OSISKO INFILL DRILLING INTERSECTS HIGH GRADE IN LYNX

Triple Lynx Zone Extended 120 Metres Up Plunge Returning 35.3 g/t Au over 2.7 Metres

(Toronto, April 29, 2020) Osisko Mining Inc. (OSK:TSX. “Osisko” or the “Corporation”) is pleased to provide new drilling results from the ongoing definition and expansion drill program at its 100% owned Windfall gold project located in the Abitibi greenstone belt, Urban Township, Eeyou Istchee James Bay, Québec.

Operations remain temporarily suspended in respect of the Government of Québec’s closure of all non-essential business in effort to contain COVID-19. When drilling resumes, it will remain focused on the Lynx deposit, the main mineralized zones, and down plunge exploration in the central areas of the mineralized system.

Significant new analytical results from the definition drilling program on Lynx and Triple Lynx are presented below and include 44 intercepts in 16 drill holes, 2 extensions and 13 wedges.

Of note is drill hole OSK-W-20-2217-W2 which returned 35.3 g/t Au over 2.7 metres, confirming the up-plunge extension of the Triple Lynx zone 120 metres from nearest wireframe (see Osisko news release dated February 19, 2020). Also, drill hole OSK-W-19-2170 returned 40.2 g/t Au over 3.5 metres confirming high grade in the down plunge area of Triple Lynx.

Selected high-grade intercepts from new results include: 104 g/t Au over 2.0 metres in WST-20-0323; 76.5 g/t Au over 2.6 metres in OSK-W-18-1747-W1; 41.2 g/t Au over 4.2 metres in WST-20-0386; and 73.6 g/t Au over 2.3 metres in OSK-W-19-1193-W2.  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-17-1000 573.0 577.3 4.3 8.92   Lynx_301 Lynx
including 573.0 574.0 1.0 17.1  
OSK-W-18-1639 754.0 757.0 3.0 8.80   Lynx_336 Lynx
including 754.0 755.0 1.0 15.6  
OSK-W-18-1741-W1 916.1 918.7 2.6 76.5 50.0 Lynx_329 Lynx
including 916.1 917.0 0.9 177 100
  926.0 928.0 2.0 4.90   Lynx 4 Lynx
OSK-W-19-1104-W4 470.6 473.0 2.4 3.42   Lynx_359 Lynx
including 471.3 471.6 0.3 25.6  
  575.0 577.7 2.7 3.72   Lynx_321 Lynx
including 576.5 576.9 0.4 17.6  
OSK-W-19-1193-W2 928.2 930.5 2.3 73.6 30.6 Lynx_314 Lynx
including 928.6 929.2 0.6 265 100
OSK-W-19-1731-W2 591.0 593.0 2.0 7.70   Lynx_322 Lynx
including 591.0 592.0 1.0 14.5  
OSK-W-19-2059-W1 833.9 836.3 2.4 11.1   Lynx_313 Lynx
including 834.8 835.7 0.9 27.3  
OSK-W-19-2067-W4 1028.0 1030.5 2.5 3.25   Lynx_368 Lynx
OSK-W-19-2139-W2 887.4 894.0 6.6 8.34   Lynx_363 Lynx
OSK-W-19-2170 923.1 926.6 3.5 40.2   Triple Lynx Triple Lynx
including 923.7 924.7 1.0 98.0  
OSK-W-19-2197 759.8 762.0 2.2 4.04   Lynx Lynx
OSK-W-20-1272-W6 898.0 900.0 2.0 10.2   Lynx_364 Triple Lynx
including 899.0 899.4 0.4 45.2  
OSK-W-20-1741-W2 860.0 862.0 2.0 3.20   Lynx_347 Lynx
  899.0 901.0 2.0 4.29   Lynx_313 Lynx
including 899.4 900.0 0.6 13.6  
OSK-W-20-2059-W3 701.3 704.0 2.7 11.2   Lynx_315 Lynx
including 703.1 704.0 0.9 29.3  
OSK-W-20-2217-W1 877.0 879.0 2.0 3.29   Triple Lynx Triple Lynx
including 877.0 877.4 0.4 9.71  
OSK-W-20-2217-W2 755.2 757.9 2.7 35.3 17.0 Triple Lynx Triple Lynx
including 756.3 756.6 0.3 265 100
OSK-W-20-2243-W1 814.0 816.0 2.0 5.36   Lynx_363 Lynx
WST-19-0328 118.0 120.0 2.0 25.9   Lynx_304 Lynx
including 118.5 119.0 0.5 99.1  
WST-20-0260 8.8 10.9 2.1 10.1   Lynx_310 Lynx
including 8.8 9.4 0.6 26.9  
  51.0 53.0 2.0 6.29   Lynx_304 Lynx
including 51.7 52.1 0.4 31.0  
WST-20-0261 55.0 57.0 2.0 8.28   Lynx_304 Lynx
including 55.7 56.2 0.5 32.9  
WST-20-0308 52.6 54.7 2.1 4.56   Lynx_311 Lynx
including 53.6 54.1 0.5 16.9  
  81.1 83.4 2.3 3.48   Lynx_320 Lynx
  95.0 98.3 3.3 4.09   Lynx_319 Lynx
WST-20-0316 58.7 61.1 2.4 19.7   Lynx_311 Lynx
WST-20-0319 66.8 69.8 3.0 24.3 18.8 Lynx_323 Lynx
including 69.4 69.8 0.4 141 100
  77.6 80.0 2.4 3.95   Lynx_308 Lynx
  86.0 88.0 2.0 8.09   Lynx_320 Lynx
including 86.0 86.5 0.5 31.4  
  94.5 97.1 2.6 22.6   Lynx_304 Lynx
including 94.5 94.9 0.4 94.4  
WST-20-0321 50.2 53.0 2.8 4.32   Lynx_303 Lynx
including 50.2 51.0 0.8 15.1  
  65.4 67.8 2.4 3.55   Lynx_323 Lynx
WST-20-0323 68.5 70.5 2.0 104 35.9 Lynx_323 Lynx
including 69.1 69.8 0.7 296 100
WST-20-0367A 110.0 112.0 2.0 4.31   Lynx_323 Lynx
including 110.0 110.6 0.6 14.3  
  126.7 128.8 2.1 4.97   Lynx_359 Lynx
including 127.6 128.4 0.8 12.9  
WST-20-0377 125.1 127.2 2.1 4.56   Lynx_304 Lynx
WST-20-0386 134.1 138.3 4.2 41.2 22.4 Lynx_304 Lynx
including 138.0 138.3 0.3 363 100
WST-20-0413 77.0 79.0 2.0 3.44   Lynx_323 Lynx
  85.8 88.0 2.2 24.3   Lynx_308 Lynx
including 85.8 86.9 1.1 48.3  
  99.5 101.7 2.2 18.9   Lynx_304 Lynx
including 101.2 101.7 0.5 69.6  
WST-20-0414 59.7 62.0 2.3 4.43   Lynx_311 Lynx
including 61.1 61.4 0.3 24.9  
WST-20-0426 141.0 143.4 2.4 9.12   Lynx_304 Lynx
including 142.2 142.8 0.6 28.8  

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See “Quality Control and Reporting Protocols” below.

 

Drill hole location

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Elevation Section
OSK-W-17-1000 142 -50 786 453408 5435462 401 3800
OSK-W-18-1639 142 -53 1164 453266 5435397 405 3625
OSK-W-18-1741-W1 144 -48 1083 453328 5435466 406 3725
OSK-W-19-1104-W4 142 -50 933 453383 5435455 402 3775
OSK-W-19-1193-W2 141 -59 1095 453807 5435721 400 4275
OSK-W-19-1731-W2 139 -51 996 453383 5435518 409 3800
OSK-W-19-2059-W1 131 -52 1041 453446 5435477 400 3825
OSK-W-19-2067-W4 123 -53 1203 453241 5435697 416 3750
OSK-W-19-2139-W2 115 -52 1203 452980 5435549 420 3450
OSK-W-19-2170 128 -59 1203 453425 5435657 413 3900
OSK-W-19-2197 121 -48 1059 453087 5435527 418 3550
OSK-W-20-1272-W6 127 -60 1035 453246 5435535 412 3675
OSK-W-20-1741-W2 144 -48 972 453328 5435466 406 3725
OSK-W-20-2059-W3 131 -52 1029 453446 5435477 400 3825
OSK-W-20-2217-W1 134 -48 1044 452943 5435566 419 3425
OSK-W-20-2217-W2 134 -48 893 452943 5435566 419 3425
OSK-W-20-2243-W1 122 -54 960 453087 5435527 418 3550
WST-19-0328 139 39 141 453217 5435115 225 3450
WST-20-0260 169 34 87 453298 5435067 206 3500
WST-20-0261 169 25 73 453298 5435066 205 3500
WST-20-0308 172 -13 160 453291 5435139 163 3525
WST-20-0316 133 -19 124 453292 5435139 163 3525
WST-20-0319 134 -3 118 453292 5435139 163 3525
WST-20-0321 127 -22 133 453292 5435139 163 3525
WST-20-0323 115 6 151 453292 5435140 163 3525
WST-20-0367A 163 -34 166 453450 5435264 115 3725
WST-20-0377 161 -42 175 453493 5435286 116 3775
WST-20-0386 163 -47 178 453493 5435286 116 3775
WST-20-0413 119 -21 139 453292 5435140 163 3525
WST-20-0414 136 -14 121 453292 5435139 163 3525
WST-20-0426 142 -47 172 453493 5435287 116 3775

 

Lynx Zone

Mineralization in the Lynx zone is typically characterized by trace to 15% disseminated, clustered or stringer pyrite (locally up to 70%), local visible gold, trace to 3% sphalerite, chalcopyrite, and galena, local ptygmatic pyrite-tourmaline or tourmaline veinlets, quartz-carbonate veins (locally crustiform), smoky quartz veins and veinlets, and local chlorite-calcite or quartz-carbonate chlorite fracture filling. Alteration consists of weak to strong sericite, weak to strong silica with areas of local pervasive silica flooding, weak to moderate chlorite and carbonate, and locally weak to strong fuchsite. Mineralization is hosted in or at the contacts of felsic porphyritic or fragmental intrusions with rhyolites, andesites (locally bleached), or gabbros.

 

Triple Lynx Zone

Mineralization in the Triple Lynx zone is typically characterized by trace to 30% disseminated, clustered or stringer pyrite, local visible gold, trace sphalerite, chalcopyrite, and galena, local quartz-tourmaline veins (up to 20%), local ptygmatic tourmaline veins, and local smoky quartz and quartz-carbonate veins. Alteration consists of weak to strong sericite, weak to strong silica with areas of local pervasive silica flooding, weak to moderate chlorite and carbonate, and locally weak to strong fuchsite. Mineralization is hosted in or at the contacts of felsic porphyritic dikes with rhyolites (locally bleached) or gabbros.

 

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), Project Manager of Osisko’s Windfall Lake 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. All NQ core assays reported 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, Thunder Bay, Ontario, Sudbury, Ontario or Vancouver, British Colombia, or (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 an Aqua Regia-ICP-AES 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 Eeyou Istchee James Bay, Québec, Canada. The mineral resource defined by Osisko, as disclosed in the news release dated February 19, 2020 and supported by the technical report entitled “An updated mineral resource estimate for the Windfall Lake Project, Located in the Abitibi Greenstone Belt, Urban Township, Eeyou Istchee James Bay, Québec, Canada” and dated April 3, 2020 (with an effective date of January 3, 2020), and assuming a cut-off grade of 3.5 g/t, comprises 4,127,000 tonnes at 9.1 g/t Au (1,206,000 ounces) in the indicated mineral resource category and 14,532,000 tonnes at 8.40 g/t Au (3,938,000 ounces) in the inferred mineral resource category. The key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in the February 19,2020 news release are further described in the full technical report prepared by Micon International Limited (“Micon”) and BBA Inc (“BBA”), in accordance with NI 43-101 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 deposit is well defined from surface to a depth of 1,200 metres and remains open along strike and at depth. Mineralization has been identified 30 metres from surface in some areas and as deep as 2,000 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 precious metal 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; the prospects, if any, of the Windfall gold deposit; the timing and ability of Osisko, if at all, to publish a feasibility study for the Windfall gold deposit; the projected capital expenditures of mining activities at the Windfall gold deposit; upgrading an inferred mineral resource to a measured mineral resource or indicated mineral resource category; future drilling at the Windfall gold deposit; the deposit remaining open along strike to the northeast and at depth; significant high-grade zones (Lynx 4, Triple Lynx) remaining open down plunge; the plunge potential of the Lynx and Underdog zones; 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 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
President & Chief Executive Officer
Telephone (416) 363-8653