Final assays from Great Boulder’s 2021 drill campaign continues to highlight the prospectivity of its Mulga Bill prospect with further high-grade gold hits.

Reverse circulation drilling returning high-grade hits of up to 1m at 97.97 grams per tonne (g/t) gold from a depth of 117m (21MBRC076) in the central area of Mulga Bill while aircore drilling has infilled the Loaded Dog area of the prospect with intersections such as 3m at 6.69g/t gold in 21SWAC147.

Aircore drilling has also extended the strike of known mineralisation at the nearby Ironbark discovery to 500m.

Great Boulder Resources (ASX:GBR) added that initial results from its recent 148-hole AC drill program completed earlier this month has resulted in the identification of anomalous mineralisation at the Jones Well prospect.

“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,” managing director Andrew Paterson said.

“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.”

Great Boulder Resources
Recent reverse circulation and aircore drilling results on the Mulga Bill trend. Pic: Supplied

He also noted that the grades returned from infill drilling at Loaded Dog were very high for AC drilling in this environment.

“We recently drilled more AC holes around the high-grade hit in 21SWAC119, which ended with 1m at 23.78g/t gold, and we will be aiming to continue to define that zone along strike,” Paterson added.

“I am also excited to see that Ironbark now has 500m of mineralised footprint, and we may also have made our first gold discovery up at Jones Well.

“The Side Well project is progressing simultaneously on several fronts, which is fantastic to see. We’re making good progress towards our 100,000m drilling target this year which will be a major step towards our goal of reporting a mineral resource estimate on Mulga Bill.”

Side Well prospects

Ironbark – located southeast of Mulga Bill – was discovered by auger sampling in 2021 with first pass AC drilling intersecting anomalous gold including 8m at 2.39g/t gold in hole 21SWAC101.

While results from AC drilling completed in October appears to have closed off mineralisation to the north, the 500m long north-northeast trending mineralisation remains open to the south with results such as 3m at 1.21g/t gold providing further encouragement.

The next stage of exploration at Ironbark will include drilling a number of RC holes to test mineralisation in fresh rock below these AC hits.

Jones Well encompasses the northern third of the Side Well project and includes several areas where cross-cutting structures and small igneous intrusions have disrupted the greenstone stratigraphy, providing ideal dilational conditions for gold mineralisation.

Great Boulder noted that while a small number of rotary air blast holes were drilled at Jones Well during the mid-1990s, 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 while assays from the AC drilling completed earlier this year has returned positive results.

End of hole mineralisation noted in several holes is particularly encouraging as it implies potential for primary gold mineralisation in the fresh rock with the company planning follow-up drilling to determine whether the results are located on a northeast-striking mineralised zone.

Other activity

The company is continuing diamond drilling at Mulga Bill with completion expected towards the end of March and will be followed by RC drilling.

Great Boulder also expects to complete a 3D induced polarisation survey in the coming week.

This survey was designed to define a 3-dimensional model of chargeable zones at Mulga Bill caused by sulphides in the rock mass that will be used to plan additional drill targets testing gold mineralisation associated with these sulphide-rich zones, both at depth and along strike.




This article was developed in collaboration with Great Boulder Resources, a Stockhead advertiser at the time of publishing.


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