Great Boulder Resources records ‘stunning high-grade’ gold intersections at Mulga Bill prospect

Great Boulder Resources (ASX:GBR) has recorded 2 ‘very high-grade’ coarse visible gold  intersections in a reverse circulation (RC) drillhole completed at the Mulga Bill prospect, located within the Side Well Gold Project in Western Australia.

The company says hole 23MBRC006A intersected 1m @ 3,451g/t Au from 114m, and 1m @ 2,379g/t Au from 158m.

The 2 visible gold intersections were submitted for analysis at ALS in Perth using the photon assay technique. This process is a non-destructive method using a coarse-crushed sample size of about 500g.

A second sample from each interval was also taken at the rig by scoping material from the 1m pile and submitted for photon assay. Great Boulder reports the large variability between the standard sample and ‘A’ sample from each interval is not unusual when sampling and assaying coarse gold particles.

The lower intersection from 158m was in an area of ‘significant’ groundwater where samples were wet and sample recovery deteriorated. As a result, the ‘extremely high-grade’ and low repeatability of assays from this zone may be caused by a combination of abundant fine gold, and possible upgrading of the sample material due to water washing away friable unmineralised material from the sample mass.

The company says this effect can be quantified using diamond core.

Great Boulder’s share price had risen 8.247% as of 9.45am AWST. 

Commenting on the results, Great Boulder Resources Managing Director Andrew Paterson says: “This stunning result is by far the highest gold assay we have yet seen at Mulga Bill. We have now drilled more than 275 RC holes within the Side Well project area.

This is the first time we’ve seen coarse visible gold and the first time we’ve seen assays over 1,000g/t. Results like this are extremely unusual at Mulga Bill, and we will need to do tight-spaced infill drilling around this area to quantify the extent and grade of this high-grade zone.

“This is the first time we’ve seen coarse visible gold and the first time we’ve seen assays over 1,000g/t”

I need to remind investors that results like these are not representative of the broader mineralisation style, as evidenced by the fact that this is the first time we have seen visible gold in drilling, and we will be able to place more context around these 2 intersections once we have assays back for the rest of the hole and the remainder of the program.

We submitted the 2 intervals containing visible gold for photon assay at ALS for a quick turnaround. The photon process works well for high-grade, and the 500g sample size helps overcome problems caused by the nuggety gold distribution.”

Great Boulder reports hole 23MBRC006A was designed to infill an area of the Mulga Bill mineral resource in the Central area, south of the HGV area where previous ‘bonanza’ grade intersections have occurred.

The upper intersections correspond to a west-dipping ‘high-grade’ vein which includes a previous intersection of 10m @ 28.74g/t Au from 96m (22MBRC067). Both locations show evidence of groundwater interacting with the mineralised structure at this depth and is therefore likely to be a component of supergene upgrade to the gold content.

While the lower visible gold intersection was originally thought to correspond to thinner subvertical lode it may also be an intersection within a west-dipping vein. The company says further drilling is required to confirm this interpretation.

Great Boulder reports hole 23MBRC006 which was drilled immediately east of 23MBRC006A has not been assayed yet. This hole was inadvertently set-up at the wrong dip angle, and as a result it was re-drilled as 23MBRC006A. This also explains why the 2-hole traces are in such close proximity.

The remaining samples from 23MBRC006A are now being analysed by fire assay. Once this is complete, the company will provide full details of all ‘significant’ intersections including any mineralisation that may be present on either side of these 2 visible gold occurrences.

Great Boulder reports RC drilling is continuing and notes it will provide further information including gold assays as soon as the data is available.

The company also says an 11,000m aircore drilling program is underway testing a range of areas along the 6km-long Mulga Bill corridor including Flagpole, Loaded Dog, and Mulga Bill North.

Great Boulder Resources is a mineral exploration company with ‘high-quality’ gold and base metal projects in Western Australia. These projects include the Side Well, Whiteheads, and Wellington projects.

Images: Great Boulder Resources Ltd
Written By Harry Mulholland
Hailing from the Central Coast region of NSW, Harry is a passionate journalist with a background in print, radio and ESG news. When not bashing away on his keyboard, he can be found brewing a coffee or playing with his dog.