Alligator Energy Expands Uranium Mineralisation at Big Lake with New Roll-Front Evidence

New Uranium Intersections Reinforce Roll-Front Model at Site 10

Alligator Energy Ltd (ASX:AGE) has bolstered its uranium exploration story at the Big Lake Project in South Australia's Lake Eyre Basin with fresh drilling results that deepen understanding of its roll-front mineralisation system. The company completed 33 aircore holes totalling 4,112 metres during its 2026 campaign, confirming uranium mineralisation at Site 10, the locus of its 2024 discovery.

Notably, drillholes AC26-006 and AC26-009 delivered significant uranium grades above 100ppm eU3O8, with a standout intercept of 1.9 metres at 0.032% eU3O8 starting at 100.9 metres depth. These results are interpreted as uranium accumulation along the redox boundary between oxidised and reduced sands, a hallmark of roll-front uranium systems. Downhole gamma logging revealed characteristic "gamma tails" trailing mineralisation peaks, consistent with typical sandstone-hosted uranium deposits exploited via in-situ recovery (ISR) methods globally.

Regional Scale Potential Evident from Southward Drilling

Extending beyond Site 10, drilling conducted six kilometres to the south intersected comparable oxidised and reduced sand units at similar depths, suggesting the roll-front system extends well beyond the original discovery zone. Seismic data interpretation indicates the prospective palaeochannel hosting mineralisation remains open to the southeast for approximately 12 kilometres, highlighting a sizeable target area for further exploration.

Alligator’s CEO Dr Andrea Marsland-Smith emphasised the significance of these findings, stating the new results provide a "much clearer picture of how the roll-front system is developing and the potential scale," and that the geological setting extends beyond Site 10, underpinning the project's regional potential.

Drilling Strategy Focuses on Redox Front Definition and Palaeochannel Mapping

The 2026 drilling program aimed to refine the geological context of the 2024 discovery by precisely locating uranium mineralisation within host sands and mapping the redox alteration state to guide future targeting. The current data confirm the mineralised system is part of a larger roll-front uranium system within the Namba Formation sands, occurring between 75 and 120 metres below surface.

Future work scheduled for the remainder of Q3 and potentially into Q4 2026 includes additional drilling to compare assay and gamma logging results, better define the redox front’s geometry and continuity, and extend stratigraphic fences to map the palaeochannel system regionally. Heritage surveys are also planned to enable access to new prospective areas.

Geological Context and Exploration History

The Big Lake Project covers over 6,400 square kilometres, largely within exploration licence EL6367, and sits on the eastern edge of the Cooper and Eromanga basins, regions historically explored for petroleum. The uranium mineralisation model draws on analogues from hydrocarbon-associated roll-front uranium deposits in the US and Kazakhstan. The source of uranium is interpreted as weathering of the underlying Big Lake Granite Suite, with uranium transported by oxidised groundwater and precipitated where it encounters reducing conditions, often linked to hydrocarbons leaking upwards.

Previous exploration included 148 rotary mud drillholes by TC Development Corporation between 2008 and 2009, with gamma logging and geochemical assays providing baseline data. The current program leverages extensive seismic and airborne electromagnetic surveys to refine targeting within the palaeochannel system.