Category: Silver / Gold

Osisko Continues to Add High-Grade at Lynx

184 g/t Au Over 2.1 Metres
34.1 g/t Au over 7.1 Metres
 
TORONTO, June 17, 2021 -- 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 68 intercepts in 22 drill holes (2 from surface, 20 from underground) and 14 wedges. The infill intercepts are located inside defined February 2021 mineral resource estimate (“MRE”) blocks (see Osisko news release dated February 17,2021). The expansion intercepts are located outside the February 2021 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: “The continued success of the infill and expansion drill programs at Lynx demonstrate how robust the system is with respect to grade and growth. Windfall is demonstrating its consistency with more high-grade infill and expansion holes, and we expect to complete our major drill program as scheduled this fall.”

Selected high-grade intercepts include: 184 g/t Au over2.1metres in OSK-W-21-2480-W3; 34.1 g/tAu over 7.1 metres in OSK-W-21-2495-W1, 94.1 g/t Auover 2.0 metres in OSK-W-21-2480-W4, 40.3 g/t Au over 4.0 metres and 41.2 g/t Au over 2.9 metres in OSK-W-21-2067-W7; 36.0 g/t Au over 4.0 metres in OSK-W-21-2503; and 41.0 g/t Au over 2.5 metres in OSK-W-21-2465-W2. Maps showing hole locations and full analytical results are available at www.osiskomining.com

Infill Drilling

Hole Number From (m) To (m) Interval (m) Au (g/t) uncut Au (g/t) cut to 100 g/t Zone Corridor
OSK-W-21-2067-W7 1029.0 1033.0 4.0 5.08   TLX_3183 Triple Lynx
  1039.5 1042.4 2.9 41.2 21.7 TLX_3183 Triple Lynx
including 1039.5 1039.8 0.3 180 100
and 1042.1 1042.4 0.3 209 100
  1115.0 1119.0 4.0 40.3 18.6 TLX_3170 Triple Lynx
including 1117.0 1117.5 0.5 274 100
  1132.1 1134.2 2.1 34.2 15.5 TLX_3172 Triple Lynx
including 1133.9 1134.2 0.3 231 100
OSK-W-21-2478-W3 891.1 893.4 2.3 5.78   TLX_3161 Triple Lynx
including 892.7 893.4 0.7 14.2  
OSK-W-21-2478-W4 842.8 846.5 3.7 7.00   TLX_3171 Triple Lynx
  863.9 866.0 2.1 4.13   TLX_3184 Triple Lynx
  874.3 876.3 2.0 26.2   TLX_3184 Triple Lynx
including 874.3 874.7 0.4 90.3  
  877.7 880.2 2.5 5.65   TLX_3161 Triple Lynx
including 879.7 880.2 0.5 20.0  
OSK-W-21-2480-W3 757.4 759.5 2.1 184 78.2 LXM_3304 Lynx
including 758.4 759.2 0.8 350 100
OSK-W-21-2480-W4 734.6 737.2 2.6 8.59   LXM_3304 Lynx
including 734.6 735.2 0.6 23.3  
  686.0 688.0 2.0 94.1 27.2 LX4_3414 Lynx 4
including 686.7 687.0 0.3 546 100
OSK-W-21-2492-W3 803.4 805.5 2.1 8.19   LX4_3414 Lynx 4
including 804.0 804.5 0.5 18.4  
  864.0 866.0 2.0 10.1   LX4_3437 Lynx 4
OSK-W-21-2495-W1 1038.0 1045.1 7.1 34.1 33.5 LX4_3430 Lynx 4
including 1040.0 1041.0 1.0 105 100
OSK-W-21-2503 1008.0 1013.0 5.0 6.59   TLX_3163 Triple Lynx
  1087.0 1089.0 2.0 3.53   TLX_3162 Triple Lynx
including 1088.3 1088.6 0.3 12.6  
  1113.0 1117.0 4.0 36.0 22.4 TLX_3172 Triple Lynx
including 1115.1 1115.8 0.7 178 100
  1120.0 1122.1 2.1 11.5   TLX_3172 Triple Lynx
including 1120.3 1120.6 0.3 72.8  
OSK-W-21-2522 735.0 737.0 2.0 4.54   LXM_3345 Lynx
WST-21-0650 232.5 236.1 3.6 9.91   LXSW_3507 Lynx
including 232.5 233.0 0.5 51.3  
WST-21-0684 267.9 269.9 2.0 6.55   LXSW_3556 Lynx
including 268.6 269.0 0.4 32.0  
WST-21-0725 262.4 264.5 2.1 7.65   TLX_3185 Triple Lynx
WST-21-0727A 334.1 336.1 2.0 15.0   TLX_3163 Triple Lynx
including 334.1 334.7 0.6 44.7  
WST-21-0734A 323.7 325.9 2.2 6.99   LXSW_3556 Lynx
including 325.2 325.9 0.7 21.1  
WST-21-0736 202.0 204.0 2.0 14.0   LXSW_3507 Lynx
including 202.0 202.7 0.7 35.1  
  297.0 299.6 2.6 13.4   LXSW_3556 Lynx
including 297.0 297.9 0.9 31.6  
  354.0 356.2 2.2 12.7   LXSW_3502 Lynx
including 355.3 355.6 0.3 33.9  
WST-21-0768 365.0 367.0 2.0 17.0   LXSW_3502 Lynx
including 366.1 366.7 0.6 56.2  
WST-21-0769 79.1 81.3 2.2 10.3   LXM_3311 Lynx
including 79.1 79.9 0.8 27.0  
WST-21-0774 479.6 482.0 2.4 12.1   LX4_3450 Lynx 4
including 480.3 481.1 0.8 35.5  
WST-21-0782 169.3 172.0 2.7 20.6   LXM_3304 Lynx
including 169.3 170.2 0.9 49.1  
WST-21-0787 129.4 133.0 3.6 5.66   LXM_3334 Lynx
WST-21-0790 95.0 97.3 2.3 5.00   LXM_3339 Lynx
including 96.0 96.7 0.7 12.3  
  105.0 107.0 2.0 10.7   LXM_3339 Lynx
including 105.4 106.0 0.6 24.3  

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 LXSW = Lynx Southwest.

Expansion Drilling

Hole Number From (m) To (m) Interval (m) Au (g/t) uncut Au (g/t) cut to 100 g/t Zone Corridor
OSK-W-21-2275-W5 1053.0 1057.1 4.1 17.2   Triple Lynx Triple Lynx
including 1053.5 1053.8 0.3 37.2  
and 1056.3 1057.1 0.8 72.5  
OSK-W-21-2391-W3 1251.0 1253.1 2.1 3.64   Triple Lynx Triple Lynx
OSK-W-21-2391-W4 1404.5 1406.5 2.0 6.39   Triple Lynx Triple Lynx
including 1404.5 1404.8 0.3 36.2  
  1409.0 1412.2 3.2 6.03   Triple Lynx Triple Lynx
including 1409.0 1409.9 0.9 18.0  
  1417.0 1419.0 2.0 3.90   Triple Lynx Triple Lynx
including 1417.6 1418.1 0.5 12.5  
OSK-W-21-2465-W2 763.7 766.2 2.5 41.0 39.1 Triple Lynx Triple Lynx
including 765.0 765.3 0.3 111 100
and 765.6 766.2 0.6 99.6 97.1
OSK-W-21-2470-W2 921.0 923.0 2.0 4.27   Triple Lynx Triple Lynx
  925.4 928.6 3.2 6.01   Triple Lynx Triple Lynx
including 925.4 925.9 0.5 18.5  
  991.7 995.0 3.3 4.20   Triple Lynx Triple Lynx
including 991.7 992.1 0.4 19.1  
  1125.0 1127.0 2.0 7.82   Triple Lynx Triple Lynx
including 1125.3 1125.6 0.3 29.8  
OSK-W-21-2470-W3 975.7 977.7 2.0 8.24   Triple Lynx Triple Lynx
OSK-W-21-2480-W2 678.8 682.0 3.2 7.66   Lynx Lynx
OSK-W-21-2495-W1 604.0 606.1 2.1 4.18   Lynx Lynx
including 605.3 605.7 0.4 15.4  
  1157.9 1160.0 2.1 5.79   Lynx 4 Lynx
including 1158.5 1159.3 0.8 12.6  
  1190.7 1193.0 2.3 4.83   Lynx 4 Lynx
including 1191.8 1192.2 0.4 26.8  
WST-21-0661 171.0 173.0 2.0 5.37   Lynx SW Lynx SW
including 171.9 172.4 0.5 21.4  
WST-21-0663 191.0 193.0 2.0 5.65   Lynx SW Lynx SW
including 191.0 191.4 0.4 27.4  
WST-21-0681 419.0 421.9 2.9 10.4   Triple Lynx Triple Lynx
  444.0 446.0 2.0 8.90   Triple Lynx Triple Lynx
including 445.0 446.0 1.0 17.4  
WST-21-0734A 192.0 194.0 2.0 4.76   Lynx SW Lynx SW
WST-21-0736 247.0 249.0 2.0 11.6   Lynx SW Lynx SW
WST-21-0767 268.0 270.2 2.2 4.67   Lynx SW Lynx SW
including 268.6 269.3 0.7 12.1  
WST-21-0768 263.0 265.2 2.2 18.2 14.3 Lynx SW Lynx SW
including 264.1 264.4 0.3 129 100
  312.0 314.0 2.0 13.5   Lynx SW LynSW
including 313.0 313.3 0.3 83.5  
WST-21-0769 320.0 322.0 2.0 4.38   Lynx SW Lynx SW
including 320.4 321.2 0.8 10.9  
  329.3 331.3 2.0 17.1 15.6 LXSW_3502 Lynx SW
including 329.3 329.6 0.3 110 100
WST-21-0774 332.0 334.0 2.0 3.64   Triple Lynx Triple Lynx
  677.5 683.0 5.5 16.4 11.0 Lynx 4 Lynx
including 677.5 677.8 0.3 198 100
WST-21-0777 311.0 313.0 2.0 3.59   Lynx SW Lynx SW
WST-21-0781 227.8 229.8 2.0 23.5   Triple Lynx Triple Lynx
including 229.2 229.5 0.3 99.6  
WST-21-0782 151.0 153.0 2.0 4.26   Lynx Lynx
including 151.3 151.6 0.3 27.2  
WST-21-0783 170.5 172.5 2.0 12.4   Lynx Lynx
including 170.5 170.8 0.3 68.0  
WST-21-0803 157.0 159.4 2.4 23.1   Triple Lynx Triple Lynx

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See "Quality Control and Reporting Protocols" below. LXSW = Lynx Southwest, SW = Southwest.

Drill hole location

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Elevation Section
OSK-W-21-2067-W7 123 -53 1166 453241 5435697 416 3750
OSK-W-21-2275-W5 127 -49 1242 452888 5435583 409 3400
OSK-W-21-2391-W3 117 -57 1566 453281 5435894 408 3900
OSK-W-21-2391-W4 117 -57 1212 453281 5435894 408 3900
OSK-W-21-2465-W2 123 -61 831 453397 5435557 413 3825
OSK-W-21-2470-W2 132 -59 1197 453304 5435639 415 3775
OSK-W-21-2470-W3 132 -59 1209 453304 5435639 415 3775
OSK-W-21-2478-W3 128 -54 1080 452997 5435607 425 3500
OSK-W-21-2478-W4 127 -53 744 452997 5435607 425 3500
OSK-W-21-2480-W2 121 -55 789 453412 5435633 412 3875
OSK-W-21-2480-W3 121 -55 810 453412 5435633 412 3875
OSK-W-21-2480-W4 121 -55 780 453412 5435633 412 3875
OSK-W-21-2492-W3 122 -53 720 453687 5435676 401 4125
OSK-W-21-2495-W1 123 -54 1301 453426 5435565 410 3850
OSK-W-21-2503 126 -58 1080 453333 5435641 413 3800
OSK-W-21-2522 128 -54 450 453451 5435594 411 3900
WST-21-0650 139 -60 466 452954 5435003 253 3175
WST-21-0661 163 -34 253 452954 5435003 254 3175
WST-21-0663 164 -40 214 452954 5435003 253 3175
WST-21-0681 160 -43 721 453322 5435235 55 3600
WST-21-0684 150 -44 301 452955 5435003 253 3175
WST-21-0725 160 -67 391 453506 5435327 -7 3800
WST-21-0727A 146 -69 361 453507 5435327 -7 3800
WST-21-0734A 129 -56 360 452956 5435003 253 3175
WST-21-0736 146 -53 448 452955 5435003 253 3175
WST-21-0767 175 -55 354 453104 5435065 231 3325
WST-21-0768 169 -53 453 453104 5435065 231 3325
WST-21-0769 171 -49 396 453103 5435064 231 3325
WST-21-0774 148 -40 724 453373 5435296 -26 3675
WST-21-0777 144 -49 352 452954 5435003 253 3175
WST-21-0781 129 -59 283 453508 5435327 -7 3800
WST-21-0782 123 -36 207 453508 5435327 -7 3800
WST-21-0783 119 -28 201 453508 5435327 -6 3800
WST-21-0787 143 -46 517 453320 5435235 54 3600
WST-21-0790 171 -65 64 453104 5435065 231 3325
WST-21-0803 162 -44 364 453356 5435271 16 3650

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
Truewidthdeterminationisestimatedat55-80%ofthereportedcorelengthintervalforthezone.Assaysareuncutexceptwhere 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 3.0 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 February 17, 2021 is supported by the technical report entitled “Preliminary Economic Assessment Update for the Windfall Project” dated April 26, 2021 (that includes Windfall Mineral Resource Estimate with an effective date  of November 30, 2020), and assuming a cut-off grade of 3.50 g/t Au, comprises 521,000 tonnes at 11.3 g/t Au (189,000 ounces) in the measured mineral resource category, 5,502,000 tonnes at 9.4 g/t Au (1,668,000 ounces) in the indicated mineral resource category and 16,401,000 tonnes at 8.0 g/t Au (4,244,000 ounces) in the inferred mineral resource category. The key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in the February 17, 2021 news release are further described in the full technical report prepared by BBA Inc. 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 occursinthreeprincipalzones:Lynx,Main Zone,andUnderdog.Mineralization is generallycomprised ofsub-vertical zonesfollowingintrusive porphyrycontactsplungingtothenortheast.The resources are defined fromsurfacetoadepthof1,600metres 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 remainsopen alongstrikeandatdepth.Mineralizationhasbeenidentifiedatsurfaceinsomeareasandasdeepas2,625metres in others with significant potential to extend mineralization down-plunge and atdepth.

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 ChibougamauinQuébecandholdsa100%undividedinterestinalargeareaofclaimsinthesurroundingUrbanBarryarea and nearby Quévillon area (over 2,700 squarekilometres).

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