ASX-listed Horizon Minerals has racked up a pile of high-grade gold hits from infill and extensional drilling at its recently acquired historical Kalpini project about 65km north-east of Kalgoorlie and 50km north-east of its flagship Boorara project in Western Australia. The company’s 6,000m-plus program returned better intersections of 12m grading 5.57 grams per tonne gold from 203m including 2m at 12.92 g/t from 211m and 5m going at 10.21 g/t from 70m including 1m at 28.83 g/t from 72m.
Other stand-out intercepts were 7m at 6.01 g/t from 91m including 1m at 22.04 g/t from 93m, 1m at 41.53 g/t from 195m, 6m at 4.45 g/t from 90m including 1m at 10.24 g/t from 92m, and 1.5m at 20.74 g/t from 99.5m.
Perth-based Horizon purchased Kalpini, which came with a remnant gold resource of more than 200,000 ounces, from private outfit NBT Metals for $2.75 million in cash late last year.
The project takes in the Camelia, Gambia and Atlas deposits on a granted mining lease.
Horizon is looking at Kalpini as one of the core satellite feeder deposits within trucking distance of its proposed Boorara processing and mining operation.
Stage one contract mining of the Gambia open pit at Kalpini was completed in 2019.
Third-party toll milling culminated in gold production of 38,800 ounces from the treatment of 485,000 tonnes of Gambia ore at a reconciled head grade averaging 2.62 grams per tonne gold and an average gold recovery of 95.1 per cent.
A JORC 2004 mineral resource statement for Kalpini of 4.61 million tonnes at an average grade of 1.7 g/t for 255,600 ounces of contained gold – before mine reserves depletion – was put out by KalNorth Gold Mines, which sold the project to NBT about four years ago.
Horizon Minerals Managing Director Jon Price said: “The first drilling program we have completed has delivered excellent results confirming the potential for further open-pit stages and significant upside at depth for potential underground development. We now look forward to completing the updated mineral resource estimate and advancing the project as part of the consolidated feasibility study.”
Horizon punched out 49 reverse circulation drill holes for an aggregate coverage of 5,677m and three diamond holes totalling 346m to a maximum depth of 240m aimed at infilling and validating historical drilling for improved geological confidence and probing for extensions.
Kalpini is situated in the Kurnalpi domain of the Norseman-Wiluna greenstone belt in the Yilgarn Craton.
The region is characterised by a series of north-north-west-trending interconnected greenstone belts that have been intruded by granitoid batholiths.
Horizon says based on assay results and observations of drill core, the more common type of primary ore identified is strongly bleached, typified by strong silicification and often accompanied by quartz veining with sulphides abundant.
The drilling program at Kalpini, designed to upgrade the resource to JORC 2012 status and convert a portion to indicated category, forms part of the company’s 50,000m campaign this year targeting high-priority resource definition and exciting prospects across its 1,100-square-kilometre portfolio of landholdings.
A “consolidated” feasibility study on the proposed Boorara project development was well underway and Kalpini was one of about half a dozen main satellite deposits being evaluated to underpin an initial five-to-seven-year production profile.
Horizon’s new drilling data is now being incorporated into the Kalpini geological model that will pave the way for an updated mineral resource estimate, which is expected to be released in the December quarter this year.
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By Matt Birney
