Duke Exploration (ASX: DEX) has announced a maiden inferred mineral resource estimate for the Mt Flora copper-silver deposit within its flagship Bundarra project in central Queensland.
It totals 16 million tonnes at an average grade of 0.5% copper and 6.9 parts per million silver for 78,000 tonnes of copper and 3.6 million ounces of silver.
The estimate is based on all work completed up until the start of June including 87 reverse circulation (RC) holes and three diamond holes, although exploration is ongoing.
Duke managing director Philip Condon said delivering this resource is a “very solid start” for the company, which only listed seven months ago.
“It is particularly pleasing to see the maiden resource at Mt Flora already close to the upper range of our exploration target in the prospectus,” he said.
Mt Flora’s target was 5.5-12Mt at 0.5-0.8% copper for 27,000-96,000t copper, 5-15 grams per tonne silver for 0.884-5.78Moz silver and 0.1g/t gold for 17,000-38,000oz gold.
Resource extension drilling
Mt Flora’s resource is believed to be open at least 300m to the north and additional drilling is being planned to extend to here, giving the deposit a strike of 1,000m.
Infill drilling will also be undertaken to achieve an indicated resource classification.
In addition, drilling is planned to test the resource potential of the copper mineralisation intersected in holes at Quorn and Absolon – two prospects expected to add to Mt Flora’s resource. Earlier this month, Duke revealed drilling results that indicated Quorn could be an even larger mineralised system than Mt Flora.
Duke’s latest announcement also reported four new RC holes drilled 300m to the north have intersected massive sulphide mineralisation up to 11m wide with visible chalcopyrite from a vertical depth of 20-200m.
The drilling also confirms that pXRF soil anomalies of greater than 140ppm copper are related to bedrock massive sulphide copper mineralisation, which Duke said has “very important implications for the potential scale of the mineralised systems in the southwest of the Bundarra Pluton in the Quorn, Absolon and Rogers prospect areas”.
“Importantly, recent drilling of conductive and pXRF soil anomalies to the north of the maiden resource area… suggest that the resource at Mt Flora should continue to grow as assays are returned from the continuing resource and exploration drilling,” Mr Condon said.
“It is also encouraging to see from the preliminary metallurgical and mining studies completed to support the resource estimate that Mt Flora on its own has potential to be a standalone mining operation,” he added.
“The new resource development areas currently being discovered by our regional exploration will only add to this potential.”
Pre-feasibility work to begin
Mr Condon said the recent positive results have given the company the confidence to start pre-feasibility work on Mt Flora to develop definitive economics for the project.
“This work will include detailed metallurgy, infill resource drilling to extend and upgrade the Mt Flora resource to indicated resource status and mining optimisation studies.”
“We will continue to explore the regional potential of the Bundarra intrusion as this work progresses, which we are confident will only add to the scale of the project,” he added.