Mining News: Drilling extends high-grade Bornite

Trilogy Metals Inc. Sep. 18 reported high-grade copper results from this summer's exploration drill program at the Bornite project, part of the Company's Upper Kobuk Mineral Projects in the Ambler mining district of Northwest Alaska. This 10,000-meter program is focused on expanding upon the more than 6 billion pounds of copper Trilogy has outlined at Bornite. Roughly 2.7 billion lb of this copper is encompassed in an open-pit resource averaging roughly 1 percent copper. The remaining roughly 3.7 billion lb is located in a deeper underground resource that averages about 2.9 percent copper. It is this higher grade underground portion of Bornite that is being targeted this year. In 2013, the last year Trilogy had drills turning at Bornite, five holes cut rich copper zones along a 1,000-meter wide front to the north. Hole RC13-0220, the most northeasterly these holes, cut two high-grade intervals from 809.1 meters (at a 0.5 percent cut-off) – 45.6 meters of 1.07 percent copper; and 80.4 meters of 1.89 percent copper. RC13-0224, drilled about 800 meters west of hole 220, cut two high-grade intervals from a depth of 513.3 meters along this northern front – 229.4 meters of 1.73 percent copper; and 6.6 meters of 7.7 percent copper. The first three holes drilled this year cut thick and continuous intervals of copper mineralization up to 300 meters beyond the 2013 drilling. "The initial three step-out holes at Bornite demonstrate that high grade copper mineralization continues to the north and east of previously drilled resources,” said Trilogy Metals President and CEO Rick Van Nieuwenhuyse.

RC17-0234, the first hole of the 2017 program, cut three high-grade copper intervals roughly 250 meters north of RC13-0220 – 21 meters of 1.29 percent copper; 26.8 meters of 1.44 percent copper; and 36 meters of 0.72 percent copper. The top of the Bornite mineralization in hole 234 was reached at a drill depth of 935.3 meters. RC17-235W, drilled about 250 meters west of hole 220, cut two zones of copper from a depth of 661.8 meters – 6.1 meters of 0.69 percent copper; and 26.9 meters of 0.94 percent copper. RC17-0234, drilled 300 meters north of hole 224, cut two high-grade copper intervals from a depth of 720.8 meters – 27.1 meters of 0.8 percent copper; and 89.3 meters of 1.13 percent copper. All reported intercepts are at a 0.5 percent cut-off grade. “Our drill program is demonstrating that the Bornite mineralized system remains strong and shows no signs of letting up as we continue to drill on trend to the north and east,” said Van Nieuwenhuyse. “In addition, we are starting to see new structural trends and controls on the axis of high-grade mineralization along a northwest vector. A recently completed detailed gravity survey is showing some very promising results and we will be integrating that information into our future targeting.”

Trilogy also reported significant amounts of cobalt are also showing up in the assays, particularly in the higher grade copper zones. Van Nieuwenhuyse said the cobalt is “occurring as the mineral carrollite and associated with one or more stages of pyrite – particularly in the higher grade copper zones with bornite and chalcocite.” More geochemical and metallurgical work is planned for the cobalt.

Trilogy is executing this US$10 million program at Bornite, which has been funded by South32 Ltd. as part of that company’s option to earn 50 percent ownership of UKMP.

–SHANE LASLEY