EXPANSION DRILLING ADDS NEW HIGH-GRADE FOR OSISKO

EXPANSION DRILLING ADDS NEW HIGH-GRADE FOR OSISKO

141 g/t Au Over 3.5 Metres in Lynx

29.2 g/t Au over 2.1 Metres in Caribou

31.4 g/t Au Over 2.4 Metres in F51

(Toronto, February 23, 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.

Approximately 200,000 metres remain in the drill program, focused on the Lynx portion of the deposit.  Osisko expects to complete resource drilling by the fall of 2021.

Osisko Chief Executive Officer John Burzynski commented: “Today’s expansion drill results are a strong confirmation that many of the zones across the deposit remain open to growth.  The results presented below fall outside the wireframes in the recently published mineral resource estimate (“MRE”), and OSK-W-20-2391 in particular extends Triple Lynx 150 metres from the closest MRE block.”

Significant new analytical results presented below include 145 intercepts in 56 drill holes (31 from surface, 25 from underground) and 33 wedges.

Selected intercepts include: 141 g/t Au over 3.5 metres in WST-20-0524; 74.9 g/t Au over 2.3 metres in WST-20-0547; 57.8 g/t Au over 2.3 metres in OSK-W-20-2275-W4; 13.3 g/t Au over 6.4 metres in WST-20-0478; 26.0 g/t Au over 3.2 metres in OSK-W-20-2354-W1; 31.4 g/t Au over 2.4 metres in OSK-W-20-2391; 25.9 g/t Au over 2.9 metres in WST-20-0570; 15.9 g/t Au over 4.7 metres in WST-20-0346; 16.9 g/t Au over 4.2 metres in OSK-W-20-2354; and 24.4 g/t Au 2.9 metres in OSK-W-20-2369. Maps showing hole locations and full analytical results are available at www.osiskomining.com

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-20-852-W2 792.2 794.5 2.3 4.68   Caribou_2219 Caribou
including 793.2 793.5 0.3 32.7
OSK-W-20-852-W3 640.4 646.8 6.4 10.6   Caribou Caribou
including 640.4 640.7 0.3 43.4
  681.0 683.0 2.0 4.20   Caribou_2255 Caribou
OSK-W-20-852-W4 814.0 816.0 2.0 13.9   Caribou Caribou
including 814.0 815.0 1.0 21.8  
OSK-W-20-913-W2 622.0 624.0 2.0 4.60   Caribou Caribou
including 622.5 622.8 0.3 28.8
  672.0 674.5 2.5 4.00   Caribou Caribou
including 673.0 673.5 0.5 16.8
  755.0 757.0 2.0 16.7   Caribou Caribou
including 755.4 756.0 0.6 53.9
  858.0 860.0 2.0 3.48   Caribou Caribou
OSK-W-20-2170-W7 1102.0 1104.0 2.0 5.61   TLX_3170 Triple Lynx
including 1102.5 1102.9 0.4 23.5
OSK-W-20-2252-W8 1190.0 1192.0 2.0 7.24   Triple Lynx Triple Lynx
including 1190.0 1190.3 0.3 24.7
OSK-W-20-2252-W10 989.0 991.0 2.0 12.2   TLX_3163 Triple Lynx
993.0 999.6 6.6 9.83   TLX_3163 Triple Lynx
including 998.9 999.3 0.4 71.3
OSK-W-20-2256-W8 987.0 989.0 2.0 4.19   TLX_3164 Triple Lynx
OSK-W-20-2271-W4 792.0 794.0 2.0 29.4   Lynx Lynx
including 792.0 793.0 1.0 55.0  
804.0 807.0 3.0 8.32   Lynx Lynx
including 804.0 804.6 0.6 21.9
OSK-W-20-2275-W4 920.7 923.0 2.3 57.8 17.6 Triple Lynx Triple Lynx
including 921.2 921.5 0.3 408 100
OSK-W-20-2280-W6 937.5 939.5 2.0 4.75   Triple Lynx Triple Lynx
including 937.5 937.8 0.3 16.1
1078.9 1081.0 2.1 11.3   TLX_3170 Triple Lynx
OSK-W-20-2280-W8 960.9 964.0 3.1 5.07   TLX_3163 Triple Lynx
OSK-W-20-2280-W9 1071.0 1075.0 4.0 4.82   TLX_3162 Triple Lynx
including 1074.0 1075.0 1.0 12.7
OSK-W-20-2283-W3 939.0 941.3 2.3 4.50   TLX_3194 Triple Lynx
including 940.2 940.6 0.4 25.0
OSK-W-20-2283-W4 983.0 985.0 2.0 4.46   TLX_3195 Triple Lynx
OSK-W-20-2287 1284.0 1286.0 2.0 8.11   LX4_3445 Lynx
including 1284.3 1284.8 0.5 32.0
OSK-W-20-2295-W2 919.6 921.6 2.0 3.76   Triple Lynx Triple Lynx
including 919.6 920.0 0.4 18.4
OSK-W-20-2300 9.2 13.0 3.8 7.10   F17 F17
24.0 26.0 2.0 9.95   F17 F17
39.0 44.3 5.3 9.59   F17 F17
OSK-W-20-2313-W4 1119.3 1121.9 2.6 4.08   Triple Lynx Triple Lynx
including 1120.2 1121.0 0.8 12.5
OSK-W-20-2313-W5 911.9 914.0 2.1 21.2 17.5 Triple Lynx Triple Lynx
including 911.9 912.2 0.3 126 100
OSK-W-20-2313-W6 929.0 931.0 2.0 5.42   Triple Lynx Triple Lynx
including 929.8 930.2 0.4 12.5
1003.2 1005.3 2.1 5.89   TLX_3195 Triple Lynx
including 1003.2 1003.7 0.5 18.5
OSK-W-20-2313-W7 868.7 872.6 3.9 6.43   TLX_3161 Triple Lynx
OSK-W-20-2319 290.0 292.5 2.5 5.93   Bobcat Bobcat
672.0 674.0 2.0 5.13   Lynx SW Lynx
including 672.0 672.9 0.9 11.4
OSK-W-20-2322-W3 812.0 814.4 2.4 24.4   Lynx Lynx
including 812.5 813.0 0.5 59.6
857.0 859.0 2.0 6.67   Lynx Lynx
including 857.7 858.5 0.8 14.5
OSK-W-20-2328 287.0 289.5 2.5 4.92   Caribou Caribou
including 289.1 289.5 0.4 24.4
351.6 353.6 2.0 3.95   Caribou Caribou
OSK-W-20-2331 51.0 53.0 2.0 4.86   Mallard_5216 Mallard
OSK-W-20-2338 37.0 39.0 2.0 5.12   F17 F17
OSK-W-20-2340 75.0 77.0 2.0 6.51   F17 F17
including 76.1 76.7 0.6 21.4
OSK-W-20-2346 590.0 592.0 2.0 6.20   LXM_3323 Lynx
809.0 811.0 2.0 3.79   Triple Lynx Triple Lynx
OSK-W-20-2354 501.0 503.3 2.3 5.33   Caribou_2116 Caribou
including 501.0 502.0 1.0 12.0
620.0 622.0 2.0 24.7   Caribou Caribou
including 620.0 620.4 0.4 76.5
695.5 697.5 2.0 7.53   Caribou_2217 Caribou
including 696.7 697.1 0.4 29.2
728.7 730.7 2.0 19.5   Caribou_2218 Caribou
including 729.4 729.8 0.4 77.0
735.3 739.5 4.2 16.9 15.1 Caribou_2218 Caribou
including 739.2 739.5 0.3 125 100
OSK-W-20-2354-W1 702.0 704.0 2.0 4.80   Caribou Caribou
including 703.0 704.0 1.0 9.26
722.2 725.4 3.2 26.0   Caribou Caribou
including 723.4 724.0 0.6 55.3
757.2 759.9 2.7 13.5   Caribou Caribou
including 757.2 757.5 0.3 74.8
OSK-W-20-2354-W2 545.0 547.5 2.5 7.42   Caribou Caribou
including 546.2 546.5 0.3 47.3
OSK-W-20-2354-W3 541.3 544.0 2.7 3.99   Caribou Caribou
OSK-W-20-2354-W4 730.4 733.0 2.6 4.65   Caribou Caribou
OSK-W-20-2362 58.0 60.0 2.0 31.7 25.6 Bobcat_2355 Bobcat
including 58.5 59.0 0.5 125 100
OSK-W-20-2363 970.6 972.6 2.0 3.88   Triple Lynx Triple Lynx
OSK-W-20-2363-W2 666.4 669.7 3.3 6.59   TLX_3196 Triple Lynx
including 669.4 669.7 0.3 31.8
OSK-W-20-2365 44.0 46.5 2.5 8.36   Bobcat Bobcat
OSK-W-20-2369 584.9 587.8 2.9 24.4   Lynx Lynx
including 586.7 587.8 1.1 35.6
640.0 642.0 2.0 29.2 26.4 LXM_3304 Lynx
including 640.4 640.9 0.5 111 100
654.1 656.3 2.2 7.16   LXM_3341 Lynx
including 654.1 654.4 0.3 36.2
660.0 662.0 2.0 6.06   LXM_3341 Lynx
OSK-W-20-2371 796.5 798.8 2.3 17.2 13.2 Triple Lynx Triple Lynx
including 796.5 796.8 0.3 131 100
1049.0 1051.0 2.0 7.30   Lynx Lynx
OSK-W-20-2371-W1 847.0 849.0 2.0 7.72   Triple Lynx Triple Lynx
OSK-W-20-2371-W2 1023.0 1025.2 2.2 4.93   Triple Lynx Triple Lynx
OSK-W-20-2375-W1 907.3 909.7 2.4 18.5   LX4_3437 Lynx
including 908.4 909.3 0.9 36.8
OSK-W-20-2376 131.6 133.8 2.2 4.01   Caribou Caribou
233.0 235.0 2.0 4.27   Caribou Caribou
including 233.0 233.3 0.3 27.6
OSK-W-20-2377-W1 876.5 878.6 2.1 28.9 24.0 Caribou extension Caribou
including 876.5 877.0 0.5 121 100
882.8 884.8 2.0 16.4   Caribou extension Caribou
including 882.8 883.8 1.0 32.7
OSK-W-20-2381 1116.4 1118.7 2.3 4.02   Lynx 4 Lynx
OSK-W-20-2384 547.0 549.0 2.0 9.31   Lynx Lynx
including 548.0 549.0 1.0 18.2
OSK-W-20-2387-W1 496.0 498.1 2.1 4.17   Caribou Caribou
including 496.0 496.4 0.4 12.2
OSK-W-20-2388 317.6 319.7 2.1 10.7   Caribou Caribou
including 317.6 318.6 1.0 22.4
  568.7 571.1 2.4 4.85   Caribou_2250 Caribou
including 570.0 570.5 0.5 18.4
663.0 665.0 2.0 11.6   Caribou_2219 Caribou
including 663.0 664.0 1.0 23.0
666.0 668.1 2.1 4.12   Caribou_2219 Caribou
including 667.5 668.1 0.6 13.7
OSK-W-20-2390 579.0 581.2 2.2 27.9   Caribou_2247 Caribou
including 580.2 580.7 0.5 93.3
OSK-W-20-2391 234.6 237.0 2.4 31.4 21.3 F51 F51
including 235.4 235.9 0.5 149 100
1372.5 1376.0 3.5 8.73   Triple Lynx Triple Lynx
including 1373.3 1373.7 0.4 36.0
1497.0 1503.0 6.0 8.84   Triple Lynx Triple Lynx
1526.0 1528.0 2.0 15.7   Triple Lynx Triple Lynx
OSK-W-20-2397 603.0 605.1 2.1 9.70   Lynx Lynx
including 603.3 604.0 0.7 27.3
612.0 614.0 2.0 7.36   Lynx Lynx
654.0 656.5 2.5 4.16   LXM_3304 Lynx
including 655.0 655.4 0.4 12.5
698.5 700.5 2.0 4.07   LXM_3304 Lynx
including 700.0 700.5 0.5 11.9
975.0 977.1 2.1 7.12   Lynx 4 Lynx
1031.0 1033.0 2.0 11.0   Lynx 4 Lynx
including 1032.7 1033.0 0.3 69.9
1039.0 1041.0 2.0 4.76   Lynx 4 Lynx
including 1039.6 1040.3 0.7 12.9
1058.0 1060.2 2.2 26.1 19.6 LX4_3430 Lynx
including 1058.8 1059.2 0.4 136 100
OSK-W-20-2399-W1 551.0 554.3 3.3 19.2   Caribou_2523 Caribou
including 553.5 554.3 0.8 69.0
OSK-W-20-2400 815.0 817.0 2.0 9.57   Caribou Caribou
including 815.4 816.0 0.6 31.5
OSK-W-20-2405 519.6 521.8 2.2 4.59   Caribou Caribou
OSK-W-20-2405-W1 518.0 520.0 2.0 8.09   Caribou Caribou
  620.0 622.0 2.0 6.44   Caribou Caribou
including 620.5 621.0 0.5 22.8
669.0 672.0 3.0 8.57   Caribou Caribou
OSK-W-20-2406 635.0 638.7 3.7 10.1   Caribou_2241 Caribou
including 636.0 637.0 1.0 21.8
642.0 649.3 7.3 6.34   Caribou_2241 Caribou
including 647.7 648.3 0.6 17.9
and 648.7 649.3 0.6 21.0
OSK-W-20-2415 639.8 643.5 3.7 7.66   Caribou_2233 Caribou
including 639.8 640.1 0.3 27.9
and 640.4 640.7 0.3 33.2
680.0 682.3 2.3 8.40   Caribou_2217 Caribou
including 681.4 682.3 0.9 19.4
OSK-W-20-2421 685.0 687.2 2.2 6.02   Caribou Caribou
OSK-W-20-2425 298.0 301.0 3.0 18.9   Caribou Caribou
including 299.0 300.0 1.0 40.4
OSK-W-20-2432 725.0 727.4 2.4 9.40   Caribou Caribou
including 726.1 726.4 0.3 32.4
794.6 799.6 5.0 6.98   Caribou Caribou
including 794.6 795.5 0.9 20.4
804.3 806.6 2.3 7.92   Caribou Caribou
including 804.3 805.1 0.8 20.0
OSK-W-20-2440 719.0 721.0 2.0 6.26   Caribou Caribou
including 719.0 719.8 0.8 15.6
OSK-W-21-2451 430.8 434.0 3.2 20.4   Caribou Caribou
including 431.2 431.6 0.4 94.7
516.8 519.0 2.2 8.78   Caribou Caribou
including 517.1 517.7 0.6 30.1
OSK-W-21-2455 479.9 482.2 2.3 21.0 15.0 Caribou_2116 Caribou
including 479.9 480.2 0.3 146 100
WST-20-0346 118.2 120.4 2.2 16.1   Caribou_2151 Caribou
including 118.2 118.7 0.5 69.8
348.0 352.7 4.7 15.9   Caribou corridor Caribou
WST-20-0476 260.9 263.1 2.2 5.92   Caribou corridor Caribou
374.8 376.8 2.0 12.7   Caribou corridor Caribou
including 376.3 376.8 0.5 45.8
WST-20-0477 52.4 55.0 2.6 9.78   Mallard Mallard
228.0 230.4 2.4 4.55   Caribou_2100 Caribou
WST-20-0478 167.6 174.0 6.4 13.3 12.8 Caribou_2151 Caribou
including 172.4 173.0 0.6 106 100
354.0 356.0 2.0 4.72   Caribou Caribou
including 354.0 354.5 0.5 18.4
WST-20-0479B 147.1 149.1 2.0 7.97   Z27_1115 Zone 27
157.5 159.8 2.3 5.66   Z27 Zone 27
WST-20-0480B 376.0 378.0 2.0 9.80   Caribou Caribou
WST-20-0496 302.0 304.2 2.2 4.24   Lynx SW Lynx SW
including 303.4 303.7 0.3 30.7
513.6 516.2 2.6 10.9   Lynx SW Lynx SW
including 513.6 513.9 0.3 81.3
WST-20-0521 367.0 369.1 2.1 12.1   Caribou Caribou
including 367.6 368.6 1.0 24.4
WST-20-0522 374.0 376.0 2.0 6.98   Lynx SW Lynx SW
including 374.8 375.5 0.7 19.7
WST-20-0524 225.8 229.3 3.5 141 28.6 Lynx SW Lynx SW
including 228.4 229.3 0.9 536 100
WST-20-0534 122.0 124.2 2.2 10.4   LXM_3359 Lynx
including 123.2 124.2 1.0 22.9
WST-20-0547 421.6 423.9 2.3 74.9 43.4 LXSW_3502 Lynx
including 423.0 423.9 0.9 181 100
WST-20-0552 127.0 129.0 2.0 11.1   LXM_3339 Lynx
including 127.6 128.3 0.7 29.9
235.7 238.0 2.3 22.7   LXSW_3506 Lynx
including 236.4 237.4 1.0 51.8
WST-20-0556 96.3 98.4 2.1 4.66   Bobcat Bobcat
including 97.8 98.4 0.6 13.5
WST-20-0566A 13.7 17.2 3.5 17.7   Mallard_5211 Mallard
including 14.6 15.3 0.7 38.3
WST-20-0567 58.0 60.0 2.0 4.55   Z27 Zone 27
including 58.0 59.0 1.0 9.01
296.0 298.0 2.0 5.01   Caribou corridor Caribou
WST-20-0569 259.9 262.0 2.1 14.6    LXSW_3507 Lynx SW
including 261.5 262.0 0.5 26.7
WST-20-0570 206.2 209.1 2.9 25.9   Lynx SW Lynx SW
including 207.8 208.4 0.6 55.0
WST-20-0572A 272.0 274.0 2.0 11.0   LXSW_3556 Lynx SW
WST-20-0574 283.6 285.9 2.3 13.7   Lynx SW Lynx SW
WST-20-0578 170.0 172.0 2.0 24.3   LXM_3304 Lynx
including 170.8 171.2 0.4 76.8
785.0 792.0 7.0 9.09   LX4_3412 Lynx
including 789.5 790.4 0.9 24.2
WST-20-0581 408.9 411.0 2.1 14.8   LXSW_3556 Lynx
including 408.9 409.8 0.9 34.4
WST-20-0589 351.0 353.1 2.1 29.2   Caribou Caribou
including 351.7 352.6 0.9 67.7
WST-20-0584 122.0 124.0 2.0 11.4   LXM_3301 Lynx
WST-20-0626 134.4 136.8 2.4 4.19   LXM_3307 Lynx
including 134.4 135.0 0.6 9.74
138.3 140.5 2.2 19.4   LXM_3307 Lynx
including 138.8 139.8 1.0 41.4

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

Drill hole location

Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Elevation Section
OSK-W-20-852-W2 330 -55 873 452874 5434552 398 2875
OSK-W-20-852-W3 330 -55 849 452874 5434552 398 2875
OSK-W-20-852-W4 330 -55 873 452874 5434552 398 2875
OSK-W-20-913-W2 334 -52 913 452878 5434419 401 2825
OSK-W-20-2170-W7 128 -59 1205 453425 5435657 413 3900
OSK-W-20-2252-W8 129 -54 1239 453241 5435694 415 3750
OSK-W-20-2252-W10 129 -54 824 453241 5435694 415 3750
OSK-W-20-2256-W8 125 -51 1056 453160 5435686 411 3675
OSK-W-20-2271-W4 120 -53 1134 453462 5435683 410 3950
OSK-W-20-2275-W4 127 -49 1052 452888 5435583 409 3400
OSK-W-20-2280-W6 127 -58 1152 453304 5435639 415 3775
OSK-W-20-2280-W8 127 -58 1134 453304 5435639 415 3775
OSK-W-20-2280-W9 127 -58 1037 453304 5435639 415 3775
OSK-W-20-2283-W3 135 -50 1004 452997 5435607 425 3500
OSK-W-20-2283-W4 135 -50 1012 452997 5435607 425 3500
OSK-W-20-2287 116 -53 1406 453607 5435714 404 4075
OSK-W-20-2295-W2 132 -51 963 452933 5435473 415 3375
OSK-W-20-2300 152 -45 192 452699 5435578 406 3225
OSK-W-20-2313-W4 134 -52 1134 452965 5435583 420 3450
OSK-W-20-2313-W5 134 -52 1086 452965 5435583 420 3450
OSK-W-20-2313-W6 134 -52 1029 452965 5435583 420 3450
OSK-W-20-2313-W7 134 -52 1086 452965 5435583 420 3450
OSK-W-20-2319 141 -50 768 452872 5435153 409 3175
OSK-W-20-2322-W3 130 -54 1274 453608 5435715 403 4075
OSK-W-20-2328 136 -56 942 452872 5435153 409 3175
OSK-W-20-2331 335 -50 239 451987 5434764 406 2200
OSK-W-20-2338 155 -57 213 452679 5435584 405 3200
OSK-W-20-2340 146 -55 201 452650 5435568 405 3175
OSK-W-20-2346 130 -53 1161 453397 5435557 413 3825
OSK-W-20-2354 336 -60 759 452739 5434474 401 2725
OSK-W-20-2354-W1 336 -60 792 452739 5434474 401 2725
OSK-W-20-2354-W2 336 -60 750 452739 5434474 401 2725
OSK-W-20-2354-W3 336 -60 750 452739 5434474 401 2725
OSK-W-20-2354-W4 336 -60 783 452739 5434474 401 2725
OSK-W-20-2362 350 -45 256 452719 5434777 398 2850
OSK-W-20-2363 139 -52 1031 452930 5435548 419 3425
OSK-W-20-2363-W2 139 -52 695 452930 5435548 419 3425
OSK-W-20-2365 354 -46 312 452673 5434766 398 2800
OSK-W-20-2369 130 -56 909 453426 5435565 410 3850
OSK-W-20-2371 123 -53 1203 452996 5435364 412 3375
OSK-W-20-2371-W1 123 -53 1032 452996 5435364 412 3375
OSK-W-20-2371-W2 123 -53 945 452996 5435364 412 3375
OSK-W-20-2375-W1 122 -56 987 453810 5435779 400 4300
OSK-W-20-2376 325 -55 510 452689 5434635 398 2750
OSK-W-20-2377-W1 132 -49 1097 452702 5435548 409 3225
OSK-W-20-2381 134 -53 1230 453620 5435791 402 4125
OSK-W-20-2384 127 -52 1164 453397 5435557 413 3825
OSK-W-20-2387-W1 336 -59 738 452694 5434440 401 2675
OSK-W-20-2388 326 -61 363 452715 5434606 397 2775
OSK-W-20-2390 330 -65 647 452597 5434393 401 2550
OSK-W-20-2391 117 -57 1230 453281 5435894 408 3900
OSK-W-20-2397 131 -58 1197 453451 5435594 412 3900
OSK-W-20-2399-W1 333 -54 425 452874 5434552 398 2875
OSK-W-20-2400 336 -53 884 452876 5434419 402 2825
OSK-W-20-2405 332 -58 723 452694 5434440 401 2675
OSK-W-20-2405-W1 332 -58 716 452694 5434440 401 2675
OSK-W-20-2406 333 -56 623 452632 5434280 400 2525
OSK-W-20-2415 328 -54 143 452738 5434474 401 2725
OSK-W-20-2421 332 -59 699 452632 5434280 400 2525
OSK-W-20-2425 336 -60 747 452715 5434606 397 2775
OSK-W-20-2432 333 -57 864 452809 5434415 404 2750
OSK-W-20-2440 330 -52 807 452739 5434474 401 2725
OSK-W-21-2451 330 -58 803 452809 5434415 404 2750
OSK-W-21-2455 328 -53 780 452738 5434474 401 2725
WST-20-0346 136 -18 391 452282 5434975 264 2575
WST-20-0476 132 -33 403 452282 5434975 263 2575
WST-20-0477 131 -30 394 452282 5434976 263 2575
WST-20-0478 123 -31 391 452282 5434976 263 2575
WST-20-0479B 138 -59 393 452281 5434975 262 2575
WST-20-0480B 142 -52 382 452281 5434975 262 2575
WST-20-0496 173 -60 537 453227 5435125 134 3475
WST-20-0521 151 -58 385 452281 5434975 262 2575
WST-20-0522 177 -52 457 453104 5435064 231 3325
WST-20-0524 182 -44 243 453104 5435064 231 3325
WST-20-0534 143 -32 135 453315 5435165 124 3575
WST-20-0547 167 -53 487 453227 5435125 134 3475
WST-20-0552 165 -39 517 453257 5435209 97 3525
WST-20-0556 155 -26 163 452955 5435003 254 3175
WST-20-0566A 133 -16 368 452208 5434898 248 2475
WST-20-0567 139 -19 379 452208 5434898 248 2475
WST-20-0569 165 -59 526 453104 5435065 231 3325
WST-20-0570 159 -50 454 453104 5435065 231 3325
WST-20-0572A 136 -51 463 452955 5435004 252 3175
WST-20-0574 139 -62 370 452955 5435004 252 3175
WST-20-0578 151 -46 802 453418 5435306 68 3725
WST-20-0581 181 -60 474 453177 5435126 173 3425
WST-20-0589 147 -55 376 452281 5434975 263 2575
WST-20-0584 174 -19 205 453417 5435304 69 3725
WST-20-0626 194 -59 471 453176 5435125 173 3425

 

Lynx Zone

Mineralization occurs as grey to translucent quartz-carbonate-pyrite-tourmaline veins and pyrite replacement zones and stockworks. The vein-type 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.

 

Caribou Zone

Mineralization most commonly occurs in gold-bearing pyrite stockworks as well as semi-massive pyrite replacement zones associated with phyllic alteration (sericite-pyrite ± silica) with sulphides, pyrite dominated with minor chalcopyrite and sphalerite ranging from trace to up to 20%, and local visible gold. Mineralization is hosted in rhyolites or mafic-intermediate volcanics frequently at or near faults or the contact with felsic porphyritic intrusions.

 

F-Zone

Mineralization is hosted in sheared andesites with carbonate replacement or quartz veining and occurs as quartz ± ankerite veinlets or in shear zones as replacement, characterised by trace to 10% pyrite with local visible gold. Alteration is dominated by sericite-fuchsite-tourmaline-pyrite.

 

Bobcat

Mineralization most commonly occurs in gold-bearing quartz-pyrite veins controlled by northeast trending faults and shears and to a lesser extent in minor crustiform quartz-tourmaline-ankerite-pyrite veins and pyrite replacement zones and stockwork. Mineralization is hosted in sheared mafic volcanics, rhyolites near faults, or at the contact with felsic porphyritic intrusions.

 

Mallard

Mineralization is hosted in sheared mafic volcanics with felsic porphyritic intrusions and occurs as veins associated with sericite-pyrite ± silica ± chlorite alteration and contains pyrite ranging from trace to 30% and local visible gold.

 

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. 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 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, certain of which are described in the February 17, 2021 news release, will be further described in the full technical report being prepared for this updated mineral resource estimate in accordance with NI 43-101, and will be available on SEDAR (www.sedar.com) under the Corporation’s issuer profile within 45 days from February 17, 2021. 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 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 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