OSISKO WINDFALL DRILLING INTERCEPTS HIGH-GRADE IN MULTIPLE LYNX ZONES

Including 272 g/t Au Over 2.3 Metres and 26.3 g/t Au Over 15.8 Metres

(Toronto, May 25, 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 71 intercepts in 27 underground drill holes and 13 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: “Infill drilling in support of the upcoming feasibility study continues to intersect high-grade across the deposit, especially in the Lynx area. This week’s expansion intercepts, including the higher-up Bobcat holes, are 25 metre step-outs which allow for these intercepts to be included in the resource estimate.”

Selected high-grade intercepts include: 272 g/t Au over 2.3 metres in WST-22-1018-W1, 26.3 g/t Au over 15.8 metres in OSK-W-22-2587-W3; 95.8 g/t Au over 3.1 metres in OSK-W-22-2601-W6; 131 g/t Au over 2.2 metres in OSK-W-22-2646-W5; 21.4 g/t Au over 13.2 metres in OSK-W-22-2605-W3; 39.9 g/t Au over 6.8 metres in OSK-W-22-2605-W2; 80.0 g/t Au over 3.2 metres in OSK-W-22-2646-W4, 125 g/t Au over 2.0 metres in WST-22-1019, 112 g/t Au over 2.2 metres in WST-22-1021 and 24.6 g/t Au over 9.6 metres in WST-22-1020. Maps showing hole locations and full analytical results are available at www.osiskomining.com. Maps: Long Section_All zones In EN 20220525, Long Section_All zones Ex EN 20220525, PR_EN_20220525_Surface, PR_EN_20220525_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-22-2587-W3 1134.0 1149.8 15.8 26.3 11.3 TLX_3172 Triple Lynx
including 1148.3 1149.1 0.8 397 100
OSK-W-22-2587-W4 1125.0 1127.0 2.0 20.6   TLX_3162 Triple Lynx
including 1126.0 1126.7 0.7 43.1  
  1139.0 1143.0 4.0 10.1   TLX_3170 Triple Lynx
including 1139.0 1139.7 0.7 43.1  
  1151.1 1153.5 2.4 30.7 24.5 TLX_3172 Triple Lynx
including 1152.0 1152.4 0.4 138 100
OSK-W-22-2601-W4 1010.0 1012.1 2.1 121 35.8 TLX_3158 Triple Lynx
including 1010.0 1010.7 0.7 356 100
OSK-W-22-2601-W6 1022.3 1025.4 3.1 95.8 70.8 TLX_3158 Triple Lynx
including 1024.0 1024.6 0.6 186 100
OSK-W-22-2605-W2 1315.5 1322.3 6.8 39.9 23.9 LX4_3449 Lynx 4
including 1315.5 1316.0 0.5 186 100
and 1321.6 1322.0 0.4 266 100
OSK-W-22-2605-W3 1332.6 1345.8 13.2 21.4 17.1 LX4_3449 Lynx 4
including 1336.0 1336.5 0.5 212 100
and 1338.5 1339.4 0.9 58.1  
OSK-W-22-2605-W4 1318.7 1322.1 3.4 11.2   LX4_3449 Lynx 4
including 1319.7 1320.0 0.3 32.9  
  1324.7 1328.0 3.3 3.79   LX4_3449 Lynx 4
  1347.0 1364.5 17.5 4.66   LX4_3445 Lynx 4
OSK-W-22-2605-W5 1299.6 1303.1 3.5 35.0 30.3 LX4_3449 Lynx 4
including 1301.1 1301.8 0.7 124 100
  1313.7 1316.1 2.4 4.99   LX4_3449 Lynx 4
including 1314.5 1315.2 0.7 10.8  
OSK-W-22-2605-W6 1361.6 1364.3 2.7 4.27   LX4_3445 Lynx 4
OSK-W-22-2646-W4 1149.0 1151.3 2.3 10.0   TLX_3162 Triple Lynx
including 1149.4 1149.9 0.5 44.4  
  1186.4 1189.6 3.2 80.0 64.5 TLX_3172 Triple Lynx
including 1186.4 1187.0 0.6 175 100
OSK-W-22-2646-W5 1046.3 1048.3 2.0 41.0 21.3 TLX_3158 Triple Lynx
including 1046.6 1046.9 0.3 231 100
  1050.1 1052.2 2.1 6.71   TLX_3158 Triple Lynx
WST-21-0713A 79.8 82.0 2.2 6.24   LXM_3371 Lynx
WST-21-0845 86.0 88.0 2.0 5.19   LXM_3336 Lynx
including 86.7 87.0 0.3 34.4  
  98.6 100.7 2.1 18.8   LXM_3371 Lynx
including 100.0 100.4 0.4 91.0  
WST-21-0847 96.2 99.8 3.6 20.2   LXM_3371 Lynx
including 96.2 97.0 0.8 59.4  
WST-21-0848 73.5 75.9 2.4 7.49   LXM_3336 Lynx
including 75.5 75.9 0.4 44.5  
  97.0 99.4 2.4 8.86   LXM_3371 Lynx
including 98.1 98.5 0.4 37.8  
  113.0 117.7 4.7 4.17   LXM_3359 Lynx
including 113.0 113.4 0.4 26.9  
WST-21-0849 74.0 76.6 2.6 11.3   LXM_3336 Lynx
including 75.7 76.3 0.6 47.7  
  96.0 98.0 2.0 29.1   LXM_3371 Lynx
including 97.2 97.6 0.4 91.9  
  110.1 112.3 2.2 6.17   LXM_3359 Lynx
including 110.4 110.9 0.5 26.5  
WST-21-0887 121.0 123.5 2.5 7.59   LXM_3359 Lynx
including 123.0 123.5 0.5 33.4  
WST-21-0891 97.8 100.0 2.2 18.4   LXM_3371 Lynx
including 97.8 98.3 0.5 69.1  
WST-21-0905 53.1 55.2 2.1 5.62   LXM_3339 Lynx
including 53.6 54.0 0.4 17.3  
WST-21-0921 47.7 49.7 2.0 21.4   LXM_3303 Lynx
including 48.6 49.7 1.1 38.5  
WST-21-0923 65.5 67.8 2.3 5.91   LXM_3336 Lynx
including 65.5 66.1 0.6 17.8  
  98.3 100.5 2.2 7.23   LXM_3371 Lynx
including 98.3 99.1 0.8 19.5  
WST-21-0941 58.8 61.1 2.3 55.1 27.3 LXM_3336 Lynx
including 59.3 59.8 0.5 228 100
WST-22-0998 200.8 205.2 4.4 8.34   MAL_5215 Mallard
including 204.0 205.2 1.2 23.8  
WST-22-1010 357.5 359.7 2.2 10.4   LX4_3405 Lynx 4
including 358.0 358.4 0.4 37.0  
WST-22-1011 200.5 202.5 2.0 84.1 67.3 TLX_3161 Triple Lynx
including 201.3 202.5 1.2 128 100
WST-22-1014-W1 473.5 477.5 4.0 20.9 12.6 LX4_3404 Lynx 4
including 473.5 473.9 0.4 183 100
  482.3 484.4 2.1 10.1   LX4_3430 Lynx 4
including 483.8 484.4 0.6 33.3  
WST-22-1015 183.3 185.3 2.0 4.03   MAL_5215 Mallard
including 184.4 185.0 0.6 12.6  
WST-22-1016 264.6 268.3 3.7 40.8   TLX_3158 Triple Lynx
including 265.3 265.8 0.5 88.6  
WST-22-1018 198.8 200.9 2.1 62.4 30.0 TLX_3161 Triple Lynx
including 200.1 200.5 0.4 270 100
  540.7 542.8 2.1 5.74   LX4_3404 Lynx 4
including 540.7 541.3 0.6 16.0  
WST-22-1018-W1 540.0 542.0 2.0 6.31   LX4_3404 Lynx 4
  545.4 547.7 2.3 272 58.9 LX4_3430 Lynx 4
including 545.4 546.0 0.6 504 100
and 547.1 547.7 0.6 512 100
WST-22-1019 227.8 230.4 2.6 9.93   TLX_3131 Triple Lynx
including 228.9 229.2 0.3 64.2  
  395.0 397.0 2.0 38.2 15.5 LX4_3410 Lynx 4
including 396.1 396.4 0.3 251 100
  425.3 428.0 2.7 16.6 11.8 LX4_3409 Lynx 4
including 425.3 425.6 0.3 143 100
  430.0 432.0 2.0 125 15.3 LX4_3409 Lynx 4
including 431.7 432.0 0.3 833 100
WST-22-1020 139.0 141.4 2.4 9.86   LXM_3334 Lynx
including 139.3 139.7 0.4 23.7  
  312.0 321.6 9.6 24.6 13.0 TLX_3131 Triple Lynx
including 318.4 319.4 1.0 211 100
  539.8 542.0 2.2 5.75   LX4_3450 Lynx 4
including 540.3 540.6 0.3 39.3  
WST-22-1021 281.0 285.0 4.0 46.6 40.4 TLX_3158 Triple Lynx
including 282.3 282.9 0.6 142 100
  323.7 327.8 4.1 10.2   TLX_3155 Triple Lynx
including 327.4 327.8 0.4 98.9  
WST-22-1025 160.3 163.0 2.7 14.0   LXM_3388 Lynx
WST-22-1036 497.9 500.3 2.4 4.87   LX4_3404 Lynx 4
including 497.9 498.3 0.4 22.9  
  513.0 515.0 2.0 11.8   LX4_3404 Lynx 4
including 514.0 514.4 0.4 41.5  
WST-22-1051 257.0 260.0 3.0 20.6   TLX_3158 Triple Lynx
WST-22-1055 86.8 89.0 2.2 7.35   TLX_3161 Triple Lynx
including 86.8 87.1 0.3 46.0  

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, TLX = Triple Lynx and MAL = Mallard.

 

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-22-2587-W4 1109.7 1118.6 8.9 3.65   TLX Triple Lynx
including 1118.2 1118.6 0.4 25.0  
OSK-W-22-2646-W4 1115.0 1120.6 5.6 4.00   TLX Triple Lynx
including 1120.0 1120.6 0.6 18.1  
  1125.0 1127.0 2.0 3.90   TLX Triple Lynx
OSK-W-22-2646-W5 1169.3 1171.5 2.2 131 31.6 TLX_3172 Triple Lynx
including 1169.7 1170.3 0.6 465 100
WST-21-0771C 104.2 107.0 2.8 11.4   BCT Bobcat
including 105.0 106.0 1.0 23.7  
WST-21-0872 74.7 76.8 2.1 8.46   LXM Lynx
including 75.7 76.3 0.6 20.0  
WST-21-0899B 35.4 37.5 2.1 11.9   BCT Bobcat
including 35.8 36.1 0.3 80.3  
WST-22-1014-W1 558.0 560.2 2.2 4.02   LX4 Lynx 4
WST-22-1019 351.3 354.0 2.7 5.09   LX4_3401 Lynx 4
WST-22-1020 295.7 300.0 4.3 7.57   TLX Triple Lynx
including 295.7 296.2 0.5 16.4  
WST-22-1021 437.4 439.6 2.2 112 83.4 TLX_3172 Triple Lynx
including 438.6 439.6 1.0 164 100

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

 

Drill hole location

Hole No. Azimuth (°) Dip

(°)

Length (m) UTM E UTM N Elevation Section
OSK-W-22-2587-W3 127 -59 1221 453350 5435673 413 3850
OSK-W-22-2587-W4 127 -59 1218 453350 5435673 413 3850
OSK-W-22-2601-W4 125 -61 1098 453425 5435656 412 3900
OSK-W-22-2601-W6 125 -61 1212 453425 5435656 412 3900
OSK-W-22-2605-W2 112 -55 1431 453551 5435669 408 4025
OSK-W-22-2605-W3 112 -55 1455 453551 5435669 408 4025
OSK-W-22-2605-W4 112 -55 1425 453551 5435669 408 4025
OSK-W-22-2605-W5 112 -55 1401 453551 5435669 408 4025
OSK-W-22-2605-W6 112 -55 1404 453551 5435669 408 4025
OSK-W-22-2646-W4 109 -58 1254 453326 5435648 414 3800
OSK-W-22-2646-W5 109 -58 1245 453326 5435648 414 3800
WST-21-0713A 158 4 94 453359 5435194 84 3625
WST-21-0771C 127 -52 357 452954 5435003 252 3175
WST-21-0845 130 -29 111 453315 5435165 124 3550
WST-21-0847 134 -30 114 453315 5435165 124 3550
WST-21-0848 135 -27 129 453315 5435165 124 3550
WST-21-0849 134 -24 118 453315 5435164 124 3550
WST-21-0872 135 -69 348 453508 5435327 -7 3800
WST-21-0887 136 -33 132 453315 5435165 123 3550
WST-21-0891 138 -28 126 453314 5435164 124 3550
WST-21-0899B 134 -60 287 452955 5435004 253 3175
WST-21-0905 141 -52 64 453221 5435121 135 3450
WST-21-0921 148 -37 114 453314 5435164 124 3550
WST-21-0923 147 -31 111 453314 5435164 124 3550
WST-21-0941 153 -23 129 453315 5435164 124 3550
WST-22-0998 358 -52 230 452207 5434903 247 2475
WST-22-1010 136 -28 481 453445 5435276 -99 3725
WST-22-1011 134 -32 630 453344 5435312 -66 3650
WST-22-1014-W1 123 -37 594 453507 5435332 -47 3800
WST-22-1015 345 -60 210 452206 5434903 247 2475
WST-22-1016 143 -65 448 453647 5435347 -189 3950
WST-22-1018 115 -43 636 453506 5435327 -90 3800
WST-22-1018-W1 115 -43 585 453506 5435327 -90 3800
WST-22-1019 140 -27 463 453444 5435276 -99 3725
WST-22-1020 142 -52 582 453322 5435236 54 3600
WST-22-1021 149 -67 468 453647 5435347 -189 3950
WST-22-1025 122 -20 189 453507 5435332 -47 3800
WST-22-1036 130 -48 627 453505 5435326 -90 3800
WST-22-1051 106 -52 327 453702 5435377 -198 4000
WST-22-1055 144 -44 120 453600 5435324 -181 3950

 

Bobcat

Mineralization most commonly occurs in gold-bearing quartz-pyrite veins controlled by northeast trending faults and shears and to a lesser extent in minor crustiform quartz-tourmaline-ankerite-pyrite veins and pyrite replacement zones and stockwork. Mineralization is hosted in sheared mafic volcanics, rhyolites near faults, or at the contact with felsic porphyritic intrusions.

 

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 thick. 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.

 

Mallard

Mineralization is hosted in sheared mafic volcanics with felsic porphyritic intrusions and occurs as veins associated with sericite-pyrite ± silica ± chlorite alteration and contains pyrite ranging from trace to 30% and local visible gold.

 

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