Aeris Resources Ltd (ASX:AIS) has discovered further high-grade copper sulphide mineralisation and extended the deeper primary sulphide mineralisation strike to 300 metres following an exploratory drilling campaign at its Constellation satellite deposit in central NSW.
An extensive reverse circulation (RC) campaign involving 110 drill holes across two programs intersected copper mineralisation within oxide and supergene horizons over a nominal 250-metre (north-south) x 200-metre (east-west) footprint with a best result of 46 metres at 2.48% copper 0.54 g/t gold and 3.2 g/t silver from 8 metres.
Additionally, high-grade copper assays were returned from diamond drilling within the deeper primary (sulphide) copper domain, including 17.9 metres at 3.21% copper and 5.7 g/t silver from 230 metres and 4.95 metres at 3.06% copper, 0.71 g/t gold and 3.2 g/t silver from 358.2 metres.
Aeris is an established Australian copper-gold producer and explorer through projects in Queensland and NSW with Constellation in proximity to the Tritton Copper Operations.
"Surprising on the upside"
“The drilling results at Constellation continue to surprise on the upside with the latest assay results from the RC program including shallow sulphide mineralisation with high copper grades,” Aeris executive chairman Andre Labuschagne said.
“Additionally, the diamond drilling program into the deeper sulphide mineralisation has now extended the strike extent to 300 metres."
RC results
As well as the 46-metre intersection, other results from 43 RC holes in the Phase 2 RC drill program within the oxide and primary sulphide domains are:
- 15 metres at 2.16% copper, 1.21 g/t gold and 6.5 g/t silver from 92 metres;
- 7 metres at 2.64% copper, 2.30 g/t gold and 10.4 g/t silver from 74 metres;
- 7 metres at 1.62% copper, 3.86 g/t gold and 15.4 g/t silver from 64 metres; and
- 2 metres at 3.36% copper, 4.14 g/t gold and 16.0 g/t silver from 76 metres.
AIS notes that RC assays indicate an increase in gold grade toward the south margin of the sulphide mineralisation.
Most RC drill holes intersecting primary sulphides in the southern margin are reporting average gold grades well above 1g/t. In comparison gold grades elsewhere in the primary sulphide mineralisation are generally less than 1 g/t.
Evolving deposit
“The deposit is now clearly evolving into zones of oxide, supergene and primary (sulphide) copper mineralisation, and within each of these zones there are areas with high copper and/or gold enrichment. We are now progressing geotechnical and metallurgical work on each of these forms of mineralisation," Labuschagne said.
“The assays from the RC program are being prioritised over those from the diamond drilling program. This will enable us to bring forward the mineral resource estimates for the supergene and oxide sections of the ore body to December 2021-January 2022.
"The maiden mineral resource for the sulphide mineralisation is still targeted by end of March 2022.
“Importantly, we already have processing pathways in place for oxide, supergene and the sulphide mineralisation, reducing both time and capital to potential first production.”
Next steps
Diamond drilling continues on-site, with an additional 11 drill holes completed within the deeper primary sulphide mineralisation. Diamond drilling has focused on testing the margins of the primary sulphide mineralisation.
Four holes intersected sparse pyrite (also known as fool’s gold) with rich disseminated sulphides, features consistent with the margins of a mineralised system.
The strike length has now been defined to a maximum of 300 metres, the drilling program having successfully delineated the southern and northern extents of the mineralisation system to 500 metres down plunge. Further mineralisation has been identified down plunge to 850 metres and remains open both in this direction and laterally.
Further EM surveying is planned to test for additional lenses (orebodies thick in the centre) further along strike beyond the current drill footprint.
The Constellation deposit remains open at depth with two large (350 metres x 75 metres) DHEM (down-hole electromagnetic) plates interpreted to extend below the current drilling footprint.
Two rigs remain onsite at Constellation with one rig continuing to focus on resource definition. The second drill has transitioned to geotechnical and metallurgic drilling programs. Data collected from each program will be used for various studies underway at the Constellation deposit.
Shares higher
Shares are 8.82% higher in early trading to 18.5 cents while the company's market cap before opening was approximately $379.1 million.