Summary

Mine Type	Underground
Study Completed	Preliminary Economic Assessment
Commodities	Copper Silver
Mining Method	Room-and-pillar Continuous
Mine Life	...
Snapshot	The White Pine North project is located in the area of the past-producing White Pine mine. A Preliminary Economic Assessment for the White Pine North project was completed in July 2023. Many assumptions are based on historical data from the old White Pine Mine. As of March 31, 2025, Kinterra Copper USA LLC, the JV partner and operator of the project, continues to advance through permitting and the pre-feasibility study: • Continued to advance the project toward a resource update. • Completed multiple key environmental baseline studies as part of ongoing preparations for permit submission. • Ongoing engineering trade-off studies are being conducted prior to commencing the Pre-Feasibility Study for the White Pine Project. Phase 1 of the metallurgical test work program has been completed. Geotechnical rock strength testing has also been finalized. In addition, trade-off studies evaluating site locations, power supply options, and tailings deposition methods have been initiated.
Latest News	Highland Copper Signs Binding Offer from Kinterra to Sell 34% Interest in White Pine North for US$30 Million     November 25, 2025

Deposit type

• Sediment-hosted

Summary:

The White Pine copper deposit is located in the Western Upper Peninsula of Michigan (USA) on the south side of Lake Superior. The copper mineralization in the area of the former White Pine Mine occurs in the bottom 6 m (20 ft) of the Nonesuch Formation at the contact with the Copper Harbor Conglomerate. The shale and siltstone in the lower part of the Nonesuch Formation are divided into two (2) mineralized shale units, the lower “Parting Shale” and the upper “Upper Shale”. The mineralized units are laterally persistent over tens of kilometres. The Parting Shale has an average thickness of 2.2 m for the entire of the deposit, and the Upper shale has a thickness of around 3.0 m.

The mineralization of the White Pine North Project is classified as a reduced facies stratiform sediment-hosted copper deposit and is often compared to the Kuperschiefer-type in Germany and Poland.

Mineralization
Copper mineralization at the White Pine North deposit occurs in two modes - as very fine-grained sulfide (chalcocite) and as native copper. Sulfide mineralization is estimated to account for 85-90% of the copper in the deposit, but both modes of copper are intimately associated throughout the deposit. The copper mineralization at White Pine North is very consistent. All drill holes within the deposit intercepted mineralized strata. Within the deposit, the grades of the copper mineralization are usually slightly above cut-off grade over normal mining configurations. Most of the beds in the mineralized horizon are interpreted as continuous over the entire deposit. The beds comprising the Parting Shale pinch out in the southwest part of the historical mine. The variation of the thickness of mineralized beds is also low from drill hole to drill hole.

Sulfide Mineralization: The dominant copper mineral in the White Pine North deposit is chalcocite (Cu2S). It occurs as fine-grained laminae in interbedded sandstone and shale, very-fine grained disseminations and discrete clots in siltstone, and in veinlets and veins. The top of the copper mineralization is identified as the Top of Mineralization (“TOM”) Line or “fringe,” a narrow transition zone between cupriferous and pyritic zones. The fringe is typically very narrow (a few inches) and is identified by the sequence: chalcocite, digenite, bornite, chalcopyrite, and pyrite. Immediately above the cupriferous zone is a narrow zone containing disseminated greenockite, galena, and wurtzite. The yellow color of greenockite is easily spotted in drill core when present. The TOM Line crosscuts stratigraphy. In the shallow areas of the mine to the west near the portal, the TOM Line is typically 9.5 m (30 ft) above the Lower Sand while to the east the TOM Line descends through the otherwise normally mineralized beds.

Native Copper: Native copper mineralization occurs throughout the deposit. The most significant occurrences are sheet copper and mineralized sandstone. Sheet copper forms along thrust surfaces in the southwest mine. The sheet copper in thrust surfaces is bedding parallel as well as cross-cutting stratigraphy. Sheets can reach spectacular sizes. It was observed that some sheets could be traced through entire pillars. Mineralized sandstone occurs in the uppermost part of the Copper Harbor Conglomerate and is invariably associated with trapped hydrocarbons. The greatest amounts of mineralized sandstone were found in areas adjacent to the White Pine fault.

Mixed Sulfide and Native Copper Mineralization: Native copper and chalcocite are found throughout the deposit. Native copper is found in close relationship to copper sulfide in sandy lenses and pods (load casts) in the Lower Transition. Native copper in the Lower Transition is more common in channels incised into the top of the CHC. Both chalcocite and native copper mineralization are ubiquitous features of the mineralization of the Dark Grey Massive bed as well; chalcocite occurs as very-fine grained disseminations; and native copper, as discrete blebs.

Structural Relationship: Structure imposes significant control on the distribution and grade of mineralization. Higher-grade mineralized zone is spatially associated with the White Pine fault and thrust and strike-slip faults in the Southwest mine. Part of the increase in grade is due to the presence of mineralized sandstone and/or sheet copper. In addition, chalcocite mineralization is also enhanced as wider lamellae and cross-cutting veins and veinlets in the laminites.

Formation Water: The formation water encountered in the CHC is an alkaline brine with a chloride and TDS content approximately twice that of seawater. These compositions are thought to represent an approximate original composition of the depositional lake water and mineralization bearing fluid. Further support for alkaline brines existing during Nonesuch times is the abundance of carbonate throughout the CHC and Nonesuch Formation. Hydrocarbons: The White Pine Mine is well-known for its hydrocarbon seeps. In many areas near the White Pine Fault, hydrocarbons seep out of the back, drip, and form puddles of “oil” on the floor. The most prolific seeps were noted in the northwest portion of the mine near and beneath the North Number One tailings dam.

Mining Methods

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Comminution

Crushers and Mills

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Processing

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Commodity Production

Operational metrics

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Personnel

Job Title	Name	Profile	Ref. Date
.......................	.......................		Aug 15, 2025
.......................	.......................		Jul 12, 2023
.......................	.......................		Jul 12, 2023
.......................	.......................		Jul 12, 2023
.......................	.......................		Aug 15, 2025

Employees	Year
......	2023