Great Boulder Resources Ltd (ASX:GBR) has been busy with reverse circulation (RC) and aircore drilling for gold proving successful at Mulga Bill deposit within the Side Well Gold Project near Meekatharra in Western Australia.
RC drilling at Mulga Bill North has identified broad zones of gold mineralisation up to 1.25 kilometres north of the currently defined 518,000-ounce Mulga Bill mineral resource.
Gold mineralisation outside resouce
One drill hole in particular, 23MBRC022, on the northernmost line of RC drilling, intersected 20 metres at 1.06 g/t gold from 107 metres, including 3 metres at 3.26 g/t from 123 metres.
Highlights from recent drilling include:
- 5 metres at 6.80 g/t gold from 146 metres in 23IBRC012 at Ironbark;
- 4 metres at 15.41 g/t from 230 metres in 23MBRC031 at Mulga Bill;
- 8 metres at 2.38 g/t from 172 metres in 23MBRC030, including 4 metres at 4.65 g/t from 172 metres at Mulga Bill; and
- 4 metres at 3.48 g/t gold from 63 metres in 23MBRC017 at Mulga Bill North.
Assays are still on their way for six holes at the new Cervelo target east of Mulga Bill, which were defined by recent aircore drilling that yielded broad shallow gold intersections:
- 16 metres at 1.66 g/t gold from 52 metres, including 8 metres at 2.78 g/t from 56 metres in 23SWAC066; and
- 12 metres at 1.10 g/t from 101 metres, including 2 metres at 3.50 g/t from 106 metres in 23SWAC056.
Great Boulder managing director Andrew Paterson said: “Our phase two RC program included holes at Ironbark, Mulga Bill North, Mulga Bill, Flagpole and the eastern target at Mulga Bill which we have named Cervelo. The name is taken from a bicycle theme, after Mulga Bill’s bicycle.
Limited exploration north of Mulga Bill
“We’ve always known the gold mineralisation at Mulga Bill remained open to the north, but to date there has been very limited drilling in that area.
"These new results at Mulga Bill North highlight the potential more than 1 kilometre north of the current resource.
“We are waiting on assays for the final six RC holes from this program. We now have a diamond drill rig on site drilling six holes at Ironbark and Mulga Bill for structural information. Drilling should take three to four weeks, after which we’re planning further aircore and RC programs.”
Assay results have now been received for the first 29 RC holes completed in the second phase of 2023 RC drilling at Side Well.
The company has also received assays for the final 19 holes drilled during the aircore program completed in April. The phase two RC drilling program comprised a total of 35 holes for 6,134 metres.
This program comprised nine holes at Ironbark, seven holes at Flagpole, seven holes at Mulga Bill, six holes at Mulga Bill North and six holes at Cervelo.
Better results include:
- 5 metres at 6.80 g/t gold from 146 metres in 23IBRC012 at Ironbark;
- 4 metres at 15.41 g/t from 230 metres, including 1-metre at 53.90 g/t gold from 230 metres, in 23MBRC031 at Mulga Bill; and
- 6 metres at 1.65 g/t from 147 metres, including 3 metres at 2.72 g/t from 149 metres, in 23MBRC019 at Mulga Bill North, roughly 1.1 kilometres north of the current resource.
Of the six holes drilled at Mulga Bill North, several holes intersected broad zones of anomalous gold mineralisation associated with the Mulga Bill pathfinder elements bismuth, silver and, in some cases, copper.
Particularly noteworthy are the levels of bismuth, grading up to 113.5 parts per million (ppm) – for context a significant bismuth anomaly in Archaean rocks is 1 ppm or more.