With silver prices rising, Golden Deeps has managed to eke out a maiden silver equivalent resource at its Khusib Springs silver-copper project in Namibia by recalculating existing drill holes using silver as the lead metal.
Khusib Springs was thought to be principally a copper project, however the recent ramp-up in the silver price led Golden Deeps to run the rule over the project again – this time promoting silver and not necessarily copper as the key metal.
The recalculation by South African-based consultant, Shango Solutions, resulted in an initial maiden resource at the project of 492,000 tonnes grading 116g/t silver equivalent for 1.9 million ounces of silver equivalent metal in the indicated and inferred categories.
Of the total resource, 900,000 ounces running at 353g/t silver equivalent are classified as indicated while the balance of 1 million ounces going 73g/t silver equivalent are in the inferred resource class.
The project is predicated on a historic mine that produced 300,000 tonnes of ore running at an uber-impressive 584 grams per tonne (g/t) silver and 10 per cent copper with zinc, lead, antimony and germanium credits. With the new resource model, the company aims to revive exploration efforts and tap into previously unmined zones at the site.
As part of the modelling, the company took the opportunity of converting previous drill results to a silver equivalent calculation from a 2022 exploration campaign.
The best of the newly calculated results was a 90m intersection drilled in 2022 grading 83g/t silver equivalent from a depth of 389m. That drill hit includes 69m running at 100g/t silver equivalent and a 28-metre section going 156g/t silver equivalent. Another shallower result threw up 26.6m going at 43g/t silver including 2m grading 269g/t from 259m.
Golden Deeps chief executive officer Jon Dugdale said: “Examination of the Company’s recent drill-core indicates that the mineralisation is associated with evenly distributed blebs and clots of the high-silver bearing sulphide mineral Tennantite, over an approximate true width thickness of over 90m. Initial Mineral Resource modelling has shown potential for this thick zone of silver-copper mineralisation to extend to the west of the company’s previous drilling, where the zone may re-develop into a massive sulphide zone, similar to the deposit previously mined.”
Historical drilling beyond the fault and at greater depths than 400m revealed further silver-copper mineralisation, suggesting potential for an offset deposit towards the southwest and deeper levels.
According to work done by Shango for Golden Deeps in 2020, there is also potential for extra open-pitable material above the old workings, while work on the existing underground mine has highlighted the prospect of extracting some high-grade material around previous stoping.
Now that the spotlight has been pointed towards maximising the value of the silver mineralisation from the new zones at depth and to the west, the company will shortly plunge the drill bit into the potential extension of the orebody.
Additionally, with the portal and haul roads from earlier mining still intact, it now plans to deepen the existing old decline to help get access to the newly identified mineral-rich areas once drilling has been completed.
Management believes that Khusib Springs has similar geology to the well-known Tsumeb deposit, 40 km to the northwest because the silver-rich minerals – mostly tennantite – are localised but in a high-grade pipe-like body that plunges steeply within brecciated rocks.
With a massive resource of 27 million tonnes grading 4.3 per cent copper, 10 per cent lead, 3.5 per cent zinc and 95g/t silver Tsumeb is one of Namibia’s best-known mines. It was first discovered in 1907 and is notable for not only huge quantities of copper, lead, zinc and silver but also no less than 240 different other minerals of which 55 have never been registered as occurring elsewhere. The mine only closed in 1986 due to an economic downturn in commodity prices.
The new Khusib Springs silver equivalent resource adds to the previously announced numbers for Golden Deeps’ nearby 100 per cent owned Nosib and Abenab deposits which contain a mix of vanadium, copper, lead, zinc and silver. At Nosib, the total resource now stands at 707,600 tonnes running at 1.06 per cent copper equivalent while at the bigger Abenab prospect, its resource now stands at 2.3 million tonnes grading 1.11 per cent vanadium equivalent.
The newly remodelled mineral resource at Khusib Springs appears to reinforce its appeal in light of the rising silver price. Added to its promising Nosib and Abenab copper-vanadium deposits, Golden Deeps’ is on a pathway to building the foundations of a formidable resource base for possible future production.