The race for critical minerals is heating up by the day, but the pace of new discoveries has never been slower. High grade, large tonnage deposits on friendly soil are rare, but Talon Nickel’s Tamarack Project may be just what everyone’s looking for. Multiple new high-grade discoveries have been made in 2024 and 2025. While it’s still too early to be sure, Tamarack shows all the signs of being a world class deposit, or even district. But it’s located in a notoriously difficult jurisdiction and getting it built will be a test of America’s critical minerals strategy.
Part one of this article will focus on the geology of the Tamarack Project, while part two will look at the reality of what it means to attempt such a project in America today.
Project Overview
The Tamarack Project is 51% owned by Talon Nickel (USA) LLC, a wholly-owned subsidiary of Talon Metal Corp, and 49% owned by Kennecott Exploration Company (a subsidiary of Rio Tinto). Talon has the right to increase its stake to 60% through an earn-in agreement.
The project is located in central Minnesota, 89 km west of Duluth and 210 km north of Minneapolis. A network of railways and paved roads provides excellent access to the site. The town of Tamarack, population 62, is within the project are but outside the area of known mineralization. The project is divided into Tamarack North, which hosts the known resource, and the less-explored Tamarack South.
The Tamarack Project’s indicated resources stand at 8.564 Mt at 2.34% NiEq (1.73% nickel (Ni), 0.92% copper (Cu), 0.05% cobalt (Co), 0.34 g/t platinum (Pt), 0.21 g/t palladium (Pd), 0.17g/t gold (Au), and 8% recoverable iron (Fe)), with inferred resources of 8.461 Mt at 1.19% NiEq (0.83% Ni, 0.55% Cu, 0.02% Co, 0.23g/t Pt, 0.13 g/t Pd, 0.13 g/t Au, and 3% recoverable Fe). It should be noted that the resource estimate includes only 3 of the mineralized zones (the Massive Sulfide Unit (MSU), Semi Massive Sulfide Unit (SMSU), and 138 zones) and doesn’t include new discoveries and several less well defined mineralized zones. A feasibility study is currently being prepared and must be released by November 7 2025 if Talon is to exercise its option to increase its stake to 60%.
Although Fe is not usually considered to add value to sulfide deposits, a 2022 supply agreement with Tesla includes Fe in sulfides as payable. Some of the project claims are subject to royalties ranging from 2-3.9%.
Talon has holds the Boulderdash and Roland properties in Michigan, which were recently optioned to Lundin Mining, owner of the nearby Eagle mine. Lundin has the right to acquire up to a 70% interest in these properties.
Geology
The Tamarack Project is a magmatic sulfide deposit hosted within the Tamarack Intrusive Complex (TIC). The TIC is often compared to a tadpole, with a ~4 km wide rounded body and a thin, 7 km long ‘tail’ extending to the north. This tail hosts all of the known mineralization.
Like all magmatic sulfide deposits, Tamarack formed when metal-rich mafic or ultramafic magma became saturated in sulfur. This saturation causes metals such as Fe, Ni, Cu, Pt, Pd, and Au to bind to sulfur forming a new sulfide melt. This sulfide melt is immiscible in regular silicate magma, causing it to separate out like oil and water. Sulfide droplets scavenge metal from silicate magma they come into contact with, so a high degree of mixing (R-factor) is essential for forming high-grade deposits. If conditions are right the dense sulfide melt will sink and accumulate in low spots to form small but exceptionally metal-rich bodies of sulfide ore.
The TIC formed 1.1 billion years age as part of the mid-continent rift. The mid-continent rift nearly split North America in half and formed a new ocean; the vast scar it left allowed ultramafic magma to rise from deep within the Earth and also formed the depression currently filled by the great lakes.
The TIC is just one of many mafic/ultramafic intrusions associated with the mid-continent rift scattered throughout Minnesota, Wisconsin, and Ontario. The TIC intruded into sulfur-rich sedimentary rocks, which provided a source of sulfur to trigger sulfide saturation and mineralization. The TIC is not well understood, in large part because it is completely buried and can only be observed through drill holes and geophysics. It is interpreted to have formed in at least two phases: a large, fine-grained orthocumulate intrusion (FGO) making up most of the TIC in the south, and a slightly later course-grained orthocumulate (CGO) dyke-like intrusion in the north.
Mineralization is mostly associated with the contact between the FGO and CGO as well as contacts with the sedimentary rocks. The FGO is believed to be a former magma conduit and to be the source of mineralization. The 2022 technical report suggests the CGO didn’t achieve sulfur saturation or contribute directly to mineralization but did partially melt sulfide formed by the FGO and redistribute some of the sulfides.
Mineralization is contained within sulfides, mainly pyrrhotite, pentlandite, chalcopyrite, and minor cubanite. The style of sulfide mineralization varies from massive to net-texture to disseminated. The tenor is said to vary but little specific information is available. Mineralization occurs over a wide range of depths. Although mineralization is believed to be mainly flat-lying, the orientation of some mineralized zones is not fully understood.
A Hunt for Deeply Buried Treasure
Although the Tamarack Project doesn’t have a long history compared to some projects, it provides an interesting case study on the importance of persistence and scientific understanding.
The Tamarack Project area is covered by ~35-55 m of glacial sediment, with no exposed bedrock on the property. The TIC was discovered by the Minnesota Geologic Survey in 1984 by drilling a magnetic anomaly. This was done for scientific reasons; at the time it was thought that magmatic sulfide deposits couldn’t form in such small intrusions.
The TIC received little attention until the late 1990’s, when improved scientific understanding of magmatic deposits proved they could also be found in smaller feeder conduits through which large volumes of magma passed. Kennecott leased the property in 2000 based on magnetic and lake sediment anomalies and began drilling in 2002. Drilling initially encountered only low-grade disseminated mineralization, but a slow and steady drill campaign continued until 2008, when more significant massive sulfide mineralization was intersected, proving the TIC’s potential.
Kennecott continued modest drilling of hundreds to a few thousand meters per year until Talon took over drilling in 2020. Talon drilled 33,375 m in 2021 and 24,508 m in 2022. This led to a maiden resource estimate (which is still current at the time of writing) in 2022.
Continued drilling is paying off: in May 2025 Talon announced a remarkable discovery. While extending a historic hole to investigate a subtle borehole EM anomaly Talon’s drill intercepted 8.25 meters grading 12.62% Ni, 13.88% Cu, 17.95g/t PGEs+Au (23.28% NiEq or 48.87% CuEq). A follow up hole struck two zones of massive sulfide, with a cumulative intercept of 34.9 m at 14.86% Ni, 15.37% Cu, 0.11% Co, 9.18 g/t Au, 16.31 g/t Pt, 8.65 g/t Pd, and 42.92 g/t Ag (28.88% NiEq and 57.76% CuEq). For perspective, today most Ni is mined at <2% Ni. These intercepts are well outside the known mineralization, suggesting Tamarack’s potential is much higher than previously realized.
As if the news out of Tamarack North wasn’t enough, there’s also the newly identified Raptor Zone, which has a strike length of >250 m and has returned intercepts up to 5.93 m at 4.09% NiEq. Intriguingly, this seems to be hosted in the CGO, hinting that this intrusion may not be barren after all. Magnetotelluric (MT) surveys also indicate a massive anomaly ~900 m below the current Tamarack resource area (~1500 m below surface). Limited drilling has yet to make a significant discovery but has yielded hints that there may be a giant lurking in the depths. Clasts of massive sulfides intercepted in drill holes may represent droplets of sulfide in the process of sinking to a deeper pool. Talon is not planning to drill these deep targets in 2025.
There’s also Tamarack South, with contains the majority of the TIC. So far limited drilling has identified widespread low grade sulfide mineralization with the occasional small high-grade intercept.
The right rocks in the wrong place?
There’s a lot of potential at Tamarack. The established mineral resource is promising, but the newly discovered intercepts are simply extraordinary. Only a handful of world class deposits can boast anything similar. Very large volumes of highly prospective rock remain to be tested. Talon is already talking about district scale potential similar to world-class areas like Sudbury and Norilsk.
But, as anyone who follows mining projects knows, potential doesn’t always lead to profits. A lot of work remains to be done before we can be sure how much ore there really is, and if it’s minable. The Great Lakes area is notoriously resistant to mining projects, with projects like New Range/Polymet turning into political and regulatory fights that have yet to be resolved after many years.
Part two of this article will take a look at Tamarack’s likely future.
List of companies mentioned
- Talon Nickel: https://talonmetals.com/
- Kennecott Exploration: https://www.riotinto.com/en/operations/us/kennecott
- Lundin Mining: https://lundinmining.com/
Further Reading
- Talon Technical Report (2022): https://talonmetals.com/wp-content/uploads/2022/11/Final_NI43101_Report_Talon_TamarackN_20221102.pdf
