect during our recent step-out exploratory drilling program at our Yarramba Uranium Project in South Australia. Our drilling continues to intersect uranium grades >1,000ppm eU3O8 and has demonstrated that high-grade mineralisation occurs in the underexplored 1.5km corridor between the Oban Deposit and Berber Prospect – now called the Delord Prospect," said Ben Vallerine, Managing Director and CEO of Koba Resources.

Roll-Front Signature Provides Key Targeting Insights

A particularly significant discovery at the Delord Prospect was the identification of a classic roll-front signature with high-grade uranium mineralisation located in the "nose" of the roll front within the mineralised redox zone. This geological feature provides critical information about the location of uranium mineralisation and will substantially improve future drill targeting accuracy.

The roll-front signature discovered at Delord is described as an "exemplar" formation, containing high-grade uranium concentrations precisely where geological models would predict – in the nose of the roll front within the mineralised redox zone.

This validation of Koba's geological understanding will enhance the efficiency of future exploration campaigns across the Yarramba Project, potentially accelerating the development timeline for the Koba Resources Ltd Yarramba uranium discovery.

Understanding Roll-Front Uranium Deposits

Roll-front uranium deposits form in permeable sandstone aquifers when uranium-rich, oxygenated groundwater encounters a reducing environment. At this boundary (known as a redox interface), the uranium precipitates out of solution, creating a distinctive curved or "C-shaped" deposit formation.

The highest uranium concentrations typically occur at the "nose" of this curve – exactly what Koba Resources Ltd has identified at the Delord Prospect. This geological understanding is crucial for efficient exploration, as it allows geologists to predict where high-grade zones are likely to occur along the redox boundary.

Successful Results Across Multiple Target Areas

The recent Koba Resources Ltd Yarramba uranium discovery wasn't limited to the Delord Prospect. Multiple targets were tested with significant results:

These positive results across multiple target areas demonstrate the extensive mineralisation potential throughout the Yarramba Project area. The company noted that significant uranium mineralisation was intersected at all targets tested during the initial step-out exploratory drilling.

Expanding Exploration Potential Across Extensive Palaeochannel Network

The latest results further validate Koba's belief in the significant potential to discover additional high-grade uranium throughout the project's extensive palaeochannel network. The Yarramba Project covers approximately 5,000km² and includes over 250km of interpreted, but largely underexplored palaeochannels.

The successful identification of multiple high-grade zones with limited drilling highlights the potential for substantial resource expansion across this large land package. Only a small fraction of the potential uranium-bearing channels within the Yarramba Project area have been adequately tested to date.

"Our team has also identified a roll-front signature at Delord which provides valuable geological information about the location of uranium mineralisation. This allows us to refine our drill targeting to maximise success – an important breakthrough in understanding the mineralisation in the greater Oban region," Vallerine added.

Future Exploration Plans

Koba Resources Ltd is planning another follow-up drill program at the Yarramba uranium discovery in the coming months that will:

1. Test strike extensions of high-grade mineralisation at the Delord Prospect, potentially linking Oban Deposit to the Berber Prospect
2. Continue exploring the 700m corridor between Oban Deposit and Chivas Prospect
3. Follow up on the high-grade Berber Prospect, targeting extensions of previously discovered mineralisation that included 1.6m @ 1,026ppm eU3O8

The company is already working to obtain necessary permits and approvals for a planned 2,000m follow-up drill program. This systematic approach demonstrates Koba's commitment to methodically unlocking the value of the Yarramba uranium discovery.

Strategic Location in World-Class Uranium District

What makes this location significant?

The Yarramba Uranium Project is strategically positioned in a world-class uranium district in South Australia, home to major deposits like Honeymoon (Boss Energy) and Four Mile (Heathgate Resources). This regional setting provides both geological validation and infrastructure advantages.

The project's location in an established uranium province with existing operations provides Koba with valuable geological context while potentially offering pathways to expedite development should economic resources be defined. Furthermore, South Australia has a history of uranium mining and established regulatory frameworks for the sector.

Investment Potential

The Koba Resources Ltd Yarramba uranium discovery represents a compelling investment opportunity for several reasons:

1. Continuous Discovery Success: The company has consistently delivered positive drilling results, with multiple new high-grade prospects identified in consecutive programs.

2. Extensive Exploration Upside: With over 250km of palaeochannels across 5,000km² of project area, only a fraction of the potential uranium-bearing channels have been adequately tested.

3. Advancing Geological Understanding: The identification of roll-front signatures provides a powerful targeting tool for future exploration, potentially increasing discovery efficiency.

4. Multiple Target Areas: With several prospects already showing high-grade mineralisation, the project offers numerous avenues for resource growth.

5. Strategic Asset: As uranium prices remain strong amid growing global demand for nuclear energy, Koba's expanding footprint in this premier uranium district positions the company to potentially develop a significant resource base.

The latest drilling results demonstrate Koba's ability to systematically advance the Koba Resources Ltd Yarramba uranium discovery through targeted exploration, with each program building on previous successes and expanding the known areas of mineralisation.

As global interest in nuclear energy continues to increase, driven by decarbonisation goals and energy security concerns, well-positioned uranium exploration projects like Koba's Yarramba stand to benefit from improving sector fundamentals.

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