Osisko Intersects 611 g/t Au Over 2.0 Metres At Windfall

Additional High Grade Results from Caribou, Wolf, Zone 27 and Underdog

(Toronto. September 20, 2017)  Osisko Mining Inc. (OSK:TSX. “Osisko” or the “Corporation”) is pleased to provide new results from the ongoing drill program at its 100% owned Windfall Lake gold project located in Urban Township, Abitibi, Québec. The recently expanded 800,000 metre drill program combines definition, expansion and exploration drilling in and around the main Windfall gold deposit and in the adjacent Lynx deposit (located immediately NE of Windfall). Significant new analytical results from 42 intercepts in 28 drill holes and wedges focused on infill and expansion drilling in the Underdog, Caribou, Zone 27 and Mallard corridors of the Windfall deposit are presented below.
 
Highlights from the new results include: 611 g/t Au over 2.0 metres (15.4 g/t Au over 2.0 metres cut) in OSK-W-17-913; 297 g/t Au over 2.1 metres (14.5 g/t Au over 2.1 metres cut) in OSK-W-17-862-W1; 120 g/t Au over 2.0 metres (28.7 g/t Au over 2.0 metres cut) in OSK-W-17-871-W1; 60.5 g/t Au over 2.4 metres in OSK-W-17-973; 65.5 g/t Au over 2.0 metres in OSK-W-17-978; and 47.0 g/t Au over 2.3 metres in OSK-W-17-820-W1. Maps showing hole locations and full analytical results are available at www.osiskomining.com.

Hole Number From
(m)
To
(m)
Interval
(m)
Au (g/t)
uncut
Au (g/t)
cut to
100 g/t
Zone Corridor
OSK-EAG-13-494 738.5 740.6 2.1 6.52   Wolf Caribou
Including 740.0 740.6 0.6 19.6  
  749.0 751.0 2.0 4.56   Wolf Caribou
OSK-OBM-16-601 657.6 659.6 2.0 16.2   FW3U Underdog
OSK-W-17-820-W1 943.0 945.0 2.0 5.78   FW0 FW Underdog
including 944.0 945.0 1.0 11.3  
  949.0 951.0 2.0 9.02   FW0 FW Underdog
  1109.2 1111.4 2.2 31.7 27.7 FW3 HW Underdog
including 1110.8 1111.4 0.6 115 100
  1146.7 1149.0 2.3 47.0 18.1 Z14 Underdog
including 1147.1 1147.5 0.4 266 100
OSK-W-17-842 540.0 545.5 5.5 14.5 8.9 CS1 Caribou
including 540.0 540.4 0.4 182 100
OSK-W-17-847 831.0 833.0 2.0 6.87   FW0 HW Underdog
  1085.1 1089.0 3.9 8.85   FW2 Underdog
OSK-W-17-855 166.6 169.4 2.8 3.93   Vein  
OSK-W-17-855-W1 752.0 754.0 2.0 21.0   FW1 Underdog
including 752.0 753.0 1.0 41.2  
OSK-W-17-855-W2 924.8 928.3 3.5 26.1   FW3 Underdog
including 924.8 925.5 0.7 33.5  
including 925.5 925.9 0.4 66.2  
including 927.0 928.3 1.3 31.5  
  1095.8 1098.0 2.2 9.20   Z14 Underdog
including 1097.0 1098.0 1.0 18.6  
OSK-W-17-858-W2 486.3 488.6 2.3 8.51   Wolf FW Caribou
  630.1 632.5 2.4 32.6   VNCR Underdog
including 631.6 632.5 0.9 76.6  
  810.7 812.7 2.0 9.50   VNCR Underdog
including 810.7 811.2 0.5 34.5  
OSK-W-17-862 369.3 372.2 2.9 17.4     Caribou
including 369.3 370.8 1.5 30.8  
OSK-W-17-862-W2 712.7 714.8 2.1 297 14.5 Vein Z27
including 713.8 714.1 0.3 2080 100
OSK-W-17-864 790.3 793.0 2.7 14.0   FW3U Underdog
including 792.0 793.0 1.0 28.6  
OSK-W-17-871 152.0 156.8 4.8 17.9 13.4 Caribou Caribou
including 155.5 156.0 0.5 143 100
OSK-W-17-871-W1 752.1 754.1 2.0 120 28.7 FW3U Underdog
including 753.7 754.1 0.4 557 100
OSK-W-17-880-W1 464.0 466.5 2.5 4.57   Z27 Z27
including 466.0 466.5 0.5 12.1  
OSK-W-17-885 1092.0 1100.0 8.0 6.69   FW0 FW Underdog
including 1092.0 1093.0 1.0 22.3  
  1366.0 1368.6 2.6 6.55   FW3 Underdog
including 1367.0 1367.8 0.8 18.2  
OSK-W-17-889 386.5 388.5 2.0 16.2   Caribou Caribou
including 388.0 388.5 0.5 58.0  
OSK-W-17-901 137.0 139.0 2.0 13.8     Caribou
  209.0 211.0 2.0 7.12     Caribou
including 210.0 211.0 1.0 13.3  
OSK-W-17-903 559.0 561.0 2.0 10.7   Z27 Z27
including 559.8 560.3 0.5 37.7  
OSK-W-17-913 719.0 721.0 2.0 611 15.4 Wolf 2 Caribou
including 719.8 720.1 0.3 4070 100
  857.0 859.0 2.0 13.6   Wolf FW Caribou
including 857.0 858.0 1.0 26.5  
OSK-W-17-937 445.0 448.0 3.0 5.58   Vein Z27
including 447.0 448.0 1.0 11.8  
OSK-W-17-968 160.0 162.4 2.4 5.77   Z27 Z27
OSK-W-17-973 57.4 59.8 2.4 60.5 51.6 Z27 Z27
including 57.9 58.9 1.0 122 100 
  64.0 66.1 2.1 5.12   Z27 Z27
including 65.7 66.1 0.4 25.2  
OSK-W-17-977 269.5 271.7 2.2 12.0   Mallard Mallard
including 270.8 271.7 0.9 25.4  
OSK-W-17-978 98.0 100.0 2.0 65.5 20.1 VNCR New
including 99.6 100.0 0.4 327 100
  108.0 110.0 2.0 14.0     New
including 109.1 109.4 0.3 92.2  
OSK-W-17-989-W1 504.0 511.0 7.0 3.59   CS1 FW Caribou
  514.0 517.0 3.0 7.74  
including 515.0 516.0 1.0 20.5  
OSK-W-17-1026 60.3 62.6 2.3 4.57   Z27 Z27
including 62.0 62.6 0.6 16.5  
OSK-W-17-1051 857.1 859.8 2.7 5.36   Z14 Underdog

Notes:

  1. True widths are estimated at 65 – 80% of the reported core length interval.  See “Quality Control” below.
  2. Definitions: FW = foot wall; HW = hanging wall; VNCR = crustiform vein.
Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Section
OSK-EAG-13-494 330 -60 1197 452731 5434557 2750
OSK-OBM-16-601 332 -51 801 452476 5434677 2600
OSK-W-17-1026 129 -45 147 452119 5434787 2325
OSK-W-17-1051 138 -68 1248 452313 5435323 2775
OSK-W-17-820-W1 332 -66 1358 452670 5434484 2675
OSK-W-17-842 331 -59 948 452509 5434390 2475
OSK-W-17-847 334 -69 1347 452645 5434429 2625
OSK-W-17-855 334 -64 717 452309 5434384 2300
OSK-W-17-855-W1 334 -64 1197 452309 5434384 2300
OSK-W-17-855-W2 334 -64 1197 452309 5434384 2300
OSK-W-17-858-W2 331 -53 909 452524 5434616 2600
OSK-W-17-862 332 -55 993 452683 5434577 2725
OSK-W-17-862-W2 332 -55 759 452683 5434577 2725
OSK-W-17-864 330 -53 813 452467 5434581 2525
OSK-W-17-871 328 -54 533 452402 5434623 2500
OSK-W-17-871-W1 328 -54 840 452402 5434623 2500
OSK-W-17-880-W1 327 -50 801 452425 5434565 2500
OSK-W-17-885 335 -67 1458 452861 5434494 2850
OSK-W-17-889 333 -57 786 452695 5434564 2725
OSK-W-17-901 328 -55 810 452391 5434638 2500
OSK-W-17-903 329 -56 801 452539 5434692 2650
OSK-W-17-913 334 -52 954 452878 5434419 2825
OSK-W-17-937 333 -57 935 452897 5434430 2850
OSK-W-17-968 152 -51 201 451948 5434759 2175
OSK-W-17-973 150 -46 96 451969 5434707 2175
OSK-W-17-977 331 -51 540 452207 5434816 2425
OSK-W-17-978 335 -67 804 452851 5434803 2975
OSK-W-17-989-W1 336 -56 751 452660 5434497 2675

 

Underdog Corridor

OSK-OBM-16-601 intersected 16.2 g/t Au over 2.0 metres. Mineralization is composed of 5% pyrite stringers and ptygmatic tourmaline veins and disseminated pyrite hosted in a strongly sericitized andesite. The interval extends the FW3 upper 40 metres north-east of OSK-OBM-16-609 (63.2 g/t Au over 7.7 metres previously reported August 1, 2017).

OSK-W-17-820-W1 returned two intersections in the FW0 Footwall Zone: 5.78 g/t Au over 2.0 metres (including 11.3 g/t Au over 1.0 metre) and 9.02 g/t Au over 2.0 metres (including 12.0 g/t Au over 1.0 metre). Mineralization is composed of 1% disseminated pyrite or pyrite stringers within a fragmental felsic intrusion. The two intersections are 50 metres up-plunge and south-west of OSK-W-17-820 (5.79 g/t Au over 6.3 metres previously reported July 19, 2017). OSK-W-17-820-W1 also intersected the FW3 Zone returning 31.7 g/t Au over 2.2 meters, (including 115 g/t Au over 0.6 metres) (27.7 g/t Au over 2.2 metres cut) and the Z14 Zone, 47.0 g/t Au over 2.3 metres (including 266 g/t Au over 0.4 metres) (18.1 g/t Au over 2.3 metres cut). Both intersections are similar and associated with felsic porphyritic dikes with up to 2% pyrite stringers and local quartz veins. The interval in FW3 is 40 metres south-west of OSK-W-17-821 (9.27 g/t Au over 3.3 metres previously reported May 30, 2017).

OSK-W-17-847 intersected two intervals: 6.87 g/t Au over 2.0 metres and 8.85 g/t Au over 3.9 metres in the Underdog corridor. In the first interval, mineralization is within the fragmental felsic dike and composed of 1% pyrite stringers, and correlates with the FW0 hanging wall. In the second interval mineralization is composed of up to 20% pyrite stringers and pyrite-tourmaline stringers hosted in a strongly silicified felsic porphyritic intrusion. The interval correlates to the FW2 Zone 50 metres north-east of OBM-15-560 (11.0 g/t Au over 6.1 metres previously reported January 28, 2016).

OSK-W-17-855-W1 intersected 21.0 metres over 2.0 metres (including 41.2 g/t Au over 1.0 metre). Mineralization is composed of up to 30% pyrite in a fragmental felsic dike. The interval correlates to the FW1 Zone.

OSK-W-17-855-W2 intersected 26.1 g/t Au over 3.5 metres (including 66.2 g/t Au over 0.4 metres, 33.5 g/t over 0.7 metres and 31.5 g/t Au over 1.3 metres) in the FW3 Zone. Mineralization is composed of up to 7% pyrite stringers, traces of tourmaline-pyrite stringers, up to 5% disseminated pyrite, and local decimeter scale pyrite massive bands. It is hosted in a porphyritic felsic dike with quartz-eyes and strong silica alteration. This intersection is 50 metres north-east of OSK-W-17-807-W2 (32. 9 g/t Au over 2.0 metres previously reported August 14, 2017). OSK-W-17-855-W2 also intersected 9.2 g/t over 2.2 metres (including 18.6 g/t Au over 1.0 metre) in the Z14 Zone. Mineralization is composed of 1% disseminated pyrite associated to large quartz-eyes porphyritic dike. It is 70 metres north-east of OSK-W-17-807-W2 (4.29 g/t Au over 2.0 metres previously reported June 20, 2017).

OSK-W-17-864 intersected 14.0 g/t Au over 2.7 metres (including 28.6 g/t Au over 1.0 metre) in the FW3 Upper Zone. Mineralization is composed of up to 3% disseminated pyrite and up to 1% pyrite stringers hosted in the andesite. It is 25 metres south-west of OSK-W-17-854-W2 (18.6 /t Au over 3.5 metres previously reported August 1, 2017) and 15 metres north-east of OSK-W-17-871-W1 (120 g/t Au over 2.0 metres, this press release).

OSK-W-17-871-W1 intersected 120 g/t Au over 2.0 metres, (including 557 g/t Au over 0.4 metres) (28.7 g/t Au over 2.0 metres cut). Mineralization is composed of local visible gold, up to 10% disseminated pyrite, up to 10% pyrite tourmaline stringers and 2% pyrite stringers in a sericitized and chloritized rhyolite. The intersection is related to the FW3 Upper Zone and is 40 metres south-west of OSK-W-17-854-W2 (18.6 /t Au over 3.5 metres previously reported August 1, 2017).

OSK-W-17-885 returned two intersections: 6.69 g/t Au over 8.0 metres (including 22.3 g/t Au over 1.0 metre) and 6.55 g/t Au over 2.6 metres (including 18.2 g/t au over 0.8 metres). The first interval consists of a strongly sericitized and moderately silicified felsic intrusion with 2-5% disseminated pyrite and 1-2 % pyrite stringers in the FW0 Footwall Zone and is 100 metres north-east of OSK-17-780-W1 (5.97 g/t Au over 17.0 metres previously reported April 11, 2017). The second interval is a silica-rich zone with 3-5% tourmaline-pyrite stringers and 2% disseminated pyrite. This intersection is in the FW3 Zone and is 50 metres south-west of OSK-W-17-780 (9.38 g/t Au over 4.0 metres previously reported April 6, 2017).

OSK-W-17-889 intersected 4.35 g/t Au over 3.5 metres in the Wolf 2 Zone. Mineralization contains up to 20% pyrite stringers within a bleached andesite. It is 40 metres west-south-west of OSK-W-17-844 (8.14 g/t Au over 2.5 metres previously reported August 1, 2017).

OSK-W-17-1051 intersected 5.36 g/t Au over 2.7 metres. The strongly sericitized felsic dike hosts 3% pyrite stringers and trace tourmaline stringers. The interval correlates to Z14 Zone, a division of the FW3 Zone, 30 metres north-east of OSK-W-16-708-W1 (3.74 g/t Au over 3.0 metres previously reported August 31, 2016).

Caribou Corridor

OSK-EAG-13-494 intersected two intervals in Wolf: 6.52 g/t Au over 2.1 metres (including 19.6 g/t Au over 0.6 metres) and 4.56 g/t Au over 2.0 metres. Both intersectiions follow a contact between the andesite and a large quartz-eye porphyritic intrusion, with mineralization comprising up to 2% disseminated pyrite and pyrite stringers and associated with strong sericite alteration. The intersections infill 35 meters north-east of OSK-W-16-708-W1, and 25 meters south-west of OSK-16-708-W2 (12.5 g/t Au over 3.8 metres and 4.47 g/t Au over 2.8 metres, previously reported August 31 and September 12, 2016).

OSK-W-17-842 intersected the CS1 Zone within the Caribou Corridor and returned 14.5 g/t Au over 5.5 metres (including 182 g/t Au over 0.4 metres) (8.90 g/t Au over 5.5 metres cut). Mineralization is composed of 10% pyrite stringers and tourmaline-pyrite veins hosted in a fragmental andesite strongly sericitized, and is 50 metres north-east of OSK-W-16-749 (12.7 g/t Au over 5.4 metres previously reported January 23, 2017).

OSK-W-17-858-W2 intersected three intervals: 8.51 g/t Au over 2.3 metres; 32.6 g/t Au over 2.4 metres (including 76.6 g/t Au over 0.9 metres) and 9.50 g/t Au over 2.0 metres (including 34.5 g/t Au over 0.5 metre). The first interval correlates to the Wolf Zone and is composed of 2% pyrite and carbonate veins in a strongly sericitized felsic dike. The second and third intervals consists of a crustiform quartz carbonate vein in the Red Dog intrusion and in the andesite. Local visible gold, 5% pyrite stringers and tourmaline-pyrite stringers are also observed. The deepest vein is within the FW3 Upper Zone, 25 metres north-east of OSK-OBM-16-697 (29.1 g/t Au over 2.6 metres previously reported May 30, 2017).

OSK-W-17-862 intersected 17.4 g/t Au over 2.9 metres (including 30.8 g/t Au over 1.5 metres). Mineralization is at a contact between a gabbro and rhyolite with up to 4% disseminated pyrite in the silica altered zone. The interval is 30 metres above OSK-W-17-889 (16.2 g/t Au over 2.0 metres in this press release).

OSK-W-17-871 was previously reported on August 1,2017 with a cut value of 13.4 g/t Au over 4.8 metres. Additional analysis was done on the samples greater than 100 g/t and the interval has been recalculated to 17.9 g/t Au over 4.8 metres (including 143 g/t Au over 0.5 metres). The cut value remains unchanged. The mineralized zone is in a bleached to strongly sericitized large quartz-eye felsic intrusion containing 7% pyrite stringers. The intersection is 25 metres north-east of OSK-W-17-901 (16.2 g/t Au over 2.1 metres previously reported August 1, 2017) within the Caribou Corridor.

OSK-W-17-889 intersected 16.2 g/t Au over 2.0 metres (including 58.0 g/t Au over 0.5 metres) in the main Caribou Zone. Mineralization is at a contact between the gabbro and the rhyolite. The 1% pyrite stringers are associated with strong sericite alteration and a quartz-tourmaline vein. The interval is 30 metres below OSK-W-17-862 (17.4 g/t over 2.9 metres in this press release).

OSK-W-17-901 intersected two intervals: 13.8 g/t Au over 2.0 metres and 7.12 g/t Au over 2.0 metres (including 13.3 g/t Au over 1.0 metre). In both intervals, mineralization is composed of up to 1% disseminated pyrite and 1% pyrite stringers. The host rhyolite is strongly alterated in silica, sericite and carbonates. The first interval correlates to Caribou Main Zone and the second interval to Caribou footwall, 65 metres below OBM-16-660 (7.25 g/t Au over 6.9 metres previously published July 11, 2016).

OSK-W-17-913 intersected 611 g/t Au over 2.0 metres (including 4070 g/t Au over 0.3 metres) (15.4 g/t Au over 2.0 metres cut). The high-grade zone contains local visible gold and 1% pyrite stringers associated with pervasive silica flooding within a felsic dike. The host rock is strongly sericitized. The intersection correlates to the Wolf 2 Zone, 50 metres east-north-east of OSK W-16-718 (8.5 g/t Au over 4.7 metres previously reported September 19, 2016). The hole also intersected 13.6 g/t Au over 2.0 metres (including 26.5 g/t Au over 1.0 metre) in the Wolf footwall. Mineralization is associated with a large quartz-eyes porphyritic dike and composed of disseminated pyrite and trace of pyrite stringers. The interval is 40 metres north-east of OSK-W-16-718 (4.78 g/t Au over 2.6 metres previously reported September 19, 2016).

OSK-W-17-989-W1 intersected two proximate intervals in Caribou South 1 Zone: 3.59 g/t Au over 7.0 metres and 7.74 g/t Au over 3.0 metres (including 20.5 g/t Au over 1.0 metre). Mineralization is associated to a porphyritic felsic intrusion crosscutting a strongly sericitized and silicified andesite. Up to 20% pyrite stringers are observed. The interval is 65 metres south-west of OSK-W-16-709 (4.90 g/t Au over 3.7 metres previously reported August 23, 2016).

Zone 27

OSK-W-17-862-W2 intersected 297 g/t Au over 2.1 metres (including 2080 g/t Au over 0.3 metres) (14.5 g/t Au over 2.1 metres cut). The mineralization correlates to Zone 27 along the Red Dog intrusion contact, with visible gold associated with disseminated pyrite and pervasive silica alteration in a strongly silicified andesite.

OSK W-17-903 intersected 10.7 g/t Au over 2.0 metres (including 37.7 g/t Au over 0.5 metres). Mineralization consists of 2% pyrite stringers, 3% pyrite-tourmaline stringers and 5% disseminated pyrite hosted in silica and sericite altered andesite. The intersection correlates to Zone 27, 45 metres above OSK-W-16-746 (16.5 g/t Au over 3.7 metres previously reported January 5, 2017).

OSK-W-17-968 intersected 5.77 g/t Au over 2.4 meters in Zone 27. Mineralization consists of 3% quartz-tourmaline veins and 5% pyrite stringers in a strongly sericitized felsic dike. This intersection is 15 meters above OBM-16-600 (12.9 g/t Au over 4.2 metres previously reported March 16, 2016).

OSK-W-17-973 intersected two intervals in Zone 27: 60.5 g/t Au over 2.4 metres (including 122 g/t Au over 1.0 metre) (51.6 g/t Au over 2.4 metres cut) and 5.12 g/t Au over 2.1 metres (including 25.2 g/t Au over 0.4 metres). The first interval is composed of semi-massive pyrite in a silica altered porpyritic felsic dike. The second interval is at the contact between two felsic dikes and is composed of 1% pyrite in clusters or stringers.

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Osisko Intersects 36 g/t Au Over 6.9 Metres At Lynx

(Toronto, September 18, 2017)  Osisko Mining Inc. (OSK:TSX. “Osisko” or the “Corporation”) is pleased to provide new results from the ongoing drill program at its 100% owned Windfall Lake gold project located in Urban Township, Abitibi, Québec. The recently expanded 800,000 metre drill program combines definition, expansion and exploration drilling in and around the main Windfall gold deposit and in the adjacent Lynx deposit (located immediately NE of Windfall). Significant new analytical results from 29 intercepts in 21 drill holes focused on infill and expansion drilling in the Lynx deposit are presented below.

Highlights from the new results include: 36.0 g/t Au over 6.9 metres (29.9 g/t Au over 6.9 metres cut) in OSK-W-17-1006; 116 g/t Au over 2.3 metres (31.8 g/t Au over 2.3 metres cut) in OSK-W-17-873; 25.5 g/t Au over 4.0 metres in OSK-W-17-924; (27.1 g/t Au over 3.5 metres (20.5 g/t Au over 3.5 metres cut) OSK-W-17-922; 24.3 g/t Au over 3.5 metres in OSK-W-1010;  and 21.3 g/t Au over 3.0 metres in OSK-W-17-1048. Maps showing hole locations and full analytical results are available at www.osiskomining.com.

Hole Number From (m) To (m) Interval (m) Au (g/t) uncut Au (g/t)
cut to
100 g/t
Zone Corridor
OSK-W-17-848 363.0 365.5 2.5 7.95   Lynx 1 Lynx
Including 364.5 365.5 1.0 19.9  
  518.5 520.6 2.1 15.1   Lynx HW Lynx
Including 518.5 519.5 1.0 26.2  
OSK-W-17-861 388.5 390.5 2.0 9.41   Lynx 2 Lynx
Including 388.5 389.5 1.0 18.7  
  506.7 507.2 2.3 4.06    Lynx HW Lynx
including 508.6 509.0 0.4 12.6  
OSK-W-17-868 267.0 269.0 2.0 8.22   Lynx 1 Lynx
including 267.4 268.2 0.8 18.0  
OSK-W-17-873 300.0 302.0 2.0 9.30   Lynx 2 Lynx
including 300.5 300.8 0.3 59.9  
  306.2 308.5 2.3 116 31.8 Lynx 2 Lynx
including 307.8 308.5 0.7 375 100
  320.9 323.3 2.4 10.7   VNCR Lynx
including 320.9 321.7 0.8 28.7  
OSK-W-17-882 417.0 420.0 3.0 3.39   VNCR Lynx
including 418.0 418.5 0.5 18.8  
OSK-W-17-883 288.5 290.5 2.0 3.89   Lynx 2 Lynx
OSK-W-17-907 952.0 954.0 2.0 30.2   TBD Lynx
including 952.4 953.1 0.7 85.2  
OSK-W-17-909 908.0 910.0 2.0 11.8   Lynx 1 Lynx
including 908.5 909.0 0.5 37.0  
  982.9 986.0 3.1 4.94   Lynx 1 Lynx
OSK-W-17-914 239.3 241.6 2.3 27.2 26.6 Lynx HW Lynx
including 240.7 241.0 0.3 105 100
OSK-W-17-921 328.6 330.6 2.0 20.6   Lynx 1 Lynx
including 329.3 329.7 0.4 97.8  
OSK-W-17-922 456.1 459.6 3.5 27.1 20.5 Lynx 2 Lynx
including 457.5 457.8 0.3 176 100
OSK-W-17-924 308.0 312.0 4.0 25.5   Lynx 2 FW Lynx
OSK-W-17-928 376.2 378.3 2.1 9.1   Lynx 2 Lynx
including 376.7 377.6 0.9 20.0  
OSK-W-17-945 481.0 483.0 2.0 5.38   Lynx 1 Lynx
OSK-W-17-949 196.0 200.0 4.0 5.18   Lynx HW Lynx
including 196.5 196.9 0.4 28.3  
  214.1 216.1 2.0 4.5   Lynx 1 Lynx
  236.3 238.3 2.0 10.4   Lynx 2 Lynx
including 236.9 237.3 0.4 49.1  
OSK-W-17-957 193.7 197.9 4.2 6.02   Lynx 2 Lynx
including 197.6 197.9 0.3 64.1  
  212.0 214.0 2.0 21.5   Lynx 2 Lynx
including 212.6 213.2 0.6 70.6  
OSK-W-17-958 441.8 444.0 2.2 9.18   Lynx 2 Lynx
OSK-W-17-974 172.0 174.0 2.0 24.2   Lynx 2 Lynx
including 172.8 173.3 0.5 94.2  
OSK-W-17-1006 383.3 390.2 6.9 36.0 29.9 Lynx 2 Lynx
including 383.3 384.2 0.9 147 100
including 384.6 385.7 1.1 62.3  
including 389.3 390.2 0.9 41.4  
OSK-W-17-1010 310.5 314.0 3.5 24.3   VNCR Lynx
including 310.5 311.5 1.0 62.9  
OSK-W-17-1048 216.0 219.0 3.0 21.3   Lynx 2 Lynx
including 217.8 219.0 1.2 37.4  

Notes:

  1. True widths are estimated at 65 – 80% of the reported core length interval.  See “Quality Control” below.
  2. Definitions: HG = Hanging wall; FT = Foot Wall; VNCR = crustiform vein and TBD = To be determined.
Hole Number Azimuth
(°)

 

Dip
(°)

 

Length
(m)

 

UTM E UTM N Section
OSK-W-17-848 135 -45 669 453311 5435357 3650
OSK-W-17-861 150 -45 726 453386 5435455 3775
OSK-W-17-868 332 -64 435 453428 5434977 3575
OSK-W-17-873 326 -61 393 453427 5434976 3575
OSK-W-17-882 331 -53 471 453369 5434846 3450
OSK-W-17-883 326 -60 396 453455 5434983 3600
OSK-W-17-907 134 -51 1317 453219 5435340 3575
OSK-W-17-909 131 -55 1119 453683 5435677 4125
OSK-W-17-914 332 -53 447 453390 5434852 3475
OSK-W-17-921 331 -57 447 453428 5434865 3525
OSK-W-17-922 144 -52 591 453360 5435437 3725
OSK-W-17-924 334 -54 375 453414 5434927 3550
OSK-W-17-928 333 -64 465 453433 5434905 3550
OSK-W-17-945 149 -50 557 453374 5435444 3750
OSK-W-17-949 333 -55 423 453434 5434969 3575
OSK-W-17-957 327 -56 228 453329 5434973 3475
OSK-W-17-958 143 -55 1212 453359 5435439 3725
OSK-W-17-974 330 -59 357 453302 5434978 3450
OSK-W-17-1006 136 -49 762 453281 5435348 3625
OSK-W-17-1010 330 -53 369 453313 5434908 3425
OSK-W-17-1048 333 -52 303 453215 5434914 3350

 

OSK-W-17-848 intersected two intervals: 7.95 g/t Au over 2.5 metres (including 19.9 g/t Au over 1.0 metre) and 15.1 g/t Au over 2.1 metres (including 26.2 g/t Au over 1.0 metre). In the first interval, the mineralization is composed of local tourmaline-pyrite stringers, tourmaline stringers and disseminated pyrite within a fragmental intrusion with sericite and silica alteration. The intersection correlates to Lynx 1, 40 metres above OSK-W-17-912 (19.8 g/t Au over 2.0 metres and 6.65 g/t Au over 2.8 metres previously reported August 24, 2017). In the second interval, the mineralization is composed of up 2% disseminated pyrite, 2% pyrite stringers and tourmaline veins. The interval correlates to Lynx HW, 120 metres south-west of OSK-W-17-836 (3.30 g/t Au over 2.3 metres).

OSK-W-17-861 intersected two intervals: 9.41 g/t Au over 2.0 metres (including 18.7 g/t Au over 1.0 metre), related to the Lynx 2, and 4.06 g/t Au over 2.3 metres (including 12.6 g/t Au over 0.4 metres), related to Lynx HW. The mineralization consists of 5% pyrite-tourmaline stringers within a silica altered rhyolite. The first intersection is 40 metres east-north-east of OSK W-17-912 (14.6 g/t Au over 2.2 meters previously reported August 24, 2017) and the second intersection is 40 metres down plunge of OSK-W-17-818.

OSK-W-17-868 intersected 8.22 g/t Au over 2.0 metres (including 18.0 g/t Au over 0.8 metres). The mineralization is composed of up to 10% pyrite stringers, up to 7% disseminated pyrite and local gold hosted in a strongly silicified and sericitized rhyolite.

OSK-W-17-873 intersected two intervals in the Lynx 2 Zone: 9.30 g/t Au over 2.0 metres (including 59.9 g/t Au over 0.3 metres) and 116 g/t Au over 2.3 metres (including 375 g/t Au over 0.7 metres) (31.8 g/t Au over 2.3 metres cut).  A third interval with a crustiform quartz vein averaged 10.7 g/t Au over 2.4 metres (including 28.7 g/t Au over 0.8 metres). In Lynx 2, the mineralization is composed of quartz-carbonate veins with up to 5% disseminated pyrite and up to 2% pyrite stringer cross cutting sericitized rhyolite and strongly silica altered gabbro, with local visible gold. The crustiform vein contains up to 3% disseminated pyrite.

OSK-W-17-882 intersected 3.39 g/t Au over 3.0 metres (including 18.8 g/t Au over 0.5 metres) in Lynx 2, contained in a weakly silicified gabbro with small crustiform veins and trace disseminated pyrite.

OSK-W-17-883 intersected 3.89 g/t Au over 2.0 metres in the Lynx 2 Zone. The mineralization consists of up to 2% pyrite stringers and ptygmatic tourmaline veins in a silica altered rhyolite. The interval is 30 metres east of OSK-W-17-873 (116 g/t Au over 2.3 metres, this press release).

OSK-W-17-907 intersected 30.2 g/t Au over 2.0 metres (including 85.2 g/t Au over 0.7 metres).  The mineralization is composed of up to 2% pyrite in a sericitized and silicified rhyolite.

OSK-W-17-909 intersected two intervals: 11.8 g/t Au over 2.0 metres (including 37.0 g/t Au over 0.5 metres) and 4.94 g/t Au over 3.1 metres. This interval consists of intense pervasive silica flooding hosted in a gabbro. Mineralization includes up to 7% pyrite stringers. The intersection correlates to Lynx 1, 400 metres down plunge and north-east of OSK-W-17-836.  The intersection is 200 metres vertically below OSK-W-17-908 (10.6 g/t Au over 4.2 metres, 7.34 g/t au over 4.1 metres and 12.6 g/t Au over 2.5 metres, previously reported August 9, 2017).

OSK-W-17-914 intersected 27.2 g/t Au over 2.3 metres, (including 105 g/t Au over 0.3 metres) (26.6 g/t Au over 2.3 metres cut). The intersection consists of pervasive silica flooding containing 10% pyrite stringers, 1% disseminated pyrite and local visible gold. Mineralization is hosted in a sericitized rhyolite with fuchsite. It correlates to the Lynx HW Zone, 50 metres south-east and sub parallel to the Lynx 1 Zone, and 75 metres down plunge of OSK-W-17-803 (5.23 g/t Au over 2.3 metres, previously reported April 11, 2017).

OSK-W-17-921 was previously reported on August 9, 2017, with a cut value of 3.05 g/t Au over 2.0 metres.  Additional analysis was done on samples greater than 10 g/t Au and the interval was upgraded to 20.6 g/t Au over 2.0 metres (including 97.8 g/t Au over 0.4 metres).  Mineralization consist of 5% pyrite stringers and 2% disseminated pyrite at a contact between gabbro and a large quartz-eye felsic dike. The intersection represents the Lynx 1 Zone, 20 metres south-west of OSK-W-17-839 (6.58 g/t Au over 8.3 metres previously reported July 12, 2017).

OSK-W-17-922 intersected 27.1 g/t Au over 3.5 metres, (including 176 g/t Au over 0.3 metres) (20.5 g/t Au over 3.5 metres cut). The intersection is hosted in a strongly silicified and fuschitized gabbro. The mineralization consists of 30% smoky quartz-carbonate-tourmaline-pyrite veins and up to 4% quartz-tourmaline veins. The high-grade sample intervals contain local visible gold, 10% pyrite-tourmaline stringers and 3-4% disseminated pyrite-tourmaline. The intersection is within the Lynx 2 Zone, 30 metres west of OSK-W-17-898 (23.5 g/t Au over 3.0 metres and 12.2 g/t Au over 2.5 metres respectively reported August 9, 2017 and July 25, 2017).

OSK-W-17-924 intersected 25.5 g/t Au over 4.0 metres in Lynx 2, with local visible gold and 1% disseminated pyrite, and pyrite stringers in a silica altered rhyolite. The interval is 25 metres south-west of OSK-W-17-873 (116 g/t Au over 2.3 metres, this press release).

OSK-W-17-928 intersected 9.1 g/t Au over 2.1 metres (including 20.0 g/t Au over 0.9 metres) in Lynx 2. Mineralization comprises 2% pyrite stringers at the contact between gabbro and a felsic porphyritic dike.

OSK-W-17-945 intersected 5.38 g/t Au over 2.0 metres in Lynx 1. The mineralization is composed of up to 1% disseminated pyrite in a chloritized gabbro. The interval is 45 metres north-east of OSK-W-17-898 (17.3 g/t Au over 2.3 metres previously reported July 25, 2017).

OSK-W-17-949 intersected three intervals: 5.18 g/t Au over 4.0 metres (including 28.3 g/t Au over 0.4 metres) in Lynx HW; 4.5 g/t Au over 2.0 metres in Lynx 1; and 10.4 g/t Au over 2.0 metres (including 49.1 g/t Au over 0.4 metres) in Lynx 2. The first interval is at a contact between the rhyolite and the gabbro; the second and the third intervals are in a strongly silicified rhyolite. Small fragmental felsic dikes crosscut the rhyolite. Mineralization is mainly composed of up to 5% pyrite stringers. The Lynx HW and Lynx 1 intersections are 25 metres north-east of OSK-W-17-870 (25.7 g/t Au over 2.7 metres and 18.9 g/t Au over 2.8 metres previously reported July 12, 2017). The Lynx 2 interval is 45 metres north-east of OSK-W-17-873 (10.0 g/t Au over 2.6 metres previously reported July 12, 2017).

OSK-W-17-957 intersected two intervals in Lynx 2 Zone: 6.02 g/t Au over 4.2 metres (including 64.1 g/t Au over 0.3 metres) and 21.5 g/t Au over 2.0 metres (including 70.6 g/t Au over 0.6 metres). Mineralization is composed of up to 3% pyrite fragments, up to 15% disseminated pyrite and local visible gold hosted in a strongly sericitized fragmental felsic intrusion. These intervals are 10 metres west of OSK-W-17-895 (8.98 g/t Au over 6.5 metres previously reported August 9, 2017).

OSK-W-17-958 intersected 9.18 g/t Au over 2.2 metres. Mineralization is composed of up to 3% disseminated pyrite and pyrite stringers in a strongly sericitized fragmental felsic intrusion. The intersection is 70 metres down plunge to the north-east of OSK-W-17-898 (12.2 g/t Au over 2.5 metres previously reported July 25, 2017).

OSK-W-17-974 intersected 24.2 g/t Au over 2.0 metres (including 94.2 g/t Au over 0.5 metres) in Lynx 2. The mineralization is composed of up to 20% disseminated pyrite and a quartz-tourmaline vein. The fragmental felsic dike host is strongly sericitized and silicified. The interval is 30 metres south-west of OSK-W-17-957 (6.02 g/t Au over 4.2 metres reported in this press release).

OSK-W-17-1006 intersected 36.0 g/t Au over 6.9 metres (including 147 g/t Au over 0.9 metres; 62.3 g/t Au over 1.1 metres; and 41.4 g/t Au over 0.9 metres) (29.9 g/t Au over 6.9 metres cut). Mineralization consists of two centimeter-scale smoky quartz veins at low core angles with 10% pyrite and local visible gold within a sericite and silica altered fragmental felsic unit. The intersection is related to the Lynx 2 Zone, 50 metres east of OSK-W-17-812 (26.0 g/t Au over 2.5 metres previously reported May 3, 2017).

OSK-W-17-1010 intersected 24.3 g/t Au over 3.5 metres (including 62.9 g/t Au over 1.0 metre). Mineralization is in a crustiform vein (quartz, carbonate and tourmaline) with local visible gold, 5% pyrite stringers and pyrite clusters hosted in a fragmental felsic volcanic. The vein is 20 metres north-east of OSK-W-17-877 (57.8 g/t Au over 2.3 metres previously reported July 25, 2017).

OSK-W-17-1048 intersected 21.3 g/t Au over 3.0 metres (including 37.4 g/t Au over 1.2 metres) in the Lynx 2 Zone. The mineralization is composed of up to 5% pyrite stringers and 2% quartz-tourmaline veins hosted in a strongly sericitized and silicified rhyolite. The intersection is 30 metres below OSK-W-17-849 (7.10 g/t Au over 2.0 metres previously reported July 12, 2017).

Quality Control and Reporting Protocols
True widths determinations are estimated at 65-80% of the reported core length intervals for most of the zones. 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 ALS Laboratories in Val dOr, Québec, Thunder Bay and Sudbury, Ontario or Vancouver, British Colombia or 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 Lake Gold Deposit
The Windfall Lake gold deposit is located between Val-dOr and Chibougamau in the Abitibi region of Québec, Canada. The mineral resource defined by the previous operator comprises 2,762,000 tonnes at 8.42 g/t Au (748.000 ounces) in the indicated category and 3,512,000 tonnes at 7.62 g/t Au (860,000 ounces) in the inferred category (sourced from a technical report dated June 10, 2015 entitled “Preliminary Economic Assessment of the Windfall Lake Gold Property, Québec, Canada” with an effective date of April 28, 2015, prepared in accordance with NI 43-101). The Windfall Lake gold deposit is currently one of the highest grade resource-stage gold projects in Canada. The bulk of the mineralization occurs in the Main Zone, a southwest/northeast trending zone of stacked mineralized lenses, measuring approximately 600 metres wide and at least 1.400 metres long. The deposit is well defined from surface to a depth of 500 metres, and remains open along strike and at depth. Mineralization has been identified only 30 metres from surface in some areas and as deep as 870 metres in others, with significant potential to extend mineralization up and 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% in the high-grade Windfall Lake gold deposit located between Val-dOr and Chibougamau in Québec and holds a 100% undivided interest in a large area of claims in the surrounding Urban Barry area and nearby Quevillon area (over 3,300 square kilometres), a 100% interest in the Marban project located in the heart of Québecs prolific Abitibi gold mining district, and properties in the Larder Lake Mining Division in northeast Ontario, including the Jonpol and Garrcon deposits on the Garrison property, the Buffonta past producing mine and the Gold Pike mine property. The Corporation also holds interests and options in a number of additional properties in northern Quebec and Ontario.  Osisko continues to be well financed with approximately $190 million in cash and investments.

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. The information in this news release about the Windfall Lake gold deposit being one of the highest grade resource-stage gold projects in Canada; the current 800,000 metre drill program; the significance of new results from the ongoing drill program at the Windfall Lake gold project; the significance of assay results presented in this press release; the type of drilling included in the drill program (definition drilling, expansion drilling to the NE of the main deposit and adjacent Lynx deposit, and exploration drilling on the greater deposit and Urban-Barry project area); potential mineralization; the potential to extend mineralization up and down-plunge and at depth at the Windfall Lake gold deposit; the ability to realize upon any mineralization in a manner that is economic; the ability to complete any proposed exploration activities and the results of such activities, including the continuity or extension of any mineralization; and any other information herein that is not a historical fact may be “forward-looking information”. Any statement that involves discussions with respect to 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”, “managements view”, “anticipates” or “does not anticipate”, “plans”, “budget”, “scheduled”, “forecasts”, “estimates”, “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 forward-looking information is based on reasonable assumptions and estimates of management of the Corporation. at the time it was made, involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of Osisko to be materially different from any future results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, risks relating to the ability of exploration activities (including drill results) to accurately predict mineralization; errors in managements geological modelling; the ability of Osisko to complete further exploration activities, including drilling; property interests in the Windfall Lake gold project; the ability of the Corporation to obtain required approvals and complete transactions on terms announced; 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.

For further information please contact:
John Burzynski. President and Chief Executive Officer
Telephone: (416) 363-8653