Alligator Energy hits major uranium find at Big Lake in SA’s Lake Eyre Basin
Alligator Energy (ASX: AGE) has made a significant discovery with its maiden drilling program at the Big Lake uranium project in South Australia.
According to chief executive officer Greg Hall, the discovery is the first proof of concept that significant uranium is present within the Lake Eyre Basin sediments that lie above the hydrocarbon-rich Cooper Basin.
To date, four air-core drill holes have intersected palaeochannel sand units hosting significant thicknesses of anomalous uranium mineralisation within interbedded palaeochannel sand units.
Greenfields discovery
Mr Hall also noted that this is the first significant greenfields discovery of uranium in the state since UraniumSA at the Samphire project in 2007.
“The thickness extent of mineralisation layers, ranging up to 20m in these discovery holes, is impressive for this style of mineralisation,” Mr Hall said.
“While estimated grades are still on the lower side, having grade-thickness intersections close to the cut-off used at our Samphire project from the initial discovery area is very encouraging.”
“The discovery appears to validate the uranium formation model developed by the previous Big Lake geologists from whom Alligator acquired the initial tenement and we acknowledge their work.”
“The sediments above the Cooper Basin cover an extensive area and we hope this has the potential to develop into a new in-situ recovery (ISR)-amenable uranium field similar to the Curnamona province, which hosts the Beverley, Four Mile and Honeymoon deposits.”
No overnight success
Mr Hall pointed out that the lead-up to the successful inaugural drilling campaign commenced with Alligator’s exploration team’s initial interpretation work on the project back in 2019 and detailed seismic interpretation work carried out during 2022/23.
Alligator has already assessed that the indicative grade-thickness of two intersections drilled to date is at or near the economic cut-off used at the company’s Samphire ISR uranium project near Whyalla.
Also of note is that indicative uranium grades found in these holes are approximately ten to 50 times background levels.
Shallow basin sediments
The objective of the inaugural program was to investigate the region’s stratigraphy and the potential for uranium mineralisation in the shallow basin sediments that lie above the hydrocarbon-rich Cooper Basin.
This setting has many attributes seen in other global hydrocarbon-related ISR uranium fields around the world.
Alligator’s strategy is to target the northern extensions of the Tertiary Namba and Eyre sedimentary formations that host the Beverley, Four Mile and Honeymoon ISR uranium mining operations south of the Big Lake project.
Initial drilling targets
The initial drilling program targeted the shallower Namba Formation, with the objective of corroborating Alligator’s seismic/airborne electromagnetic survey interpretations of potential mineralisation-bearing palaeochannels.
Alligator said that of significance is the presence of oxidised and reduced sands in all holes drilled in this area, which is synonymous with roll-front uranium mineralising systems.
Two further holes are currently being drilled, with all samples to be transported to Adelaide for detailed laboratory assaying and analysis.
The company will commence approvals and initiate heritage clearances for follow-up drilling following full analysis of data including refinement of the geological model.