Bonterra Intersects High-Grade, Visible Gold at O'Brien East Deep Target at its 100% Owned Desmaraisville South Project
Bonterra’s 2026 drilling at Desmaraisville South has returned high-grade visible-gold intercepts and opened multiple gold-bearing target areas, with many assays still pending.
Rhea-AI Summary
Bonterra Resources (BONXF) reported preliminary 2026 drilling results from its 100% owned Desmaraisville South Project, including high-grade visible gold at the O'Brien East Deep and Céré-Murgor targets.
At O'Brien East Deep, hole BRDS-26-114 intersected 4.75 g/t Au over 1.4 m, including 16.03 g/t Au over 0.4 m with visible gold, while hole BRDS-26-124A returned 0.71 g/t Au over 2.2 m. At Céré-Murgor, hole BRDS-26-128A cut 0.79 g/t Au over 8.2 m, including 1.33 g/t Au over 2.7 m and 4.05 g/t Au over 0.6 m with visible gold, plus 1.99 g/t Au over 0.7 m. The Mistik 13 target yielded 1.03 g/t Au over 1.5 m in hole BRDS-26-116A.
The 2026 campaign totals 23 holes for 10,136 m, with assays received for 14 holes and additional results pending. Extensive relogging, structural and geophysical studies, and hyperspectral core scanning are being integrated to refine future drill targets. Gold analyses were conducted at third‑party accredited labs under a documented QA-QC program.
Positive
- High-grade intercept at O'Brien East Deep: 4.75 g/t Au over 1.4 m, including 16.03 g/t Au over 0.4 m (VG) in BRDS-26-114
- Broad mineralized interval at Céré-Murgor: 0.79 g/t Au over 8.2 m, including 1.33 g/t Au over 2.7 m and 4.05 g/t Au over 0.6 m (VG) in BRDS-26-128A
- Additional mineralization at depth: 0.71 g/t Au over 2.2 m in BRDS-26-124A at O'Brien East Deep
- Multiple targets confirmed: mineralized intercepts reported at O'Brien East Deep, Céré-Murgor and Mistik 13 in the same campaign
- Comprehensive technical work: 70 historic holes relogged and sampled, 19,834 m of core scanned, and 3D geophysical and structural studies completed to refine targets
- Strong JV backing on other assets: Gold Fields can earn 70% of Urban-Barry JV by funding C$30 million of work by November 2026
Negative
- Incomplete dataset: assays received for only 14 of 23 drill holes, with several holes having partial or pending results
- True widths unknown: reported mineralized intervals are core lengths and true widths have not yet been established
AI-generated analysis. How Rhea-AI works. Not financial advice.
Val-d'Or, Quebec--(Newsfile Corp. - September 15, 2026) - Bonterra Resources Inc. (TSXV: BTR) (OTCQB: BONXF) (FSE: 9BR2) ("Bonterra" or the "Company") is pleased to present preliminary results of its 2026 exploration campaign at its
Cesar Gonzalez, Executive Chairman and Interim CEO commented: "Our 2026 drilling campaign at the
2026 Exploration Campaign Highlights to Date (see Table 1 and 2, Figures 1 to 4)
- O'Brien East Deep Target - 4.75 g/t Au over 1.4 m. including 16.03 g/t Au over 0.4 m (visible gold or VG), in hole BRDS-26-114, and 0.71 g/t Au over 2.2 m, in hole BRDS-26-124A
- Céré-Murgor Target - 0.79 g/t Au over 8.2 m, including 1.33 g/t Au over 2.7 m and 4.05 g/t Au over 0.6 m (VG), in hole BRDS-26-128A , and 1.99 g/t Au over 0.7 m, in hole BRDS-26-128A
- Mistik 13 Target - 1.03 g/t Au over 1.5 m, in hole BRDS-26-116A
Figure 1: Desmaraisville South Project - 2026 Diamond Drill Hole Locations
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Figure 2: Desmaraisville South Project - O'Brien East Deep Target Area Plan View - Assay Results
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O'Brien East Deep Target Highlights
- 4.75 g/t Au over 1.4 m. including 16.03 g/t Au over 0.4 m (VG), in hole BRDS-26-114
- 0.71 g/t Au over 2.2 m, in hole BRDS-26-124A
In drill hole BRDS-26-114, located east of the O'Brien intrusion, the zone containing visible gold corresponds to a quartz veinlet with fluorite, grading 16.03 g/t Au. The host rock consists of the O'Brien intrusive. Very weak hematization, thin quartz-fluorite veinlets are ubiquitous throughout the drill hole (see core photograph below).
This type of mineralization could be similar to the stockwork located on the western side of the O'Brien intrusive and may be pervasive and contain high-grade values.
BRDS-26-114 à 261.5 m: 16.03 ppm Au
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Drill hole BRDS-26-124A, with a total length of 1,566 m, was designed to intersect a mineralized system along the eastern side of the O'Brien intrusive. The emplacement of the intrusive may have generated a fracture network, providing pathways for hydrothermal fluids to percolate through the host rocks, or may have intersected pre-existing mineralized structures. Three zones containing anomalous gold grades were intersected. These zones are characterized by quartz-hematite-sericite alteration with approximately 1 to
Figure 3: Desmaraisville South Project - Céré-Murgor Target Area - Assay Results
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Céré-Murgor Target Highlights
- 0.79 g/t Au over 8.2 m, including 1.33 g/t Au over 2.7 m and 4.05 g/t Au over 0.6 m (VG), in hole BRDS-26-128A
- 1.99 g/t Au over 0.7 m, in hole BRDS-26-128A
The mineralized system is characterized by discordant quartz veinlets containing visible gold, as well as quartz veinlets parallel to the schistosity, hosted within strongly deformed and sericitized fine-grained sediments with disseminated pyrite. The drilling results indicate a favorable geological setting for extensive gold mineralization. This target area may be part of the Opiwaca-Guercheville deformation corridor.
BRDS-26-128 à 529.7 m
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Figure 4: Desmaraisville South Project - Mistik 13 Target Area Plan View - Assay Results
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Mistik 13 Target Highlights
- 1.03 g/t Au over 1.5 m, in hole BRDS-26-116A
The mineralized interval intersected in drill hole BRDS-26-116A occurs within a basalt cut by quartz-carbonate veinlets forming an anastomosing network and accounting for approximately
Other 2026 Exploration Activities
Bonterra completed a relogging and sampling program on 70 historic diamond drill holes in which altered and mineralized intervals had not previously been sampled. The Company has received 1,308 assay results, and several significant intercepts have yet to be incorporated into its database.
Laurentia Exploration ("Laurentia") based in Jonquière, Québec, has completed a metallogenic and structural study on the Desmaraisville South Property. Dr. Damien Gaboury, consultant for Laurentia, visited the site in late July to improve the understanding of the gold exploration potential.
Sander Geophysics ("Sander") based in Ottawa, Ontario, was commissioned to generate a 3D inversion model of the 2023 gravimetric data to model three-dimensional volumes that could correspond to late intrusions such as the O'Brien intrusion which hosts the Bachelor and Moroy deposits.
LithologIQ based in Montréal, Québec, has scanned 19 834 m of drill core using their hyperspectral core scanning technology. Historic and recent drill core from all gold mineralized environments at the Project have been scanned directly at the mine site. Identifying minerals associated with gold-bearing environments will allow for the rapid identification of new high-potential area during future drilling campaigns. Interpretation of the data collected and recommendations made by Laurentia, Sander and LithologIQ are being incorporated for future exploration work and better define drill targets.
Table 1: Drill Hole Locations - Desmaraisville South Project
| Hole ID | Easting | Northing | Elevation (m) | Azimuth (°) | Dip (°) | Length (m) |
| BRDS-26-114 | 417833 | 5483244 | 342 | 315 | -55.0 | 390.0 |
| BRDS-26-128A | 404370 | 5478105 | 295 | 300 | -50.0 | 558 |
| BRDS-26-116A | 417251 | 5486170 | 315 | 180 | -50.0 | 290 |
| BRDS-26-124A | 417850 | 5482575 | 346 | 360 | -65.0 | 1566 |
UTM Coordinates, System: NAD83-UTM Z 18N
Table 2: Significant Mineralized Intersections from Drilling on the Desmaraisville South Project
| Hole ID | Zones | From (m) | To (m) | Length (m) | Grades (g/t Au) | Metal Factor (Length x Grade) |
| BRDS-26-114* | O'Brien East Deep | 261.3 | 262.7 | 1.4 | 4.75 | 6.7 |
| Including | 261.3 | 261.7 | 0.4 | 16.03 | 6.4 | |
| BRDS-26-128A* | Céré-Murgor | 528.3 | 536.5 | 8.2 | 0.79 | 6.5 |
| Including | 528.3 | 531.0 | 2.7 | 1.33 | 3.6 | |
| Including | 529.5 | 530.1 | 0.6 | 4.05 | 2.43 | |
| Including | 466.0 | 466.7 | 0.7 | 1.90 | 1.33 | |
| BRDS-26-116A | Mistik 13 | 96.7 | 98.2 | 1,5 | 1.03 | 1.5 |
| BRDS-26-124A | O'Brien East Deep | 1088.8 | 1091 | 2.2 | 0.71 | 1.5 |
1) Reported intervals represent drilled core lengths; true widths are not yet known.
2) Gold results obtained above 0.5 g/t Au with a Metal Factor above 1.
3) * Visible Gold (VG).
Quality Control and Reporting Protocols
The Desmaraisville South Project's drill core gold analyses were performed at the MSALABS and the AGAT Laboratories located in Val-d'Or, Québec. These external laboratories employ a rigorous QA-QC analysis program that meets industry standards. At the AGAT laboratory, the analyses are carried out by fire assay (A.A.) with atomic absorption finish and with gravimetric finish for assay above 10 g/t Au. Blanks, duplicates, and certified reference standards are inserted into the sample stream to monitor the Laboratory's performance. Other core samples gold analysis was performed at MSALABS of Val d'Or, Québec. The samples were crushed to a particle size of
The Company's QA-QC program requires that at least 5 to
The verification shows a high degree of correlation with the laboratory's results.
Qualified Person
M. Donald Trudel, P.Geo. (OGQ # 813), Director Geology for the Company, oversees all exploration activities on the Desmaraisville Property and has compiled and approved the information contained in this press release. Mr. Trudel is a qualified person as defined by National Instrument 43-101 on standards of disclosure for mineral projects.
About Bonterra Resources Inc.
Bonterra is a Canadian gold exploration company with a portfolio of advanced exploration assets anchored by a central milling facility in Québec, Canada. The Company's assets include the Gladiator, Barry(1), Moroy, and Bachelor(2) gold deposits, which collectively hold 16.8 million tonnes ("Mt") at an average grade of 3.02 g/t Au for 1.63 million ounces ("Moz") of Measured & Indicated Mineral Resources, plus 15.6 Mt at 4.32 g/t Au for 2.17 Moz of Inferred Mineral Resources.
In November 2023, the Company entered into an earn-in and joint venture agreement with Osisko Mining Inc. ("Osisko Mining") for the Urban-Barry properties (the "JV Agreement"), which include the Gladiator and Barry deposits. In October 2024, Gold Fields Ltd, through a wholly owned Canadian subsidiary, completed the acquisition of Osisko Mining for C
1) See news release of the Company dated February 23, 2026, and titled "Bonterra Reports Significant Mineral Resources Growth at Barry and Gladiator Deposits" for further details.
2) See news release of the Company dated April 1st, 2026, and titled "Bonterra Reports Significant Mineral Resource Growth at Bachelor and Moroy,
FOR ADDITIONAL INFORMATION
Cesar Gonzalez, Executive Chairman & Interim CEO
ir@btrgold.com
2872 Sullivan Road, Suite 2, Val d'Or, Québec J9P 0B9
819-825-8678 | Website: www.btrgold.com
Neither 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.
Caution regarding forward-looking statements
This news release contains forward-looking statements within the meaning of applicable securities laws. All statements other than statements of historical fact may be forward-looking and are often identified by words such as "may", "will", "plan", "expect", "anticipate", "estimate", and "intend". Forward-looking statements in this release include, without limitation, statements regarding, the 2026 exploration program at the Desmaraisville South project and at the Phoenix JV, including planned drilling activities, deep-drilling objectives at the Barry deposit, proposed camp upgrades, and Gold Fields' ability to complete the remaining earn-in expenditures under the JV Agreement.
These statements are based on assumptions considered reasonable by management, including assumptions regarding exploration plans, budgets, schedules, regulatory approvals, and the continued advancement of work by Gold Fields. However, forward-looking statements involve known and unknown risks, uncertainties, and other factors that may cause actual results to differ materially. Such risks include, but are not limited to, changes to exploration plans, results that differ from expectations, operational or permitting challenges, the ability of the parties to complete the Joint Venture, the timing and completion of earn-in expenditures, the speculative nature of mineral exploration, commodity price fluctuations, and the availability of financing. Additional information regarding risks can be found in the Company's filings at www.sedarplus.ca.
Readers are cautioned not to place undue reliance on forward-looking statements. The Company does not undertake to update any forward-looking statement except as required by applicable securities laws. All forward-looking statements in this release are expressly qualified by this cautionary statement.
To view the source version of this press release, please visit https://www.newsfilecorp.com/release/314277
FAQ
AI-generated questions and answers. How Rhea-AI works. Not financial advice.
How extensive was Bonterra’s 2026 drilling program at Desmaraisville South?
The 2026 program comprised 23 diamond drill holes totaling 10,136 m, with five abandoned holes totaling 125 m. Assay results have been received for 14 drill holes. Five drill holes are undergoing core cutting, and nine drill holes have either partial assay results or pending results. Drilling started in January 2026, paused for three months, resumed in April, and was completed in late August.
What other exploration work besides drilling has been completed at Desmaraisville South?
Bonterra completed relogging and sampling on 70 historic drill holes, receiving 1,308 assay results. Laurentia Exploration carried out a metallogenic and structural study, Sander Geophysics generated a 3D inversion model of 2023 gravimetric data to image intrusive bodies, and LithologIQ scanned 19,834 m of historic and recent drill core using hyperspectral technology. These datasets are being integrated to better define future drill targets.
How were the gold assays and QA-QC procedures handled?
Gold analyses were performed at MSALABS and AGAT Laboratories in Val-d'Or, Québec. At AGAT, gold was analyzed by fire assay with atomic absorption finish and gravimetric finish for assays above 10 g/t Au, with blanks, duplicates and certified reference standards inserted into the sample stream. At MSALABS, samples were crushed to 70% passing 2 mm and a 500 g portion was analyzed by PhotonAssay, with blank samples and certified reference materials systematically inserted. At least 5–10% of samples were reanalyzed at ALS Minerals as an independent check, and the company reports a high degree of correlation.
What are the key drill hole locations and orientations for the main reported intercepts?
Key holes include BRDS-26-114 (O'Brien East Deep) at 417833E, 5483244N, elevation 342 m, azimuth 315°, dip -55°, length 390 m; BRDS-26-128A (Céré-Murgor) at 404370E, 5478105N, elevation 295 m, azimuth 300°, dip -50°, length 558 m; BRDS-26-116A (Mistik 13) at 417251E, 5486170N, elevation 315 m, azimuth 180°, dip -50°, length 290 m; and BRDS-26-124A (O'Brien East Deep) at 417850E, 5482575N, elevation 346 m, azimuth 360°, dip -65°, length 1,566 m. Coordinates use the NAD83-UTM Z 18N system.
Who is the qualified person responsible for the technical information?
M. Donald Trudel, P.Geo. (OGQ # 813), Director Geology, oversees all exploration activities on the Desmaraisville Property and has compiled and approved the technical information. He is a qualified person as defined by National Instrument 43-101 for mineral projects.
What are Bonterra’s broader resource holdings and JV arrangements mentioned in the release?
Bonterra’s portfolio includes the Gladiator, Barry, Moroy and Bachelor gold deposits, with stated resources of 16.8 Mt at 3.02 g/t Au for 1.63 Moz of Measured & Indicated and 15.6 Mt at 4.32 g/t Au for 2.17 Moz of Inferred. In November 2023, Bonterra entered an earn-in and joint venture agreement for the Urban-Barry properties with Osisko Mining, now held by Gold Fields through its 2024 acquisition of Osisko Mining. Gold Fields can earn a 70% interest by incurring C$30 million in work expenditures on or before November 2026.