Argonaut Resources NL (ASX:ARE) has completed drilling a second hole targeting the Smith Dam 2 gravity anomaly within the broader West Lake Torrens bouguer gravity anomaly at the Murdie Project in South Australia and is now moving onto its third drill hole.
Moderate to strong iron oxide copper-gold (IOCG) alteration intersected at Smith Dam 2 target confirms the prospectivity of the West Lake Torrens gravity anomaly.
The second hole, WLTD002, intercepted basement at 645 metres and was drilled to a depth of 853 metres.
The company is moving drilling equipment and protective matting to the third drill hole at Murdie, which is offshore from the south-eastern corner of Andamooka Island.
Confirmation of IOCG geology
The presence of further IOCG alteration in the basement rocks of the West Lake Torrens gravity anomaly continues to provide encouragement to the Argonaut team.
Argonaut’s 2021 Murdie drilling program has confirmed the presence of the critical prerequisites to the discovery of an IOCG deposit which comprise:
- The same brecciated, hematite alteration system as Olympic Dam, Carrapateena and Oak Dam;
- Preservation, rather than erosion, of the IOCG system; and
- Intersection at around the correct level within the system.
Basement rocks intercepted in drill hole WLTD002 feature breccia zones with moderate to strong hematite and potassic alteration.
These observations are supported by portable XRF analysis.
Brecciation is the breaking of rock into fragments that are then re-cemented by a matrix, in this case an iron-rich matrix.
This process is generally considered to be a prerequisite to IOCG mineralisation.
The system appears not to have been subject to destructive, paleo-erosion and the upper, prospective portion of the IOCG system appears to have been preserved.
Drilling targets
The Murdie exploration licences cover two large-scale, regional gravity anomalies – West Lake Torrens and Murdie.
These anomalies represent locations with significant volumes of high-density rock that could contain economic IOCG deposits. Initial efforts were focused on the West Lake Torrens anomaly.
Drilling at WLTD001 and WLTD002 targeted residual gravity anomalies.
WLTD001 drill core has been cut and the samples are being submitted for assay with results expected in four weeks.