View from above Hess Creek

View from above Hess Creek on the Dalton Highway.

An unusually gloomy summer has so far scuttled more than half of drilling work planned at the most advanced metal prospect in the remote Ambler mining district, according to the owners of the project.

Leaders of Vancouver-based Trilogy Metals said in a field season update provided Sept. 7 that as of late August, approximately 6,450 meters of core had been drilled during a season that began with expectations to collect more than 14,600 meters.

Just more than half of the drilling was originally planned for within the Arctic multi-metal deposit with another 7,000 meters scheduled for targets nearby and elsewhere in the prospective Ambler region, according to the company.

Trilogy Metals is a joint owner with Australian South 32 Ltd. in Ambler Metals LLC, the operating company for the Arctic and Bornite prospects first owned by Trilogy.

Ambler Metals spokeswoman Shalon Harrington wrote via email that the 2021 work season has been impacted by persistent overcast and rainy conditions that hamper the ability to safely conduct helicopter flights, which are needed to access nearly all of the drill sites.

While overcast and wet weather is typical in the Ambler region as it is across much of the state, Harrington wrote that this is the first year since the notoriously cool and dreary summer of 2011 that it was a season-long issue.

The village of Bettles east of the remote upper Kobuk metal prospects has seen about 45% more precipitation than normal since the start of June, according to National Weather Service data.

Most recently pegged as a $1.2 billion open-pit mine with a 12-year life, the Arctic deposit was first known as primarily a copper prospect, but subsequent drilling tapped into substantial zinc and precious metal resources as well.

Located in the middle of the Ambler mining district on the southern edge of the Brooks Range, the Arctic mine project is the most advanced prospect of more than a dozen in the roughly 75-mile long district. It also would likely be the first mine serviced by the state-sponsored Ambler access road, which has drawn the ire of many area residents and conservation groups.

Trilogy CEO Tony Giardini said in the update that the company was still able to complete the metallurgical drilling at Arctic and keep advancing pre-permitting work as well. Drilling work at Arctic is done for the year.

“We are now well into our regional drilling program with two drills following up on targets within our Ambler belt and the greater Bornite area,” Giardini said. “We are looking forward to seeing the regional drilling results, which should be available within the next couple of months and in commencing mine permitting once we have completed the permitting review process.”

Drilling at the regional targets will continue as long as the weather allows, according to Trilogy.

Donlin does more

Work at the Donlin gold prospect to the southwest has been busier than originally planned, with the company expecting to drill roughly 80 holes totaling approximately 24,000 meters, according to figures provided Sept. 2.

The company originally planned to drill about 65 holes totaling 20,000 meters but the additional work should help fill in the remaining gaps about mineralization continuity in the pit and aid feasibility work, according to a statement from NovaGold, a 50% partner in the $6.7 billion Donlin project with mining giant Barrick Gold.

The best core intervals surveyed so far from this year’s drilling include 92 meters of core with an average grade of 7.8 grams of gold per ton of ore and 41 meters of core averaging 10.5 grams per ton, according to NovaGold.

“As with last year’s program, drilling has delivered multiple examples of outstanding gold intercepts,” NovaGold CEO Greg Lang said in a formal statement. “Excellent results, such as those reported ( Sept. 2) reinforce our belief in the uniqueness of an asset like Donlin gold, whose combination of outstanding size, quality, and exploration upside are clearly among the only answers to an industry defined by an era of declining reserves, lackluster gold grades and ever-increasing jurisdictional risk.”

Donlin representatives have long said the project generally needs sustained, high gold prices because of the extensive network of support infrastructure that needs to be developed but have declined to specify what parameters they believe are needed to green-light development. Gold was trading for about $1,796 per ounce on Sept. 7.

The $6.7 billion construction cost estimate was developed from the last feasibility study done on the project in 2011.

Elwood Brehmer can be reached at elwood.brehmer@alaskajournal.com.