Alma Metals (ASX: ALM) said the first assays from its 2026 infill drilling at the Briggs copper project in central Queensland had matched its resource model.

The company reported consistent copper mineralisation down the full length of the first three diamond holes, with grades mostly between 0.15 and 0.20 per cent.

Hole 26BRD0039 returned 322 metres at 0.17 per cent copper, including 87 metres at 0.23 per cent, and each hole ended in mineralisation.

Alma said the results showed low variance between predicted and actual grades, and validated its block model and surface soil sampling.

Main image: Drilling at Briggs, courtesy Canterbury Resources

The drilling formed part of a program to infill the Briggs resource to a nominal 80-metre spacing.

The company said this would upgrade Inferred resources to the higher-confidence Indicated category and supply samples for metallurgical testing.

About 2,300 metres had been drilled in seven holes so far, with a further 34 infill holes planned this year and 35 more in 2027.

Related: The Briggs development rollout and spatial location

Four exploration holes were also planned to test copper anomalies in soil west of the current resource, which the company said could expand it.

The infill holes were being drilled largely across the deposit’s north-west to south-east grain, with results reported as downhole lengths.

Alma said the assays supported an interim resource update, a revised scoping study and, ultimately, a pre-feasibility study on the project.

Alma described Briggs as a large, low-grade porphyry deposit, whose resource held two million tonnes of contained copper in the Indicated and Inferred categories.

The project was about 60 kilometres from the deep-water port of Gladstone, near power, rail and gas infrastructure.

Earlier metallurgical work had indicated copper recoveries of about 95 per cent into high-grade concentrates, the company said, with molybdenum and silver credits.

Managing director Frazer Tabeart said the results gave “great confidence that the infill program will ultimately deliver the appropriate update to the MRE”.

Alma managed Briggs and held 51 per cent under a joint venture with Canterbury Resources (ASX: CBY), and was earning up to 70 per cent.

Rio Tinto retained a 1.5 per cent royalty over part of the project.