“This update confirms the Lundberg Deposit as a large, pit-constrained copper-zinc resource in one of Newfoundland’s most prolific mining districts and a cornerstone for development of the Buchans District, including Canterra’s other hub-and-spoke deposits.” – Chris Pennimpede, President and CEO

Highlights – 2026 Lundberg Mineral Resource Estimate (effective September 2, 2026)

• 55% increase in Indicated tonnage. The Lundberg Deposit now hosts 26.1 million tonnes (Mt) in the Indicated category, compared with 16.8 Mt in the 2019 estimate, reflecting 4,779 m of drilling completed since acquiring the project in 2024 together with an optimized pit shell at updated metal prices.
• 34% increase in Indicated contained copper equivalent (“CuEq”). 226 thousand tonnes (kt) of CuEq, including 95 kt of copper, 342 kt of zinc and 146 kt of lead, together with 4.2 million ounces of silver and 51,000 ounces of gold contained in the Indicated category. Copper is the largest contributor to CuEq value (approximately 42%).
• 97% of Mineral Resource tonnage is in the Indicated category. The resource is constrained within an optimized pit shell with an overall strip ratio of 3.16:1 (waste to mineralized material), providing a well-defined, open-pit resource base.
• High-grade growth at Two Level zone. Inferred resource grade of 1.54% CuEq includes the massive sulphide mineralization of the Two Level zone. Follow-up drilling will target opportunities to expand the resource, increase grade and upgrade resource confidence.
• Near-resource exploration. The 2.5 km Mine Trend extending northwest of the Lundberg resource represents a high-priority, near-resource exploration target, with potential to expand the resource through drilling at the limits of the resource and on extensions of the existing high-grade underground mine workings.
• A brownfields platform for district growth. The expanded resource strengthens the foundation for evaluating development options across the Company’s central Newfoundland portfolio. The high-grade satellite deposits within a 45 km radius of Lundberg offer potential opportunities to grow the district’s resource inventory, and a shared processing or development concept remains a priority.
• Extensive exploration drilling underway with results expected into 2027. Results are pending for 6,000 m of drilling, to be reported through the remainder of the year and into 2027.

Canterra Minerals Corporation (TSX-V: CTM) (OTCQB: CTMCF) (FSE: DXZB) is pleased to announce an updated Mineral Resource Estimate for the Lundberg Deposit, part of its 100%-owned Buchans Project in central Newfoundland. The 2026 MRE is constrained within an optimized pit shell and provides a strong foundation for the next phase of exploration and technical evaluation at Buchans, including the integration of satellite deposits.

Chris Pennimpede, President and CEO of Canterra, commented:

“Lundberg now hosts 226 kt of contained copper equivalent in the Indicated category, including significant zinc, lead, silver and gold. Having significantly increased the deposit’s metal inventory, we now expect work at Lundberg to shift towards delineating the high-grade Two Level zone, testing extensions of the deposit and systematically drilling the Mine Trend, where significant opportunities remain for Buchans-style discoveries. Together with continued exploration at our other satellite deposits, the expanded Lundberg resource will serve as the foundation for our broader district development strategy.”

Video Overview

Chris Pennimpede, Canterra’s President and CEO, discusses the Lundberg resource update and the Company’s exploration priorities in this video overview. Click here to watch. The full Mineral Resource tables, assumptions and qualifications are provided in this release.

2026 Lundberg Mineral Resource Estimate

The 2026 MRE was prepared by Matthew Harrington, P.Geo., of Mercator Geological Services Limited (“Mercator”) and is summarized in Table 1, which presents tonnes and grades together with contained metal by Mineral Resource category.

Table 1. Lundberg Deposit Mineral Resource Estimate – Effective Date September 2, 2026

Contained metal is in situ and does not represent recovered metal. Contained metal and CuEq grades are calculated from unrounded tonnes and grades before rounding for presentation. Mt = million tonnes; kt = thousand tonnes; Moz = million ounces; koz = thousand ounces. A complete statement of Mineral Resources, including the accompanying notes, can be found in Table 4 of this release.

Table 2. Comparison of the 2026 MRE with the 2019 MRE (now historical) by Mineral Resource category

Percentage changes are calculated from unrounded quantities and may differ from changes calculated from the rounded figures shown. 2019 contained metal is calculated from the published 2019 tonnes and grades. (1) 2019 CuEq grades and contained CuEq have been recalculated using the 2026 MRE metal prices, recoveries and payability factors (Note 7 to Table 1) to allow a like-for-like comparison and differ from the CuEq values originally published with the 2019 MRE.

Table 3. Principal economic assumptions – 2019 MRE and 2026 MRE

2026 MRE metal prices and NSR cut-off as set out in Notes 3 and 8 to Table 1. Percentage changes are calculated from the prices shown.

 Figure 1. Longitudinal view comparing the 2019 (blue) and 2026 (red) Lundberg Mineral Resource extents and constraining pit shells; in the inset plan view, the black outline marks the 2026 shell. The shells are resource reporting constraints, not proposed mine plans.

Resource Growth and the Buchans District Opportunity

Canterra’s 2024–2026 exploration has defined additional stockwork mineralization at greater depth, extended the deposit to the northeast and down plunge to the northwest, and defined additional massive to brecciated sulphide mineralization at Two Level (Figure 2). The Two Level mineralization, a horizon of transported massive sulphide that plunges moderately northward, is continuous with historical Two Level mining and remains open to the north, east and west. It contributes to the Inferred resource and is a priority for potential expansion and upgrading.

Previous drilling demonstrates the grade potential at Two Level:

• Hole H-25-3542 intersected 4.45 m grading 1.11% Cu, 11.38% Zn, 7.02% Pb, 125.5 g/t Ag and 1.24 g/t Au (7.73% CuEq) from 188.90 m to 193.35 m downhole (reported November 19, 2025; estimated true widths approximately 90% of core length), expanding the zone’s mineralized footprint to approximately 200 m by 50 m.
• Hole H-26-3563 intersected 1.65 m grading 0.63% Cu, 6.11% Zn, 3.43% Pb, 92.3 g/t Ag and 0.69 g/t Au (4.34% CuEq) from 165.75 m to 167.40 m downhole (reported June 3, 2026; estimated true widths approximately 80–90% of core length).

Figure 2. Oblique view of the modelled Lundberg and Two Level mineralization domains relative to the 2026 Mineral Resource reporting pit shell. Remnant massive sulphide domains are shown in dark blue; the inset shows their position in plan view.

These results support further testing of Two Level along strike and at depth. Canterra will also use the updated Lundberg model, historical mine records, recent drilling and geophysical results to rank targets along the Buchans Mine Trend. The Two Level zone and areas beyond the Lundberg pit shell provide opportunities to test for additional high-grade massive sulphide mineralization near the past-producing orebodies. Follow-up drilling will focus on targets with the strongest combined geological and geophysical support (Figure 3). In parallel, the Company intends to define the scope of metallurgical testing to advance its assessment of processing options.

Figure 3. Plan view of the Buchans Mine Trend showing the 2026 Lundberg Mineral Resource outline, historical mine areas, Two Level horizon and priority areas for follow-up exploration. Target outlines indicate areas for investigation and do not represent Mineral Resources.

Beyond the current resource, Canterra has identified prospects and targets for additional high-grade Buchans-style deposits, including mineralized trends that remain underexplored at depth and geophysical anomalies identified by deep-seeking surveys completed in 2025 and 2026. The Company intends to use this growing geological and geophysical dataset to prioritize targets with the potential to expand known mineralization or deliver new discoveries, which could broaden the opportunities for future development at Buchans.

The Lemarchant satellite deposit adds another avenue for resource growth and discovery within Canterra’s central Newfoundland portfolio. Exploration at this satellite deposit is targeting extensions to known mineralization and new deposits that could complement the longer-term vision for a hub-and-spoke development strategy centred on the Buchans Project (Figure 4).

Figure 4. Canterra’s projects in central Newfoundland, showing the Buchans District with the Lundberg Deposit, the satellite deposits and the Wilding Gold Project in their regional setting.

Pit Shell and Infrastructure

The Lundberg Deposit is at a brownfields past-producing mine site and is adjacent to the community of Buchans and has access to road, power and water infrastructure. The optimized pit shell was developed to assess reasonable prospects for eventual economic extraction; it does not represent an estimate of Mineral Reserves or a proposed mine plan, and it was not constrained by surface infrastructure. The shell has an overall strip ratio of 3.16:1 (waste to mineralized material). Historical mining within the resource area has been accounted for as described in Note 12 to Table 1, and the topographic surface has been modified to accommodate the Lucky Strike glory hole. Figure 5 shows the distribution of modelled NSR values within the pit shell.

Figure 5. Oblique sectional view looking northeast showing modelled NSR values (US$/t) within the 2026 Lundberg Mineral Resource reporting pit shell. The inset identifies the section line in plan view.

Ongoing Exploration in the District

At the Lemarchant satellite deposit, drilling is underway and forms part of a 6,000 m district exploration program, with results pending and to be reported through the remainder of the year and into 2027. Gravity survey results are expected in Q4 2026. Together, drilling and geophysical interpretation are intended to refine targeting and identify further opportunities for resource growth and discovery (Figure 6).

Figure 6. Lemarchant Project exploration target areas.

Drill Hole Database, QA/QC and Data Verification

The resource database is a subset of Canterra’s Buchans District drill hole database. A total of 414 drill holes occur within the modelled limits of the mineralized zones, of which 299 have sampling results for 10,508 m of assayed intervals. Canterra completed 23 diamond drill holes totalling 4,778.7 m at Lundberg and Two Level from 2024 up to the MRE database cut-off date of August 3, 2026, of which 20 contribute to the 2026 MRE. An additional hole, H-26-3568, was completed at Lundberg after the database cut-off date and will be considered in future resource estimation.

Canterra’s drilling programs use quality assurance and quality control procedures that include reference standards, blanks, duplicates and independent check assays. Samples comprise half of the sawn NQ core, with the remaining half retained. Assays from Canterra’s 2024–2026 programs were prepared and analyzed by SGS Canada (“SGS”) or Eastern Analytical Ltd. (“Eastern”). SGS samples were prepared in Grand Falls-Windsor and analyzed in Burnaby using fusion and ICP-OES methods for base metals, with separate silver and gold methods and over-limit procedures. Eastern samples were prepared at its Springdale laboratory and analyzed by 30 g gold fire assay, with metals by four-acid ICP-OES multi-element analysis and atomic absorption for over-limit results. Representative pulps were also submitted to ALS Geochemistry in Moncton for independent check assays.

The drill hole database supporting the 2019 MRE was carried forward and supplemented with Canterra’s exploration results. Canterra drill holes underwent verification against original assay records, collar information, downhole surveys and geological interval data. Earlier holes comprise pre-2007 drilling and programs attributed to Buchans Minerals Corporation (“BMC”) and related operators during 2007–2024. Compilation and validation of the pre-2007 information included checks against original assay records, historical maps, sections and plans, together with relogging, resampling and twin drilling completed during BMC’s operations.

BMC drilling programs in 2008, 2012, 2014/2015 and 2018 were subject to validation of collar data, downhole surveys, geological intervals, original assay certificates and sample records. Several core sampling programs were analyzed by both Eastern and ALS Geochemistry; where both sets of results were available, Eastern results were given priority.

For partially sampled holes, included unsampled intervals were assigned a grade of zero for all metals. In holes with limited or no sampling, unsampled intervals were either assigned zero grade or excluded. Unsampled holes were excluded where compiled geological data supported the presence of a well-mineralized stockwork zone but analytical results were unavailable. Unsampled or partially sampled intervals in historical holes that were subsequently twinned and sampled during BMC and/or Canterra programs were also excluded, with the more recent information used instead.

Matthew Harrington, P.Geo., the Qualified Person responsible for the 2026 MRE, visited the property in 2018, 2024 and 2026, completing independent witness check sample programs during the 2018 and 2026 visits with satisfactory results. The QP verified the data underlying the 2026 MRE and is of the opinion that it is acceptable for Mineral Resource estimation purposes.

Exploration Targets and Historical Estimates

Exploration targets outside the reported Lundberg Mineral Resource are conceptual and include historical mineral resource estimates. A QP has not done sufficient work to classify the historical estimates as current Mineral Resources or Mineral Reserves, and Canterra is not treating historical estimates related to the satellite deposits as current Mineral Resources or Mineral Reserves. Further exploration is required to determine whether they can support Mineral Resources, there is no certainty that new resources will be defined, and references to satellite deposits do not imply that their resources have been incorporated into the 2026 MRE.

Table 4. Lundberg Deposit Mineral Resource Estimate – Effective Date September 2, 2026

Contained metal is in situ and does not represent recovered metal. Contained metal and CuEq grades are calculated from unrounded tonnes and grades before rounding for presentation. Mt = million tonnes; kt = thousand tonnes; Moz = million ounces; koz = thousand ounces.

Notes to Tables 1 and 4

1. Mineral Resources are defined within an optimized pit shell using pit slope angles between 33° and 50°, based on a pit slope stability study by The Mines Group Inc. (2013). The optimized pit shell has an overall strip ratio of 3.16:1 (waste to mineralized material).
2. Pit optimization costs include mineralized material mining costs of US$3.60/t, waste mining costs of US$3.00/t, processing costs of US$18.00/t, general and administrative costs of US$2.40/t, and an exchange rate of C$1.37 per US$1.00.
3. Metal price assumptions are US$4.97/lb Cu, US$1.35/lb Zn, US$0.95/lb Pb, US$42.30/oz Ag and US$3,285.90/oz Au.
4. Metallurgical recoveries to concentrates are based on the “Centralized Milling of Newfoundland Base Metal Deposits – Bench Scale DMS and Flotation Test Program” (Thibault & Associates Inc., 2017). Metal recoveries are 83.0% Cu, 13.3% Au, and 7.84% Ag in the copper concentrate, 84.31% Pb, 10.54% Au, and 50.26% Ag in the lead concentrate, and 87.20% Zn, 8.28% Au, and 14.77% Ag in the zinc concentrate.
5. Net Smelter Return (“NSR”) US$/t values were determined for each resource model block using an NSR calculator. The NSR calculator incorporates the stated metal prices, metallurgical recoveries to concentrates, concentrate payable factors, and current shipping and smelting terms for similar concentrates.
6. The NSR calculator’s payable assumptions for each metal in each concentrate result in overall recovery and payability factors (payable factor × metal recovery) of 80.18% Cu, 80.09% Pb, 74.12% Zn, 65.69% Ag and 23.05% Au.
7. Copper equivalent (CuEq) grades were calculated using the stated metal prices, metallurgical recoveries to concentrates and concentrate payable factors: CuEq (%) = Cu (%) + (Pb (%) × 0.1909) + (Zn (%) × 0.2511) + (Ag (g/t) × 0.0102) + (Au (g/t) × 0.2772).
8. Mineral Resources are reported at a cut-off of US$20.40/t NSR within the optimized pit shell and are considered to reflect reasonable prospects for eventual economic extraction by open pit mining methods.
9. Mineral Resources were interpolated using inverse distance squared methods applied to 1.5 m downhole assay composites constrained within three-dimensional solid models representing stockwork and massive sulphide mineralization. No grade capping was applied.
10. An interpolated inverse distance squared bulk density model (g/cm³) was applied.
11. The block model uses blocks measuring 5 m (x) by 5 m (y) by 5 m (z), with a minimum block size of 0.625 m (x) by 0.625 m (y) by 0.625 m (z).
12. Mineral Resources were depleted for the Buchans Lucky Strike glory hole and historical mining. Historical stopes are assumed to be sand-filled with a density of 1.92 g/cm³, and historical development workings are assumed to be open void space.
13. The classification of the current Mineral Resource Estimate into Indicated and Inferred is consistent with the Canadian Institute of Mining, Metallurgy, and Petroleum (“CIM”) Definition Standards for Mineral Resources and Mineral Reserves, May 10, 2014 (“CIM Definition Standards”).
14. Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability. There is no certainty that all or any part of the estimated Mineral Resources will be converted into Mineral Reserves. An Inferred Mineral Resource has a lower level of confidence than a Measured or Indicated Mineral Resource. It is reasonably expected that the majority of Inferred Mineral Resources could be upgraded to Indicated Mineral Resources with continued exploration.
15. Mineral Resource tonnages have been rounded to the nearest 10,000 tonnes. Totals may vary due to rounding.
16. The MRE was completed in consideration of the CIM Estimation of Mineral Resources and Mineral Reserves Best Practice Guidelines (November 29, 2019).
17. The technical report in support of the 2026 MRE will be filed by the Company within 45 days of this news release.

Qualified Persons

Matthew Harrington, P.Geo., of Mercator, is an independent Qualified Person as defined under National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”) and is responsible for the technical disclosure regarding the 2026 MRE contained in this news release.

Paul Moore, MSc., P.Geo. (NL), Vice President of Exploration, is the Qualified Person for the Company and has reviewed and approved the other scientific and technical information in this news release.

Newfoundland and Labrador Junior Exploration Assistance

Canterra would like to acknowledge financial support it received from the Government of Newfoundland and Labrador’s Junior Exploration Assistance Program related to completion of its 2024 and 2025 programs, and any support it may receive for its 2026 exploration programs in the Buchans District.

About Canterra Minerals

Canterra is a diversified minerals exploration company focused on critical minerals and gold in central Newfoundland. The Company’s projects include seven mineral deposits located in close proximity to the world-renowned, past-producing Buchans Mine and Teck Resources’ Duck Pond Mine, which collectively produced copper, zinc, lead, silver and gold. Several of Canterra’s deposits support current and historical Mineral Resource Estimates prepared in accordance with National Instrument 43-101 and the Canadian Institute of Mining, Metallurgy, and Petroleum Definition Standards for Mineral Resources and Mineral Reserves. Canterra’s gold projects are located on trend of Equinox Gold’s Valentine Mine and cover an approximately 55 km extension of the same structural corridor that hosts gold mineralization within Equinox Gold’s mine. Past drilling by Canterra and others within the Company’s gold projects intersected multiple occurrences of orogenic-style gold mineralization within a large land position that remains underexplored.