VANCOUVER — EnGold Mines (TSXV: EGM) has mobilized another drill rig onto its Lac La Hache polymetallic property in central B.C., following the discovery of a new copper-gold-silver skarn zone in recent drilling.
The company intercepted 26.6 metres of 1.76% copper, 0.27 gram gold per tonne, 10.3 grams silver per tonne and 35.8% iron at 337 metres depth, in a hole designed to test a poorly constrained, 1 km by 1.4 km wide gravity anomaly.
The Feb. 22 announcement triggered shares of the company to almost double to 40¢ at press time.
The hole was a diversion from the company’s current 6,200-metre drill program, which was intended to target the extensions of a gold-bearing structure at the project’s Aurizon South zone (see ‘EnGold explores for high-grade gold at Lac La Hache,’ T.N.M. Dec 26, 2016 – Jan. 1, 2017.)
EnGold president and CEO David Brett tells The Northern Miner during a phone interview that the gravity anomaly could reflect the presence of skarn mineralization similarly seen at the projects Spout deposit, 1.8 km northwest.
The deposit contains a resource of 7.6 million indicated tonnes of 11.4% magnetite and 0.3% copper, and 15.8 million inferred tonnes of 8.3% magnetite and 0.2% copper.
“It was an itch we just had to scratch … so I agreed to add another hole to the current program, and sure enough, we hit this amazing looking core,” Brett says. “Aurizon South is absolutely the most compelling target on the property, but this discovery has changed that. We now have a dual focus.”
The company has begun drilling extensions of the new zone, and has plans to complete a more detailed gravity survey, which will guide future drilling.
While Brett wouldn’t comment on further details of the program, he expects it’ll be “aggressive.”
“The resource calculation at Spout rendered the deposit quite unappealing as a focus … but we see significant size potential at this new zone compared to the Spout deposit,” he says. “We have a fairly large anomaly, and if we step out from where we are, we could potentially build tonnes much faster than we can at Spout.”
But the size of the anomaly doesn’t necessarily reflect the size of a potential ore body, according to Rob Shives, EnGold’s vice-president of exploration.
“The gravity survey is very poorly constrained by sparse data. We have one line of data and that defines the size of the anomaly,” he explains. “So we are careful to not suggest an ore body of these dimensions, but what we do have suggests it could be quite extensive.”
The gravity method in geophysics aims to calculate the density of rocks, whereby the highest gravity values equate to the rocks with the most density, and vice-versa.
Shives says the company first conducted the survey in 2015, as “proof of concept” that skarn-style mineralization on the property — which occurs with dense magnetite and focused along a stratigraphic contact — lights up as a gravity high in the data.
He adds that magnetic geophysical surveys — which measures the magnetism of rocks beneath the surface — isn’t as useful, as the rocks magnetic response falls off at depth.
“The skarn mineralization we’re seeing in this new zone is lying within the same volcaniclastic unit as the Spout deposit, but we’ve never seen this uniformity of grade,” he says. “It’s got a sense of continuity that we don’t have at Spout, which is a lot more spotty and difficult to follow.”