OSISKO WINDFALL DRILLING INTERCEPTS MORE HIGH-GRADE

Including 120 g/t Au Over 6.2 Metres

(Toronto, April 13, 2022) Osisko Mining Inc. (OSK:TSX. “Osisko” or the “Corporation”) is pleased to provide new analytical results from the ongoing drill program at its 100% owned Windfall gold project located in the Abitibi greenstone belt, Urban Township, Eeyou Istchee James Bay, Québec.

Significant new analytical results presented below include 31 intercepts in 12 underground drill holes and 5 wedges. The infill intercepts are located inside defined January 2022 mineral resource estimate (“MRE”) blocks (see Osisko news release dated January 10, 2022). The expansion intercepts are located outside the January 2022 MRE blocks and either expand resource wireframes or are in a defined zone or corridor but do not yet correlate to a specific wireframe.

Osisko Chief Executive Officer John Burzynski commented: “We remain very pleased with the results of our infill and expansion drill program at Lynx. High grade zones continue to be intersected where expected and the expansion drilling continues to define additional zones nearby.”

Selected high-grade intercepts include: 120 g/t Au over 6.2 metres in OSK-W-21-2287-W14; 67.1 g/t Au over 4.4 metres in OSK-W-22-2646-W3; 111 g/t Au over 2.5 metres in WST-22-1009A; 82.6 g/t Au over 2.2 metres in WST-21-0997; 76.0 g/t Au over 2.3 metres in WST-21-0974; 63.9 g/t Au over 2.1 metres in WST-22-0999 and 60.8 g/t Au over 2.2 metres in OSK-W-22-2540-W13. Maps showing hole locations and full analytical results are available at www.osiskomining.com. Maps: Long Section_Infill EN 20220413, Long Section_Expan EN 20220413, PR_EN_20220413_Surface, PR_EN_20220413_UG.

Infill Drilling

Hole No. From (m) To (m) Interval (m) Au (g/t) uncut Au (g/t)         cut to 100 g/t Zone Corridor
OSK-W-21-2287-W14 1253.0 1259.2 6.2 120 51.4 LX4_3449 Lynx 4
including 1256.7 1257.2 0.5 768 100
OSK-W-22-2646-W3 1057.6 1062.5 4.9 15.6   TLX_3158 Triple Lynx
including 1058.3 1058.7 0.4 99.1  
WST-21-0839 512.0 514.0 2.0 5.16   LX4_3470 Lynx 4
including 512.3 512.7 0.4 21.9  
WST-21-0974 44.0 46.3 2.3 76.0 31.8 TLX_3161 Triple Lynx
including 45.2 45.9 0.7 245 100
WST-21-0979 189.4 194.8 5.4 15.6 12.9 TLX_3154 Triple Lynx
including 192.0 192.5 0.5 130 100
  197.1 199.2 2.1 19.3   TLX_3184 Triple Lynx
including 197.4 197.7 0.3 44.4  
WST-21-0980 602.8 605.0 2.2 50.3 31.9 LX4_3448 Lynx 4
including 602.8 603.5 0.7 158 100
WST-21-0997 191.1 193.3 2.2 82.6 44.7 TLX_3121 Triple Lynx
including 191.7 192.4 0.7 219 100
WST-22-0999 227.0 229.0 2.0 9.37   TLX_3131 Triple Lynx
including 227.7 228.5 0.8 23.4  
  351.0 353.1 2.1 4.13   LX4_3405 Lynx 4
including 352.7 353.1 0.4 20.8  
  376.9 379.0 2.1 63.9 38.8 LX4_3410 Lynx 4
including 377.2 378.0 0.8 166 100
  390.5 394.0 3.5 27.4   LX4_3440 Lynx 4
including 393.0 394.0 1.0 76.3  
WST-22-1000 202.3 212.0 9.7 3.83   TLX_3145 Triple Lynx
including 204.0 205.2 1.2 11.7  
WST-22-1004 320.5 325.3 4.8 5.78   TLX_3131 Triple Lynx
including 324.5 324.8 0.3 18.1  
  504.0 506.0 2.0 44.7 25.4 LX4_3402 Lynx 4
including 505.5 506.0 0.5 177 100
WST-22-1005 149.2 157.6 8.4 4.96   TLX_3161 Triple Lynx
WST-22-1006 566.7 569.1 2.4 15.1   LX4_3430 Lynx 4
including 566.7 567.0 0.3 89.3  
WST-22-1008 147.8 150.0 2.2 8.76   TLX_3161 Triple Lynx
  210.0 212.1 2.1 11.0   TLX_3169 Triple Lynx
  217.7 220.0 2.3 3.98   TLX_3175 Triple Lynx
  226.0 228.0 2.0 5.42   TLX_3175 Triple Lynx
WST-22-1009A 172.0 174.0 2.0 8.64   LXM_3388 Lynx
including 172.8 173.3 0.5 22.9  
  485.5 488.0 2.5 111 60.3 LX4_3404 Lynx 4
including 485.5 486.1 0.6 240 100
  499.0 501.1 2.1 11.7   LX4_3430 Lynx 4
including 499.9 500.6 0.7 32.8  
  511.0 513.0 2.0 3.52   LX4_3454 Lynx 4
including 511.9 512.3 0.4 14.9  

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See “Quality Control and Reporting Protocols” below. LXM = Lynx Main, LX4 = Lynx 4 and TLX = Triple Lynx.

 

Expansion Drilling

Hole No. From (m) To (m) Interval (m) Au (g/t) uncut Au (g/t)         cut to 100 g/t Zone Corridor
OSK-W-21-2381-W3 1204.2 1210.7 6.5 4.41   TLX_3172 Triple Lynx
including 1209.7 1210.7 1.0 15.6  
OSK-W-21-2646-W1 1046.0 1055.4 9.4 11.6   TLX_3158 Triple Lynx
including 1048.4 1048.7 0.3 65.8  
and 1054.5 1055.4 0.9 54.7  
OSK-W-22-2540-W13 987.8 990.0 2.2 60.8 24.2 TLX_3158 Triple Lynx
including 988.1 988.6 0.5 261 100
OSK-W-22-2646-W3 1181.7 1186.1 4.4 67.1 31.7 TLX_3172 Triple Lynx
including 1184.9 1186.1 1.2 230 100
WST-22-1008 249.0 251.5 2.5 5.05   TLX Triple Lynx
WST-22-1009A 576.1 578.3 2.2 3.54   LX4 Lynx 4
including 577.5 578.3 0.8 9.57  

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See “Quality Control and Reporting Protocols” below., LX4 = Lynx 4 and TLX = Triple Lynx.

 

Drill hole location

Hole No. Azimuth (°) Dip (°) Length (m) UTM E UTM N Elevation Section
OSK-W-21-2287-W14 116 -53 1338 453607 5435714 404 4075
OSK-W-21-2381-W3 134 -53 1392 453620 5435790 402 4125
OSK-W-21-2646-W1 109 -58 1236 453326 5435648 414 3800
OSK-W-22-2540-W13 117 -60 1220 453466 5435639 410 3925
OSK-W-22-2646-W3 109 -58 1251 453326 5435648 414 3800
WST-21-0839 140 -38 577 453321 5435235 55 3600
WST-21-0974 142 -11 67 453441 5435223 -157 3700
WST-21-0979 178 -55 255 453358 5435296 -149 3675
WST-21-0980 131 -38 681 453374 5435297 -26 3675
WST-21-0997 119 -45 640 453506 5435326 -90 3800
WST-22-0999 134 -26 454 453445 5435276 -99 3725
WST-22-1000 139 -45 447 453360 5435297 -148 3675
WST-22-1004 137 -40 600 453322 5435236 54 3600
WST-22-1005 145 -44 334 453360 5435297 -148 3675
WST-22-1006 121 -45 616 453506 5435326 -90 3800
WST-22-1008 148 -42 420 453360 5435297 -148 3675
WST-22-1009A 120 -40 603 453507 5435332 -47 3800

 

Lynx Zone

Mineralization occurs as grey to translucent quartz-carbonate-pyrite-tourmaline veins and pyrite replacement zones and stockworks. Vein-type mineralization is associated with haloes of pervasive sericite-pyrite ± silica alteration and contain sulphides (predominantly pyrite with minor amounts of chalcopyrite, sphalerite, galena, arsenopyrite, and pyrrhotite) and local visible gold. Replacement mineralization is associated with strong pervasive silica-sericite-ankerite ± tourmaline alteration and contains disseminated pyrite from trace to 80% with local visible gold. Pyrite stockworks can form envelopes that reach several tens of metres in thickness. Fuchsite alteration is common and is spatially constrained to near the gabbros. Mineralization occurs at or near geological contacts between felsic porphyritic or fragmental intrusions and the host rhyolites or gabbros and locally can be hosted along the gabbro-rhyolite contact.

 

Qualified Person

The scientific and technical content of this news release has been reviewed, prepared and approved by Mr. Louis Grenier, M.Sc.A., P.Geo. (OGQ 800), Director of Exploration for Osisko’s Windfall gold project, who is a “qualified person” as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects (“NI 43-101”).

 

Quality Control and Reporting Protocols

True width determination is estimated at 55-80% of the reported core length interval for the zone. Assays are uncut except where indicated. Intercepts occur within geological confines of major zones but have not been correlated to individual vein domains at this time. Reported intervals include minimum weighted averages of 3.5 g/t Au diluted over core lengths of at least 2.0 metres. NQ core assays were obtained by either 1-kilogram screen fire assay or standard 50-gram fire-assaying-AA finish or gravimetric finish at (i) ALS Laboratories in Val d’Or, Québec, Vancouver, British Colombia, Lima, Peru or Vientiane, Laos (ii) Bureau Veritas in Timmins, Ontario. The 1-kilogram screen assay method is selected by the geologist when samples contain coarse gold or present a higher percentage of pyrite than surrounding intervals. Selected samples are also analyzed for multi-elements, including silver, using a Four Acid Digestion-ICP-MS method at ALS Laboratories. Drill program design, Quality Assurance/Quality Control (“QA/QC”) and interpretation of results is performed by qualified persons employing a QA/QC program consistent with NI 43-101 and industry best practices. Standards and blanks are included with every 20 samples for QA/QC purposes by the Corporation as well as the lab. Approximately 5% of sample pulps are sent to secondary laboratories for check assay.

 

About the Windfall Gold Deposit

The Windfall gold deposit is located between Val-d’Or and Chibougamau in the Abitibi region of Québec, Canada. The Mineral Resource Estimate (“MRE“) defined by Osisko, as disclosed in the news release dated January 10, 2022 is supported by the technical report entitled “Mineral Resource Estimate Update for the Windfall Project” dated February 10, 2022 (with an effective date  of October 21, 2021), and assuming a cut-off grade of 3.50 g/t Au, comprises 565,000 tonnes at 11.6 g/t Au (210,000 ounces) in the measured mineral resource category, 8,907,000 tonnes at 10.5 g/t Au (2,994,000 ounces) in the indicated mineral resource category and 13,035,000 tonnes at 8.6 g/t Au (3,585,000 ounces) in the inferred mineral resource category. The key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in the January 10, 2022, news release, certain of which are described in the January 10, 2022, news release, are further described in the full technical report for this updated mineral resource estimate in accordance with NI 43-101 and is available on SEDAR (www.sedar.com) under the Corporation’s issuer profile. The Windfall gold deposit is currently one of the highest-grade resource-stage gold projects in Canada and has world-class scale. Mineralization occurs in three principal zones: Lynx, Main Zone, and Underdog. Mineralization is generally comprised of sub-vertical zones following intrusive porphyry contacts plunging to the northeast. The resources are defined from surface to a depth of 1,600 metres as it now includes the Triple 8 (T8) zone. The resources excluding T8 are defined from surface to a depth of 1,200 metres. The deposit remains open along strike and at depth. Mineralization has been identified at surface in some areas and as deep as 2,625 metres in others with significant potential to extend mineralization down-plunge and at depth.

 

About Osisko Mining Inc.

Osisko is a mineral exploration company focused on the acquisition, exploration, and development of gold resource properties in Canada. Osisko holds a 100% interest in the high-grade Windfall gold deposit located between Val-d’Or and Chibougamau in Québec and holds a 100% undivided interest in a large area of claims in the surrounding Urban Barry area and nearby Quévillon area (over 2,500 square kilometres).

 

Cautionary Note Regarding Forward-Looking Information

This news release contains “forward-looking information” within the meaning of the applicable Canadian securities legislation that is based on expectations, estimates, projections and interpretations as at the date of this news release. Any statement that involves predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often, but not always, using phrases such as “expects”, or “does not expect”, “is expected”, “interpreted”, “management’s view”, “anticipates” or “does not anticipate”, “plans”, “budget”, “scheduled”, “forecasts”, “estimates”, “potential”, “feasibility”, “believes” or “intends” or variations of such words and phrases or stating that certain actions, events or results “may” or “could”, “would”, “might” or “will” be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This news release contains the forward-looking information pertaining to, among other things: the Windfall gold deposit being one of the highest-grade resource-stage gold projects in Canada and having world-class scale; the key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in this news release; the prospects, if any, of the Windfall gold deposit; timing and ability of Osisko to file a technical report for the mineral resource estimate disclosed in this news release; the timing and ability of Osisko, if at all, to publish a feasibility study for the Windfall gold deposit; the amount and type of drilling to be completed and the timing to complete such drilling; the focus of the remaining infill drilling; the trend of grade increase; the Lynx zone remaining open to expansion down plunge; upgrading a inferred mineral resource to a measured mineral resource or indicated mineral resource category; future drilling at the Windfall gold deposit; the significance of historic exploration activities and results. Such factors include, among others, risks relating to the ability of exploration activities (including drill results) to accurately predict mineralization; errors in management’s geological modelling; the ability of Osisko to complete further exploration activities, including (infill) drilling; property and royalty interests in the Windfall gold deposit; the ability of the Corporation to obtain required approvals; the results of exploration activities; risks relating to mining activities; the global economic climate; metal prices; dilution; environmental risks; and community and non-governmental actions. Although the forward-looking information contained in this news release is based upon what management believes, or believed at the time, to be reasonable assumptions, Osisko cannot assure shareholders and prospective purchasers of securities of the Corporation that actual results will be consistent with such forward-looking information, as there may be other factors that cause results not to be as anticipated, estimated or intended, and neither Osisko nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. Osisko does not undertake, and assumes no obligation, to update or revise any such forward-looking statements or forward-looking information contained herein to reflect new events or circumstances, except as may be required by law.

 

CONTACT INFORMATION:

John Burzynski
Chief Executive Officer
Telephone (416) 363-8653