Aeris Resources Ltd (ASX:AIS) will review geological information gathered from drilling of the Torrens copper-gold anomaly in South Australia to determine future drilling campaigns.
The most recent drill hole on Lake Torrens, TD10, reached its target depth of about 1,300 metres on May 28.
Visual observations from the hole have shown highly altered K-feldspar and magnetite rich intervals with trace amounts of pyrite and chalcopyrite.
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The visible pyrite and chalcopyrite are encouraging from a geological perspective.
A review of information collected from the drilling and recently finalised geophysical interpretation work will now begin.
Drilling paused
Drilling operations at the 70%-owned property will be paused whilst the review is undertaken.
Assays from hole TD7 returned no significant copper mineralisation with the highest-grade interval being 20 metres at 0.15% copper from 542 metres downhole.
However, Aeris said that the presence of elevated cerium concentrations toward the bottom of the hole were encouraging.
Cerium and other rare earth elements are considered important geochemical vectors toward potential iron-oxide-copper-gold (IOCG) systems.
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Drilling of TD10 was completed without incident at very productive drill rates.
The revised drill hole procedure used to mitigate the risks encountered on the previous two drill holes, TD8 and TD9, proved successful.
Aeris is confident that the new approach will ensure future drill holes on Lake Torrens will be completed at industry competitive drill productivity rates.
Gravity survey flown
A detailed interpretation of the airborne Falcon gravity gradiometric survey flown over the project area in March 2018 was recently finalised.
This survey was designed to enhance the gravity and magnetic geophysical signatures over the tenement, both of which are primary datasets used to interpret basement rocks which host IOCG mineralisation in the eastern Gawler Craton.
The geophysical interpretation from the Falcon Survey supports earlier observations that the Torrens project remains highly prospective for IOCG mineralisation.
Subtle responses
Completed geological work has indicated the geophysical responses associated with an IOCG mineralised system are more subtle than previously thought.
Further technical geological work is required to refine the geological interpretation to ensure the most prospective anomalies are prioritised for targeting.
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In addition, several areas outside the permissible area for drilling, one of which is on land immediately west of Lake Torrens, show encouraging geophysical characteristics.
Aeris will begin the process for obtaining the necessary regulatory approvals to allow drilling to occur within each of these areas.
Review of practices
The unique pontoon supported drilling platform has been successful in enabling drilling on the surface of Lake Torrens.
Operating costs per hole, however, have been higher than originally targeted.
Whilst the technical review is being undertaken, Aeris will also take the opportunity to rigorously review operational practices and costs.