Osisko Drilling Returns High Grade at Lynx

 

180 g/t Au Over 2.2 Metres

46.8 g/t Au Over 3.3 Metres

TORONTO, May 11, 2021 (GLOBE NEWSWIRE) -- Osisko Mining Inc. (OSK:TSX "Osisko" or the "Corporation") is pleased to provide new analytical results from the ongoing drill program at its 100% owned Windfall gold project located in the Abitibi greenstone belt, Urban Township, Eeyou Istchee James Bay, Québec.

Significant new analytical results presented below include 28 intercepts in 18 drill holes (5 from surface, 13 from underground) and 3 wedges. The infill intercepts are located inside defined February 2021 mineral resource estimate (“MRE”) blocks (see Osisko news release dated February 17, 2021). The expansion intercepts are located outside the February 2021 MRE blocks and either expand resource wireframes or are located in a defined zone or corridor but do not yet correlate to a specific wireframe.

Osisko Chief Executive Officer John Burzynski commented: “Today’s infill results continue to demonstrate the strong continuity inside defined MRE blocks as well as our ability to add resources in the immediate surrounding areas.”

Selected high-grade intercepts include: 180 g/t Au over 2.2 metres in OSK-W-21-2495; 46.8 g/t Au over 3.3 metres in OSK-W-21-2470, 32.2 g/t Au over 2.4 metres in OSK-W-21-2480, 27.2 g/t Au over 2.0 metres in WST-20-0585 and 21.9 g/t Au over 2.3 metres in WST-20-0639B. Maps showing hole locations and full analytical results are available at www.osiskomining.com

Infill Drilling

Hole Number	From (m)	To (m)	Interval (m)	Au (g/t) uncut	Au (g/t) cut to 100 g/t	Zone	Corridor
OSK-W-20-2313-W9	826.3	829.0	2.7	6.53		TLX_3184	Triple Lynx
including	827.2	827.9	0.7	24.0
	832.7	835.0	2.3	7.10		TLX_3184	Triple Lynx
including	833.5	834.4	0.9	17.4
OSK-W-20-2394-W3	659.0	663.0	4.0	4.16		TLX_3171	Triple Lynx
OSK-W-21-2470	993.0	996.3	3.3	46.8	34.3	TLX_3164	Triple Lynx
including	993.4	993.8	0.4	203	100
OSK-W-21-2482	625.3	627.6	2.3	10.4		TLX_3171	Triple Lynx
including	626.4	627.0	0.6	23.2
OSK-W-21-2495	1023.0	1025.0	2.0	4.80		LX4_3430	Lynx
including	1023.0	1023.3	0.3	18.0
	1027.0	1029.2	2.2	180	30.7	LX4_3430	Lynx
including	1027.5	1028.1	0.6	646	100
WST-20-0585	157.7	159.7	2.0	27.2		LXM_3359	Lynx
including	158.2	159.0	0.8	63.4
WST-20-0639B	269.0	271.3	2.3	21.9		LSX_3510	Lynx SW
including	269.5	270.4	0.9	41.7
	298.0	300.0	2.0	3.62		LSX_3556	Lynx
including	298.4	298.8	0.4	11.1
WST-21-0665	328.4	331.0	2.6	4.59		TLX_3166	Triple Lynx
including	330.4	331.0	0.6	11.4
WST-21-0677	490.4	492.4	2.0	11.8		LX4_3450	Lynx
including	491.8	492.4	0.6	39.1
WST-21-0696	276.6	279.2	2.6	3.66		TLX_3166	Triple Lynx
including	277.4	278.2	0.8	10.8
WST-21-0709	27.0	29.3	2.3	6.72		LXM_3303	Lynx
including	27.6	28.7	1.1	13.8
WST-21-0710	28.0	30.0	2.0	5.14		LXM_3303	Lynx
	79.0	81.0	2.0	18.5		LXM_3304	Lynx
including	79.6	80.3	0.7	52.5
WST-21-0729	398.0	403.0	5.0	3.69		TLX_3165	Triple Lynx
including	402.6	403.0	0.4	14.7
WST-21-0735	338.0	340.1	2.1	5.06		LSX_3501	Lynx SW
including	338.8	339.1	0.3	34.5

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

Expansion Drilling

Hole Number	From (m)	To (m)	Interval (m)	Au (g/t) uncut	Au (g/t) cut to 100 g/t	Zone	Corridor
OSK-W-21-2480	997.8	1000.2	2.4	32.2	25.1	Lynx 4	Lynx
including	998.9	999.5	0.6	129	100
OSK-W-21-2487	691.2	693.3	2.1	5.28		Lynx 4	Lynx
including	691.7	692.5	0.8	12.2
OSK-W-21-2487-W2	655.0	657.0	2.0	5.14		Lynx 4	Lynx
OSK-W-21-2495	986.0	988.0	2.0	4.46		Lynx 4	Lynx
WST-21-0640A	308.7	311.0	2.3	4.90		Lynx SW	Lynx SW
	342.0	344.0	2.0	4.85		Lynx SW	Lynx SW
including	342.5	343.1	0.6	16.0
WST-21-0680	51.5	54.0	2.5	4.11		Lynx	Lynx
WST-21-0692	532.3	534.9	2.6	12.7		Triple Lynx	Triple Lynx
including	532.3	532.6	0.3	71.8
WST-21-0729	421.3	425.3	4.0	5.72		Lynx 4	Lynx
including	421.3	421.8	0.5	26.9
WST-21-0757	630.9	633.0	2.1	6.99		Lynx 4	Lynx
including	630.9	631.7	0.8	18.3

^{Notes: True widths are estimated at 55 – 80% of the reported core length interval. See "Quality Control and Reporting Protocols" below. SW = Lynx Southwest (SW).}

Drill hole location

Hole Number	Azimuth (°)	Dip (°)	Length (m)	UTM E	UTM N	Elevation	Section
OSK-W-20-2313-W9	134	-52	1218	452965	5435583	420	3450
OSK-W-20-2394-W3	138	-52	1020	452923	5435467	414	3375
OSK-W-21-2470	132	-59	1230	453304	5435639	415	3775
OSK-W-21-2480	121	-55	1230	453412	5435633	412	3875
OSK-W-21-2482	131	-57	939	453009	5435387	413	3400
OSK-W-21-2487	359	-73	897	454135	5435058	397	4225
OSK-W-21-2487-W2	359	-73	777	454135	5435058	397	4225
OSK-W-21-2495	123	-54	1257	453426	5435565	410	3850
WST-20-0585	161	-25	189	453418	5435305	69	3725
WST-20-0639B	147	-54	351	453105	5435065	231	3325
WST-21-0640A	165	-51	456	453104	5435064	231	3325
WST-21-0665	141	-52	552	453229	5435127	134	3475
WST-21-0677	144	-42	652	453257	5435209	96	3525
WST-21-0680	161	-47	559	453322	5435235	55	3600
WST-21-0692	157	-54	541	453356	5435272	16	3650
WST-21-0696	137	-49	492	453229	5435127	134	3475
WST-21-0709	155	-7	94	453360	5435194	83	3625
WST-21-0710	154	-9	94	453360	5435195	83	3625
WST-21-0729	132	-49	510	453229	5435127	135	3475
WST-21-0735	132	-58	475	452956	5435003	253	3175
WST-21-0757	145	-50	706	453228	5435126	135	3475

Lynx Zone
Mineralization occurs as grey to translucent quartz-carbonate-pyrite-tourmaline veins and pyrite replacement zones and stockworks. Vein-type mineralization is associated with haloes of pervasive sericite-pyrite ± silica alteration and contain sulphides (predominantly pyrite with minor amounts of chalcopyrite, sphalerite, galena, arsenopyrite, and pyrrhotite) and local visible gold. Replacement mineralization is associated with strong pervasive silica-sericite-ankerite ± tourmaline alteration and contains disseminated pyrite from trace to 80% with local visible gold. Pyrite stockworks can form envelopes that reach several tens of metres thick. Fuchsite alteration is common and is spatially constrained to near the gabbros. Mineralization occurs at or near geological contacts between felsic porphyritic or fragmental intrusions and the host rhyolites or gabbros and locally can be hosted along the gabbro-rhyolite contact.

Qualified Person
The scientific and technical content of this news release has been reviewed, prepared and approved by Mr. Louis Grenier, M.Sc.A., P.Geo. (OGQ 800), Director of Exploration for Osisko's Windfall gold project, who is a "qualified person" as defined by National Instrument 43-101 – Standards of Disclosure for Mineral Projects ("NI 43-101").

Quality Control and Reporting Protocols
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 Estimate (“MRE“) defined by Osisko, as disclosed in the news release dated February 17, 2021 is supported by the technical report entitled “Preliminary Economic Assessment Update for the Windfall Project” dated April 26, 2021 (that includes Windfall Mineral Resource Estimate with an effective date  of November 30, 2020), and assuming a cut-off grade of 3.50 g/t Au, comprises 521,000 tonnes at 11.3 g/t Au (189,000 ounces) in the measured mineral resource category, 5,502,000 tonnes at 9.4 g/t Au (1,668,000 ounces) in the indicated mineral resource category and 16,401,000 tonnes at 8.0 g/t Au (4,244,000 ounces) in the inferred mineral resource category. The key assumptions, parameters and methods used to estimate the mineral resource estimate disclosed in the February 17, 2021 news release are further described in the full technical report prepared by BBA Inc. in accordance with NI 43-101 and is available on SEDAR (www.sedar.com) under the Corporation's issuer profile. The Windfall gold deposit is currently one of the highest-grade resource-stage gold projects in Canada and has world-class scale. Mineralization 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 gold 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