OSISKO INFILL DRILLING RETURNS HIGH GRADE AT LYNX

248 g/t Au Over 2.2 Metres

164 g/t Au over 2.2 Metres

(Toronto, June 8, 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 34 intercepts in 15 underground drill holes and 8 wedges. The infill intercepts are located inside defined February 2021 mineral resource estimate (“MRE”) blocks (see Osisko news release dated February 17, 2021).

Osisko Chief Executive Officer John Burzynski commented: “Infill drilling in Lynx consistently delivers evenly distributed high-grade throughout the Lynx zones. Top results released today are all greater than an ounce per ton over two metres.”

Selected high-grade intercepts include: 248 g/t Au over 2.2 metres in WST-21-0750; 164 g/t Au over 2.2 metres in OSK-W-21-2492-W1, 128 g/t Au over 2.3 metres in OSK-W-21-2067-W6, 56.5 g/t Au over 2.9 metres in WST-21-0655 and 46.8 g/t Au over 2.6 metres in WST-21-0727A. Maps showing hole locations and full analytical results are available at www.osiskomining.com

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-21-2067-W6 1078.7 1080.8 2.1 4.77   TLX_3162 Triple Lynx
1095.7 1098.0 2.3 128 19.0 TLX_3170 Triple Lynx
including 1095.7 1096.1 0.4 725 100
OSK-W-21-2275-W5 909.0 911.0 2.0 24.7   TLX_3129 Triple Lynx
including 910.0 911.0 1.0 47.6
918.0 920.0 2.0 36.9 21.5 TLX_3129 Triple Lynx
including 918.9 919.3 0.4 177 100
OSK-W-21-2478-W1 583.0 588.0 5.0 4.10   TLX_3178 Triple Lynx
including 587.0 588.0 1.0 13.1
OSK-W-21-2478-W3 901.0 903.0 2.0 9.94   TLX_3161 Triple Lynx
including 902.0 903.0 1.0 19.8
OSK-W-21-2487-W3 674.3 676.3 2.0 19.8   LX4_3414 Lynx 4
OSK-W-21-2492-W1 771.0 773.2 2.2 164 18.4 LX4_3414 Lynx 4
including 771.8 772.2 0.4 902 100
OSK-W-21-2492-W2 759.0 762.0 3.0 4.22   LX4_3424 Lynx 4
including 761.2 762.0 0.8 14.7
794.0 796.0 2.0 4.40   LX4_3414 Lynx 4
OSK-W-21-2495-W1 668.0 670.0 2.0 28.0   LXM_3304 Lynx
including 669.6 670.0 0.4 60.5
675.3 678.0 2.7 34.4   LXM_3304 Lynx
including 675.3 676.2 0.9 89.7
WST-21-0653A 362.0 364.2 2.2 12.8   LXSW_3556 Lynx
including 362.4 363.2 0.8 33.3
WST-21-0655 299.0 301.9 2.9 56.5 32.1 Lynx SW Lynx SW
including 301.0 301.9 0.9 179 100
WST-21-0664 85.2 88.0 2.8 34.7 25.2 LXM_3307 Lynx
including 85.2 85.9 0.7 138 100
477.8 479.9 2.1 11.0   LX4_3450 Lynx 4
including 479.1 479.9 0.8 24.8
WST-21-0681 290.0 292.0 2.0 4.71   TLX_3131 Triple Lynx
including 291.4 292.0 0.6 15.0
321.0 323.0 2.0 6.38   TLX_3167 Triple Lynx
including 321.4 321.8 0.4 31.5
482.0 484.2 2.2 10.8   LX4_3450 Lynx 4
WST-21-0705A 243.3 245.3 2.0 4.56   LXSW_3500 Lynx SW
including 244.6 245.3 0.7 13.0
WST-21-0718 25.9 28.0 2.1 15.0   LXM_3303 Lynx
including 26.7 27.3 0.6 47.4
88.7 90.7 2.0 26.7   LXM_3304 Lynx
including 88.7 89.4 0.7 69.0
WST-21-0719 88.7 90.7 2.0 17.0   LXM_3304 Lynx
including 89.3 90.0 0.7 48.2
WST-21-0727A 260.1 262.7 2.6 46.8 22.0 TLX_3161 Triple Lynx
including 261.2 261.7 0.5 229 100
WST-21-0750 232.6 234.8 2.2 248 55.6 TLX_3161 Triple Lynx
including 233.8 234.3 0.5 740 100
WST-21-0755 318.0 320.0 2.0 4.92   TLX_3131 Triple Lynx
including 319.2 320.0 0.7 12.0
WST-21-0757 200.5 202.7 2.2 21.9   LXSW_3506 Lynx
including 201.0 201.3 0.3 75.2
255.0 257.0 2.0 11.3   TLX_3131 Triple Lynx
including 256.3 257.0 0.7 31.8
272.6 275.0 2.4 4.69   TLX_3166 Triple Lynx
357.0 359.5 2.5 34.8 19.4 TLX_3165 Triple Lynx
including 358.3 358.7 0.4 197 100
WST-21-0762 98.3 100.4 2.1 4.54   LXM_3311 Lynx
including 98.7 99.4 0.7 11.6
WST-21-0768 281.0 283.0 2.0 12.8   LXSW_3556 Lynx
including 281.3 281.6 0.3 77.7
WST-21-0769 268.0 270.0 2.0 8.16   LXSW_3556 Lynx SW
including 268.7 269.6 0.9 17.9
WST-21-0787 489.0 491.1 2.1 10.3   LX4_3450 Lynx 4
including 490.3 490.7 0.4 53.4

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.

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Drill hole location

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Elevation Section
OSK-W-21-2067-W6 123 -53 1281 453241 5435697 416 3750
OSK-W-21-2275-W5 127 -49 1242 452888 5435583 409 3400
OSK-W-21-2478-W1 128 -54 764 452997 5435607 425 3500
OSK-W-21-2478-W3 128 -54 1080 452997 5435607 425 3500
OSK-W-21-2487-W3 359 -73 762 454135 5435058 397 4225
OSK-W-21-2492-W1 122 -53 843 453687 5435676 401 4125
OSK-W-21-2492-W2 122 -53 879 453687 5435676 401 4125
OSK-W-21-2495-W1 123 -54 1301 453426 5435565 410 3850
WST-21-0653A 155 -65 427 453104 5435065 231 3325
WST-21-0655 162 -63 402 453104 5435065 231 3325
WST-21-0664 140 -51 760 453229 5435127 134 3475
WST-21-0681 160 -43 721 453322 5435235 55 3600
WST-21-0705A 161 -57 351 453104 5435065 231 3325
WST-21-0718 162 0 100 453359 5435195 84 3625
WST-21-0719 163 -4 100 453359 5435194 83 3625
WST-21-0727A 146 -69 361 453507 5435327 -7 3800
WST-21-0750 124 -54 280 453357 5435273 15 3650
WST-21-0755 158 -48 358 453356 5435272 15 3650
WST-21-0757 145 -50 706 453228 5435126 135 3475
WST-21-0762 136 -60 381 453105 5435065 231 3325
WST-21-0768 169 -53 453 453104 5435065 231 3325
WST-21-0769 171 -49 396 453103 5435064 231 3325
WST-21-0787 143 -46 517 453320 5435235 54 3600

 

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 3.0 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 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 2,700 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