Great Boulder Resources Ltd (ASX:GBR) has enhanced the gold bounty of its Side Well Project near Meekatharra in Western Australia through an updated mineral resource estimate (MRE) that has increased the total resource by 29% to 668,000 ounces at 2.8 g/t gold.
Importantly, 51% of the resources are now in the indicated JORC category, a key factor in enhancing the geological understanding of Side Well and de-risking the project as it moves towards development.
The updated MRE incorporates additions to the resources at the Mulga Bill and Ironbark deposits and there is considerable scope to take the overall Side Well resource well beyond 1 million ounces.
Side Well mineral resources.
“Significant increase”
Great Boulder’s managing director Andrew Paterson said: “This is an important step for Great Boulder, with a significant increase in contained ounces at Mulga Bill and Ironbark as well as the conversion of a large proportion of both deposits from the inferred to indicated JORC category.
"That means both deposits are defined with sufficient confidence to commence economic studies once the current inflationary cycle peaks and we can confidently predict future cost inputs.”
Higher-grade core
Another important factor for future development economics is that the 668,000-ounce resource contains a higher-grade core of 496,000 ounces at 5.3 g/t when reported at a 2 g/t cut-off.
There are 410,000 ounces of this core at Mulga Bill and 85,000 ounces at Ironbark.
Side Well mineral resource summary, November 2023.
As the resources are shallow, having been delineated from ~10 metres to 300 metres at Mulga Bill and from surface to 150 metres at Ironbark, 68% of resource ounces have open pit mining potential.
Resource additions at Mulga Bill include extensions to the high-grade Cervelo lodes and new mineralisation linking the HGV and Central zones, with high-grade results returned from infill drilling also boosting the overall gold grade.
Perspective view of Mulga Bill looking northwest (top) and in long section (bottom) with the west-dipping veins in red and sub-vertical lodes in brown.
About the MRE update
This MRE update was prepared by an independent consultant using geological and mineralisation interpretations prepared by GBR using all available aircore, RC and diamond data.
The updated Side Well MRE incorporates all drilling completed and assayed up to September 30, 2023.
Since the maiden resource estimate, GBR’s exploration team has completed an additional 21,299 metres of RC and diamond drilling and 14,111 metres of aircore drilling.
Shallow, high-grade deposit
“All our infill drilling at Mulga Bill this year has confirmed the geological model we used for the initial resource, which reflects the excellent technical work involved in understanding this exceptional orebody,” Paterson said.
“Side Well sets itself apart as a shallow, high-grade greenfields deposit on the outskirts of an historic, operating gold field, which is almost unprecedented in the junior gold sector.”
“We are now looking forward to commencing the first exploration on new targets within the Ironbark Corridor, starting with Saltbush.
“This is another important step towards our goal of defining the first of what could be several million ounces of gold in resource at Side Well.”
Long section view of the Ironbark lodes and projected drilling intersections.
Further prospects
The company says that the Mulga Bill North prospect is showing potential as a significant northern extension to the existing resource with mineralisation now defined over 700 metres of strike and open in all directions.
Great Boulder’s strategy is to delineate a significant gold camp at Side Well through advancing an extensive exploration prospect pipeline spanning advanced resource to greenfield discovery targets.
The project is strategically located neighbouring multiple resources, mines and processing infrastructure with the closest operating mill located c.25 kilometres southwest by road.
Heritage surveys have been completed within the Ironbark Corridor, with drilling expected to recommence shortly on high-priority targets.
Future work
GBR is awaiting final approvals before commencing initial drill testing on priority targets in the area.
The first target to be drilled will be Saltbush, where rock chip sampling around old workings has returned assays up to 14.85 g/t gold and three RC holes drilled in 1987 included an intersection of 3 metres at 7.42 g/t from 14 metres.
Targets within the Ironbark corridor have potential to deliver significant resource growth over the next 12 months, and as such this is an important step towards Great Boulder’s 1-million-ounce target at Side Well.
Exploration will begin with drilling on 200-metre-spaced lines to cover targets as efficiently as possible using aircore drilling, followed by infill and RC drilling on new discoveries.