Great Boulder Resources Ltd (ASX:GBR) is riding high after it unveiled 15 metres at 35.82 g/t gold during reverse circulation (RC) drilling at the Side Well Gold Project’s Mulga Bill deposit in WA.
The 15-metre intersection includes a higher-grade 6-metre hit, clocking in at 83.58 g/t, and extends the Mulga Bill gold vein 30 metres to the south with shares up by as much as 23.72% higher this morning to $0.12.
In the past, drilling along this vein has intersected other high-grade gold hits, such as 5.9 metres at 39.37 g/t and 6 metres at 24.33 g/t.
GBR’s phase three exploration program continues at the Ironbark prospect, where initial metallurgical test-work is underway.
Meanwhile, an aircore rig is mobilising to kickstart work at Mulga Bill and the Loaded Dog target. It will also test geochemical anomalies immediately north of Ironbark.
The gold explorer expects to receive more assays from the Mulga Bill and Ironbark programs later this month.
Highest-grade intersection to date
Great Boulder managing director Andrew Paterson said of the 15-metre finding: “This spectacular result is the highest-grade intersection and the highest individual gold assay drilled to date at Side Well.
“It’s interpreted to be close to true width, so it’s among the widest intersections of more than 25 g/t gold in drilling we’ve yet seen.
“It demonstrates that we’ve not yet closed off this high-grade vein area, which sits in the northern end of Mulga Bill containing many of the highest-grade intersections in the project.
“This area has been the focus of recent drilling in our phase three and four RC campaigns this year.
“The new result will be used to fine-tune the 3D vein model and target more drilling in the near future.
“Meanwhile we’re making good progress with the third phase of RC drilling at Ironbark as we attempt to define the extent of mineralisation to the north and south and advance the prospect towards an initial mineral resource estimate.”
Drilling down at Mulga Bill
So far, GBR has received initial assays for 13 of the 19 holes drilled in its phase three program at Mulga Bill, as well as five of the 23 holes in the phase four program.
Other strong results from Mulga Bill include 6 metres at 5.52 g/t, including 4 metres at 7.99 g/t, and 2 metres at 52 g/t.
Assays are pending for the remaining 19 RC holes drilled in phase four, with all results expected by the end of September.
The next phase of drilling is now being planned, including holes into the high-grade vein area as well as additional infill drilling on the less well-defined eastern zone.
Recent drilling in this area is helping to define high-grade areas within the eastern zone, where more than 400 metres of mineralised strike remains poorly tested.
High-grade composite samples from the hole that recorded the 15-metre gold hit have been re-split into one-metre samples for assay. Results are expected in four to five weeks.
Flagpole, Loaded Dog and Ironbark
Great Boulder has also secured assays from all the holes drilled in the recent RC programs at Loaded Dog and the Flagpole prospect.
At Flagpole, one of the RC holes, which intersected 3 metres at 9.39 g/t from 86 metres, appears to have uncovered a separate mineralised structure to that seen in a previous aircore hole, which recorded 3 metres at 8.56 g/t, including 1-metre at 23.78 g/t.
As a result, more RC work is planned at Flagpole, where only five holes of this nature have been completed to date.
Over at Loaded Dog, results from the latest round of RC drilling have failed to bear fruit: no high-grade gold was recorded in the five holes drilled over July.
Moving ahead, Great Boulder will take to the soil with aircore work instead, hoping to refine its geological interpretation before returning to any RC drilling.
Finally, at Ironbark, a phase three drill program is ticking away, with 10 holes completed to date.
First assays are expected in September and once all the data is compiled, GBR will weigh up whether it has enough information to define an inferred mineral resource.
Coming up
Great Boulder has lined up a solid activity schedule that should keep the results flowing over the rest of the September quarter.
An aircore rig will mobilise to site this month to complete infill drilling at Loaded Dog and Mulga Bill and test geochemical anomalies immediately north of Ironbark.
This reconnaissance drilling will be the first in the area since the Ironbark discovery was confirmed by aircore drilling in May 2021.
In the meantime, RC drilling will continue on all prospects in sequence. Metallurgical test-work on drill chips from the Ironbark prospect continues, with results expected in around four weeks.