Helix Resources Ltd (ASX:HLX) has successfully trialed the use of an Induced Polarisation (IP) geophysical survey technique at the Canbelego Main Lode Mineral Resource in NSW.
The results received clearly identify the ‘known’ Canbelego copper deposit and highlight two new chargeable IP anomalies that have never been drilled.
“While it is still early days, the application of IP geophysics is looking like a game-changer for Helix and our exploration of the Rochford Trend,” Helix’s Executive Technical Director, Kylie Prendergast, said.
“Copper mineralisation occurs as ‘sulphide’ minerals in either disseminated, vein stockworks or sometimes massive- sulphide textures. The latter can be conductive and to date we have relied on measuring that massive, conductive feature utilising ‘electromagnetic’ or “EM” survey techniques to identify potential deposits.
“However, at Bijoux we intersected copper sulphides at grades well above 1% copper but occurring as veins and disseminations and hence unlikely to give an EM response.
IP detects ‘sulphide’ minerals regardless of the textures and we think this technique offers a very cost effective, direct detection method for finding new copper deposits in the Cobar district.
“With our multi-disciplinary approach including pathfinder geochemistry, we think IP can identity quite ‘refined’ drill targets or eliminate targets, which offers significant savings on drilling expenditure and time.
“We will now move on to build a fuller picture of the Rochford Trend copper potential by expanding to a wide coverage ‘gradient array IP’ geophysical survey over known surface copper anomalies and where drillholes have intersected copper sulphide mineralisation, such as the Cabellero and Bijoux prospects.
“This is an exciting development; fast-tracking Helix on a discovery pathway while saving money and optimising our drill targeting.”
Next Steps
Two GAIP surveys are planned; the first covering a 16 sq. km area from north of Canbelego to south of Caballero, and the second covering a 5 sq. km area over the Bijoux prospect.
A GAIP survey is a cost-effective method surveying large areas to detect chargeability and resistivity anomalies, however GAIP will not provide a depth constraint on any identified anomalies.
GAIP anomalies will need to be followed-up with PDIP surveys to accurately define the depth and geometry of the anomalies. Utilisation of GAIP to detect sulphide mineralisation and then PDIP to better define the target ahead of drilling will fast track drill testing and, optimise the drill success rate – saving drill metres and hence expenditure.
The GAIP surveys will commence in early March 2024, with the surveys expected to be completed in late-March. Follow-up PDIP surveys will be undertaken after that to define drill targets.