Special Report

Thu, 29 Aug 2024 8:30AM


Alma Metals copper-bearing porphyry outcrop at Briggs.
  • Infill drilling has returned the best copper intersection to date at Briggs
  • Enhanced copper grades include a 276m intersection at 0.45% copper from surface
  • Further assay results are expected in 4-6 weeks

 

Special Report: Initial assay results from infill drilling at Alma Metals’ Briggs copper project has highlighted significantly enhanced copper grades close to surface.

 

Alma Metals’ (ASX:ALM) flagship Briggs porphyry copper deposit has an inferred resource of 415Mt at 0.25% copper and 31 parts per million molybdenum, and is just 60km from Queensland’s deep-water port of Gladstone.

Core drilling kicked off in June, targeting an upgrade in resource confidence to the indicated category, which is deemed sufficient to support the initiation of a scoping study later this year.

Drilling is focused on testing and infill drilling the southwest part of the large geochemical anomaly at the Briggs Central inferred resource.

The explorer also recently completed a strategic tenement expansion, finalising the acquisition of two further exploration permits previously owned by Tropex Metals.

Stand out drilling results

Initial results have delivered the best drill intersection to date at Briggs, hitting 276m at 0.46% copper as well as 24ppm molybdenum from surface.

This included 49m at 1.01% copper and 17ppm molybdenum from 3m.

ALM says hole 24BRD0026 was testing for near-surface, higher-grade copper mineralisation as part of an infill drilling program to identify potential areas for higher-grade starter pit operations.

Drilling is also targeting an upgrade in resource confidence sufficient to support the initiation of a scoping study later this year.

Under the JV agreement with Canterbury Resources, completion of the current drilling program will meet the expenditure requirements to complete Stage 2 of the earn-in, and for ALM’s interest to increase to 51%.

Wide zone starting at surface earmarked for follow-up

“These results demonstrate that significantly higher copper grades are present within the Briggs resource and give us confidence in our strategy to define a higher overall resource grade,” ALM managing director Frazer Tabeart said.

“The wide zone of high-grade starting at surface is particularly important and will be a focus for follow-up drilling.

“While this is part of a longer campaign, it sets a strong foundation for the continued exploration and development of the Briggs copper project.”

Strongly silicified and altered Briggs granodiorite with micro-UST textures and extensive copper sulphides. Pic: Alma Metals

What happens next?

ALM says the copper grades are particularly strong in the top 52m of the first hole (24BRD0026) with results indicating the entire hole was mineralised from surface.

Copper mineralisation is present in the form of copper oxides and malachite from surface to 29.25m and in the form of chalcopyrite and secondary chalcocite between 29.25m and 39m downhole depth before passing into chalcopyrite below 39m down-hole depth in strongly silicified and mineralised granodiorite.

The economic significance of oxide copper mineralisation will be evaluated as further drilling is undertaken.

Assays for the remaining holes on this section are expected in 4-6 weeks’ time, and drilling is expected to continue into next quarter.

Samples from the drilling program will also provide material for metallurgical test work, which will contribute to the scoping study for Briggs.