Lion at a Glance

~406Mlb contained CuEq | ~3.9% CuEq | >85% Indicated | Starts at surface |~59% of tonnes within open-pit resource | >98% Cu recovery | 25%+ Cu concentrate | MRE cut-off April 19| 5 rigs active| Post cut-off deep drilling not included | Assays expected by end of September

TORONTO, Sept. 8, 2026 /PRNewswire/ -- Power Metallic Mines Inc. (the "Company" or "Power Metallic") (TSXV: PNPN) (OTCBB: PNPNF) (Frankfurt: IVV1) is pleased to announce an updated Mineral Resource Estimate ("MRE") for its Nisk Project (Power Metallic 80% / Critical Elements Lithium Corp. 20%) in the Eeyou Istchee James Bay territory of Québec, including the inaugural mineral resource for the Lion Zone and an updated mineral resource for the Nisk Main deposit. The MRE was prepared by SGS Canada Inc. ("SGS") in accordance with National Instrument 43-101 – Standards of Disclosure for Mineral Projects ("NI 43-101") and the CIM Definition Standards for Mineral Resources and Mineral Reserves (2014), has an effective date of June 19, 2026, and incorporates drilling completed to April 19, 2026.

Power Metallic has declared the inaugural Mineral Resource Estimate for the Lion Zone, a high-grade, copper-dominant polymetallic deposit discovered in 2023 at the Nisk property. Over 85% of the initial Lion resource is classified as Indicated, while mineralisation remains open for expansion.

Lion contains 4,145,000 Mt Indicated at 3.86% CuEq (1.68% Cu, 2.61 g/t Pd, 0.85 g/t Pt, 0.49 g/t Au, 12.21 g/t Ag, 0.10% Ni), and 601,000 Mt Inferred at 4.01% CuEq (1.84% Cu, 2.86 g/t Pd, 0.59 g/t Pt, 0.41 g/t Au, 12.47 g/t Ag, 0.13% Ni).

Locked-cycle testing completed by SGS Canada of representative mineralization from Lion has returned copper recoveries above 98% across all composite samples tested, producing concentrates grading over 25% Cu, with high recoveries also reported for gold, palladium, platinum and silver.

The Company is currently assessing proposals from engineering firms to complete a Preliminary Economic Assessment ("PEA") evaluating the development potential of Lion including the integration of the Nisk resource.

Ongoing resource expansion drilling with 5 active rigs is targeting extensions at depth and along strike with assays from the summer 2026 program expected starting in September 2026.

The updated MRE also restates the existing Nisk nickel-copper resource, which will be assessed alongside Lion as part of the broader PEA development strategy.

Mineral Resource Statement

2026 Lion Deposit Mineral Resource Estimate at a cut-off grade of 0.35% CuEq for the open pit MRE and 0.90% CuEq for the underground MRE, June 19, 2026.

2026 Nisk Deposit Mineral Resource Estimate at a cut-off grade of 0.30% NiEq for the open pit MRE and 0.80% NiEq for the underground MRE, June 19, 2026.

Terry Lynch, CEO of Power Metallic, commented:

" This inaugural Lion resource confirms what the drilling has been telling us: Lion is a high-grade polymetallic deposit. Approximately 4.75 million tonnes grading close to 4% CuEq has been defined, containing approximately 406 million pounds of CuEq, with more than 85% of the resource already in the Indicated category. Importantly, high-grade mineralisation begins at surface, and the deposit remains open at depth. We believe the quality of Lion has been demonstrated. Now our focus is on demonstrating its scale.

The Federal and Québec governments have put a number of incentive programs in place for critical-minerals projects, and we believe the Company may qualify for several of them. Combining these potential incentives with the high-grade mineralisation from surface and our location next to existing road and major power infrastructure, Lion has the potential to be developed with a relatively modest initial footprint and capital requirement.

From here, the exploration question is how deep Lion goes and where the nickel went. Lion carries the copper and precious metals that come out of a magmatic sulphide system last; the nickel-rich sulphide that comes out first should be somewhere in the system, and we have not found it yet. The summer program has been aimed at the down-dip extension of the shoot, with some holes targeting hundreds of metres below the current resource. Assays on Lion Deep are expected by the end of September"

Joe Campbell, VP Exploration of Power Metallic, added:

"Lion is a textbook fractionated copper- and precious-metal-rich shoot within a magmatic sulphide system. The advantage at Lion over similar deposits of this type is that it begins at surface and is modelled continuously to more than 600 metres vertical depth. The deposit remains open at depth and our priority since the April 19, 2026 cut-off date for drill holes in the MRE has been to test the shoot below 600 metres with deep step-out drilling, following up with borehole EM to delineate more mineralization."

Lion Zone Geology and Depth Potential

The Lion Zone comprises multiple modelled lenses of copper–PGE–gold–silver–nickel–cobalt sulphide mineralization that together form a continuous, steeply plunging shoot extending from surface to approximately 675 metres down-dip (more than 600 metres vertical depth), the limit of drilling included in the MRE to April 19, 2026. The modelled shoot is approximately 400 metres along strike at its widest and 290 metres at its narrowest, and consists of multiple subparallel lenses, each approximately 2 to 15 metres thick, within a mineralized package up to 50 metres thick that dips at approximately 65° to the north-northwest. The high-grade core of the shoot is dominated by massive to brecciated chalcopyrite and cubanite with pyrrhotite, pentlandite and pyrite. The deepest reported hole intersecting the core of the Lion shoot to date (PML-25-002) intersected 1.95 metres at 7.95% CuEqRec* at approximately 610 metres vertical depth (see news release dated April 30, 2025). The Deposit remains open at depth with subsequent deeper drilling, as illustrated by drill targets PML26-121A, PML-26-125 and PML-26-128A in Figure 1, completed after the cut-off date for the MRE and below the modelled zone intersecting visible copper mineralization (assays pending).

Lion is interpreted as a magmatic sulphide system. As the sulphide liquid cools, nickel-rich monosulphide solid solution crystallizes first and the residual liquid becomes progressively enriched in copper, platinum, palladium, gold and silver. This fractionated, copper- and precious-metal-rich liquid is the most mobile phase and migrates furthest away, from the original source; the copper–PGE footwall vein deposits of the Sudbury district are the classic example. Lion's metal endowment – dominated by copper, palladium, platinum, gold and silver with subordinate nickel and cobalt, and with the highest palladium grades hosted in massive copper sulphide – is consistent with that fractionated end-member. The Company's working model is that the Lion shoot represents a gravity-driven sulphide accumulation whose down-plunge extent has not yet been tested.

Depth continuity of this order is well documented in analogous camps. In the Sudbury district, the Creighton mine has been developed to approximately 2.4 kilometres below surface; Glencore's Onaping Depth project has reached ore at approximately 2,600 metres; Nickel Rim South was mined between approximately 1,100 and 1,720 metres; and the copper–PGE footwall veins of the Morrison deposit at Levack were developed between approximately 1,200 and 1,650 metres and remain open at depth. Readers are cautioned that the depth extent and grade of mineralization at these deposits are not necessarily indicative of the mineralization at Lion, which has been drilled to approximately 600 metres vertical depth (see "Cautionary Notes" below).

Power Metallic's program to test the down-plunge extension of the Lion shoot includes borehole electromagnetic surveys from the deepest holes on the shoot, and deep step-out and wedge drilling from existing collars. Results will be incorporated into future resource updates.

Metallurgy

Metallurgical test work on Lion mineralization has been carried out by SGS at its Quebec City and Lakefield laboratories (see news releases dated January 19, 2026 and May 26, 2026). Two locked-cycle flotation tests have been completed: LCT1, on a blended composite of high-grade and low-grade material representative of run-of-mine feed, and LG2, on a low-grade composite of disseminated mineralization designed to test whether lower-grade material responds to conventional flotation. Both tests produced a single high-grade copper concentrate carrying the platinum, palladium, gold, silver and nickel, with results summarized in Table 4. The LG2 results support the inclusion of lower-grade disseminated material in the Mineral Resource. Mineralogical work indicates that copper occurs as coarse-grained chalcopyrite and cubanite and that most platinum-group minerals occur within or attached to those copper sulphides (see news release dated July 23, 2025). Hydrometallurgical testing of the copper concentrate to evaluate a direct-to-metal processing route is in progress. The metallurgical recoveries applied in the MRE are set out in Note 7 to Table 1.

These metallurgical results are analogous to similar deposits in the Sudbury camp noted above and typical of the high-grade Cuprous zone or Copper zone of these deposits.

Table 4: Lion Zone locked-cycle flotation test results (SGS Canada Inc.)

Location and Infrastructure

The Nisk Project is in the Eeyou Istchee James Bay territory of Québec, approximately 280 kilometres north-northwest of Chibougamau and 425 kilometres northeast of Matagami.