Zenith Minerals has released an updated mineral resource estimate for its Develin Creek project, bumping up tonnage by 90 per cent.

The company said its drilling at the site, 80 km north-west of Rockhampton, had verified past results that extended and improved the geological interpretation.

The updated resource for the Sulphide City, Scorpion and Window copper–zinc deposits at Develin Creek stands at 4.9 Mt grading at 1.2 per cent copper, 1.4 per cent zinc, 0.2 g/t gold and 7 g/t silver.

The estimate does not include the massive copper-zinc sulphide mineralisation identified at Snook and other prospects to the south, also within the Develin Creek project.

“I am pleased to report an updated mineral Resource estimate for the Develin Creek project that represents a 90 per cent increase in tonnage and a 30 per cent increase in overall contained metal from the previous 2015 estimate,” Zenith Minerals managing director Michael Clifford said.

“Mineralisation at the main Sulphide City lens remains open to the southwest.

“Multiple additional geological, geochemical and geophysical targets remain to be tested in both proximity to the deposit as well as along strike in the extensive project landholdings.

“There remains much to do on this project and our confidence in further discoveries remains high.”

The latest mineral resource is interpreted and reported at a 0.5 per cent CuEq (copper equivalent) cut-off suitable for open pit assessment.

The difference compared to the 2015 estimate is attributed in part to a lower cut-off grade for reporting as well as the resource extensions from recent Zenith drilling and what the company describes as a more robust interpretation that captures more of the mineralisation.

Zenith has announced plans to demerge its base metals and gold assets, including Queensland’s Develin Creek and Red Mountain projects, into a new company called Mackerel Metals to be listed on ASX.

This would allow the Zenith team to focus on activities that generate battery minerals projects.