Fireweed Metals Announces Mineral Resources for the Mactung Project: the Largest High-Grade Tungsten Deposit in the World*
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NEWS RELEASE
June 13, 2023 TSXV: FWZ
OTCQB: FWEDF
FSE:20F
Fireweed Metals Announces Mineral Resources for the Mactung Project:
the Largest High-Grade Tungsten Deposit in the World*
• Mactung is the world’s largest high-grade deposit of the critical mineral tungsten*.
• Mineral resources total 41.5 Mt Indicated Resource at 0.73% WO3 and 12.2 Mt Inferred
Resource at 0.59% WO3.
• In addition, an Exploration Target is estimated at 2.5 Mt to 3.5 Mt at a grade between 0.4%
and 0.6% WO3, within the mining shapes that constrain the Mineral Resource.
• The resource estimate includes estimates for the critical mineral copper in addition to gold
and metallurgical test work is underway to determine recoveries of these by -product
metals.
• Mactung is contiguous with Fireweed’s Macmillan Pass zinc-lead-silver project, accessible
by the North Canol Road, and provides potential for future project synergies.
Vancouver, British Columbia: FIREWEED METALS CORP. (“Fireweed” or the “Company”)
(TSXV: FWZ; OTCQB: FWEDF) is pleased to announce a new mineral resource estimate for its
Mactung Project located in Yukon and Northwest Territories, Canada (Map 1) , within the
Traditional Territories of the Kaska Dena Nation and First Nation of Na-Cho Nyäk Dun, and the
Sahtú Settlement Area.
CEO Statement
Brandon Macdonald, CEO, stated “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.
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*. 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 expected demand for
decades. 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.”
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Table 1: Mineral Resource Statement(1,2,3,4) for the Mactung Project.
Classification Cut-off Tonnage WO3 Contained
Grade (tonnes) Grade WO3
WO3 (%) (%) (mtu5)
Indicated (underground) 0.50 12,168,000 1.05 12,789,000
Indicated (open pit) 0.25 29,319,000 0.59 17,367,000
Total Indicated (OP+UG) 0.25/0.50 41,487,000 0.73 30,156,000
Inferred(4) (underground) 0.50 2,817,000 0.73 2,066,000
Inferred(4) (open pit) 0.25 9,430,000 0.55 5,139,000
Total Inferred(4) (OP+UG) 0.25/0.50 12,247,000 0.59 7,205,000
For table footnotes 1, 2, 3, 4, and 5 see page 9.
Mineral Resource Estimate
The current Mineral Resource at Mactung ranks it the largest high-grade tungsten resource in the
world and it is a clear statistical outlier in terms of grade and contained metal*. It is a tungsten
skarn deposit associated with Tombstone-Tungsten suite granitic intrusions that are more broadly
linked to a variety of gold and tungsten deposits across Yukon-Northwest Territories. The
Mactung deposit is sub -divided into an upper and lower zone that both occur at surface and
extend to depths of approximately 400 m below surface.
A very high-grade portion of the resource was constrained by underground mining volumes at a
0.5% WO3 cut-off grade, within the gently to moderately dipping, roughly tabular, lower zone that
is approximately 20-30 m thick, extending for a kilometre in strike and up to 380 m down-dip.
In the upper zone, a high-grade open pit resource was constrained by a conceptual pit shell at a
0.25% WO3 cut-off grade.
The Mineral Resource estimate considers and employs reasonable prospects for eventual
economic extraction, is applied within classification domains that are continuous, and uses a
classification scheme involving a drill spacing that was based on drill-spacing studies. Additional
bulk density and assay data were collected during an extensive Fireweed campaign of re-
sampling historic drill core in late 2022 and early 2023, and a new geological interpretation of the
deposit has been made. These factors have resulted in a robust estimate of the Mineral Inventory
at Mactung, providing a solid foundation for future mine development studies.
Copper and gold by-product reporting
Copper and gold were estimated as by -product metals for underground constrained resources
only (Table 2). No metallurgical test work has been conducted to assess the recovery of copper
or gold at Mactung. Based on historic al production of small quantities of gold and of copper
concentrate from the geologically similar Cantung mine †, it has been reasonably assumed that
gravity separation and a copper circuit could be incorporated into the flowsheet to recover a
portion of the gold and copper in the Current Mineral Resource to satisfy the reasonable prospects
of eventual 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 within the
Mineral Resource Statement for open-pit constrained resources.
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Table 2: Copper and gold by-product metals for underground mineral resources subdivided by
geological unit(1,2,3,4)
Unit
Cut-off
WO3
(%)
Tonnage
(tonnes)
Grade
WO3
(%)
Contained
WO3 (mtu5)
Copper
(%)
Contained
Copper
(lbs)
Gold
(g/t)
Contained
Gold (troy
oz)
Indicated
20 0.50 3,710,000 0.83 3,076,000 0.010 834,000 0.034 4,000
21 0.50 1,845,000 1.21 2,229,000 0.036 1,448,000 0.060 4,000
22 0.50 6,496,000 1.13 7,366,000 0.093 13,261,000 0.107 22,000
23 0.50 55,000 1.28 70,000 0.092 111,000 0.205 0
3D 0.50 62,000 0.78 48,000 0.011 15,000 0.018 0
Total 0.50 12,168,000 1.05 12,789,000 0.058 15,666,000 0.078 30,000
Inferred
21 0.50 932,000 0.83 775,000 0.014 288,000 0.023 1000
22 0.50 638,000 0.66 420,000 0.047 654,000 0.016 0
23 0.50 6,000 0.84 5,000 0.108 14,000 0.068 0
3D 0.50 1,241,000 0.70 866,000 0.009 252,000 0.013 1000
Total 0.50 2,817,000 0.73 2,066,000 0.020 1,208,000 0.017 2,000
For table footnotes 1, 2, 3, 4, and 5 see page 9.
Sensitivity to Cut-Off Grade
A range of cut-off grades were applied to the estimate within the mining volumes established for
open-pit and underground resources (Tables 4 and 5).
Table 3: Sensitivity to Underground Cut-Off Grade (Current Resource Highlighted) (2,4)
Underground
Cut-off Grade
(WO3%)
Tonnage (tonnes) WO3 grade
(%)
Copper
grade (%)
Gold
grade (g/t)
Indicated
0.40 12,885,000 1.02 0.074 0.057
0.45 12,548,000 1.03 0.076 0.058
0.50 12,168,000 1.05 0.078 0.058
0.55 11,702,000 1.07 0.080 0.059
0.60 10,979,000 1.11 0.083 0.061
Inferred
0.40 3,231,000 0.70 0.016 0.019
0.45 3,062,000 0.71 0.016 0.019
0.50 2,817,000 0.73 0.017 0.019
0.55 2,521,000 0.76 0.018 0.020
0.60 2,042,000 0.80 0.019 0.020
For table footnotes 2, and 4 see page 9.
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Table 4: Sensitivity to Open-pit Cut-Off Grade (Current Resource Highlighted) (2,4)
Open-pit
Cutoff Grade
(WO3%)
Tonnage
(tonnes)
WO3
grade
(%)
Indicated
0.15 36,452,000 0.51
0.20 32,668,000 0.55
0.25 29,319,000 0.59
0.30 26,207,000 0.63
0.35 23,395,000 0.67
Inferred
0.15 11,335,000 0.49
0.20 10,143,000 0.52
0.25 9,430,000 0.55
0.30 8,699,000 0.57
0.35 7,539,000 0.61
For table footnotes 2, and 4 see page 9.
Cut-Off Grade and Prospects for Eventual Economic Extraction
The cut-off grades of 0.5% WO3 for underground mining and 0.25% WO3 for open-pit mining were
selected based on a tungsten concentrate price assumption of approximately US D$240/mtu,
supported by updated estimates from trading companies that specialize in tungsten, and
preliminary estimates of operating costs (Table 5).
Reasonable prospects for eventual economic extraction of the mineral resources, as required by
NI43-101, were demonstrated by developing underground constraining volumes, conceptual pit
shells using a Lerchs -Grossman algorithm and input parameters derived from preliminary cost
estimates (see Map 2 and Cross -Sections). Only mineral resources above these cut-offs and
within the mineral resource-limiting underground constraining volumes and pits are reported;
mineralization falling below this cut- off grade or outside the resource-limiting volumes or pits is
not reported, irrespective of the grade. Potential underground resources are constrained initially
to only the lower zone ( 2B unit) and a portion of the upper zone (3D unit) below the pit shell
leaving a crown pillar. The potential open-pit resource was optimized for only the upper zone (3C,
3D, 3E, 3F, 3G and 3H units). Gold and copper are considered by-products and were not utilized
in cut-off grades, pit optimizations , underground constraints , or for establishing reasonable
prospects of eventual economic extraction. Sensitivity to cut-off grade is reported in Tables 3 and
4 above.
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Table 5: WO3 Cut-off Grade Calculation Assumptions
Input Parameters Unit Value Notes
OP Mining Cost – Resource or Waste US$/tonne mined 3.00
UG Mining Cost – Resource US$/tonne mined 38.00 Incl. maintenance and surface
Processing Cost US$/tonne milled 32.00
G&A and Site Services Cost US$/tonne milled 20.00
WO3 Recovery % 82
Royalties % 2 Assumes buy-down from 4%
Pit Slopes degrees 50
WO3 Concentrate Selling Price US$/mtu con 240.00
Mining dilution % 0
Mining recovery % 100
Assumptions used to derive the cut-off grades and define the resource-limiting pits are estimated
in order to meet the NI43-101 requirement for mineral resource estimates to demonstrate
“reasonable prospects for eventual economic extraction”.
Updated Technical Report
The details of the updated mineral resource estimate for Mactung will be provided in a Technical
Report compliant with NI43-101 to be filed on www.sedar.com in the next 45 days.
2023 Mineral Resource Estimate Methodology
The mineral resource estimate for Mactung was completed by Garth Kirkham, P.Geo., of Kirkham
Geosystems Ltd. using commercial mine-modeling and geostatistical software and adhering to
Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Estimation of Mineral Resources
and Mineral Reserves Best Practice G uidelines (adopted by CIM council November 29, 2019) .
The deposit was segregated into multiple estimation domains based on a re vised geological
model. The lower zone is hosted by Unit 2B (see Cross Sections), and this is subdivided into four
spatial zones (20, 21, 22, and 23). The upper zone is hosted by Units 3C, 3D, 3E, 3F, 3G, and
3H (see Cross Sections). Grades of WO3, copper and gold were estimated using ordinary kriging
interpolation of capped composites in multiple estimation passes. Search ellipse orientation and
anisotropy were based on structural and geological controls and/or variogram models with first
pass major axis search distances generally 100 m, and subsequent pass distances generally 60
m.
Mineral Resources are classified under the categories of Measured, Indicated and Inferred
according to CIM Definition Standards for Mineral Resources and Mineral Reserves (Adopted by
CIM council May 19, 2014) . Mineral resource classification for WO 3 was based primarily on an
analysis of viability and risk, drillhole spacing and on continuity of mineralization. In ferred and
Indicated resources were defined as using increasing thresholds of continuity, confidence, and
data density . No Measured resources were defined. Final resource classification shells were
manually constructed using interpreted solids. Gold and copper are not classified separately and
are reported as by -products based on WO3 classification. A full description of the modeling
methodologies for each deposit will be included in a Technical Report scheduled for release within
45 days.
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Mactung Exploration Potential
It is estimated that there is the potential for an Exploration Target at Mactung of between 2.5 and
3.5 Mt at a grade of between 0.4 and 0.6% WO 3 in addition to the current Mineral Resources
disclosed in this news release. The Exploration Target is within the current geological model,
supported by drilling and surface mapping. The Exploration Target includes material located
beyond the boundaries of the Inferred and Indicated resource classification but is located within
the boundaries of the open-pit shell and underground volumes used to constrain the current
Mineral Resource.
The Exploration Target is conceptual in nature and requires additional drilling to test the geological
model, grade continuity , and extent of mineralization. It is uncertain if additional drilling will
validate the geological potential or fulfill the mining and economic criteria necessary to establish
reasonable prospects of eventual economic extraction to lead to the classification of the
Exploration Target as Mineral Resources.
Data Validation and QA/QC
Fireweed and its consultants conducted extensive statistical analyses to assess the quality of the
pre-Fireweed legacy drill hole data in preparation for this mineral resource estimate. The recent
re-assaying program has generally shown the data to be of good quality, but use of historical data
still presents certain risks in mineral resource estimation due to historical drilling, surveying,
sampling, and assaying methodologies. Data from a selection of assay intervals were checked
from each year of historical drilling against the original assay certificate or logs, representing 6%
of all samples, and was found to be free of errors with minor exceptions.
Assay standards, blanks and duplicates were monitored in Fireweed’s resampling program and
were found to be within acceptable levels of precision and accuracy. Surface assay samples were
taken by Garth Kirkham in 2022 and confirm the presence of tungsten in the locations tested. The
presence of UV-fluorescent scheelite was confirmed visually in outcrop and in core by the use of
a blacklight. A subset of historic al collar locations were surveyed by Fireweed personnel using
differential GPS and historical drillpad locations were further validated against a Digital Elevation
Model derived from a 2022 airborne LiDAR survey with good accuracy.
Mactung Location & History
Mactung straddles the Yukon and Northwest Territories border and is located 13 km north of
Fireweed’s Macmillan Pass Project camp and the government-maintained Macmillan Pass airstrip
(Map 1). It can also be accessed via the North Canol Road about 230 km from the town of Ross
River, Yukon.
Mactung was discovered and staked in 1962 by an Amax company geologist. Extensive drilling,
metallurgical testing, and multiple historical resource estimates were completed over the next
twenty years. The property changed ownership several times and was subsequently acquired by
North American Tungsten Corporation (“NATC”) in 1997. In 2007 NATC published updated
mineral resources (see Table 2) and in 2009 published a positive feasibility study (available at
www.sedar.com under the NATC profile). The Yukon Environmental and Socio-economic
Assessment Board (“YESAB”) Executive Council issued its Referral Report and New
Recommendation for Project Number 2008-0304 for the Mactung Mine Project in June 2014.
Following a recommendation to Decision Bodies that the Project be allowed to proceed to
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licensing without review, subject to specific terms and conditions, Decision Documents were
issued by the Yukon Government and Federal Government on September 3, 2014 and
August 1, 2014, respectively.
Subsequently, in June 2015, NATC filed for and was granted creditor protection mainly related to
operation of their Cantung mine located to the south. The Government of Northwest Territories
(“GNWT”) purchased the Mactung Project for $4.5 mill ion in 2015, and subsequently obtained a
Class 4 Mining Land Use Approval in 2020 for mineral exploration activities in the Yukon .
Fireweed recently signed a definitive Asset Purchase Agreement for the Mactung Project with the
GNWT (see Fireweed news release dated February 28, 2023 for details).
Mactung Geology & Mineralization
Mactung is a tungsten skarn deposit located on the eastern margin of the Selwyn basin in the
Canadian Cordillera’s Tombstone-Tungsten Belt (“TTB”). The mid-Cretaceous TTB spans Alaska,
Yukon, and Northwest Territories , and hosts many other significant mineral deposits. The
Mactung deposit is associated with Tungsten Suite intrusions that intruded late Precambrian to
Palaeozoic age, variably metamorphosed clastic and interbedded carbonate rocks of the Selwyn
Basin. The tungsten mineralization at Mactung i s comprised mostly of scheelite (CaWO4) and is
dominated by calcic mineral assemblages associated with abundant pyrrhotite that developed
within permeable limestone units of the Cambrian-Ordovician host rocks near a granite intrusion
contact.
About Tungsten
Tungsten is the hardest metal with the highest melting point, which makes it an important and
often essential metal for use in the automotive, tec hnology, energy, military, and manufacturing
industries. World tungsten production is dominated by China and there is currently limited
Western tungsten production, which has led tungsten to be listed as a critical mineral by many
governments, including Canada. The Canadian government has developed several initiatives to
support and advance the exploration and mining of critical minerals in Canada, including zinc and
tungsten.
Sustainability Context
Fireweed respectfully acknowledges that the Mactung Project is located within the T raditional
Territories of the Kaska Dena Nation and First Nation of Na-Cho Nyäk Dun, and the Sahtú
Settlement Area. For the benefit of present and future generations, Fireweed will conduct mineral
development activities in a sustainable manner by working collaboratively with Indigenous groups
and local communities, establishing a respectful and safe working environment, achieving a high
standard of environmental stewardship, and undertaking studies and implementing measures to
address local interests and issues.
Qualified Person Statement
Jack Milton, Ph.D., P.Geo. (BC), Fireweed’s VP Geology , and a Qualified Person as defined
under Canadian National Instrument 43-101, approved the technical information in this news
release except for information related to the Mactung mineral resource estimates. The re-
assaying activities at Mactung carried out by Fireweed were undertaken under the supervision of
Jack Milton.
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Garth Kirkham, P.Geo., of Kirkham Geosystems Ltd. is the Qualified Person, as defined in
National Instrument 43-101, is responsible for the Mactung mineral resource estimate and directly
related information as reported herein. He has read and approved the relevant technical portions
of this news release related to the mineral resource estimates for which he is responsible.
About Fireweed Metals Corp. (TSXV: FWZ; OTCQB: FW EDF; FSE:20F): Fireweed is a public
mineral exploration company on the leading edge of Critical Minerals project development.
Fireweed is well-funded, with a current cash position of over C$30,000,000 and is well-positioned
to carry out a large 2023 exploration program . The Company has three projects located in
Canada:
• Macmillan Pass Project (Zinc-Lead-Silver): Fireweed owns 100% of the district-scale
940 km2 Macmillan Pass project in Yukon, Canada, which is host to one of the largest
undeveloped zinc resources in the world* where the Tom and Jason zinc -lead-silver
deposits have current Mineral Resources 1 (11.21 Mt Indicated Resource at 6.59% zinc,
2.48% lead, and 21.33 g/t silver; and 39.47 Mt Inferred Resource at 5.84% zinc, 3.14%
lead, and 38.15 g/t silver ) and a Preliminary Economic Assessment 2 (PEA). In addition,
Boundary Main, Boundary West, Tom North and End Zone have significant zinc -
lead-silver mineralization drilled but not yet classified as mineral resources. The project
also includes large blocks of adjacent claims with known showings and significant upside
exploration potential.
• Mactung Project (Tungsten): The Company recently signed a definitive Asset Purchase
Agreement and acquired 100% interest in the 37.6 km2 Mactung Project located adjacent
to the Macmillan Pass Project. New mineral resources for Mactung described above
(41.5 Mt Indicated Resource at 0.73% WO3 and 12.2 Mt Inferred Resource at 0.59% WO3)
make it the world’s largest high-grade resource of the critical mineral tungsten*. Located
in Canada, it is one of the rare large tungsten resources outside of China.
• Gayna River Project ( Zinc-Lead-Gallium-Germanium): Fireweed has 100% of the
128.75 km 2 Gayna River project located 180 kilometres north of the Macmillan Pass
project. It is host to extensive mineralization including Critical Minerals zinc, gallium and
germanium as well as lead and silver, outlined by 28,000 metres of historic al drilling and
significant upside potential.
In Canada, Fireweed (TSXV: FWZ) trades on the TSX Venture Exchange. In the USA, Fireweed
(OTCQB: FWEDF) trades on the OTCQB Venture Market (www.otcmarkets.com ) and is DTC
eligible for enhanced electronic clearing and settlement. In Europe, Fireweed (FSE: 20F) trades
on the Frankfurt Stock Exchange.
Additional information about Fireweed and its projects can be found on the Company’s website
at FireweedMetals.com and at www.sedar.com.
ON BEHALF OF FIREWEED METALS CORP.
“Brandon Macdonald”
CEO & Director