Great Boulder Resources Ltd (ASX:GBR) has received all remaining assays for the Phase 5 reverse circulation (RC) and aircore drilling programs completed in 2021 at the Side Well Gold Project with highlights of 1-metre at 97.97 g/t and 1-metre at 25.78 g/t.
The company has also received assays for the first 38 holes of a 148-hole aircore program from earlier this year at Mulga Bill and Jones Well prospects.
RC results continue to define high-grade mineralisation in the central area of Mulga Bill, with best intersections of:
- 1-metre at 97.97 g/t gold from 117 metres;
- 25 metres at 1.85 g/t from 84 metres, including 1-metre at 25.78 g/t from 108 metres; and
- 12 metres at 3.23 g/t from 3 metres.
Aircore results
The Phase 5 aircore results have infilled the Loaded Dog area of Mulga Bill with intersections such as 3 metres at 6.69 g/t and have also extended known mineralisation at the nearby Ironbark discovery to 500 metres.
Another strong result from the 2021 aircore drilling was 8 metres at 1.79 g/t from 80 metres, including 4 metres at 3.00 g/t from 80 metres.
Extensional aircore drilling at Ironbark, 1.5 kilometres east of Mulga Bill, has now defined mineralisation over 500 metres of strike and this is open to the south.
Follow-up RC drilling is planned here to test the fresh rock below the significant aircore intersections.
Information on orientations
Great Boulder managing director Andrew Paterson said these results from 2021 removed a significant bottleneck in the exploration process with the new lab already sending results for holes sampled in February.
“The balance of the RC assays at Mulga Bill have provided important information on mineralised orientations in the high-grade zones, and we are starting to see evidence of interacting sub-vertical and flat-dipping structures.
"This observation may be interpreted as an orogenic overprint on an earlier epithermal system which we inferred from the lithogeochemical studies with Dr Scott Halley.
“Infill aircore drilling in the Loaded Dog area of Mulga Bill returned some significant grades up to 3 metres at 6.69 g/t gold, which is very high for aircore drilling in this environment.
"We recently drilled more aircore holes around the high-grade hit in [previous hole] 21SWAC119, which ended with 1-metre at 23.78 g/t gold and we will be aiming to continue to define that zone along strike.
“I am also excited to see that Ironbark now has 500 metres of mineralised footprint, and we may also have made our first gold discovery up at Jones Well.”
Encouraging 2022 results
Initial results have also been received from the recent 148-hole aircore drill program completed in early March 2022.
This program included 25 holes exploring further south on the Mulga Bill corridor and 123 holes testing geochemical anomalies at Jones Well.
Results from the first 19 holes at Jones Well have identified anomalous mineralisation on the first target, with results pending for 106 holes in that area and four follow-up holes at the southern end of Mulga Bill.
Ironbark
Ironbark prospect was discovered in 2021 by auger sampling while first-pass aircore drilling in September confirmed the presence of gold.
Results from aircore drilling in October last year appear to have closed off mineralisation to the north, but the 500-metre-long northeast mineralised zone remains open to the south and results are providing further encouragement.
The next stage of exploration at Ironbark will include drilling a number of RC holes to test mineralisation in fresh rock.
Jones Well
Several areas at Jones Well have disrupted the greenstone stratigraphy, providing ideal dilational conditions for gold mineralisation.
While a small number of RAB holes from the mid-1990s still exist, the area remains largely unexplored.
A first-pass, broad-spaced soil sampling program and subsequent infill soil sampling during 2021 identified several discrete, low-tenor geochemical anomalies at Jones Well.
Assays for 19 of 123 AC holes drilled at Jones Well have been received, which is a big improvement on sample assay turnaround.
The results are very positive and end-of-hole mineralisation is particularly encouraging as it implies potential for primary gold mineralisation in the fresh rock.
Follow-up drilling will test whether these two results are located on a northeast-striking mineralised zone.
"A big year" in 2022
“The Side Well project is progressing simultaneously on several fronts, which is fantastic to see," Paterson said.
"We’re making good progress towards our 100,000-metre drilling target this year which will be a major step towards our goal of reporting a mineral resource estimate on Mulga Bill. It’s really going to be a big year for Great Boulder.”
Looking ahead
Diamond drilling continues to progress at Mulga Bill with the work expected to be completed towards the end of March.
The 3D IP survey is expected to be completed in the coming week, with results and analysis anticipated as soon as the data has been processed.
This survey is designed to define a 3-dimensional model of chargeable zones at Mulga Bill caused by sulphides in the rock mass.
The 3D model will be used to plan additional drill targets testing gold mineralisation associated with these sulphide-rich zones.
- By Duncan Bailey