Great Boulder Resources Ltd (ASX:GBR) has extended the Mulga Bill gold prospect and identified a new exploration target during drilling at the Side Well Gold Project in Western Australia.
The gold explorer recently embarked on reverse circulation (RC) and aircore (AC) drilling at its wholly-owned gold play’s intrusive-related gold system.
During a July-August drilling program, Great Boulder confirmed mineralisation to the east, added more than 1 kilometre to Mulga Bill’s mineralised footprint — bringing the anomaly out to 5.1 kilometres in length — and pinpointed a new gold prospect 1.5 kilometres to the south.
Side Well represents a key exploration asset for the GBR team: it sits at the heart of a multi-million-ounce goldfield in Meekatharra, where historical production totals roughly 3.9 million ounces.
Some of the best results from the phase three RC program included:
- 1-metre at 11 g/t gold from 89 metres and 8 metres at 1.50 g/t from 99 metres;
- 4 metres at 3.34 g/t from 88 metres and 3 metres at 5.34 g/t from 105 metres; and
- 8 metres at 3.63 g/t from 72 metres.
And the AC drill returned:
- 8 metres at 2.39 g/t from 40 metres; and
- 24 metres at 0.36 g/t from 12 metres.
“A big, intrusive-related gold system”
Great Boulder managing director Andrew Paterson said infill RC drilling continues to define the high-grade zones in the central area of Mulga Bill.
“We have now completed a fourth round of RC drilling, which is continuing to build our confidence in the high-grade gold structures.
“We are also very excited the regional AC drilling has significantly extended Mulga Bill to the south, meaning it is now over five kilometres long and still open in both directions.
“This is a big, intrusive-related gold system with potential for significant scale and high-grade gold.
“The discovery of a completely new prospect to the east is also hugely exciting, and we will be looking to extend that discovery further in the next round of drilling.”
Side Well is located in the Meekatharra Gold Field, an area with a total gold endowment of almost 7 million ounces.
RC campaign defines gold in the east
Today’s announcement marks the last eight drill hole results from the phase three RC program at Mulga Bill.
Ultimately, the recent campaign defined the continuity of Mulga Bill’s mineralisation in the east over a 400-metre zone.
Here, minimal drilling has been undertaken up or down dip, where fresh rock intercepts include 3 metres at 11.13 g/t gold from 126 metres.
The strike extensions of this zone are yet to be adequately tested by RC drilling.
AC program extends footprint
Over July, the GBR team drilled 62 aircore holes for 5,841 metres across the Side Well project.
Drilling was designed to test both the northern extensions to the western zone of mineralisation at Mulga Bill, as well as other regional mineralised trends.
Interestingly, the campaign hit a new zone of mineralisation 1.5 kilometres to the east, with aircore results indicating a northeast-trending, gold-bearing structure.
This mineralisation is currently open in all directions, with no drilling within 5 kilometres to the north or south.
Two regional aircore lines were also completed to the south of Mulga Bill to test the strike extensions.
This activity extended the mineralised footprint 1.4 kilometres to the south, broadening the Mulga Bill gold system to over 5 kilometres of strike.
Importantly, mineralisation remains open along strike to the north and south.
Next on the agenda
Not long after completing its phase three RC program at Mulga Bill, GBR has already executed a phase four campaign over the gold target.
The latest program was designed to test deeper extensions to the high-grade intersections from the phase three program, with 10 holes drilled over the Mulga Bill soil.
Another campaign — dubbed phase five — is slated to kick off late next month, chasing up the mineralised zones identified in earlier drilling stages.
In the meantime, assays from the phase one diamond drilling (DD) and phase four RC drilling campaigns are expected in October.
The diamond drilling results are expected to provide important structural context to the gold mineralisation identified to date at Mulga Bill.
Outside of the Side Well asset, Great Boulder’s Whiteheads Project regional aircore program began on September 18.
Roughly 6,000 metres of drilling is planned to test the asset’s regional auger anomalies and follow up on previous significant intersections.