Cooper Metals Ltd (ASX:CPM) has positive news from exploration at Brumby Ridge prospect, part of the Mt Isa East Copper-Gold Project, some 30 kilometres to the east of Mt Isa in northwest Queensland.
The company conducted an induced polarisation (IP) survey that confirmed a minimum 300-metre-long chargeability response at Brumby Ridge with follow-up drilling underway.
All survey lines return response
Each of the four 100-metre spaced pole-dipole (PDP) IP survey lines returned a chargeability response, with strong depth potential through the centre of the prospect.
The company is now in the throes of around 1,200 metres of diamond drilling and up to 2,000 metres of reverse circulation (RC) drilling at Brumby Ridge to help ascertain the size and grade potential of the mineralisation.
Initial diamond drilling will consist of scissor holes – two holes drilled in opposite directions – to test the width and dip of the mineralisation. Following this, diamond holes will be drilled along strike and possibly down dip as required.
A 3D view of 2D PDP chargeability models with existing drill holes.
Managing director Ian Warland said: “The IP survey has now been completed at Brumby Ridge and it is highly encouraging to extend the strong chargeability response along strike for around 300 metres and at depth.
“The IP chargeability response starts around 50 metres below surface and at least on two of the lines continues at depth beyond the 200-metre model.
“Diamond drilling has recently commenced and we look forward to updating the market when results come to hand.”
Strong previous results, open mineralisation
In November last year, the company fielded some strong RC results at Brumby Ridge, such as up to 71 metres at 2.80% copper and 0.05 g/t gold from 115 metres, including 24 metres at 5.37% copper and 0.10 g/t gold from 115 metres.
One drill hole ended in copper-gold mineralisation, with the last 3 metres to the end of hole (186 metres) averaging 1.88% copper and 0.04 g/t gold.
Five RC holes have been drilled into Brumby Ridge to date. The mineralisation is associated with extensive magnetite, hematite and albite alteration typical of iron oxide copper-gold (IOCG) systems in the area.
Based on this previous drilling, the orientation of the mineralisation is thought to be striking northwest, though the dip of the mineralisation is unknown – and three of the holes have ended in mineralisation.
The true width of the mineralisation is yet to be discovered at this early stage of exploration, and therein lies the promise of the prospect.