Sirios Completes Phase 1 of Expansion Drilling at Cheechoo and Intersects 39.94 g/t Gold over 6.5 m and 9.07 g/t Au over 12.5 m

Visible gold observed in 68 intervals from 18 drill holes, with a total of 23,037.5 m drilled in Phase 1

Sirios Resources Inc. (TSXV: SOI,OTC:SIREF) (OTCQB: SIREF) (FSE: 377A) (“Sirios” or the “Company”) announces assay results from 15 holes totalling 6,850 m from Phase 1 drilling at its Cheechoo gold project, located in the Eeyou Istchee James Bay region of Quebec.

Highlights:

High-grade intervals:

• 39.94 g/t Au over 6.5 m, including 129.00 g/t Au over 2.0 m (CH26-337)
• 9.07 g/t Au over 12.5 m, including 103.11 g/t Au over 1.0 m (CH26-345)
• 25.21 g/t Au over 3.0 m, including 50.06 g/t Au over 1.5 m (CH26-337)

Main intervals:

• 122.1 m at 0.43 g/t Au (CH26-334)
• 92.0 m at 0.43 g/t Au (CH26-332)
• 58.4 m at 0.62 g/t Au (CH26-334)
• 21.8 m at 1.29 g/t Au (CH26-345)
• 91.5 m at 0.30 g/t Au (CH26-337)
• 54.0 m at 0.49 g/t Au (CH26-342)
• 88.5 m at 0.30 g/t Au (CH26-334)
• 58.5 m at 0.45 g/t Au (CH26-339)
• 41.0 m at 0.60 g/t Au (CH26-336)

Visible gold was observed in 68 intervals across 18 drill holes, confirming the continuity and strong potential of the mineralized system. Holes with no significant results drilled along the northern and northeastern margins of the gold resources mainly intersected a barren paragneiss unit, distinct from the wacke and tonalite units associated with mineralization.

Phase 1 of the drilling campaign was completed on September 28, with a total of 45 holes and 23,037.5 metres drilled. Planning is underway for Phase 2, which will comprise approximately 12,000 metres and will complete the 35,000 m campaign announced on April 1 (see press release). Phase 2 is scheduled to begin in January 2027.

“The results received to date are encouraging,” said Dominique Doucet, Head of Exploration at Sirios. “Our drilling continues to demonstrate expansion potential along the margins of the deposit within the tonalite and at depth. We look forward to receiving the complete assay results from this campaign.”

“We have now received nearly half of the results from our summer campaign at Cheechoo, and we are once again seeing the combination of high-grade mineralization and long, lower-grade intervals that is characteristic of the Cheechoo project,” said Jean-Félix Lepage, Chief Executive Officer of Sirios. “The updated modelling is progressing well, and the resource estimate will begin in the coming weeks.”

Figure 1: Location of observations of visible gold 

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Table 1: 2026 Drilling Program – Main Results from the 15 New Drill Holes

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*Visible gold.
Interval lengths are measured along the drill holes and do not necessarily represent true thicknesses. At this stage of the program, true thicknesses remain unknown.

Figure 2: Location of the 15 drill holes

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Table 2: Drill Collar Locations

 

* UTM Zone 18 coordinates

In addition, the on-site analytical program scanned 39 drill holes from the current campaign using Élémission’s ECORE LIBS (Laser-Induced Breakdown Spectroscopy) instrument. The analytical program now totals 116 drill holes representing more than 37,350 m of scanned core.

Quality Assurance and Quality Control
Drill core was logged and sampled by Sirios personnel at the Cheechoo exploration camp. The core was sawn into two halves, one of which was sent to a certified commercial laboratory for analysis, while the other half was retained for future reference. In accordance with a strict analytical quality assurance and quality control program, blanks and certified reference materials were inserted into the sampling sequence. Samples were analyzed for gold using approximately 500 g of crushed material with the PhotonAssay™ method at the MSALABS laboratory in Val-d’Or. Samples containing visible gold were analyzed using the entire crushed sample with the PhotonAssay™ method.

Qualified Person
The scientific and technical content of this press release has been reviewed and approved by Dominique Doucet, Eng., Head of Exploration at Sirios, a Qualified Person as defined by National Instrument 43-101.

About the Cheechoo Project
Cheechoo is located approximately 15 km from the Éléonore mine and near infrastructure, including roads and hydroelectric facilities, in the Eeyou Istchee Baie-James region of Canada. Cheechoo is in the resource development stage, with 35 Mt of indicated resources at 1.12 g/t (1,262 koz) and 42.7 Mt of inferred resources at 1.23 g/t (1,688 koz) (see NI 43-101 Technical Report on the Cheechoo Project with an Updated Mineral Resource Estimate for the Cheechoo Gold Deposit, Eeyou Istchee James Bay, Québec, dated August 22, 2025 and deposited on the Company’s website and on SEDAR+). In addition, a conceptual exploration target of 31 to 40 million tonnes of mineralization grading between 1.27 and 1.45 g/t Au has been estimated.

About Sirios
Sirios Resources is a Quebec-based mineral exploration company focused on developing its Cheechoo gold deposit, as well as exploring and advancing its other high-potential gold projects in the Eeyou Istchee James Bay region of Canada.

Cautionary Note Regarding Forward-Looking Statements
This press release contains “forward-looking statements” within the meaning of applicable Canadian securities laws, based on expectations, estimates, and projections as of the date of this press release. Forward-looking statements involve risks, uncertainties, and other factors that could cause actual events, results, performance, expectations, and opportunities to differ materially from those expressed or implied in such forward-looking statements. Factors that could cause actual results to differ materially from those indicated in these forward-looking statements include, but are not limited to: capital and operating costs that differ materially from estimates; the preliminary nature of metallurgical test results; delays or failures in obtaining required governmental, environmental, or other approvals; uncertainties regarding the availability and cost of necessary future financing; changes in financial markets; inflation; fluctuations in metal prices; delays in project development; other risks associated with the mineral exploration and development industry; and the risks disclosed in the Company’s public filings on SEDAR+ at www.sedarplus.ca. Although the Company believes that the assumptions and factors used to prepare the forward-looking statements contained in this press release are reasonable, readers should not place undue reliance on this information, which is valid only as of the date of this press release, and there is no guarantee that these events will occur or occur within the timeframes indicated. The Company disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events, or otherwise, except as required by applicable law.

Neither the TSX Venture Exchange nor its regulatory services provider (as defined in the policies of the TSX Venture Exchange) accepts any responsibility for the adequacy or accuracy of this press release.

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