The Italy-focused company trebled resources in July to 7.79 million tonnes grading 6.8% zinc, 1.8% lead and 32 grams per tonne silver for 528,000t zinc, 140,000t lead and 8.04 million ounces silver using a 1% zinc cut-off.

 

While the overall resource tonnage is unchanged, indicated resources have increased around 18% to 73%, while the oxide component of the mineralisation has reduced by 27% to 730,000t at 6.1% zinc, 1.6% lead and 26 grams per tonne silver for 45,000t zinc, 13,000t lead and 620,000oz silver.

 

The resources are contained within the Pian Bracca, Ponente and Zorzone areas.

 

Alta managing director Geraint Harris said the changes emerged from its ability to enter the existing underground workings and directly map the rocks, while also comparing its own drilling to historical production records.

 

He said the resource review showed the company has increased its knowledge over very specific areas of the resource, including a new interpretation of the oxide wireframes and historical sludge drilling that had helped better understand the overall mineralisation.

 

Gorno is described as host to a number Alpine Type lead-zinc deposits, which are to Mississippi Valley Type deposits.

 

The improved understanding will help feed into ongoing technical studies will produce a further de-risked mining plan.

 

Gorno's mineralisation remains open in all directions outside the resource with numerous step-out targets ready to be drill tested from existing underground development.

 

Recent drilling has intersected new, high-grade mineralisation outside the resource areas, and the company has an exploration target of 17.4-22Mt at 8.5-10.4% zinc, 1.9-2.4% lead and 19-23gpt silver has been estimated for 13 discrete areas either within the extensive underground workings, or adjacent areas.

 

There are priority targets at Pezel East and Zorzone Deeps around the mine, and in the Fortuna workings where there was a historical resource when that mine ceased in the 1980s that require attention.

 

Alta hopes Gorno will emerge as one of Europe's premier zinc-lead-silver mines.

 

The company started the quarter with A$2.3 million cash, and at estimated cash burn rates is likely to require fresh capital in early 2022.

 

Alta shares closed on Friday at 8.2c, valuing the company at $24 million.

 

The stock has traded between 6-13.5c over the past year.