Miramar Resources Ltd (ASX:M2R) has intersected bedrock copper sulphide mineralisation during maiden diamond drilling at the Whaleshark Project in the Ashburton region of WA, confirming the potential for iron oxide copper-gold (IOCG) mineralisation for the first time.
This discovery follows the drilling of three diamond holes for 1,050 metres in a program co-funded by the Western Australian Government's Exploration Incentive Scheme (EIS) to the tune of A$180,000.
The drill program targeted a discrete gravity anomaly within the Whaleshark granite, which previously returned strong 'interface' aircore results of up to 435 parts per million (ppm) copper, 889 ppm cobalt and 7.7 g/t silver.
Core from WSDD002 showing chalcopyrite 'seam'.
Bedrock copper mineralisation
Chalcopyrite, the principal ore for copper, was seen in two of the three holes, with the most significant mineralisation observed within a steeply dipping shear zone in drill hole WSDD002 at 231.6 metres downhole.
Rafts of brown iron oxide-rich material were also observed within the shear zone, indicating that the copper sulphides and iron-rich rafts had been dragged into the northwest-trending structure from elsewhere.
Core from the three holes has been shipped to Kalgoorlie for cutting, sampling and analysis and results will be announced when they are ready.
WSDD002 drill core showing iron oxide 'raft'.
Significant discovery
“We have now confirmed the presence of bedrock copper sulphide mineralisation at Whaleshark for the first time, indicating the mobile metal ion (MMI) and aircore anomalies have a bedrock source,” Miramar executive chairman Allan Kelly said.
“This is the most significant evidence of the potential for IOCG mineralisation at Whaleshark since the project was first highlighted by WMC Resources in the mid-1990s.
“Given the strong relationship between copper mineralisation and iron oxides in this style of deposit, our next step will be to drill-test the other MMI, gravity and aircore anomalies associated with the banded iron formation at each end of the northwest-trending structure.”
Next steps
Miramar is planning to extend the diamond drill program at Whaleshark, focusing on the northwest-trending fault, to follow up on this maiden success.
It will also complete the interface aircore drilling over all MMI anomalies identified to date.
Additionally, investigation of suitable geophysical methods to help target further drilling will be undertaken.
About Whaleshark
This project in the Ashburton region of WA about 40 kilometres east of Onslow is a potentially large and shallow IOCG deposit.
Since commencing exploration at Whaleshark in mid-2021, Miramar has identified strongly anomalous copper, cobalt, gold, silver and other IOCG pathfinders in shallow aircore drilling beneath surface geochemical anomalism.
The scale, magnitude and suite of elements seen at Whaleshark is very similar to the large Ernest Henry IOCG in Queensland.
Additionally, there is potential for rare earth element (REE) anomalism in the buried IOCG mineralisation at Whaleshark based on a comparison of aircore results with published results from research carried out at the Prominent Hill IOCG deposit in South Australia.