Colomac gold resource now at 2.6M ounces
North of 60 Mining News – June 15, 2018
Last updated 9/25/2020 at 5:27am
Nighthawk Gold Corp. June 13 reported a 24 percent increase in the gold resource for the Colomac gold project at the company's Indin Lake property in Northwest Territories. Incorporating the results from 913 historical holes and 175 holes completed by Nighthawk from 2012 through 2017, Colomac now hosts 50.3 million metric tons of inferred resource averaging 1.62 grams per metric ton (2.61 million ounces) of gold.
Located about 160 kilometers (100 miles) north of Yellowknife, the 899-square-kilometer (222,200 acres) Indin Lake property hosts a number of gold deposits, including zones that extend out from the historical Colomac open-pit mine, which produced 527,908 ounces of gold during the 1990s.
In 2013, the last time a resource was calculated for Colomac, the project hosted 39.8 million metric tons of inferred resource averaging 1.64 g/t (2.1 million oz) gold.
Since the 2013 resource estimate, Nighthawk has drilled 145 holes for 44,600 meters which is captured within this latest resource update.
Roughly 2.55 million oz of this year's gold resource is found at Colomac and Goldcrest, parallel trends of dikes and sills within a larger greenstone belt.
"We are very pleased to see that the consistent strength and continuity of mineralization hosted by the Colomac and Goldcrest sills continues to deliver strong resource growth," said Nighthawk Gold President and CEO Michael Byron. "It is notable that to date, the deposit has only had 141,013 meters of drilling, yet is tracking to exceed 3 million ounces with an abundance of real estate not yet explored."
Zone 1.5, discovered by Nighthawk in 2014, hosts roughly 317,000 ounces of the current inferred resource in 5.3 metric tons of material averaging 1.85 g/t gold.
Highlights from 2017 drilling at Zone 1.5, which is below one historical pit, include: 55.35 meters of 3 g/t gold; 23.7 meters of 4.78 g/t gold; 51.4 meters of 2.46 g/t; 22.7 meters of 6.78 g/t gold; and 34.75 meters of 3.12 g/t gold.
In March, the company kicked off a 25,000-meter drill program that is focused on the delineation of known high-grade gold zones such as Zone 1.5; explore for high-grade gold zones at Colomac; and test select priority gold targets across the vast Indin Lake gold camp.
"In addition to the ongoing exploration at Colomac, we are also drilling several of our regional gold deposits and showings, building on the gold camp's vastly underexplored potential beyond Colomac," said Byron. "The first property we drilled prior to consolidating the camp, the Damoti Lake gold deposit, will be drilled this summer, in preparation for delivering a maiden resource estimate in early 2019."
Damoti Lake, which lies about 28 kilometers (17 miles) south of Colomac, hosts a small but high-grade, near-surface gold deposit.
A resource calculated for Anaconda Gold Corp. in 2005 outlined 40,600 metric tons of measured and indicated resource averaging 26.17 g/t gold; plus 17,800 metric tons of inferred resource averaging 16.38 g/t gold.
Nighthawk completed more than 13,000 meters of drilling at Damoti Lake in 2009 and 2010, which expanded known zones there as well as discovered new ones. The company plans to follow up on drill ready targets at Damoti Lake later this year.
In addition to the expansive drill program slated for this year, Nighthawk plans to carry out metallurgical testing of additional zones along the Colomac and Goldcrest sills. This program will also involve a greater number of tests to continue the evaluations of the deposits' heap leach potential.
"Given that the current resource contains over 50 million tonnes (metric tons) of mineralized material, a number that may only account for less than half of its near surface potential, we believe that assessing a heap leach opportunity for Colomac is not only warranted, but if proven, could drastically change the nature of the opportunity," said Byron.
While heap leaching – a process that involves stacking the ore on a lined pad and using a mildly acidic leaching agent trickled over the ore to dissolve the gold into a solution that is pumped through a facility that recovers the gold – is considered better suited for warmer climates, it is being implemented more commonly in Alaska and northern Canada.
Kinross Gold Corp. is currently having great success with heap leaching at its Fort Knox gold mine in Alaska, and this process is being implemented at Victoria Gold Corp.'s Eagle Gold Mine development project in the Yukon.
Kinross Gold, Osisko Royalties and McEwen Mining are strategic investors in Nighthawk.