Nevsun makes VMS discovery near Bisha
Kip Keen | 19 June 2015 11:24
HALIFAX – Nevsun Resources reported a notable volcanogenic massive sulphide discovery Thursday not far from its operating Bisha copper-zinc-gold mine in Eritrea. Calling it Asheli, Nevsun drilled as much as 23 metres @ 2.39% copper and 4.5% zinc, 0.45 g/t gold and 37 g/t silver with a higher grade zone therein. So far Nevsun drilling reveals massive sulphides in a few intercepts over 100 metre strike and 100 metres vertically in a steeply dipping VMS deposit.
How significant the discovery is will remain unclear until Nevsun finishes and reports results from the rest of the dozen-plus drillholes it has drilled over roughly 1 kilometre of strike at the target. The miner – which began mining Bisha in 2011 – has taken a fairly aggressive approach to exploring Asheli. As it notes in a statement Thursday, it made 100-metre step-outs, which should begin to give a rough picture of the immediate size of the Asheli sulphide zone quite quickly.
Even if Asheli proves small, it will nonetheless wet Nevsun's appetite to focus on exploration in the region, 20 kilometres southwest of Bisha. VMS deposits frequently form in clusters and pods. So where there's one, it's usually a good idea to look for others. Indeed, Nevsun has long contended that Bisha and environs, poorly explored, has a good chance of showing more VMS deposits. In that sense, Asheli lends credence to Nevsun's approach and supports the possibility it may find more ore near its operating Bisha mine.
Stefan Ioannou, a Haywood Securities analyst, framed it that way. These are "definitely some very good results…especially given the new discovery's proximity to Bisha," he noted in an email.
The Asheli discovery is also another case of a just-missed deposit by a previous operator on the project. Near surface portions of Asheli had been drilled before Nevsun's tenure, testing for a gold in an oxidized surface anomaly. No deposit was outlined, but that program showed minor chalcopyrite (a copper sulphide) and sphalerite (a zinc sulphide) in stringers. This attracted Nevsun to map the area in greater detail, which showed indications of a VMS deposit. As Nevsun put it in a statement Thursday, "This work defined a 700-metre long zone of highly sericite and chlorite altered felsic volcanic stratigraphy associated with gossan zones enhancing the probability that a VMS deposit was likely to be found in the area".
That led Nevsun to drill a little deeper beneath the near-surface holes, which were duds from the point of view of economic mineralization but not geological information. Just 100 metres below these old holes, Nevsun hit Asheli's massive sulphides.