- Review finds the Austin, Shelby and Yannery prospects could add significantly to copper resources at the 6.2Mt Whundo project
- Three prospects have a combined ‘signature’ ~3X larger than the Whundo and Ayshia resource areas
- GreenTech planning upcoming exploration, which could include drilling
Special Report: Three underexplored copper prospects could deliver significant resource growth at GreenTech Metals’ 6.2Mt Whundo copper-zinc project in WA’s Pilbara region.
This potential was outlined by a high-level review which considered resurgent copper prices — which is up 23% to US$9,894/t from a three-month low of US$8,065/t – and the Austin, Shelby and Yannery prospects having a combined fixed loop electromagnetic (FLEM) signature about three times larger than the Whundo and Ayshia resource areas.
EM surveys detect anomalies in the earth’s natural magnetic field caused by zones of rock that conduct or resist electrical current more than the surrounding rock, like ore deposits.
These three prospects are also known to host copper and other minerals with drilling returning significant intercepts such as:
Austin
- 8m at 2.65% copper, 0.64% zinc and 0.11g/t gold from 141m (22GTRC017); and
- 10m at 2.85% copper and 0.96% zinc from 162m (22GTRC023)
Shelby
- 5.8m at 2.4% copper, 0.6% zinc and 7.6g/t silver from 391.25m (SHDD016)
Yannery
- 21m at 2.1% copper from 22m, including 8m at 5.2% copper from 31m, with an even higher grade zone of 1m at 23.1% copper and 37.1g/t silver from 34m
These underexplored prospects are also not currently included in GreenTech Metals’ (ASX:GRE) existing resource of 6.2Mt grading 1.2% copper and 1.04% at the Whundo project.
GRE previously noted that Austin not only appeared to be a separate mineralising event from the overlying Whundo East resource, but it also has the potential to eclipse Whundo East in size.
Copper opportunity
Volcanogenic massive sulphide plays typically have deposits that occur in clusters and Whundo is no exception with six significant deposits, each associated directly with an EM anomaly, identified within 1500m of the Whundo mining leases.
The high-level resource and project review prioritised targets which include the largely untested conductor anomalies at Austin and Shelby as well as the much smaller shallower tested anomalies at Yannery and Ayshia.
GRE notes that at Whundo and Ashyia, which have been subject to significant resource drilling, the anomalies closely reflect the extent of the unweathered sulphide mineralisation.
Additionally, the near surface oxide mineralisation at Whundo and Yannery extends beyond the bounds of the EM anomaly.
The company adds that the EM anomalies can give a good approximation of the spatial extent of the mineralisation at each of the VMS prospects.
Executive director Thomas Reddicliffe said that while its field exploration activities have focused on progressing its Ruth Well and Osborne JV lithium projects, the review has recognised that Whundo presents a significant exploration opportunity in the current resurgent copper market.
“We believe there is considerable scope particularly at Austin, Shelby, Yannery and Ayshia to identify additional resource tonnes to enable a step change in the resource scale,” Reddicliffe said.
“Based on the conductive footprints of these VMS prospects, they are all under-explored at depth with very little drilling done below 150m depth on any of the deposits. We will be commenting on our plans to methodically explore these prospects in the near future.”
Next steps
With completion of the high-level resource and project review, GRE is now planning upcoming exploration, which is likely to include drilling and down-hole EM surveying at Whundo.
This article was developed in collaboration with GreenTech Metals, a Stockhead advertiser at the time of publishing.
This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.