OSISKO WINDFALL INFILL DRILLING ADDS WIDE HIGH-GRADE

Including 293 g/t Au Over 11.0 Metres

(Toronto, June 7, 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 43 intercepts in 15 underground drill holes and 12 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: “Lynx continues to return wide high-grade intercepts which will be included in the upcoming feasibility study. Our headline hole, with an estimated true thickness of eight meters, and other holes with sub-intervals over a kilogram of gold per tonne, demonstrate the robust nature of the high-grade areas in the Lynx 4 and Triple Lynx zones.”

Selected high-grade intercepts include: 293 g/t Au over 11.0 metres in OSK-W-22-2605-W6, 199 g/t Au over 2.9 metres in OSK-W-22-2587-W6; 24.3 g/t Au over 13.4 metres in OSK-W-22-2587-W5; 73.4 g/t Au over 2.3 metres in WST-22-1041B and 54.9 g/t Au over 3.0 metres in WST-22-1046B. Maps showing hole locations and full analytical results are available at www.osiskomining.com. Maps: Long Section_All zones In EN 20220607, Long Section_All zones Ex EN 20220607, PR_EN_20220607_Surface, PR_EN_20220607_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-W4 1084.4 1093.7 9.3 5.67   TLX_3155 Triple Lynx
including 1088.5 1088.9 0.4 26.9  
OSK-W-22-2587-W5 1040.5 1043.0 2.5 8.52   TLX_3158 Triple Lynx
including 1040.5 1040.9 0.4 41.0  
  1052.4 1055.0 2.6 4.30   TLX_3158 Triple Lynx
including 1052.4 1052.8 0.4 18.9  
  1110.0 1112.1 2.1 8.85   TLX_3162 Triple Lynx
including 1110.7 1111.1 0.4 32.9  
  1120.7 1125.4 4.7 4.54   TLX_3162 Triple Lynx
including 1125.0 1125.4 0.4 23.6  
  1129.0 1131.0 2.0 8.25   TLX_3162 Triple Lynx
  1136.3 1149.7 13.4 24.3 14.6 TLX_3172 Triple Lynx
including 1141.3 1142.3 1.0 129 100
and 1142.3 1142.8 0.5 302 100
OSK-W-22-2587-W6 1122.0 1126.0 4.0 15.3 15.0 TLX_3162 Triple Lynx
including 1122.0 1122.4 0.4 104 100
  1134.6 1141.2 6.6 10.3   TLX_3162 Triple Lynx
including 1134.6 1135.2 0.6 33.8  
  1149.1 1152.0 2.9 199 31.0 TLX_3172 Triple Lynx
including 1149.1 1149.6 0.5 423 100
and 1150.1 1150.4 0.3 1185 100
OSK-W-22-2601-W5 1011.0 1013.6 2.6 37.5   TLX_3158 Triple Lynx
including 1011.7 1012.1 0.4 95.5  
OSK-W-22-2605-W4 1301.2 1303.4 2.2 5.95   LX4_3449 Lynx 4
including 1302.5 1302.8 0.3 31.0  
OSK-W-22-2605-W6 1316.4 1327.4 11.0 293 32.3 LX4_3449 Lynx 4
including 1317.4 1320.7 3.3 961 92.3
with 1318.8 1319.1 0.3 3040 100
with 1319.9 1320.2 0.3 5400 100
OSK-W-22-2646-W7 1066.0 1070.1 4.1 5.06   TLX_3158 Triple Lynx
including 1069.8 1070.1 0.3 30.6  
WST-21-0929A 191.0 193.2 2.2 20.0   TLX_3161 Triple Lynx
including 192.4 192.9 0.5 78.5  
WST-22-1014-W1 257.0 259.0 2.0 40.7   LXM_3367 Lynx
including 257.0 258.0 1.0 81.2  
WST-22-1017 455.8 459.5 3.7 6.76   LX4_3401 Lynx 4
including 456.1 456.5 0.4 19.2  
WST-22-1022 403.0 405.0 2.0 4.59   TLX_3162 Triple Lynx
WST-22-1023 204.0 206.1 2.1 27.2   TLX_3121 Triple Lynx
including 205.2 206.1 0.9 61.1  
  566.0 571.1 5.1 10.2   LX4_3404 Lynx 4
including 567.0 567.3 0.3 54.9  
WST-22-1031A 449.0 451.0 2.0 7.47   LX4_3401 Lynx 4
including 450.2 450.7 0.5 19.4  
  499.6 503.1 3.5 4.52   LX4_3457 Lynx 4
including 499.6 500.1 0.5 13.0  
and 502.7 503.1 0.4 17.5  
WST-22-1041B 526.8 529.1 2.3 73.4 61.1 LX4_3430 Lynx 4
including 528.4 528.7 0.3 143 100
WST-22-1043 330.7 332.7 2.0 6.19   TLX_3131 Triple Lynx
including 330.7 331.0 0.3 20.6  
WST-22-1045 291.5 293.7 2.2 29.8   TLX_3158 Triple Lynx
including 291.5 291.8 0.3 56.5  
WST-22-1046B 315.0 318.0 3.0 54.9 41.8 TLX_3158 Triple Lynx
including 315.0 315.6 0.6 157 100
WST-22-1047 138.0 140.1 2.1 5.46   LXM_3345 Lynx
WST-22-1048 111.3 113.6 2.3 32.2   LXM_3314 Lynx
including 112.7 113.2 0.5 95.2  
WST-22-1054 66.0 68.3 2.3 12.8   LXM_3388 Lynx
including 67.4 67.9 0.5 34.3  
WST-22-1058C 339.3 344.7 5.4 10.6   TLX_3158 Triple Lynx
including 339.3 339.9 0.6 41.2  
WST-22-1060 99.6 102.1 2.5 19.4   TLX_3121 Triple Lynx
including 100.9 101.2 0.3 66.9  
WST-22-1062 153.6 156.0 2.4 35.6   TLX_3121 Triple Lynx
including 155.0 156.0 1.0 66.8  

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-22-2587-W3 1101.8 1104.7 2.9 17.8   TLX Triple Lynx
OSK-W-22-2587-W5 1094.3 1096.7 2.4 8.91   TLX Triple Lynx
including 1096.3 1096.7 0.4 36.9  
OSK-W-22-2587-W6 1104.0 1106.0 2.0 9.11   TLX Triple Lynx
including 1104.3 1104.7 0.4 38.5  
OSK-W-22-2601-W6 1096.2 1099.1 2.9 3.97   TLX_3162 Triple Lynx
including 1096.5 1096.9 0.4 13.9  
OSK-W-22-2605-W4 1377.1 1379.1 2.0 6.74   LX4 Lynx 4
including 1378.0 1378.7 0.7 14.2  
OSK-W-22-2646-W6 1069.7 1072.4 2.7 30.6   TLX_3158 Triple Lynx
including 1070.1 1070.5 0.4 72.0  
and 1071.0 1071.4 0.4 75.8  
  1190.1 1194.2 4.1 16.1   TLX_3172 Triple Lynx
including 1190.1 1190.8 0.7 58.1  
OSK-W-22-2646-W7 1110.4 1112.5 2.1 8.53   TLX Triple Lynx
including 1111.7 1112.0 0.3 57.1  
OSK-W-22-2646-W8 1165.0 1167.3 2.3 7.79   TLX_3162 Triple Lynx
including 1166.0 1166.3 0.3 38.8  
  1220.2 1222.3 2.1 9.82   TLX_3172 Triple Lynx
including 1220.2 1221.0 0.8 23.2  
WST-22-1017 467.0 469.0 2.0 7.03   LX4 Lynx 4
including 468.0 469.0 1.0 12.4  

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-22-2587-W3 127 -59 1221 453350 5435673 413 3850
OSK-W-22-2587-W4 127 -59 1218 453350 5435673 413 3850
OSK-W-22-2587-W5 127 -59 1227 453350 5435673 413 3850
OSK-W-22-2587-W6 127 -59 1203 453350 5435673 413 3850
OSK-W-22-2601-W5 125 -61 1215 453425 5435656 412 3900
OSK-W-22-2601-W6 125 -61 1212 453425 5435656 412 3900
OSK-W-22-2605-W4 112 -55 1425 453551 5435669 408 4025
OSK-W-22-2605-W6 112 -55 1404 453551 5435669 408 4025
OSK-W-22-2646-W6 109 -58 1263 453326 5435648 414 3800
OSK-W-22-2646-W7 109 -58 1227 453326 5435648 414 3800
OSK-W-22-2646-W8 109 -58 1254 453326 5435648 414 3800
WST-21-0929A 117 -45 379 453506 5435326 -90 3800
WST-22-1014-W1 123 -37 594 453507 5435332 -47 3800
WST-22-1017 138 -26 561 453344 5435312 -66 3650
WST-22-1022 132 -62 479 453510 5435330 -127 3800
WST-22-1023 120 -48 646 453506 5435326 -90 3800
WST-22-1031A 136 -28 577 453344 5435312 -66 3650
WST-22-1041B 127 -43 585 453507 5435331 -48 3800
WST-22-1043 133 -26 561 453344 5435312 -66 3650
WST-22-1045 104 -54 339 453702 5435376 -198 4000
WST-22-1046B 125 -58 436 453510 5435331 -127 3800
WST-22-1047 130 -12 226 453647 5435347 -187 3950
WST-22-1048 139 -1 169 453647 5435347 -187 3950
WST-22-1054 120 -29 196 453647 5435347 -188 3950
WST-22-1058C 121 -60 520 453511 5435331 -127 3825
WST-22-1060 140 -55 156 453601 5435325 -181 3900
WST-22-1062 144 -59 171 453601 5435325 -181 3900

 

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.

 

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