2023-06-13
Acquiring the Mactung tungsten project from the Northwest Territories government for C$15 million last year, Fireweed quickly consolidated previous data and new assessments to release a mineral resource estimate that ranks this property as the largest high-grade tungsten resource in the world.
“In one year, we have gone from signing an initial letter of intent to a definitive asset purchase agreement to the publication of new mineral resource for Mactung,” said Fireweed Metals CEO Brandon Macdonald. “We have taken the historic resource through a process involving relogging, resampling, and a rigorous, modern estimation methodology, and confirmed an impressive and world-class tungsten resource at Mactung.”
Additional bulk density and assay data were collected during an extensive campaign of resampling historical drill core late last year and earlier this year, and a new geological interpretation of the deposit has been made. These factors resulted in a robust estimate of the mineral inventory at Mactung, providing a solid foundation for future mine development studies.
With the thorough work, the calculation shows that Mactung hosts 41.5 million metric tons of indicated underground and open pit resource averaging 0.73% (665 million pounds) tungsten trioxide and 12.3 million metric tons of inferred underground and open pit resource averaging 0.59% (158.7 million lb) tungsten trioxide.
In addition to the main tungsten resource, Fireweed also estimated copper and gold as byproduct metals for underground constrained resources only. According to this calculation, Mactung hosts 12.17 million metric tons of indicated underground resource averaging 0.058% (15.67 million lb) copper, and 0.078 grams per metric ton (32,914 ounces) gold; and 2.8 million metric tons of inferred underground resource averaging 0.02% (1.2 million lb) copper, and 0.017 g/t (2,194 oz) gold.
An impressive byproduct that could bolster the economics of mining the tungsten at Mactung.
While no metallurgical test work has been conducted to assess the recovery of copper or gold, Fireweed says that based on historical production of small quantities of gold and copper concentrate from the geologically similar Cantung mine, it can be reasonably assumed that gravity separation and a copper circuit could be incorporated into a flowsheet to recover a portion of the gold and copper in the current mineral resource to satisfy the reasonable prospects of economic extraction.
Fireweed and its consultants are currently completing metallurgical test programs to validate the recovery of tungsten and assess the recovery of gold and copper at Mactung. Grades of copper and gold were considered too low to include in a mineral resource calculation for the open-pit portion of the Mactung deposit.
“This not only reaffirms Mactung’s unmatched combination of grade and scale but establishes it as a truly strategic critical minerals project for the West with the underground resource alone able to supply much of North America’s demand for decades,” said Macdonald. “Fireweed is looking forward to collaborating with federal, territorial, and Indigenous governments to advance Mactung through the permitting and detailed engineering stages of this unique project.”
Mactung
Located roughly 13 kilometers (8 miles) north of and adjoining Fireweed’s flagship Macmillan Pass zinc-lead-silver project camp and government-maintained airstrip, Mactung is a 37.6-square-kilometer (14.5 square miles) contiguous land package that is also accessible via the North Canol Road about 230 kilometers (143 miles) from the town of Ross River, Yukon.
This tungsten-rich project lies within the Traditional Territories of the Kaska Dena Nation, the First Nation of Na-Cho Nyäk Dun, and the Sahtú Settlement Area. While remote, Fireweed has taken necessary considerations for the land’s First People in its approach to exploration and development.
Discovered and staked in 1962 by an AMAX Northwest Mining Co. geologist, extensive drilling, metallurgical testing, and multiple historical resource estimates were completed over the next twenty years.
Changing ownership several times, the property was subsequently acquired by North American Tungsten Corp. in 1997. In 2007, North American Tungsten published several updated mineral resource estimates and in 2009 published a positive feasibility study.
With subsequent licensing and reviews by various governing bodies, in 2015, North American Tungsten filed for and was granted creditor protection mainly related to its operations of the Cantung mine located further south.
The Government of Northwest Territories purchased the Mactung project for C$4.5 million, which it held onto until Fireweed signed a definitive asset purchase agreement for the property.
Ideally found within the eastern margin of the Selwyn Basin in the Canadian Cordillera’s Tombstone-Tungsten belt, Mactung hosts a skarn deposit associated with Tombstone-tungsten suite granitic intrusions that are more broadly linked to a variety of gold and tungsten deposits across Yukon-NWT.
The deposit is further subdivided into an upper and lower zone that both occur at surface and extend to depths of approximately 400 meters below surface.
Despite the enormous promise of Mactung, Fireweed estimates that there is the potential for an exploration target at Mactung between 2.5 and 3.5 million metric tons averaging 0.4 and 0.6% tungsten trioxide, which is in addition to the current resource estimate.
This target is currently within the geologic model, which is supported by drilling and surface mapping, and includes material located beyond the boundaries of the Inferred and Indicated resource classification.
While outside the bounds of the current resources, this expansion target is within the boundaries of the open-pit shell and underground volumes used to constrain the current mineral resource.
While exciting to imagine, this target is conceptual in nature and will require additional drilling to test the geological model, grade continuity, and extent of mineralization. Furthermore, Fireweed stresses it is uncertain if additional drilling would validate the geological potential or fulfill the mining and economic criteria necessary to establish reasonable prospects of an eventual extraction.