- Maiden exploration identifies priority uranium drill target at Adavale’s Mundowdna licences
- Gravity surveying has also identified numerous potential paleochannels
- Surface uranium anomalies defined by soil sampling
- Adavale to define further targets and finalise design for drill program
Special Report: Maiden exploration at Adavale Resources’ Mundowdna licences in South Australia has delivered an abundance of targets including a significant new area for uranium deposition that has been marked as a priority drill target.
The Mundowdna licences EL6821 and EL6957, which now form part of the company’s newly defined Marree Embayment project (MEP), cover ancient river channels known as paleochannels and buried valley systems cut into bedrock (paleovalleys) that are known to host significant sandstone-uranium deposits.
This has been underscored by a review of historical electromagnetic data with over 400,000 survey data points carried out by Adavale Resources (ASX:ADD).
Additionally, there is every reason to believe that uranium is indeed present in the region given that it is home to major mining operations such as BHP’s polymetallic Olympic Dam – the world’s largest uranium deposit – plus Honeymoon well, Four Mile, Goulds Dam, Lyndhurst, Mount Gee and Yarramba.
Priority target area
The company’s maiden multi-technique program has now identified significant new uranium targets.
Reprocessing of historical airborne electromagnetic (EM) data over the Mundowdna licences identified a large EM low running in a northwest direction along the western margin of the Mundowdna licences.
The sharpness of the low feature, particularly along its northeast edge, suggests it may be fault controlled in part creating a half graben-like feature.
This indicates that the EM low represents the greatest thickness of the uranium prospective Eyre and Namba Formations overlying the basement Maree Subgroup sediments, making it a prime pathway and potential trap site for the earliest uraniferous groundwaters shedding uranium from the adjacent Flinders Ranges.
A gravity survey undertaken as part of the maiden exploration program provided support to the EM interpretation, showing a consistent rising gravity trend towards the northeast along all surveyed lines, indicating thickening sediment cover in the southwest and thinning towards the northeast.
Detailed interpretation of the gravity data for subtle variations in the gravity that may reflect potential palaeochannels identified numerous such anomalies which were subsequently classified as either modern day or older palaeochannel depending on their location with respect to the modern-day drainage system.
Meanwhile, soil sampling defined numerous surface uranium anomalies, which represent targets for follow up work programs to test and validate as they are significantly elevated compared to the surrounding samples in the data.
These targets are also coincident with the interpreted gravity anomalies related to the palaeochannels.
ADD is also investigating the use of element ratios as a proxy for elevated uranium at depth, a technique that has been used to define such zones from surface in basins in Wyoming.
Uranium-rich paleo drainage system
“The positive outcomes generated by our maiden, multi-technique exploration program indicates a uranium-rich paleo drainage system,” executive director David Riekie said.
“What is most exciting is that collectively this data has now identified a significant basement structure at depth that appears to be a large trap site for the ancient uraniferous groundwaters washing/shedding from the adjacent Flinders Ranges.
“This area of the Marree Embayment will be a priority uranium exploration focus. Most pleasing is this basement structure does not appear to have been previously recognised or drilled.
“The multiple surface uranium anomalies and prospective palaeochannel features will be further tested and are expected to generate high priority targets as part of our next MEP exploration program.
“These outcomes vindicate our expanded regional exploration focus in the uranium friendly jurisdiction of South Australia and we look forward to reporting on follow-up exploration programs including drilling activities that are now being prepared.”
Next steps
ADD will now seek heritage clearances along tracks and trails crossing interpreted basement low/depocentre on western margin of the MEP and additional possible targets for advanced exploration.
It will also finalise design of the drill program to test structures for uranium redox boundaries and expand clearances on MacDonnell Creek licence areas to undertake a broader exploration and drilling program.
Other work on the cards include further development and analysis of lead/uranium data to define its potential for use in the Australian environment along with ongoing development of targets and additional areas of interest based on current and historical work as well as recently acquired datasets.
This article was developed in collaboration with Adavale Resources, a Stockhead advertiser at the time of publishing.
This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.