Alaska exploration trends north ... slowly
Despite lackluster investor interest, 2018 spending tops $100M
Last updated 3/1/2019 at 4:54am
Thanks largely to increased investments from Aussie mining explorers, mineral exploration spending across Alaska topped US$100 million in 2018.
This is well above the roughly US$95 million invested last year and nearly double the US$58 million spent at the bottom of the market in 2015.
"Canadian and Australian companies continue to be the source for the bulk of funds spent in Alaska in 2018, together comprising well over 80 percent of the exploration expenditures earmarked for Alaska," Avalon Development President Curt Freeman penned in a July column for North of 60 Mining News.
While Alaska's mineral exploration sector is improving, the venture capital needed to discover and delineate Alaska's next big mine is still hard to come by. This lackluster enthusiasm by investors means a lot of programs to explore promising mineral projects remain on the shelf and many others were smaller than planned.
"To be sure, more companies are exploring in Alaska this year and they are spending 10-15 percent more than they did in 2017, but macro-economic conditions are still not great for the exploration sector," Freeman said.
Alaska Range Aussies
Australian investments into exploring Alaska's vast and largely underexplored mineral potential has surged over the past three years, including three Aussie explorers seeking gold, copper and zinc along the slopes of the Alaska Range in 2018.
Along the north side of this iconic range that separates Southcentral Alaska from the state's Interior and Southwest regions, Australian junior White Rock Minerals Ltd. is exploring zinc-rich volcanogenic massive sulfide deposits on its Red Mountain property.
Two deposits on this property – Dry Creek and West Tundra Flats – had significant historical drilling, which White Rock incorporated into a resource that meets modern reporting standards.
This maiden Australian Joint Ore Reserves Committee- (JORC) compliant calculation outlined 16.7 million metric tons of inferred resource averaging 4.1 percent (1.49 billion pounds) zinc; 1.7 percent (630 million lb) lead; 0.2 percent (57.3 million lb) copper; 99 grams per metric ton (53.5 million oz) silver; and 0.7 g/t (352,000 oz) gold.
The 2018 program cut high-grade VMS mineralization at both deposits, such as 3.45 meters averaging 15.1 percent zinc, 6.7 percent lead, 518 g/t silver, 2.1 g/t gold and 0.2 percent copper, or 35.2 percent zinc-equivalent in hole WT18-28 at WTF; and 4.8 percent zinc, 2.3 percent lead, 1,435 g/t (46.1 oz/t) silver, 2.2 g/t gold and 0.5 percent copper, or 43.2 percent zinc-equivalent in hole DC18-77 at Dry Creek.
Reconnaissance exploration carried out this year generated seven targets across the wider Red Mountain property for follow-up exploration and drilling.
"While a lot of focus and interest is on the diamond drilling we are doing, the background work by the reconnaissance mapping and geochemical sampling crew is key to our next discovery," White Rock CEO Matt Gill said.
About 50 miles south of Red Mountain, Perth-based PolarX Ltd. is expanding rich deposits of gold and copper at its Alaska Range project.
A 13-hole program completed in 2017, coupled with historical drilling, outlined 3.4 million metric tons of JORC-compliant inferred resource grading 1.2 percent (90.4 million pounds) copper, 2 grams per metric ton (213,000 oz) gold and 14 g/t (1.5 million oz) silver.
This shallow deposit has been traced for a length of about 1,000 meters and 2018 drilling is tapping rich copper and gold more than 100 meters below the deposit and 850 meters to the east.
Near the southwest end of the Alaska Range, another Australian junior, Nova Minerals Ltd. is expanding the gold and copper identified on the Estelle property.
A roughly 8,000-meter drill program that began in August targeted Oxide, an Estelle prospect previously drilled by Millrock.
SE11-01, the discovery hole drilled at Oxide in 2011, cut 450.7 meters averaging 0.38 g/t gold.
SE12-04, drilled to the southeast of the discovery hole in 2012, cut 41.5 meters averaging 1.1 g/t gold, indicating the drilling was vectoring toward higher gold grades as it approached a strong geophysical anomaly further southeast.
Using previous drill and geophysical data, Nova has calculated that a 740-meter section of the Oxide prospect provides an exploration target with between 1.1 million to 2.3 million ounces of gold. The Aussie explorer's primary focus for 2018 is to expand this target area and calculate a JORC-compliant resource by the end of the year.
Kuskokwim Gold Belt
Another Aussie junior, Riversgold Ltd., is exploring three gold exploration properties – Luna-Quicksilver, Kisa and Gemuk – about 95 miles southwest of the 39-million-ounce Donlin Gold Mine project.
Until this year, only one target on the Kisa property had ever been drilled across Rivergold's entire land package.
The company started its 2018 exploration program with geophysical and surface sampling surveys at the Luna, Luna East and Quicksilver prospect areas. This targeting work was followed up with a 366-meter drill program that tested each target with one hole
Kelly, who has been exploring this region of the Kuskokwim Gold Belt for more than two decades, hopes this exploration will lead to the large gold deposits Southwest Alaska is now famed for.
"I have personally been involved with these projects since 1997, when I was part of the team that discovered outcropping high-grade gold mineralization at Quicksilver," he said. "In that time, Donlin Creek (Donlin Gold) has grown from a potential 2 million-ounce prospect to a 45 million-ounce world-class gold project, highlighting the significant potential of this region."
Donlin Gold is now well on its way to being Alaska's next major gold mine.
The partners, however, have not yet made a go-ahead decision to build the mine. Instead, they are putting the finishing touches on optimization studies to enhance the mine plan detailed in a 2011 feasibility study.
The 2011 study envisions a 53,500-metric-ton-per-day operation that is estimated to average roughly 1.1 million oz gold annually over a projected 27-year mine-life.
This is based on the 504.8 million metric tons of proven and probable reserves averaging 2.09 g/t (33.85 million oz) gold.
"One of the opportunities being studied is the ability to mine more selectively, which could improve feed grade," said Novagold President and CEO Gregory Lang.
This plan will likely entail feeding higher grade ore into a smaller mill than envisioned in 2011, with the option to scale up production in stages.
US$17.5M invested in Ambler District
The biggest Australian investment in Alaska's mineral potential in 2018 is a US$10.8 million program at the Upper Kobuk Mineral Projects in Northwest Alaska, funded by South32 Ltd.
The Perth-based major got involved with the copper-zinc-lead-gold-silver-cobalt project early in 2017 when it cut a deal with Trilogy Metals Inc. to acquire a 50 percent interest in this large land package that blankets most of the metals-prolific Ambler Mining District.
To keep this option in good standing, South32 agreed to invest US$30 million in exploration over three years. So far, the company has invested US$20.8 million in expanding and upgrading the Bornite deposit at UKMP.
The most recent resource calculations estimate that Bornite hosts roughly 6.36 billion lb of copper and 77 million lb of cobalt.
The work funded by South32 has expanded Bornite well beyond the resource.
An updated resource and inaugural preliminary economic assessment for Bornite are slated for completion by mid-2019.
A prefeasibility study published for Arctic early in 2018 details plans for a mine that is expected to produce 1.9 billion lb of copper, 2.4 billion lb of zinc, 405 million lb of lead, 367,531 oz of gold and 40.2 million oz of silver over an initial 12-year mine life.
A US$6.7 million work program completed this year includes drilling needed to advance the engineering design for these facilities to a feasibility level of study.
Crews are also collecting environmental and other data needed to submit a mine permit application for Arctic, which is expected in 2019.
With Trilogy and South32 advancing Arctic and Bornite toward development, and the prospect that a 211-mile road will be extended to the region, Valhalla Metals Inc., a new Alaska-based explorer, has emerged to advance large VMS projects at each end of the Ambler District.
Sun, located at the east end of the district, is the most advanced of the projects.
According to an NI 43-101-compliant resource calculated for Valhalla in August, Sun contains 1.71 million metric tons of indicated resource averaging 4.32 percent (163 million pounds) zinc, 1.48 percent (55.8 million lb) copper, 1.11 percent (42 million lb) lead, 60 g/t (3.3 million oz) silver and 0.21 g/t (12,000 oz) gold; plus 9.02 million metric tons of inferred resource averaging 4.18 percent (831.3 million lb) zinc, 1.21 percent (239.6 million lb) copper, 1.46 percent (290.3 million lb) lead, 81.7 g/t (22.7 million oz) silver and 0.25 g/t (73,000 oz) gold.
Valhalla plans to initiate exploration focused primarily on Sun in 2019.
"Recent developments in the Ambler Mining District have significantly enhanced the economic potential of the Sun deposit and we are excited to be part of this district's path to production," said Valhalla Metals President Curt Freeman.
Smucker, at the west end of the Ambler District, is an earlier staged project that shows similar potential.
In a 1986 report, it was estimated that Smucker hosts more than 8 million metric tons averaging 0.8 percent copper, 6.8 percent zinc, 2.3 percent lead and 200 g/t silver. This, however, is a rough estimate based on sparse drilling.
Prolific Red Dog District
About 150 miles northwest of the Ambler District, Teck Resources Ltd. continues to add high-grade zinc reserves and expand new deposits near the Red Dog Mine.
Going into 2018, Red Dog had 57.6 million metric tons or reserves averaging 13.6 percent (13.9 billion pounds) zinc and 3.9 percent (2.5 billion lb) lead, enough to last the operation until 2031.
Aktigiruq, a large and high-grade zinc deposit roughly five miles northwest of the current operations, could extend the life of Red Dog much deeper into the 21st Century.
Teck has estimated that Aktigiruq hosts somewhere between 80 million and 150 million metric tons of material averaging around 13 percent zinc and 4 percent lead.
Drilling is now focused on upgrading this target to a world-class zinc deposit that meets modern reporting standards.
Teck has also taken the exploration lead at Lik, a zinc deposit about six miles west of Aktigiruq it owns equally with Solitario Zinc Corp., a Colorado-based company that bought 50 percent ownership of the project in 2017.
At the time of the acquisition, Lik hosted a promising deposit with 17.3 million metric tons of indicated resource averaging 8 percent zinc, 2.7 percent lead and 51 g/t silver; and 2.9 million metric tons of inferred resource at 8.6 percent zinc, 2.6 percent lead and 37 g/t silver.
Solitario has opted to have Teck operate the field work there, leveraging the Red Dog Mine operator's three decades of experience in the region.
"We are excited to take advantage of Teck's long-term experience in the Red Dog zinc district," said Solitario President and CEO Chris Herald.
The 2018 work at Lik includes geophysics and mapping to aid in the development of drill targets.
The partners are also relogging core from the 229 holes previously drilled at Lik, which will allow Teck's technical team to compare the mineralization there to deposits in other parts of the prolific Red Dog zinc district.
"The 2018 work program will pave the way for planning the best path forward for the project," said Herald.
Yukon explorer jumps border
Another positive sign for Alaska is that the first splashes of Yukon's mineral exploration rush is spilling across the border into the Far North State.
While mining explorers in the Yukon have staked large blocks of claims up to the Alaska border, just over the international boundary the land remains largely unclaimed.
Recognizing that mineral-rich geology knows no international borders, K2 Gold Corp. staked 123 mining claims along the Alaska side of the border about 20 miles (30 kilometers) northeast of Northway.
Known as McArthur Creek, this new eastern Alaska project covers roughly 18,300 acres in the Moosehorn Range, a cross-border region that has produced more than 100,000 ounces of placer gold.
With three gold projects in western Yukon – Wels, Storck and Ladue – K2 Gold is familiar with the geology of this stretch of the Tintina Gold Belt, a 125- by 750-mile gold-rich province that arcs from northern British Columbia, through the southwest corner of Yukon, and across Alaska.
"Exploration thus far on the Canadian side of the border seems to indicate that there is an extensive orogenic style mineralized gold system in the range. The McArthur Creek project represents a large, prospective district scale opportunity in an area that has seen limited exploration to date," said K2 Gold Vice President of Exploration Jo Price.
While K2 Gold only carried out early stage exploration at McArthur Creek this year, it is the first company exploring the Yukon to jump across the border.
About 25 miles north of McArthur Creek, Kenorland Minerals is exploring Tanacross, a project that hosts numerous porphyry copper targets. The most advanced of these, Taurus, hosts 68.3 million metric tons of inferred resource averaging 0.275 percent copper, 0.032 percent molybdenum and 0.166 g/t gold, according to a calculation completed in 2011.
In addition to large porphyry copper-gold systems, Tanacross is prospective for epithermal, intrusion-related, and orogenic gold systems; as well as carbonate replacement and skarn deposits.
Some 50 miles southwest of Tanacross, Peak Gold LLC, a joint venture between Contango ORE Inc. (60 percent) and Royal Gold Inc. (40 percent), is investigating the economics of mining the gold-rich Main Peak and North Peak skarn deposits on the enormous Peak Gold (formerly Tetlin) property.
Together, the Peak deposits host of 15.65 million metric tons of resource averaging 2.98 g/t (1.5 million oz) gold, 14.68 g/t (7.39 million oz) silver and 0.16 percent (55 million lb) copper, according to a calculation published in 2017.
This year's US$9.1 million program for Peak Gold is defining a path to commercialization of Peak and North Peak; explore for a third skarn orebody close to these deposits; and acquire data that would help evaluate the potential for porphyry or epithermal deposits across the 850,000-acre Peak Gold land package.
A preliminary economic assessment for Peak Gold is expected before the end of the year.
Golden Interior developments
Exciting developments at both Fort Knox and Pogo hold promise for Interior Alaska's two large gold mines.
In August, Kinross Gold Corp. broke ground on Gilmore, an expansion project that is expected to add roughly 1.5 million oz of gold to Fort Knox and extend the life of the mine out to 2030.
According to Kinross executives, Kinross will likely serve as a bridge to further expansions of one of the largest and most successful mines in the company's global portfolio of gold operations.
"Gilmore is the toehold that allows us to explore the full potential of this property," Kinross COO Lauren Roberts told the crowd gathered at Fort Knox for the Aug. 15 ceremonial groundbreaking for Gilmore. "We needed a decade to give us more time to look through the analysis to see what we can do with this going forward and we plan to be here for many years to come."
The Toronto-based major sees further expansions in both the original Fort Knox pit and Gilmore.
In addition, generative exploration work is underway around the Fort Knox property. This includes a review of the gold resource at Gil Sourdough, a deposit about seven miles northeast of the mill.
According to the most recent calculation, Gil hosts 29.5 million metric tons of indicated resource averaging 0.56 g/t (533,000) oz. of gold.
Kinross said it is evaluating potential synergies between Gil and ongoing operations at Fort Knox.
"We see a lot of potential, we are going to keep exploring, and I personally believe this is the first of many phases of expansion," said Kinross Gold President and CEO J. Paul Rollinson.
About five miles north of the Fort Knox pit, Freegold Ventures Ltd. is building gold resources on its Golden Summit property, which hosts 61.5 million metric tons of indicated resource averaging 0.69 g/t (1.36 million oz) gold; and 71.5 million metric tons of inferred resource averaging 0.69 g/t (1.58 million oz) gold.
The oxide portion of this deposit, largely within the upper 60 meters, has 16.2 million metric tons of indicated resource averaging 0.66 g/t (345,000 oz) gold; and 9.6 million metric tons of inferred resource averaging 0.59 g/t (183,000 oz) gold.
A drill program completed early in 2017 extended the heap-leachable oxide resource to the north. Sampling and geophysics have also outlined a large expansion area to the west.
Freegold also completed a modest drill program at Shorty Creek, a porphyry copper-gold project that also hosts significant amounts of silver, tungsten and cobalt.
Shorty Creek is located just across the pave Elliot Highway from Livengood, where International Tower Hill Mines Ltd. invested around US$5.1 million this year on studies for optimizing the plan for developing a mine at the 11.5-million-oz gold deposit there.
About 80 miles southeast of Fairbanks, mid-tier Australia miner Northern Star Resources Ltd. cut a deal in August to buy full ownership of the Pogo gold mine.
Sumitomo Metal Mining Pogo, a joint venture between Japanese firms Sumitomo Metal Mining Company (85 percent) and Sumitomo Corp. (15 percent), agreed to sell the high-grade underground mine to Northern Star for US$260 million.
Before the sale, SMM Pogo was carrying out an extensive drill program, originally slated at roughly US$15 million for 2018, on defining and expanding known deposits currently being mined at its underground operation as well as new discoveries such as Goodpaster and Fun zone.
The Fun zone extension, which is adjacent to the areas currently being mined, is a vertical structure that hosts mineralization that is different than what is typically encountered at Pogo.
While the Pogo team still has a lot to learn about Fun zone extension, one thing they do know is that it hosts some very high-grade gold.
Despite grades as high as 10 oz/t gold, the SMM Pogo exploration team was even more enthusiastic about the potential at Goodpaster, a high-grade gold prospect on the north side of the Goodpaster River, about a mile away from the underground workings at Pogo.
The first hole drilled at Goodpaster in 2017 tapped 22.8 feet averaging 0.103 oz per ton gold and the second cut 17.5 feet of 1.739 oz/t gold.
Geophysical results indicate this prospect could extend for 5,000 meters along strike trending onto Millrock Resources' adjacent Pogo West property.
Northern Star said it plans to invest in intensive resource expansion and upgrade drilling over the coming months with the goal of having Australian Joint Ore Reserves Committee, or JORC-compliant resources and reserves calculated for Pogo in 2019.
"By investing in exploration and development, we are confident we can grow the resource, production and mine life for the benefit of the mine's employees, contractors, the local community and our shareholders," said Northern Star Executive Chairman Bill Beament.
Metals rich SE Panhandle
The two remaining large-scale metal mines in Alaska are found in Southeast, a panhandle rich in gold, silver, copper, zinc, rare earth elements and now barite.
According to a resource calculated in 2015, the South Wall-RW deposit at Palmer hosts 8.1 million metric tons of inferred resource averaging 5.25 percent (940.4 million pounds) zinc, 1.41 percent (252.6 million lb) copper, 0.32 g/t (83,600 ounces) gold and 31.7 g/t (8.3 million oz) silver.
This resource contains roughly 22 to 25 percent barite by weight. Metallurgical work completed this year demonstrates that 91.1 percent of the barite at Palmer can be recovered in a clean high-grade concentrate.
"These results confirm that a premium-quality barite concentrate can be produced from the copper-zinc ores at Palmer, and that it can be achieved by the addition of simple steps to mineral processing," said Constantine Metal Resources President and CEO Garfield MacVeigh. "This may have very positive implications with the potential to both enrich gross metal value per tonne (metric ton) and provide significant environmental and operational benefits by reducing waste."
In addition to the metallurgical work, the roughly US$9 million exploration program budgeted by the partners for 2018 includes approximately 10,000 meters of drilling to expand the South Wall-RW resource as well as explore targets across the wider property.
The drilling completed over the past four seasons will be incorporated into a new resource calculation slated for later this year.
This updated resource will form the basis of a preliminary economic assessment for Palmer, the first ever look at the viability of developing a mine at the VMS project.
In April, the Chicago-based miner updated the Kensington reserves to 2.96 million tons averaging 0.21 oz/t (620,700 oz) gold.
In addition to these reserves, Kensington has 2.74 million tons of measured and indicated resources averaging 0.26 oz/t (712,600 oz) gold; and 1.39 million tons of inferred resource averaging 0.22 oz/t (304,800 oz) gold.
This roughly 1 million oz of gold in resources and the numerous targets Coeur's exploration team has identified on the property provide numerous opportunities for reserve growth at this high-grade gold mine.
About 40 miles further southeast, Grande Portage Resources Ltd. is expanding high-grade gold at its earlier staged Herbert Gold project.
A resource published this year outlines 1.1 million metric tons of indicated resource averaging 7.25 g/t (267,950 oz) gold; and 423,200 metric tons of inferred resource averaging 6.04 g/t (82,200 oz) gold.
This year, the company completed a small drill program to expand two gold-bearing veins – Goat and Deep Trench – that make up this resource.
Hecla Mining Company continues to add years to the life of its Greens Creek Mine near Juneau.
Going into 2018, Greens Creek had 7.55 million tons of proven and probable reserves averaging 11.9 oz/t (90.22 million oz) silver, 0.1 oz/t (725,000 oz) gold, 8.1 percent (614,840 tons) zinc and 3 percent (225,050 tons) lead.
This is an increase of all four metals, despite the operation producing 10.8 million oz of silver, 78,245 oz of gold, 60,858 tons of zinc and 22,870 tons of lead during 2017.
Strong assay results from drilling at numerous zones at Greens Creek indicate that Hecla will continue a long-running tradition of extending the life of this iconic underground mine near Alaska's capital.
Agnico Eagle Mines Ltd., a newcomer to that part of Alaska, has staked a large land package known as Helm Bay over a region a few miles north of Ketchikan that produced high-grade gold from small underground mines around the turn of the 20th Century. This year, Agnico is carrying out mapping, sampling and geophysics in order to define drill targets for 2019.
Residents of Ketchikan are also excited about the potential of a rare earth elements separation facility Ucore Rare Metals Inc. is planning to build near the Southeast Alaska town.
Known as the Strategic Metals Complex, or SMC, this facility will utilize molecular recognition technology to separate rare earths and produce individual REE oxides used in many high-tech applications.
Using a solution derived from Ucore's Bokan Mountain project, an REE mining project about 30 miles southwest of Ketchikan on Prince of Wales Island, this new technology was proven with a pilot plant known as SuperLig-One.
Ucore now hopes to have Alaska SMC, a commercial scale separation facility being planned for Ketchikan, producing high quality rare earths by 2021.
"When completed, we will have established a significant domestic source of saleable rare earth oxides, which will go a long way towards establishing technology metals independence for the U.S. in an environmentally sustainable and safety conscious manner," said Ucore President and CEO Jim McKenzie.