Alta Zinc Ltd (ASX:AZI) has honed in on a large-scale exploration target that stands to extend the size and scope of the Gorno Zinc Project in northern Italy.
The conceptual exploration target, which is thought to host between 17.4 million and 22 million tonnes of resource at anywhere from 8.5% to 10.4% zinc, includes 13 areas within AZI’s exploration licence and rubs shoulders with the historical Gorno zinc mine.
With an aim to increase the mineral resource estimate (MRE) at Gorno, Alta has started drill testing at two target areas, with drilling scheduled at three more in the coming months.
Ultimately, Alta hopes the target will support Gorno’s transition to a tier-one zinc asset in the years to come.
Opportunity to broaden scope
Alta Zinc managing director Geraint Harris said: “The development of our exploration target significantly leverages the knowledge synthesised during the last 18 months of exploration drilling and data analysis.
“The fact our significant MRE upgrade is surrounded by evidence of continuing mineralisation gives great confidence that we have an opportunity to add considerable scale to our Gorno Project without the need for any additional permitting, land acquisition or extension of our current exploration licence.
“Gorno has the geologic potential that is typical of world-class Mississippi Valley deposits around the world.
“This exploration target is within close proximity to the existing historical underground development, offering both short-term opportunities to drill test from existing underground development, plus longer-term growth potential once our development footprint is extended during project construction.”
All eyes on exploration upside
Although Gorno’s newfound target is conceptual in nature, it acts as a litmus test for the potential scale of extensional mineralisation within Alta’s exploration licence.
The ASX-lister relied on a suite of geological information from historical drilling and underground development to synthesise the target.
Overall, the area of interest comprises 13 separate but contiguous areas which surround the extensive production stopes and development drives of the Gorno mine.
Areas one through four lie to the west of the western fault in a downfaulted area, area 13 lies to the east of the Pezel Fault and the remaining areas (5 to 12) lie between the two faults.
Specifically, the target is forecast to host anywhere from 17.4 million to 22 million, grading between 8.5% and 10.4% zinc, 1.9% and 2.4% lead, and 19 g/t and 23 g/t silver.
The estimates were prepared in accordance with JORC 2012 stipulations.
Exploration campaign
As it aims to grow the mineral resources at Gorno, Alta has planned drilling activity over several high priority areas within the wider target.
Work has already commenced over areas 10 and 11 while drilling at 7, 8 and 12 is poised to kick off within the next 12 months.
The outcomes of this exploration, as well as the current MRE, will be integrated into a proposed definitive feasibility study, which the company intends to commence in early 2022.
Meanwhile, drilling across the other exploration target areas will continue in parallel with any prospective mine construction, development and production phases as Alta works to realise the full potential of its mineral resource estimate.
Potential beyond new target
In addition to the current exploration target, the ground immediately to the east, termed 'Pezel East', between the Pezel and Grem faults is highly prospective.
At this stage, there is insufficient drilling or definitive historical evidence for this area to be included in the exploration target, but it will be assessed once more evidence is collected.
Further exploration potential also exists in the down-dip extensions south and beyond areas 6 and 9, termed 'Zorzone Deeps', where there are clear observations of mineralisation in development walls and mineralised intersections in nearby diamond drilling.
However, with insufficient exploration data at depth, any estimate of an exploration target must await further exploration efforts.
Continuity of mineralisation is also demonstrated east of the Grem Fault in the stopes of the historical Fortuna workings.
This ground is contained within the mining licence application area but lies outside of the company’s granted EL.
Therefore, a subsequent exploration target for the Fortuna extension areas will be considered once the mining licence is granted.