Great Boulder Resources Ltd (ASX:GBR) has highlighted a broad, tubular zone of copper and silver mineralisation close to high-grade gold mineralisation previously defined at Mulga Bill within the Side Well Gold Project in WA.
This new mineralised zone was identified through a combination of diamond drilling results and retrospective assays of earlier reverse circulation (RC) holes, hindered by a lack of access to base metal assays until now.
Highlight multi-element assays from the copper-silver zone include:
- 14.5 metres at 0.59% copper, 1.17g/t gold and 10.74 g/t silver from 189.5 metres, including 0.7 metres at 2.25% copper, 1.48 g/t gold and 27.10 g/t silver;
- 17 metres at 1.21% copper, 0.35 g/t gold and 8.92 g/t silver from 83 metres;
- 24 metres at 0.49% copper, 0.25 g/t gold and 3.65 g/t silver from 94 metres;
- 4 metres at 1.30% copper, 0.18 g/t gold and 68.68 g/t silver from 100 metres, including 1-metre at 3.44% copper, 0.15 g/t gold and 171.38 g/t silver.
Data evaluation and target planning are underway for follow-up drilling of the copper zone.
Potential scope to recover copper
“After recognising the chalcopyrite-rich copper zone in our initial RC programs last year we recently started retrospectively assaying RC samples for a 48-element suite including silver and base metals,” Great Boulder Resources managing director Andrew Paterson said.
“It’s exciting to see this zone now appears to be a large tabular zone of elevated copper and silver with low-grade gold mineralisation.
“This doesn’t change our focus on drilling high-grade gold intersections at Mulga Bill but it helps us understand the project’s full potential. There may be scope for recovering copper as part of a potential mining scenario.
“The fact that we see individual samples with copper as high as 3.44% and silver at 171.38 g/t indicates this zone could host a significant amount of metal."
Plan view of the central area of Mulga Bill, showing sulphide zone in the context of surrounding drill collars. Sulphide interpretation is based on visual logging, pXRF data and multi-element assay data.
Focus remains on gold
“Our field program is progressing well with a focus on defining high-grade gold as we continue drilling the 6-kilometre footprint of Mulga Bill," Paterson continued.
“An aircore program is currently underway, which will be followed by RC drilling running continuously to the end of the year as we move towards an exploration target and mineral resource as quickly as possible.”
An aircore drilling program has also begun in the southern half of Mulga Bill-Loaded Dog corridor, concentrating on infill drilling.
The rig will then move to Whiteheads later in the month to test geochemical targets and follow-up previous aircore programs.