Osisko Intersects 56.1 g/t Au Over 8.9 Metres At Windfall

New Bobcat Zone Returns 42.4 g/t Au over 3.3 Metres Near Surface

(Toronto, January 25, 2018)  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 the Abitibi greenstone belt, Urban Township, Eeyou Istchee James Bay, Québec. The 800,000 metre drill program combines definition, expansion and exploration drilling in and around the main Windfall gold deposit and the adjacent Lynx deposit (located immediately NE of Windfall).

Significant new analytical results from 72 intercepts in 39 drill holes and 6 wedges focused on infill and expansion drilling in the Main Windfall lake deposit are presented below.

  • New “Bobcat Zone” with high-grades discovered near surface and at shallow depths
  • Continued high-grade infill and expansion from Underdog
  • New hit from Drake

Highlights from the new results include: 56.1 g/t Au over 8.9 metres in OSK-W-17-1336-W1; 218 g/t Au over 2.1 metres in OSK-W-17-1191; 160 g/t over 2.0 metres in OSK-W-17-1142-W1; 106 g/t Au over 3.0 metres in OSK-W-17-1305; 30.8 g/t over 9.9 metres in OSK-OBM-16-693; 83.5 g/t Au over 3.4 metres in OSK-W-17-780-W1; 128 g/t Au over 2.1 metres in OSK-W-17-1203; 58.8 g/t Au over 2.5 metres in OSK-W-17-1095; 72.8 g/t Au over 2.0 metres in OSK-W-17-1020; 42.4 g/t Au over 3.3 metres in OSK-W-17-1138;  52.8 g/t Au over 2.3 metres in OSK-W-17-1381; 26.2 g/t Au over 3.8 metres in OSK-W-17-1374;  41.9 g/t Au over 2.0 metres in OSK-W-17-1289; 14.1 g/t Au over 5.6 metres in OSK-W-17-1255; and 26.5 g/t Au over 2.1 metres in OSK-W-17-1142. 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-OBM-16-630 518.2 521.0 2.8 4.82   FW3U HW Underdog
OSK-OBM-16-693 654.1 664.0 9.9 30.8 22.2 FW3U HW Underdog
including 654.1 656.0 1.9 80.0 45.5
including 658.1 661.9 3.8 37.4 32.1
OSK-W-16-747 936.9 939.3 2.4 6.96   FW3 Underdog
including 938.1 938.6 0.5 32.5  
OSK-W-17-780-W1 1343.8 1347.2 3.4 83.5 29.4 FW3 HW Underdog
including 1346.6 1347.2 0.6 407 100
OSK-W-17-936-W1 776.0 778.0 2.0 3.65   Z27 Zone 27
including 777.2 778.0 0.8 8.07  
  785.0 787.7 2.7 4.03   Z27 Zone 27
including 787.0 787.7 0.7 7.71  
OSK-W-17-936-W2 671.1 673.3 2.2 11.1   Wolf HW Wolf
OSK-W-17-968 102.0 109.4 7.4 4.02   Z27 Zone 27
including 107.4 109.4 2.0 7.77  
  118.0 122.3 4.3 11.2 10.5 QTV Zone 27
including 122.0 122.3 0.3 109 100
OSK-W-17-989-W2 664.6 667.0 2.4 4.56   Wolf Wolf
OSK-W-17-1020 271.5 273.5 2.0 72.8   Bobcat Bobcat
including 272.0 273.5 1.5 96.9  
OSK-W-17-1095 88.2 90.7 2.5 58.8 52.9 Z27 Zone 27
including 88.6 89.7 1.1 114 100
OSK-W-17-1125 427.0 429.0 2.0 6.80   Vein Caribou
including 427.0 428.0 1.0 13.5  
  616.0 618.0 2.0 3.87   SHR Caribou
including 617.2 618.0 0.8 9.35  
OSK-W-17-1138 11.0 14.3 3.3 42.4   Bobcat Bobcat
including 13.0 14.3 1.3 98.1  
  21.0 24.0 3.0 3.28   Bobcat Bobcat
OSK-W-17-1139 148.0 150.2 2.2 4.29   Vein  
  157.5 160.1 2.6 4.53   Vein  
including 159.5 160.1 0.6 9.21  
OSK-W-17-1140 781.2 783.3 2.1 7.07   Caribou Ext. Caribou
including 783.0 783.3 0.3 48.8  
OSK-W-17-1142 13.1 15.2 2.1 26.5   CW4 Caribou
including 14.0 14.6 0.6 84.5  
OSK-W-17-1142-W1 370.0 372.0 2.0 160   Vein  Drake 
including 370.5 371.5 1.0 320  
OSK-W-17-1178 78.0 80.1 2.1 5.89   Bobcat Bobcat
including 79.5 80.1 0.6 17.5  
OSK-W-17-1191 235.4 237.5 2.1 218 34.6 Z27 FW Zone 27
including 236.8 237.5 0.7 650 100
OSK-W-17-1203 27.9 30.0 2.1 128 42.9 Z27 Zone 27
including 27.9 28.8 0.9 298 100
OSK-W-17-1218 27.0 29.0 2.0 3.99   VNCR Bobcat
  189.0 191.5 2.5 4.46   Bobcat Bobcat
OSK-W-17-1251 24.0 27.0 3.0 8.89   Bobcat Bobcat
including 24.0 25.0 1.0 21.0  
  55.0 59.0 4.0 3.86   Bobcat Bobcat
including 55.0 56.0 1.0 12.3  
  192.0 195.0 3.0 4.11   VNCR Bobcat
including 193.4 193.7 0.3 40.2  
OSK-W-17-1255 156.0 161.6 5.6 14.1   Bobcat Bobcat
including 156.6 159.5 2.9 21.1  
OSK-W-17-1273 54.9 57.0 2.1 4.05   Z27 HW Zone 27
including 54.9 55.4 0.5 14.3  
OSK-W-17-1280 369.8 372.7 2.9 3.19   Caribou Ext. Caribou
OSK-W-17-1288 749.0 751.0 2.0 4.41   Caribou Ext. Caribou
OSK-W-17-1289 343.0 345.0 2.0 41.9   QTV Mallard
including 343.0 344.0 1.0 83.5  
OSK-W-17-1305 348.0 351.0 3.0 106 50.1 Vein Caribou
including 349.5 351.0 1.5 211 100
OSK-W-17-1309 218.1 220.2 2.1 5.64   Z27 FW Zone 27
including 218.1 218.8 0.7 16.5  
OSK-W-17-1313 425.1 427.3 2.2 5.46   Z27 FW Zone 27
including 425.9 426.7 0.8 14.2  
  443.0 445.5 2.5 3.50   Z27 FW Zone 27
  19.0 22.0 3.0 3.05   Vein Caribou
OSK-W-17-1317 45.0 47.5 2.5 4.31   Z27 HW Zone 27
  170.0 172.0 2.0 4.60   Z27 Zone 27
OSK-W-17-1336-W1 1064.1 1073.0 8.9 56.1 15.1 FW2 Underdog
including 1067.0 1070.1 3.1 151 33.7
OSK-W-17-1371 604.6 607.0 2.4 3.61   Caribou Ext. Caribou
OSK-W-17-1374 312.6 315.0 2.4 4.27   Z27 HW Zone 27
  324.5 328.3 3.8 26.2   Z27 HW Zone 27
  721.0 723.7 2.7 3.09   FW3 Underdog
including 723.0 723.7 0.7 10.5  
OSK-W-17-1378 382.0 384.0 2.0 4.21   CS3 Caribou
  477.2 479.3 2.1 5.49   Wolf Wolf
OSK-W-17-1381 111.5 113.8 2.3 16.7   Bobcat Bobcat
including 112.5 112.9 0.4 94.6  
  653.0 655.3 2.3 52.8 13.2 Vein Zone 27
including 654.2 654.5 0.3 404 100
OSK-W-17-1383 29.5 34.2 4.7 13.1   Bobcat Bobcat
  83.0 87.0 4.0 4.01   Bobcat Bobcat
  94.9 97.0 2.1 5.01   Bobcat Bobcat
  102.0 104.1 2.1 5.33   Bobcat Bobcat 
including 103.1 104.1 1.0 10.5  
OSK-W-17-1385 734.7 737.2 2.5 8.40   Caribou Ext. Caribou
including 735.9 736.6 0.7 28.6  
  741.6 745.3 3.7 5.04   Caribou Ext. Caribou
including 744.3 745.3 1.0 13.0  
  820.5 824.0 3.5 6.64   Caribou Ext. Caribou
including 820.5 821.1 0.6 26.2  
OSK-W-17-1388 368.6 371.0 2.4 11.9   CS1 Caribou
  697.0 699.2 2.2 4.59   Wolf FW Wolf
OSK-W-17-1390 505.0 507.2 2.2 3.44   FW3 Underdog
OSK-W-17-1391 297.0 299.9 2.9 12.2   Bobcat Bobcat
including 299.4 299.9 0.5 65.4  
OSK-W-17-1393 157.0 159.0 2.0 3.91   Bobcat Bobcat
including 158.3 158.7 0.4 16.7  
OSK-W-17-1399 574.0 576.0 2.0 3.55   Caribou Ext. Caribou
OSK-W-17-1400 325.6 328.0 2.4 4.05   Caribou corridor Caribou
OSK-W-17-1404 141.4 144.0 2.6 4.28   Bobcat Bobcat
including 142.0 143.0 1.0 11.0  
  168.0 171.0 3.0 4.54   Bobcat Bobcat
including 170.7 171.0 0.3 13.4  
  535.0 537.0 2.0 3.96   Caribou Ext. Caribou
  539.7 543.0 3.3 4.33   Caribou Ext. Caribou
  356.8 359.5 2.7 10.4   Caribou Ext. Caribou
including 358.6 359.0 0.4 53.2  
OSK-W-17-1406 79.3 81.8 2.5 6.97   VNCR Bobcat
including 79.7 80.0 0.3 47.7  
  248.5 250.9 2.4 3.47   Bobcat Bobcat
  322.0 324.5 2.5 5.71   Bobcat Bobcat

Notes:

  1. True widths are estimated at 65 – 80% of the reported core length interval.  See “Quality Control” below.
  2. Definitions: HW = Hanging Wall, FW = footwall, VNCR = Crustiform Vein, TBD = To be determined, Ext = extension.
Hole Number Azimuth (°) Dip (°) Length (m) UTM E UTM N Section
OSK-OBM-16-630 329 -51 699 452252 5434614 2375
OSK-OBM-16-693 331 -54 861 452443 5434600 2525
OSK-W-16-747 331 -57 1050 452449 5434488 2475
OSK-W-17-780-W1 331 -60 1533 452929 5434374 2850
OSK-W-17-936-W1 332 -56 808 452773 5434547 2775
OSK-W-17-936-W2 332 -56 819 452773 5434547 2775
OSK-W-17-968 152 -51 201 451948 5434759 2175
OSK-W-17-989-W2 335 -56 743 452660 5434497 2675
OSK-W-17-1020 337 -54 312 453217 5434928 3350
OSK-W-17-1095 147 -50 147 451959 5434734 2175
OSK-W-17-1125 331 -58 975 452563 5434568 2625
OSK-W-17-1138 327 -51 402 452888 5434989 3100
OSK-W-17-1139 333 -56 1092 452473 5434470 2500
OSK-W-17-1140 336 -55 975 453006 5434522 2975
OSK-W-17-1142 324 -45 680 452202 5434628 2325
OSK-W-17-1142-W1 324 -45 699 452202 5434628 2325
OSK-W-17-1178 330 -63 411 452917 5435014 3150
OSK-W-17-1191 315 -69 255 452067 5434617 2200
OSK-W-17-1203 333 -53 372 452275 5434867 2500
OSK-W-17-1218 327 -62 405 453004 5435009 3225
OSK-W-17-1251 326 -60 372 452889 5434989 3100
OSK-W-17-1255 130 -65 276 452947 5435107 3225
OSK-W-17-1273 338 -66 225 452081 5434634 2225
OSK-W-17-1280 335 -57 467 452857 5434931 3050
OSK-W-17-1288 331 -56 912 452945 5434561 2950
OSK-W-17-1289 339 -61 375 452277 5434866 2500
OSK-W-17-1305 330 -54 888 452499 5434592 2575
OSK-W-17-1309 330 -69 237 452073 5434610 2200
OSK-W-17-1313 331 -51 876 452279 5434573 2375
OSK-W-17-1317 327 -65 274 452072 5434611 2200
OSK-W-17-1336-W1 335 -61 1335 452616 5434449 2600
OSK-W-17-1371 334 -69 981 453100 5434875 3225
OSK-W-17-1374 317 -59 873 452273 5434579 2375
OSK-W-17-1378 331 -56 741 452688 5434638 2750
OSK-W-17-1381 329 -63 723 453018 5434935 3200
OSK-W-17-1383 331 -63 597 452767 5434864 2925
OSK-W-17-1385 319 -49 906 453379 5434741 3400
OSK-W-17-1388 332 -57 762 452716 5434605 2775
OSK-W-17-1390 329 -47 657 451911 5434437 1975
OSK-W-17-1391 327 -62 663 452981 5434900 3150
OSK-W-17-1393 332 -62 573 452725 5434862 2900
OSK-W-17-1399 332 -61 1053 453411 5434870 3500
OSK-W-17-1400 332 -52 769 452310 5434408 2325
OSK-W-17-1404 335 -67 635 452854 5434823 3000
OSK-W-17-1406 334 -60 579 452911 5434879 3075

 

OSK-OBM-16-693 intersected 30.8 g/t Au over 9.9 metres in the Underdog Corridor. Mineralization is composed of up to 10% pyrite-silica flooding, up to 5% pyrite stringers, 3% disseminated pyrite, and local visible gold. The host rhyolite, in contact with a porphyritic felsic dike, is strongly silica and sericite altered.

OSK-W-17-780-W1 intersected 83.5 g/t Au over 3.4 metres in FW3 HW. Mineralization is composed of 4% pyrite stringers and smoky quartz veins within a strongly silica altered porphyritic felsic dike.

OSK-W-17-1020 intersected 72.8 g/t Au over 2.0 meters in the new Bobcat Zone. This zone is NE along strike and on top of the Caribou corridor. The two zones have parallel plunges to the North-East. Mineralization is composed of 1% disseminated pyrite and 2% of pyrite-silica flooding within a strongly sericitized rhyolite.

OSK-W-17-1095 intersected 58.8 g/t Au over 2.5 metres in Zone 27. Mineralization is composed of up to 5% pyrite with low angle silica flooding hosted in a strongly silicified and fuchsitized andesite.

OSK-W-17-1138 intersected 42.4 g/t Au over 3.3 metres in Bobcat. Mineralization is very near surface (starting 11 metres downhole) and is composed of 3% silica flooding, 1% disseminated pyrite and crustiform vein within a sericitized rhyolite.

OSK-W-17-1139 intersected two veins in a sheared andesite south of the main zone. Mineralization, 4.29 g/t Au over 2.2 metres and 4.53 g/t au over 2.6 metres, is composed of up to 4% disseminated pyrite within a chloritized andesite.

OSK-W-17-1142-W1 intersected 160 g/t Au over 2.0 metres providing a new hit for Drake. Mineralization is composed of up to 10% pyrite, local visible gold and electrum associated in quartz-carbonate veins. The bleached andesite is near the Red Dog contact.

OSK-W-17-1191 intersected 218 g/t Au over 2.1 metres in Zone 27. Mineralization is composed of 5% pyrite stringers and 3% pyrite fragments within a strongly sericitized and silicified andesite.

OSK-W-17-1203 intersected 128 g/t Au over 2.1 metres in Zone 27. Mineralization is composed of up to 20% pyrite, pyrite silica flooding and local visible gold within a strongly silicified rhyolite.

OSK-W-17-1251 intersected 8.89 g/t Au over 3.0 metres, 3.86 g/t Au over 4.0 metres and 4.11 g/t Au over 3.0 metres in Bobcat. The first interval is composed of up to 7% pyrite-silica flooding and 1% ptygmatic tourmaline veins within a strongly sericitized and silicified felsic porphyritic dike. The second interval is within a sericitized rhyolite and composed of up to 5% pyrite stringers and disseminated pyrite. The third interval is within a quartz crustiform vein.

OSK-W-17-1255 intersected 14.1 g/t Au over 5.6 metres in Bobcat. Mineralization is composed of up to 10% pyrite within a pyrite-silica flooding running at low core angle. The hosting gabbro is strongly altered in silica and sericite.

OSK-W-17-1289 intersected 41.9 g/t Au over 2.0 meters in Mallard. Mineralization is composed of 1% disseminated pyrite in quartz-tourmaline veins within a chloritized andesite.

OSK-W-17-1305 intersected 106 g/t Au over 3.0 metres in Caribou Corridor. Mineralization is composed of disseminated pyrite within quartz-carbonate veins hosted in a sericitized andesite.

OSK-W-17-1336-W1 intersected 56.1 g/t Au over 8.9 metres in Underdog Corridor. Mineralization is composed of local visible gold with up to 8% pyrite stringers, disseminated chalcopyrite and quartz-tourmaline veins within a silicified porphyritic felsic dike.

OSK-W-17-1381 intersected 16.7 g/t Au over 2.3 metres in Bobcat and 52.8 g/t Au over 2.3 metres in Zone 27. The first interval is composed of 2% pyrite stringers, 3% pyrite fragments and a 10 centimetres quartz-carbonate vein within a sericitized and silicified rhyolite. The second interval, is composed of 4% disseminated pyrite and local visible gold within a quartz-cabonate vein hosted in a chloritized andesite.

OSK-W-17-1383 intersected four intervals in Bobcat: 13.1 g/t Au over 4.7 metres, 4.01 g/t Au over 4.0 metres, 5.01 g/t Au over 2.1 metres and 5.33 g/t Au over 2.1 metres. Mineralization is composed of up to 5% pyrite stringers, 1% pyrite tourmaline stringers and up to 1% disseminated pyrite. The first interval is in a porphyritic felsic dike and the three others are in crustiform veins within a silicified rhyolite.

Zone 27 results also include 12 intercepts from 7 drill holes and one wedge. Mineralization is composed of up to 15% pyrite, disseminated or in stringers associated with quartz-tourmaline veins. Host rocks are rhyolites, andesites and felsic dikes.

Caribou results also include 18 intercepts from 12 drill holes. Mineralization is composed of up to 20% pyrite, usually in stringers, locally semi-massive, and quartz-tourmaline veins hosted in altered porphyritic felsic dikes, andesites and rhyolites.

Wolf results include 4 intercepts from 2 drill holes and 2 wedges. Mineralization is composed of up to 70% pyrite-silica flooding, up to 20% pyrite stringers, and ptygmatic tourmaline veins hosted in silicified, sericitized and fuchsitized andesite.

Underdog results also include 4 intercepts from 4 drill holes. Mineralization is composed of up to 20% pyrite, usually in stringers associated with trace quartz-tourmaline veins and hosted in porphyritic felsic dikes. Host dikes are strongly silica altered.

Bobcat results also include 11 intercepts from 7 drill holes. Mineralization is composed of up to 10% pyrite-silica flooding, up to 5% disseminated pyrite and crustiform quartz veins within chloritized, sericitized andesites, rhyolites and felsic dikes.

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 the 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 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 rele