After receiving more strong results at the Mount Isa East Copper-Gold Project in northwest Queensland during the December quarter of 2023, Cooper Metals Ltd (ASX:CPM) has a firm foundation to achieve further success in 2024.
A number of new prospects, including Brumby Ridge, Raven and Mafic Sweats South, have provided further signs of the discovery potential with the former emerging strongly after RC drilling produced bonanza-grade copper.
Riding high on Brumby Ridge
One reverse circulation (RC) drill hole, 23MERC028, returned 71 metres at 2.8% copper and 0.05 g/t gold from 115 metres to the end of hole, including 24 metres at 5.4% copper and 0.10 g/t gold from 115 metres.
Another, 23MERC024, returned 50 metres at 1.32% copper and 0.05 g/t gold from 80 metres including 2 metres at 6.1% copper and 0.23 g/t gold.
Mineralisation at Brumby Ridge is open in all directions and with higher grades in the deeper hole 23MERC028 ending in mineralisation.
Raven also soars
Significant copper-gold mineralisation was also returned from RC drilling at Raven:
- 10 metres at 1.35% copper and 0.10 g/t gold from 62 metres including 3 metres at 3.37% copper and 0.26 g/t gold in 23MERC032;
- 8 metres at 1.0% copper and 0.08 g/t gold from 85 metres in 23MER033;
- 15 metres at 1.0% copper and 0.10 g/t gold from 35 metres in 23MERC019; and
- 10 metres at 1.27% copper and 0.17 g/t gold from 77 metres in 23MERC018.
Meanwhile, in the Gullewa Greenstone Belt of Western Australia, Cooper is continuing a geochemical soil sampling program at its Gooroo Copper-Gold Project, about 413 kilometres northeast of Perth.
“Set for exciting 2024”
Cooper Metals managing director Ian Warland said: “The Brumby Ridge copper-gold discovery has been an exciting outcome of initial scout drilling completed during the quarter and validation of the prospectivity of the Mt Isa East Copper-Gold Project.
"We also intercepted significant copper-gold mineralisation at the Raven and Mafic Sweats South prospects.
"These excellent drill results set the company up well for an exciting 2024 where our focus will be assessing the size and grade potential of these new discoveries while also continuing to test our extensive pipeline of copper-gold targets.”
Mt Isa East Copper-Gold Project.
About Mt Isa East
The flagship Mt Isa East Project covers around 1,637 square kilometres of tenure with numerous historical copper-gold workings and prospects already identified for immediate follow-up exploration.
These priority areas are based on historical exploration results and conceptual targeting of favourable host lithologies and structures with potential to host significant copper-gold mineralisation, including iron sulphide copper gold (ISCG), iron oxide copper gold (IOCG) and shear-hosted copper-gold mineralisation.
Drilling during quarter
During the December quarter on-ground exploration was concentrated on Mt Isa East with two RC campaigns on five prospects with highly encouraging results received from Brumby Ridge, Raven and Mafic Sweats South.
The company also carried out geochemical and geophysical programs throughout the project area.
Twenty-one drill holes for 2,633 metres were completed in two drill campaigns in October and November on five prospects - Mafic Sweats South, Raven, Long Slot, Brumby Ridge and Yarraman - with significant copper intersected at Brumby Ridge, Raven and Mafic Sweats South.
Prospect location map Mt Isa East Project.
Brumby Ridge shines
Brumby Ridge is around 30 kilometres east of Mt Isa and 3 kilometres SSE (LON:SSE) of Mafic Sweats South prospect along a regional NNW trending Brumby fault.
Five RC holes were drilled into Brumby Ridge during the period with several holes returning significant mineralised intersections.
Drill hole 23MERC030, drilled about 22 metres to the NW of 23MERC028, intersected a broad mineralised brecciated sequence closer to surface where it decreases in copper grade.
It returned 115 metres at 0.37% copper from 86 metres with several elevated zones including:
- 2 metres at 2.18% copper and 0.03 g/t gold from 88 metres;
- 4 metres at 1.1% copper and 0.02 g/t gold from 101 metres;
- 1 metre at 1.02% copper and 0.01 g/t gold from 143 metres; and
- 3 metres at 1.00% copper and 0.01 g/t gold from 159 metres.
Based on drilling to date, the orientation of the mineralisation is thought to be striking NW, however, the dip of the mineralisation is unknown as holes 23MERC024, 23MERC028 and 23MERC030 all ended in mineralisation, hence the true width of the mineralisation is unknown at this early stage.
Cooper began a downhole electromagnetic survey at Brumby Ridge during the quarter as well as a detailed drone aeromagnetic survey with results from these expected in the March quarter of 2024.
Raven and Mafic Sweats South
Raven prospect is 3 kilometres to the south of Brumby Ridge with seven RC holes for 942 metres averaging around 135 metres in depth completed in October and November.
A downhole electromagnetic (DHEM) survey was completed over some of the drill holes at Raven and is being interpreted and modelled by a consultant geophysicist.
At Mafic Sweats South, four RC drill holes for 431 metres were drilled with three testing a coincident copper soil anomaly conducted with a portable XRF machine and VTEM conductor (1550b) and one testing a copper anomaly on the sheared contact between pegmatite and volcanic rocks.
The three holes into the coincident VTEM conductor 1550b and geochemical anomaly intersected thick low-grade copper oxide mineralisation from surface including:
- 65 metres at 0.34% copper from surface in 23MERC014;
- 66 metres at 0.25% from 6 metres in 23MERC015; and
- 60 metres at 0.11% from surface in 23MERC016.
RC drill hole 23MERC014 was collared in mineralisation and ended in mineralisation at 65 metres due to a drilling issue.
Mineralisation remains open in all directions with the strong copper in soil anomaly continuing north of the drilling for around 280 metres, making a total strike length of the soil anomaly about 500 metres.
The widespread low-grade mineralisation from surface is highly encouraging and warrants further investigation as a potential low-grade copper oxide accumulation and/or indication of sulphide mineralisation at depth.
Other prospects
At Long Slot prospect three RC holes for 324 metres were drilled with anomalous copper and gold intersected in all three. The best result was 16 metres at 0.4% copper and 0.16 g/t gold from 1 metre.
A desktop review of Long Slot is in progress with plans to extend geochemical surveys to the south in the March 2024 quarter.
Yarraman prospect is about 5.5 kilometres west of Raven with two RC holes for 210 metres completed during the quarter with anomalous copper intersected in both.
The best result was 2 metres at 1.78% copper and 0.06 g/t gold from 24 metres in a hole drilled underneath a historical working.
Another hole testing a geochemical anomaly intersected 10 metres at 0.55% copper from 94 metres including 1 metre at 2.05% from 102 metres.