CEO.CA Chairman's Briefing

Toronto, Ontario--(Newsfile Corp. - September 9, 2026) - Nuvau Minerals Inc. (TSXV: NMC) is pleased to report initial assay results from its summer drilling program at Thundermine (also called Thunderwood), one of the primary gold-focused targets, within its Matagami Mining District Property, in Québec, Canada. Initial drilling has intersected exceptionally high-grade quartz-tourmaline veins within a much broader intrusive-hosted mineralized system, providing important new information on the scale and character of the emerging Thundermine gold system.

VIDEO DISCUSSING THUNDERMINE AND TODAY’S RESULTS
Hear directly from Nuvau management on the Thundermine results and what the geology is telling us.

Highlights of drill results:

• TH-26-08 intersected 138.87 grams per tonne (g/t) gold (Au) over 4.45 metres, including two exceptionally high-grade quartz-tourmaline veins grading 629.15 g/t Au over 0.85 metres and 236.95 g/t Au over 0.35 metres.
• Widespread gold mineralization (TH-26-05) intersected over 180.4 metres, averaging 0.57 g/t Au across the interval and containing multiple mineralized veins and veinlets, including 10.52 g/t Au over 2.70 metres and five individual intervals above 10 g/t Au.
• All 10 summer drillholes intersected the targeted tonalitic intrusive and associated hydrothermal system, with visible gold observed in seven holes.
• Assays from seven drillholes remain pending, while the mineralized system remains open at depth and to the southeast within a broader kilometre-scale structural and geophysical area of interest.

"These initial assay results from Thundermine, together with the geological data accumulated from 10 holes of drilling, are very encouraging and have established this as a highly prospective gold target. These are the first assays from our summer drill program," said Christina McCarthy, Nuvau's Chief Executive Officer. "We have intersected high-grade gold veins within a much broader disseminated intrusive and are seeing the same setting continue as we step away from the limited area that was drilled historically."

McCarthy added, "The similarities to the quartz-tourmaline gold systems with the large-scale gold deposits in the Sigma-Lamaque district in Val-d'Or provide a compelling geological model to follow, and Thundermine remains open at depth and along strike. With seven holes still pending and only a small part of the larger prospective trend tested, we are just getting started."

Figure 1: Mineralization and visible gold in quartz-tourmaline veining from TH-26-08.

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From Historical Gold Occurrences to an Emerging Gold System
Thundermine, located in the northern sector of Nuvau's Matagami property, was first explored for copper in the late 1950s, before limited drilling in the 1980s identified an adjacent gold showing in six holes. Selective historical sampling returned non-verified intervals¹ including 78.16 g/t Au over 1.0 metre, 26.40 g/t Au over 0.8 metres, and 3.73 g/t Au over 9.4 metres. Despite these results, the gold showing saw no follow-up drilling for nearly 40 years.

Nuvau returned to Thundermine in 2026 for the first modern, systematic, evaluation of its gold potential. Winter drilling intersected 5.28 g/t Au over 6.1 metres, including 7.22 g/t Au over 3.1 metres, approximately 200 metres below the historical intercepts. In the summer, Hole TH-26-05 tested a historical mineralized position, providing modern geological observations and assays against which the historical information could be compared. Subsequent holes stepped out approximately 25 to 50 metres from historical intercepts and from one another (Figure 2), extending the tested footprint approximately 80 metres to the southeast and 200 metres deeper than historical drilling, with all 10 holes intersecting the targeted tonalitic intrusive and associated hydrothermal system.

The emerging picture is increasingly compelling.

Drilling is outlining a broad, mineralized intrusive cut by multiple generations of gold-bearing veins, including locally very high-grade quartz-tourmaline veins. The setting shares characteristics with the well-known orogenic gold systems of the Sigma-Lamaque district in Val-d'Or, providing an important geological model for continued exploration. Combined historical and Nuvau drilling now traces the geological framework for more than 300 metres along trend and more than 400 metres vertically, and it remains open to the southeast and at depth within a broader kilometre-scale area of interest.

Table 1: Selected Thundermine drillhole assays above 5 grams of gold per tonne of rock (g/t). All reported lengths are measured along the drill core and do not necessarily represent the true thickness of the mineralized zone.

Figure 2: Plan View (A) of Thundermine target (B) Location of Thundermine within Nuvau's Matagami property package.

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Geological Context and Emerging Model
Drilling is progressively defining the three-dimensional architecture of the Thundermine intrusive-hosted gold system. The tonalitic intrusive forms a steeply dipping body interpreted to be approximately 150 metres thick, with locally developed branches or apophyses extending into the surrounding volcanic sequence (Figure 3).

Pervasive sericite-silica alteration is associated with multiple generations of quartz-carbonate-tourmaline(-fuchsite) veins containing pyrite and minor chalcopyrite. The relative timing and spatial relationships between these vein generations and associated alteration are not yet fully resolved, and alternative interpretations are being evaluated.

Gold mineralization is spatially associated with the vein system, with locally high-grade mineralization hosted in discrete veins and broader disseminated and veinlet-hosted mineralization developed in the altered intrusive around and between them. The persistence of the intrusive, alteration, and vein assemblages across the drillholes supports geological continuity of the hydrothermal system, although their intensity and associated gold grades vary between and within holes (Figure 4).

At a broader scale, drilling, structural interpretation and geophysical data define a kilometre-scale prospective trend centred on the intersection of local and regional structural breaks, interpreted to have provided a favourable setting for intrusive emplacement and subsequent hydrothermal fluid circulation (Figure 5).

With assays from seven holes pending, Nuvau is integrating analytical results with lithological, alteration, structural, and mineralogical observations to refine the geological model and controls on higher-grade mineralization. The expanded dataset will test these interpretations and guide subsequent step-out drilling along trend and at depth.

Figure 3: Cross section B and C, looking northwest (60 m projection window). All reported lengths are core lengths; true widths are unknown. All reported gold grades are length-weighted averages. Unsampled intervals resulting from selective sampling are assigned a grade of 0 g/t Au for the purpose of calculating composite grades.

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Figure 4: Selected core photographs showing representative veining and alteration within the mineralized tonalitic intrusive. Gold occurs in veins, veinlets, and disseminated in the associated alteration.

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Figure 5: Geological and structural setting of the Thundermine target within Nuvau's Matagami property integrating drilling and magnetic data and highlights the currently tested area relative to the broader prospective footprint.

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Table 2: Selected Thundermine summer drillhole assays above 1 g/t Au. Composite intervals represent the length-weighted average gold grade across the main mineralized intervals within the tonalitic intrusive; mineralization also occurs outside these intervals. Unsampled intervals and assays below the detection limit are assigned 0 g/t Au for composite calculations. All reported intervals are lengths measured along the drill core. The true thickness of the mineralized zones cannot yet be determined from the available drilling.

Table 3: Drillhole locations.

Quality Assurance, Quality Control, and Data Verification
Drill core is logged, photographed, sawn in half, and sampled at Nuvau Minerals' secure core facility. One half of the core is submitted for analysis, and the remaining half is retained on site for reference. Samples are sealed in individually labelled plastic bags and transported under chain-of-custody procedures to MSALABS in Val-d'Or, Québec, an independent ISO/IEC 17025-accredited laboratory.

Samples are dried, crushed to achieve approximately 70% passing 2 mm, and prepared for analysis. Gold assays are completed using PhotonAssay™ technology on a nominal 500 g aliquot. The Company's quality assurance and quality control (QA/QC) program includes certified reference materials, blanks and duplicate samples, representing approximately 11% of all submitted samples. Additional QA/QC samples are inserted at intervals that contain visible mineralization. MSALABS also applies its internal quality control procedures in accordance with its accredited analytical protocols.

Analytical results are reviewed through a comprehensive QA/QC verification process, including the evaluation of standards, blanks, and duplicate samples. Reanalysis is conducted systematically where QA/QC criteria are not met. The Qualified Person reviews the analytical results, QA/QC data, and verification procedures disclosed herein and considers the results to be reliable and suitable for reporting.

Qualified Person
The scientific and technical information contained in this news release has been reviewed and approved by Bastien Fresia, P. Geo. (Qc), Director of Technical Services and a "qualified person" for the purposes of National Instrument 43-101.

About Nuvau
Nuvau Minerals (TSXV: NMC) is a Canadian mining and exploration company advancing a historic mining camp toward a production restart while generating new critical metal and gold discoveries. Its flagship asset is the past-producing Matagami mining district in northern Québec. Nuvau controls a 1,380-square-kilometre land package and benefits from access to permitted mining infrastructure, including an option on a 3,000 tpd concentrator. The Company's strategy is to combine district-scale exploration targeting zinc-copper VMS deposits and newly recognized gold potential with resource growth and project development.

Cautionary Statements
This news release contains forward-looking statements and forward-looking information (collectively, "forward-looking statements") within the meaning of applicable securities laws. Any statements that are contained in this news release that are not statements of historical fact may be deemed to be forward-looking statements. Forward-looking statements are often identified by terms such as "may", "should", "anticipate", "will", "estimates", "believes", "intends", "expects" and similar expressions which are intended to identify forward-looking statements. More particularly and without limitation, this news release contains forward-looking statements concerning: the completion and timing of any remaining post-closing filings and registrations with governmental authorities; the timing and form of payments contemplated by the Earn-In Agreement (including any election to satisfy a portion of such payments in Common Shares), and if applicable, the receipt of any required stock exchange and other regulatory approvals; the potential future acquisition of the excluded property and satisfaction of applicable conditions related thereto; the Company's planned exploration activities and the timing thereof; the completion of the 2026 summer drill program at Thundermine; the timing and receipt of outstanding assay results; the interpretation of drill results, including the geometry, thickness, strike extent and continuity of mineralization; the potential for mineralization to extend at depth and along strike; the Company's plans for follow-up drilling and further exploration at Thundermine; and the timing and ability of the Company to advance the Property to production decision. Forward-looking statements are not a guarantee of future performance and are based upon a number of estimates and assumptions of management, in light of management's experience and perception of trends, current conditions and expected developments, as well as other factors that management believes to be relevant and reasonable in the circumstances. Readers are cautioned that assumptions used in the preparation of any forward-looking statements may prove to be incorrect. Events or circumstances may cause actual results to differ materially from those predicted as a result of numerous known and unknown risks, uncertainties and other factors, many of which are beyond the control of the Company. Factors that could cause actual results to differ materially from such forward-looking statements are set out in the Company's public disclosure record available on SEDAR+ (www.sedarplus.ca) under the Company's issuer profile. Readers are further cautioned not to place undue reliance on any forward-looking statements, as such information, although considered reasonable by the management of the Company at the time of preparation, may prove to be incorrect and actual results may differ materially from those anticipated.

The forward-looking statements contained in this news release are made as of the date of this news release, and are expressly qualified by the foregoing cautionary statement. Except as expressly required by securities law, the Company does not undertake any obligation to update publicly or to revise any of the included forward-looking statements, whether as a result of new information, future events or otherwise.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release. No stock exchange, securities commission or other regulatory authority has approved or disapproved the information contained herein.

¹ Historical Results and Reported Lengths: The historical drill results referred to above are taken from assessment reports GM 48216 and GM 08790, available through the Government of Québec's GESTIM system. The historical core is no longer available; the reported assay results have not been independently verified by Nuvau and are not compliant with NI 43-101. Nuvau's drilling has tested the position and geological context of selected historical mineralization and, where appropriate, uses historical drilling to support the evolving geological interpretation. All lengths reported in this news release, both historical and current, are drilled core lengths; true widths are not known at this time.

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