Sterling Metals Announces High-Grade Copper Discovery at the Soo Copper Project Intersecting 262.5m of 1.05% CuEq, Including 68.3m of 3.25% CuEq and 9.3m of 19.8% CuEq from Near Surface

Rhea-AI Summary

Sterling Metals (OTCQB:SAGGF) has announced a significant high-grade copper discovery at its Soo Copper Project in Batchewana Bay, Ontario. The discovery hole MEPS-25-02 intersected remarkable grades including 262.5m of 1.05% CuEq, with a high-grade zone of 68.3m grading 3.25% CuEq, and an exceptional interval of 9.3m of 19.8% CuEq from near surface.

The drilling revealed record-breaking results, including 33% Cu over 0.55m and 196 g/t Au with 21.3% Cu over 0.6m. Due to these promising results, Sterling has expanded its Phase 2 drilling program from 3,000m to at least 6,000m. The discovery indicates potential for a large-scale Cu-Au-Ag-Mo porphyry system, with the project strategically located just one hour north of Sault Ste. Marie, with access to rail and deep-water facilities.

Positive

• Exceptional high-grade copper discovery with 262.5m of 1.05% CuEq from near surface
• Record-breaking grades including 33% Cu over 0.55m and 196 g/t Au with 21.3% Cu over 0.6m
• Phase 2 drilling program doubled from 3,000m to 6,000m due to success
• Strategic location with excellent infrastructure access
• No pyrite or pyrrhotite in reported section, indicating high-quality mineralization

Negative

• True widths of mineralization not yet known
• Early-stage discovery requiring further delineation
• Metal recovery assumptions based on different project in Peru

TORONTO, ON / ACCESS Newswire / September 29, 2025 / Sterling Metals Corp. (TSXV:SAG)(OTCQB:SAGGF) ("Sterling" or the "Company") is pleased to announce the discovery of a high-grade copper zone at its Soo Copper Project ("Soo Copper" or the "Project") located in Batchewana Bay, Ontario. Drill hole MEPS-25-02, part of the Company's Phase 2 exploration program, discovered a high-grade copper and gold zone within a continuous, bulk-tonnage copper-molybdenum-silver-gold porphyry system (Figure 5).

Highlights

• Discovery hole intersects 262.5m of 1.05% CuEq starting from 47.5m downhole, including a new high-grade bornite zone with 68.3m grading 3.25% CuEq starting at 179.7m downhole, featuring semi-massive bornite and chalcopyrite grading up to 9.3m of 19.98% CuEq (see Table 1 for full results and Figure 6).

• Highest copper and gold grades encountered to date at Soo Copper, including:

  • 33% Cu over 0.55m starting at 220.45m depth; and

  • 196 g/t Au and 21.3% Cu over 0.6m starting at 219.85m depth.

• Newly discovered high-grade Cu-Au mineralization, characterized by bornite and associated porphyry dykes, indicates a robust, large-scale Cu-Au-Ag-Mo system with the potential to transform the Project.

• Phase 2 drilling has been expanded from a minimum of 3,000m to at least 6,000m.

• A core photo gallery is now available on Sterling's website, click here to view.

• The Company will be hosting a live webinar to discuss the results on Wednesday, October 1, 2025, at 11:00 am eastern. To register, click here.

Significance of the MEPS Target
The MEPS target was selected for its surface mineralization at the Cave Showing where Sterling Metals sampled veins with up to 15.9% Cu in 2024 (see press release dated October 29, 2024), its coincidence with a large resistivity low, and its proximity to the GFP Porphyry discovered in Phase 1 (hole MJ-25-01). The first hole drilled at MEPS provided critical geological context, refining the interpretation of the mineralized trend and guiding adjustments to subsequent drill angles.

Building on this foundation, MEPS-25-02 was designed to test a more favourable portion of the target. The hole revealed bornite within the first 25m and intersected continuous visible mineralization to over 350m downhole. Assays confirmed a 68.3m high-grade copper zone within a broader mineralized interval, including the highest copper and gold grades ever recorded at Soo Copper. Importantly, the reported interval contained no pyrite or pyrrhotite, reinforcing the high tenor of the system.

Sterling's leadership emphasized both the technical precision that guided the targeting of MEPS-25-02 and the bold decision-making that led to its success.

Jeremy Niemi, Senior Vice President Exploration and Evaluation, commented:
"By integrating surface geology, resistivity data, and insights from our Phase 1 drilling, we refined our targeting model and were able to adjust in real time. MEPS-25-02 immediately delivered bornite from near surface and went on to produce the highest copper and gold grades drilled to date. This validates our geological approach and confirms the GFP Porphyry as a key driver of mineralization at Soo Copper."

Dr. Neil O'Brien, Technical Advisor, added:
"This discovery clearly indicates the potential for a giant magmatic hydrothermal ('porphyry') Cu-Au-Mo deposit within the Batchewana peninsula. The high Cu-Au grades due to bornite, coupled with strongly developed potassic alteration and extensive porphyry dykes, all point to a robust and focused mineralizing event that we have just begun to tap."

Mathew Wilson, CEO and Director, concluded:
"The decision to drill MEPS-25-02 was not part of the original plan, but the team recognized the opportunity and had the conviction to act on it. That ability to combine rigorous science with decisive execution is exactly what positions Sterling to continue unlocking discoveries of this caliber."

Figure 1. Bornite, chalcopyrite and gold mineralization in MEPS-25-02 at 219.85m depth grading 23.1% Cu, 196 g/t Au and 168 g/t Ag over 0.6m.

Figure 2. Bornite-chalcopyrite mineralization at 220.75m depth in MEPS-25-02 grading 33% Cu, 0.342 g/t Au and 210 g/t Ag over 0.55m.

Figure 3. Massive chalcopyrite mineralization at 181.55m depth in MEPS-25-02 grading 13.3% Cu, 1.03 g/t Au and 22.9 g/t Ag over 0.4m.

Figure 4. Chalcopyrite and bornite copper mineralization in GFP porphyry unit in MEPS-25-02 at 216.2m depth grading 0.847% Cu, 0.054g/t Au and 7.1g/t Ag

Table 1. Phase 2 Drilling Mineralization Intervals

Hole	From	To	Length	Cu %	Mo%	Au g/t	Ag g/t	CuEq %
MEPS-25-01	Results pending
MEPS-25-02	5	341	336	0.43	0.004	0.39	2.75	0.85
Including	47.5	310	262.5	0.52	0.005	0.49	3.15	1.05
Including	179.72	248.0	68.28	1.39	0.007	1.83	8.46	3.25
Including	181.25	181.65	0.4	13.3	0.0003	1.03	22.9	14.5
Including	215.6	224.75	9.15	6.80	0.008	13.20	46.26	19.81
Including	219.85	220.45	0.6	21.3	0.0002	196	168	209.0
Including	220.45	221	0.55	33	0.0002	0.342	210	35.3

Intervals may not represent true widths which are not yet known and capping has not been applied to grades. CuEq grade calculations for reporting assumes spot metal prices September 23, 2025 metal prices of US$4.49/lb Cu, US$25.18/lb Mo, US$3750/oz Au and US$43.82/oz Ag and recoveries of 90% Cu, 85% Mo, 70% Au, 60% Ag. Recoveries used are from recent test work on the Solaris, Warintza Project in Peru which is a similar style mineralization to Copper Road. See "Mineral Resource Estimate Update - NI 43-101 Technical Report, Warintza Project, Ecuador" with an effective date of July 1, 2024, and available on SEDAR+ under Solaris Resources profile.

Figure 5. MEPS-25-02 and hole locations from Sterling Metals inaugural drilling at the Soo Copper Project.

Figure 6. Cross section showing trace of hole MEPS-25-02, mineralization and resistivity from Dias 3D IP survey in the background which matches porphyry alteration and mineralization.

Important Geological Observations in MEPS-25-02

• Bornite mineralization observed from 24m downhole to 350m.

• Highest gold and copper grades drilled to date.

• Close association of the high tenor and high-grade copper mineralization with GFP porphyry, present as strongly potassic altered and multiply veined aplitic dykes that were discovered in phase one drilling in April. No pyrite or pyrrhotite observed in the reported section of the drill hole - only chalcopyrite, bornite and lesser molybdenite.

• Broad extent of potassic (early biotite followed by potassic feldspar) alteration zone associated with GFP porphyry dykes and Cu-Au mineralization.

• Strongly altered and foliated Archean mafic volcanics are preferred host to copper sulphides, and particularly bornite mineralization in proximity to GFP porphyry dykes.

• Multiple stages and types of veining present, including early biotite, A-type quartz(-feldspar)-copper sulphides and copper sulphide-only veins, B-type quartz Mo-Cu sulphides veins and late quartz-carbonate-hematite retrograde veins.

Project Context
The Soo Copper Project sits just 20 minutes off the Trans-Canada Highway, one hour north of Sault Ste. Marie, and 20km from rail and deep-water access. With near-surface copper-one of the most critical of all critical metals-alongside gold, and with the project now demonstrating both scale and grade, Sterling sees the potential for Soo Copper to become a nationally significant asset as Canada accelerates its efforts to secure strategic copper resources. Prime Minister Carney's recent designation of copper as one of Canada's first five strategic assets underscores the importance of this discovery and its potential to emerge as a key project of national interest.

Table 2. Hole locations, direction and final depths.

Hole ID	Easting	Northing	Elevation	Depth (m)	Dip	Azimuth
MEPS-25-02	681061	5212471	457	597	-70	330

Sampling Procedures - Quality Assurance/Quality Control
Analytical services were provided by Actlabs, which is an independent, CALA- and SCC-accredited analytical services firm registered to ISO 17025 and ISO 9001 standard. Drill core samples were logged and split in half with a diamond core saw. Half-core samples were securely stored at the core logging facility until being delivered to Actlabs Thunder Bay lab by commercial transport. Samples were crushed (< 7 kg) up to 90% passing 2mm (10 mesh), riffle split to 250 g and pulverized by mild steel to 95% passing 105μm (150 mesh). Samples splits underwent a 4-acid near total digestion followed by a multi-element analysis, including base metals, using an ICP method for 35 elements. Selected sample pulps were then analyzed for gold using a 30 g aliquot mixed with fire assay fluxes and Ag as a collector, placed in a fire clay crucible, gradually heated to 1060ºC for 60 min, and followed with an AA finish.

Laboratory QA/QC for the ICP analysis was 14% for each batch, including 5 method reagent blanks, 10 in-house controls, 10 samples duplicates, and 8 certified reference materials. An additional 13% QA/QC was performed as part of the instrumental analysis to ensure quality in the areas of instrumental drift. Laboratory quality control for the gold fire assay included two blanks per 42 samples, three sample duplicates and 2 certified reference materials, one high and one low (QC 7 out of 42 samples). In-house QA/QC included the systematic insertion of blanks, duplicates, and certified reference materials (CRM).

Qualified Person
Jeremy Niemi, P.Geo., Senior Vice President, Exploration and Evaluation for Sterling Metals has reviewed and approved the technical information presented herein.

About Sterling Metals
Sterling Metals is a mineral exploration company focused on large scale and high-grade Canadian exploration opportunities. The Company is advancing the 25,000-hectare Soo Copper Project in Ontario which has past production, and multiple breccia and porphyry targets strategically located near robust infrastructure and the 29,000-hectare Adeline Project in Labrador which covers an entire sediment-hosted copper belt with significant silver credits. Both opportunities have demonstrated potential for important new copper discoveries, underscoring Sterling's commitment to pioneering exploration in mineral rich Canada.

Sterling Metals acknowledges that its exploration activities within the Soo Copper project are conducted on the traditional lands of the Batchewana, Garden River, and Michipicoten First Nations of the North Shore of Lake Superior. We recognize and respect the longstanding and diverse relationships Indigenous Peoples have with the land and are committed to engaging in a manner that is respectful, transparent, and inclusive.

For more information, please contact:

Sterling Metals Corp.
Mathew Wilson, CEO and Director
Tel: (416) 643-3887
Email: info@sterlingmetals.ca
Website: www.sterlingmetals.ca

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 release.

This news release contains certain "forward-looking information" within the meaning of applicable securities laws. Forward looking information is frequently characterized by words such as "plan", "expect", "project", "intend", "believe", "anticipate", "estimate", "may", "will", "would", "potential", "proposed" and other similar words, or statements that certain events or conditions "may" or "will" occur. These statements are only predictions. Forward-looking information is based on the opinions and estimates of management at the date the information is provided and is subject to a variety of risks and uncertainties and other factors that could cause actual events or results to differ materially from those projected in the forward-looking information. For a description of the risks and uncertainties facing the Company and its business and affairs, readers should refer to the Company's Management's Discussion and Analysis. The Company undertakes no obligation to update forward-looking information if circumstances or management's estimates or opinions should change, unless required by law. The reader is cautioned not to place undue reliance on forward-looking information.

SOURCE: Sterling Metals Corp.

View the original press release on ACCESS Newswire

FAQ

What were the key copper grades discovered in Sterling Metals' (SAGGF) MEPS-25-02 drill hole?

The MEPS-25-02 hole intersected 262.5m of 1.05% CuEq, including a high-grade zone of 68.3m grading 3.25% CuEq, and an exceptional interval of 9.3m of 19.8% CuEq from near surface.

Where is Sterling Metals' Soo Copper Project located and what is its infrastructure access?

The Soo Copper Project is located in Batchewana Bay, Ontario, just 20 minutes off the Trans-Canada Highway, one hour north of Sault Ste. Marie, and 20km from rail and deep-water access.

What was the highest grade copper intersection in Sterling Metals' MEPS-25-02 hole?

The highest grade intersection was 33% Cu over 0.55m starting at 220.45m depth, along with another exceptional intersection of 196 g/t Au and 21.3% Cu over 0.6m.

How has Sterling Metals modified its Phase 2 drilling program after these results?

Following the discovery, Sterling Metals has expanded its Phase 2 drilling program from 3,000m to at least 6,000m to further explore the potential of the copper system.

What type of mineralization system was discovered at the Soo Copper Project?

The discovery indicates a robust, large-scale Cu-Au-Ag-Mo porphyry system, characterized by bornite and associated porphyry dykes, with continuous mineralization observed from near surface.