Adavale Resources Limited (ASX: ADD) has confirmed uranium mineralisation with the results of the initial reconnaissance drilling programme undertaken at the company’s 100% owned Lake Surprise Uranium Project in South Australia during February 2023.
The drilling programme was ultimately designed to penetrate the silcrete horizons and test a prospective zone in EL5893. The prospective zone was identified from previous exploration that showed a helium anomaly, surface gamma anomaly and rock chip data.
The recent drilling encountered a series of braided channels, confirming the pre-drill interpretation that the area was part of a broad delta like fan system. The drilling intersected anomalous uranium with associated gamma anomalies and indicates an increase in concentration of anomalous readings, trending in a southerly direction, within Adavale’s tenure.
The programme has confirmed the need to isolate the braided channel geometry to target higher grade mineralised zones. Geophysics including magnetics and resistivity is being planned to cover this drilled area as well as the Canegrass, Jubilee and Mookwarinna prospects to calibrate the drill results achieved.
The results of this low-cost reconnaissance drilling programme have provided significant technical data for Adavale to plan the next programme,” Executive Director, David Riekie, said.
“In particular, our technical team will now focus on the geometry of the braided channel system that is becoming evident as the concentration of uranium hosted horizons and improved future targeting methods. We will use this knowledge to plan geophysics to better map the target horizons and support future drilling. Drilling was cheaper than anticipated & demonstrated the broader paleochannel system is host to targeted uranium mineralised channels.”
Drilling Programme
The original aircore drill programme was for approximately 4,500 drill metres across 150 holes with a planned average depth of ~30m. The presence of silcrete horizons and unconsolidated sandstone resulted in a change to a slim-hole RC hammer for the programme. The intersected palaeochannel system was also found to be much shallower than expected with the deepest hole only 18m.
The programme was completed with 56 holes for 742 metres drilled at a cost approximately of $70,000.
Next Steps
The drilling confirmed that uranium mineralisation is hosted within silcrete lenses within a braided channel system, with several episodes of channels overlying each other.
The best results were in the southern line with eight of 10 holes containing anomalous uranium over several metres.
The drill chips show changes between holes that indicate there were individual streams as part of a broader channel system. Often there is little to no continuity between drill holes over the 80m spacing between holes. This is consistent with a braided channel system as the individual streams and channels in the system represent a different period of deposition within the broader fan of sediments. The presence of uranium was noted as being stronger towards the southern end of the drill pattern.
It is reasonably well understood that the palaeochannels that drain north-westward from the Flinders Ranges are broad in nature (up to 10-20km across) but contain individual sub-channels that contain elevated concentrations of uranium.
Geophysical methods including magnetics, gravity and resistivity have been shown elsewhere in the region to be useful tools for identifying uranium channels and vectoring exploration.
Adavale will assess detailed magnetics and resistivity surveys over the recent drill area as well as the Canegrass, Jubilee and Mookwarinna prospects. It is hoped that the geophysical methods will correlate with the drilling results from these areas and provide a methodology for success from these prospects.