Advancing Arctic and the Ambler District
Mining Explorers 2022 - January 19, 2023
Last updated 1/18/2023 at 8:54am
Ambler Metals LLC, a joint venture company equally owned by Trilogy and South32 Ltd., invested roughly US$28.5 million into a 2022 exploration program that included 10,738 meters of drilling targeting resource upgrades within the Arctic deposit and testing earlier-stage copper-rich prospects across the Upper Kobuk Mineral Projects in Northwest Alaska.
Covering 448,217 acres of the famed Ambler Mining District, UKMP hosts the advanced staged Arctic Mine project and more than a dozen similar volcanogenic massive sulfide targets on state lands, plus the world-class Bornite copper-cobalt deposit and similar carbonate-hosted prospects on land owned by the Northwest Alaska Native regional corporation, NANA Corp.
The 2022 field program at UKMP included infill and geotechnical drilling at the Arctic deposit; testing for similar volcanogenic massive sulfide mineralization near Arctic; and exploration of the copper-rich targets similar to Bornite in the Cosmos Hills and the Ambler Lowlands.
Nearly 80% of Ambler Metals' 2022 drilling was focused on upgrading the resource and collecting geophysical data at Arctic, the most advanced of the UKMP projects.
A 2020 feasibility study for developing a mine at Arctic details a financially robust operation that would produce 1.9 billion lb of copper, 2.3 billion lb of zinc, 388 million lb of lead, 386,000 oz of gold, and 40.6 million oz of silver over an initial 12-year mine life.
This operation is based on 43 million metric tons of reserves averaging 2.32% copper, 3.24% zinc, 0.57% lead, 0.49 grams per metric ton gold, and 36 g/t silver.
During a 2021 program focused largely on upgrading resources within the Arctic deposit, Ambler Metals cut stacked layers of high-grade volcanogenic massive sulfide mineralization.
One such hole, AR21-0181, cut six mineralized intervals; the best three are:
• 13.1 meters of 4.42% copper, 7.91% zinc, 1.13% lead, 0.70 g/t gold, and 72.37 g/t silver from a depth of 131.7 meters.
• 25.43 meters of 2.35% copper, 4.56% zinc, 1.09% lead, 0.11 g/t gold, and 20.49 g/t silver from a depth of 155 meters.
• 22.56 meters of 2.6% copper, 5.6% zinc, 1.19% lead, 0.81 g/t gold, and 89.15 g/t silver from a depth of 201.3 meters.
Following up on the 2021 program, Ambler Metals completed another 8,376 meters of infill drilling in 47 holes – 40 focused on upgrading indicated resources to the higher confidence measured category, and seven for geotechnical and hydrogeological study purposes.
The infill drilling at Arctic continued to cut multiple layers of VMS mineralization. One such hole, AR22-0192. cut four mineralized intervals, including:
• 9.63 meters averaging 3.58% copper, 5.89% zinc, 1.07% lead, 0.32 g/t gold, and 53.52 g/t silver from a depth of 118.5 meters.
• 7.36 meters averaging 2.38% copper, 2.4% zinc, 0.81% lead, 0.35 g/t gold, and 51.25 g/t silver from a depth of 145.3 meters.
In addition to Arctic, the 2022 program at UKMP included 2,363 meters in seven holes targeting copper-rich satellite prospects along the volcanogenic massive sulfide belt that hosts Arctic and the Cosmos Hills area of UKMP, which is related to the Bornite copper-cobalt deposit.
Located about 16 miles (26 kilometers) southwest of Arctic, Bornite hosts 41.7 million metric tons of indicated resource averaging 1.04% (955 million lb) copper; and 144 million metric tons of inferred resource averaging 1.68% (5.33 billion lb) copper.
The deposit also hosts 88 million lb of cobalt in 184.8 million metric tons of inferred resource averaging 0.021% cobalt.
Outside of Bornite itself, this area has not been systematically explored for similar carbonate-hosted copper mineralization since Kennecott Exploration during the 1990s.
Soil sampling, mapping, relogging historical core, trenching, and two holes drilled in 2021 outlined four areas for 2022 drilling – Bornite West, Pardner Hill, Pardner Hill North, and Ambler Lowlands.
One of the 2021 scout holes encountered low-grade copper in Bornite sequence carbonates about 2,000 meters west of the Bornite deposit and on the projected northeast trend of mineralization at Pardner Hill, a 3,000-meter-long copper soil and rock geochemical anomaly.
During the 2022 season, field crews completed 1,350 meters of trenching at Pardner Hill.
In addition to the drilling and trenching, Ambler Metals 2022 field program included detailed mapping and soil sampling to build on the work performed during the prior year.