Category: Silver / Gold

Osisko Infill and Expansion Drilling Hits More High-Grade

124 g/t Au Over 2.7 Metres in Triple Lynx
78.7 g/tAu over 2.0 metres in Lynx SW
 
TORONTO, May 04, 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 52 intercepts in 35 drill holes (9 from surface, 15 from underground) and 11 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 located in a defined zone or corridor but do not yet correlate to a specific wireframe.
 
Osisko Chief Executive Officer John Burzynski commented: “Today’s highlighted intercepts in the Lynx and Triple Lynx zones, as seen on the accompanying long sections available on our website, demonstrate the continued distribution of high-grade intersected throughout these areas in both infill and expansion drilling.”

Selected high-grade intercepts include: 124 g/t Au over2.7metres in WST-21-0729; 78.7 g/tAu over 2.0 metres and 39.3 g/t Au over 2.2 metres in WST-21-0703, 34.6 g/t Auover 3.6 metres in OSK-W-21-2465, 41.6 g/t Auover 2.9 metres in WST-21-0696, 41.9 g/t Au over 2.1 metres in WST-21-0652, 31.5 g/t Au over 2.4 metres in OSK-W-21-2472 and 37.1 g/t Au over 2.0 metres in WST-21-0749. 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-20-2252-W11 851.0 853.0 2.0 3.99   TLX_3189 Triple Lynx
OSK-W-20-2283-W2 789.6 791.8 2.2 4.14   TLX_3171 Triple Lynx
including 790.9 791.2 0.3 18.5  
OSK-W-21-2394-W4 643.2 646.2 3.0 9.31   TLX_3171 Triple Lynx
including 643.2 643.6 0.4 18.8  
OSK-W-21-2394-W6 674.6 676.7 2.1 10.7   TLX_3171 Triple Lynx
including 675.1 676.0 0.9 21.7  
  694.0 696.0 2.0 4.57   TLX_3184 Triple Lynx
OSK-W-21-2436-W3 805.0 807.0 2.0 21.4 20.4 LX4_3437 Lynx 4
including 806.6 807.0 0.4 105 100
OSK-W-21-2445-W3 601.6 605.1 3.5 3.68   TLX_3171 Triple Lynx
OSK-W-21-2470 976.0 978.0 2.0 4.62   TLX_3163 Triple Lynx
OSK-W-21-2478 887.0 889.2 2.2 8.94   TLX_3184 Triple Lynx
including 887.8 888.2 0.4 44.7  
OSK-W-21-2492 775.0 777.5 2.5 17.2   LX4_3414 Lynx 4
including 776.9 777.5 0.6 42.9  
  783.9 786.2 2.3 22.4 20.9 LX4_3414 Lynx 4
including 784.8 785.2 0.4 109 100
OSK-W-21-2495 659.0 661.0 2.0 3.65   LXM_3304 Lynx
including 659.4 659.7 0.3 20.9  
WST-21-0652 336.0 338.1 2.1 41.9 22.1 LXSW_3556 Lynx
including 337.7 338.1 0.4 204 100
WST-21-0658 185.0 187.1 2.1 15.7   TLX_3161 Triple Lynx
including 185.0 185.6 0.6 51.3  
WST-21-0671A 171.0 173.0 2.0 25.0   LXM_3304 Lynx
including 171.0 172.0 1.0 43.6  
WST-21-0675 159.2 161.4 2.2 14.2   LXM_3304 Lynx
including 159.2 159.9 0.7 39.4  
WST-21-0676 152.7 155.1 2.4 3.93   LXM_3304 Lynx
including 152.7 153.3 0.6 10.4  
WST-21-0677 399.0 401.0 2.0 8.52   TLX_3165 Triple Lynx
  409.5 411.5 2.0 11.4   TLX_3165 Triple Lynx
including 410.5 411.0 0.5 28.8  
WST-21-0692 334.2 336.4 2.2 5.34   TLX_3131 Triple Lynx
WST-21-0698 138.3 140.3 2.0 10.3   LXM_3334 Lynx
WST-21-0703 252.0 256.2 4.2 11.6   LXSW_3506 Lynx
including 255.1 255.5 0.4 66.5  
  463.7 465.9 2.2 39.3 28.1 LXSW_3502 Lynx
including 464.7 465.3 0.6 141 100
WST-21-0729 304.9 307.6 2.7 124 23.5 TLX_3166 Triple Lynx
including 305.9 306.3 0.4 780 100
WST-21-0739 128.2 130.2 2.0 23.5   LXM_3304 Lynx
including 129.0 129.7 0.7 63.8  
WST-21-0749 144.9 146.9 2.0 37.1   LXM_3304 Lynx

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 No. From (m) To (m) Interval (m) Au (g/t) uncut Au (g/t)        cut to 100 g/t Zone Corridor
OSK-W-21-2394-W6 914.0 916.0 2.0 5.70   TLX_3195 Triple Lynx
including 914.8 915.2 0.4 27.2  
OSK-W-21-2436-W2 614.2 617.0 2.8 7.16   Lynx 4 Lynx
OSK-W-21-2445-W1 878.0 880.0 2.0 4.68   Triple Lynx Triple Lynx
OSK-W-21-2445-W2 618.2 620.6 2.4 4.22   Triple Lynx Triple Lynx
OSK-W-21-2445-W4 918.5 920.5 2.0 16.9   Triple Lynx Triple Lynx
including 918.5 919.5 1.0 32.0  
OSK-W-21-2465 919.0 921.0 2.0 8.88   Lynx 4 Lynx
  951.4 955.0 3.6 34.6   Lynx 4 Lynx
including 952.0 954.0 2.0 54.3  
OSK-W-21-2465 962.5 964.6 2.1 12.4   Lynx 4 Lynx
OSK-W-21-2470 1020.9 1023.0 2.1 6.37   Triple Lynx Triple Lynx
including 1021.8 1022.1 0.3 39.1  
  1178.0 1180.1 2.1 5.63   Triple Lynx Triple Lynx
including 1179.2 1180.1 0.9 12.9  
OSK-W-21-2470-W1 963.0 968.0 5.0 10.8   Triple Lynx Triple Lynx
including 963.0 964.0 1.0 41.4  
  987.0 989.0 2.0 27.7 27.6 Triple Lynx Triple Lynx
including 987.3 987.7 0.4 101 100
OSK-W-21-2472 731.8 734.2 2.4 31.5   LX4_3437 Lynx 4
including 733.4 734.2 0.8 78.3  
  781.1 783.9 2.8 11.2   Lynx 4 Lynx
including 783.1 783.9 0.8 31.8  
OSK-W-21-2473 625.6 630.0 4.4 10.0   Lynx Lynx
including 625.6 626.2 0.6 49.1  
OSK-W-21-2478 1117.0 1119.0 2.0 7.22   Triple Lynx Triple Lynx
OSK-W-21-2482 782.0 784.0 2.0 11.7   Triple Lynx Triple Lynx
including 782.0 782.9 0.9 26.0  
OSK-W-21-2489 1005.0 1007.0 2.0 8.26   Triple Lynx Triple Lynx
WST-21-0652 216.0 218.0 2.0 4.15   Lynx SW Lynx SW
  448.0 450.0 2.0 4.35   Lynx SW Lynx SW
including 448.7 449.2 0.5 15.6  
WST-21-0657 442.3 444.3 2.0 4.26   Triple Lynx Triple Lynx
WST-21-0696 370.7 373.6 2.9 41.6 36.7 Triple Lynx Triple Lynx
including 371.8 372.7 0.9 116 100
  464.0 466.0 2.0 5.62   Lynx 4 Lynx
WST-21-0703 43.2 45.2 2.0 78.7 37.1 Lynx SW Lynx SW
including 43.5 44.2 0.7 219 100
WST-21-0706 314.5 316.9 2.4 14.1   Lynx SW Lynx SW
including 315.3 315.9 0.6 54.1  
WST-21-0729 174.3 177.6 3.3 8.95   Lynx Lynx

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

Drill hole location

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Elevation Section
OSK-W-20-2252-W11 129 -54 1191 453241 5435694 415 3750
OSK-W-20-2283-W2 135 -50 1011 452997 5435607 425 3500
OSK-W-21-2394-W4 138 -52 920 452923 5435467 414 3375
OSK-W-21-2394-W6 138 -52 978 452923 5435467 414 3375
OSK-W-21-2436-W2 130 -57 789 453709 5435618 400 4125
OSK-W-21-2436-W3 130 -57 879 453709 5435618 400 4125
OSK-W-21-2445-W1 141 -50 909 452906 5435433 415 3325
OSK-W-21-2445-W2 141 -50 822 452906 5435433 415 3325
OSK-W-21-2445-W3 141 -50 753 452906 5435433 415 3325
OSK-W-21-2445-W4 141 -50 944 452906 5435433 415 3325
OSK-W-21-2465 123 -61 1253 453397 5435557 413 3825
OSK-W-21-2470 132 -59 1230 453304 5435639 415 3775
OSK-W-21-2470-W1 132 -59 1227 453304 5435639 415 3775
OSK-W-21-2472 12 -72 900 454135 5435058 397 4225
OSK-W-21-2473 123 -56 1272 453420 5435610 413 3875
OSK-W-21-2478 128 -54 1257 452997 5435607 425 3500
OSK-W-21-2482 131 -57 939 453009 5435387 413 3400
OSK-W-21-2489 133 -54 1140 453121 5435509 419 3550
OSK-W-21-2492 122 -53 870 453687 5435676 401 4125
OSK-W-21-2495 123 -54 1257 453426 5435565 410 3850
WST-21-0652 128 -60 481 452955 5435003 253 3175
WST-21-0657 141 -56 448 453357 5435272 16 3650
WST-21-0658 137 -49 255 453357 5435272 16 3650
WST-21-0671A 142 -51 372 453507 5435327 -7 3800
WST-21-0675 133 -40 336 453508 5435327 -7 3800
WST-21-0676 129 -32 318 453508 5435327 -7 3800
WST-21-0677 144 -42 652 453257 5435209 96 3525
WST-21-0692 157 -54 541 453356 5435272 16 3650
WST-21-0696 137 -49 492 453229 5435127 134 3475
WST-21-0698 167 -40 160 453356 5435272 16 3650
WST-21-0703 146 -60 489 453104 5435065 231 3325
WST-21-0706 165 -54 417 453104 5435065 231 3325
WST-21-0729 132 -49 510 453229 5435127 135 3475
WST-21-0739 164 -37 195 453507 5435326 -7 3800
WST-21-0749 136 -30 196 453357 5435272 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 defined by Osisko, as disclosed in the news release dated February 17, 2021 and supported by the technical report entitled “Mineral Resource Estimate Update for the Windfall Project, Eeyou Istchee James Bay, Québec, Canada” dated March 8, 2021 (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