The mining newspaper for Alaska and Canada's North
The mining newspaper for Alaska and Canada's North
North of 60 Mining News – October 12, 2018
Drilled in early August, this hole cut three copper-rich zones about 175 meters northeast of the resource boundary at Trilogy Metals' Bornite project in Northwest Alaska.
Trilogy Metals is having a feasibility study completed for the world-class Arctic Mine project in the mountains about 16 miles beyond the Bornite Camp.
Trilogy Metals Inc. Oct. 9 reported high-grade copper and cobalt assay results from four holes drilled outside of the resource area at the Bornite project, part of the company's Upper Kobuk Mineral Projects in the Ambler Mining District of Northwest Alaska.
According to a 2016 calculation, the open-pit deposit at Bornite contains 40.5 million metric tons of indicated resource averaging 1.02 percent (913 million lb) copper; and 84.1 million metric tons of inferred resource averaging 0.95 percent (1.77 billion lb) copper. The underground portion hosts 57.8 million metric tons of inferred resource averaging 2.89 percent (3.68 billion lb) copper.
The deposit also hosts 182.4 million metric tons of inferred resource averaging 0.019 percent (77 million lb) cobalt, according to a resource calculated for the battery metal in June.
Last year, Australia-based South32 Ltd. funded a US$10 million drill program that demonstrates the underground portion of Bornite covers at least a 1,500- by 2,500-meter area north of the resource.
Eight of the 12 holes completed this year were targeted to infill the 300- to 400-meter spaced holes drilled in 2017, with the goal of bringing a portion of this expansion area into the Bornite resource.
All four of the latest drill results are from this northern expansion drilling.
• RC18-243 drilled about 175 meters north of the Bornite underground resource boundary, cut two meters averaging 2.23 percent copper.
• RC18-244, drilled about 175 meters further north, cut 20.4 meters averaging 0.83 percent copper.
• RC18-246 cut three mineralized intervals about 175 meters northeast of the resource boundary: 19.6 meters averaging 2.06 percent copper; 6.1 meters averaging 2.36 percent copper; and 7.6 meters averaging 1.04 percent copper.
• RC18-247 cut two mineralized intervals about 380 meters east of RC18-243: 20.1 meters averaging 4.55 percent copper, including 16.4 meters grading 5.34 percent copper and 0.21 percent cobalt, and 33.4 meters averaging 0.82 percent copper. The 20.1-meter intercept was reported by Trilogy in August.
"We continue to see narrow zones of high-grade copper and cobalt mineralization overlain by broader zones of lower grade mineralization at Bornite," said Trilogy Metals President and CEO Rick Van Nieuwenhuyse. "The continuity of the mineralized envelop continues to impress."
South32, which has an option to acquire a 50 percent interest in the Upper Kobuk Mineral Projects for US$150 million, agreed to invest US$10 million annually on exploration over the three-year option period.
This year, the Australian miner agreed to up its annual investment to US$10.8 million, which allowed the companies to increase the 2018 program from about 8,000 meters to 10,123 meters. The additional funding reduces South32's 2019 commitment to US$9.2 million.
Assay results from an additional four holes drilled in the northern expansion area at Bornite and four infill holes drilled inside the resource area are pending.
"After all results are in, we expect to complete an updated resource estimate at Bornite in the first half of next year," said Van Nieuwenhuyse.
In addition to the drilling at Bornite, Trilogy invested US$6.7 million this year on gathering the information for a feasibility study for Arctic, a volcanogenic massive sulfide deposit about 16 miles to the north.
A prefeasibility study published earlier this year details plans for an open-pit operation at Arctic expected to produce 1.9 billion pounds of copper, 2.4 billion lb of zinc, 405 million lb of lead, 367,531 ounces of gold and 40.2 million oz of silver over an initial 12-year mine life.
To provide the additional information needed to elevate Arctic to the feasibility level, the company completed 24 holes (592 meters) this year to gather geotechnical and hydrological information at the proposed tailings dam, waste rock facility and grinding mill locations.
Trilogy also gathering environmental data in preparation of its plan to submit a mine permit application for Arctic in the first half of 2019.
–SHANE LASLEY
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