Aquila Resources Inc. on Feb. 7 announced an updated resource estimate for its polymetallic Back Forty deposit in Michigan, which incorporates results from an additional 22 diamond drillholes completed in 2015 through 2017 as well as updated net smelter return calculations.
The company highlighted a 10% increase in measured and indicated tonnage, as compared to the 2013 estimate, as well as a 12% increase in contained zinc and a 4% increase in contained gold.
Back Forty hosts measured and indicated resources totaling 16.6 million tonnes grading 1.92 g/t of gold, 24.7 g/t of silver, 3.13% zinc, 0.32% copper and 0.26% lead for 1 million ounces of gold, 13.2 million ounces of silver, 1.15 billion pounds of zinc, 116.9 million pounds of copper and 94.9 million pounds of lead.
Inferred resources are estimated at 1.1 million tonnes grading 3.42 g/t of gold, 43.2 g/t of silver, 1.03% zinc, 0.35% copper and 0.44% lead for 124,000 ounces of gold, 1.6 million ounces of silver, 25.7 million pounds of zinc, 8.7 million pounds of copper and 11 million pounds of lead.
The estimate uses data from 741 boreholes totaling 128,670 meters of drilling as well as net smelter return cutoffs of US$21/tonne for floatable open pit material, US$22/t for leachable open pit material and US$70/t for underground material.
"This estimate will form the basis for a feasibility study on Back Forty that is in its final stages," Aquila CEO Barry Hildred said. "In the coming months, we will also announce details of an exploration drilling program at Back Forty that will seek to further define the underground potential of the deposit, where mineralization remains open at depth."
