Drilling at Arizona Mining’s (TSX:AZ) Taylor zinc-lead-silver deposit, 80 km southeast of Tucson, Ariz., is revealing what could become a “world-class asset,” according to the company’s chief operating officer Donald Taylor.
A recent step-out drill hole 400 metres northwest of the carbonate-replacement deposit (CRD) returned 23.1% zinc, 13.5% lead and 207 grams per tonne silver over 7.5 metres, within a 15.1-metre interval of 13.6% zinc, 8% lead, 0.1% copper and 136 grams silver.
The mineralization matches other step-out drill holes in the area, including a 32.6-metre intercept grading 4.6% zinc, 5.5% lead, 0.04% copper and 136 grams silver, drilled 323 metres northeast of the deposit.
“Everything we’ve drilled so far has hit ore-grade intercepts over minable thicknesses, and we’re still trying to find the edges of the deposit,” Taylor tells The Northern Miner from the company’s office branch in Tucson.
Mineralization at Taylor occurs within a package of carbonate rocks underlying a volcanic stratigraphy cap that spans the company’s wholly owned, 71.1 sq. km Hermosa property.
The company first discovered the CRD in 2015, after probing below the volcanic rocks that host Hermosa’s Central manto-style oxide deposit, which has proven and probable reserves of 59.7 million tonnes grading 69 grams silver and 8.3% manganese.
In early 2016, Arizona Mining delivered Taylor’s maiden resource, which stands at 39.4 million inferred tonnes of 4.5% lead, 4.5% zinc, 0.14% copper and 67 grams silver, using a 6% equivalent zinc cut-off.
“It all started with an idea. We believed there was a clear zonation between the oxide deposit at surface and what we perceived could be a sulphide deposit located down-dip,” Taylor says. “We drilled four holes, and then bingo. The rest of the history is still being written.”
The company’s current infill and expansion drill program, totalling 38,000 metres in 28 holes, aims to test the prospective carbonate horizon below its newly acquired Trench patented mining claims, which encompass a 1.2 sq. km area northwest of the deposit.
Taylor says the carbonate rocks absorbed metal-rich fluids off-gassing from a nearby porphyry system like a sponge, and that mineralization likely bled out into the volcanic rocks above.
He adds that the past-producing Trench Camp mine — a lead-silver vein deposit that cross-cuts the volcanic rocks — could indicate what lurks below.
“We know that the prospective carbonate unit extends for 2 km beyond our current resource area, and our plan is to fully test that length by year-end,” he says. “We have very little data in that direction, but there’s an opportunity to hit mineralization all along its length.”
Taylor cites a historical drill hole at the northwestern edge of the target area, which returned intercepts of 1.4 metres of 12.7% lead, 15.6% zinc, 2.7% copper and 49 grams silver at 1.2 km deep, and 37.8 metres of 1% lead, 14.1% zinc, 0.2% copper and 208 grams silver at 1.5 km deep.
The current drill campaign is all part of the company’s larger mandate to deliver a resource update for the deposit by early next year, followed by a preliminary economic assessment.
“We’ll have to draw a line in the sand and get the resource update out, so the plan is to drill as much as possible until then,” he says.