Osisko Continues to Add High-Grade at Lynx

 

184 g/t Au Over 2.1 Metres

34.1 g/t Au over 7.1 Metres

TORONTO, June 17, 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 68 intercepts in 22 drill holes (2 from surface, 20 from underground) and 14 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 in a defined zone or corridor but do not yet correlate to a specific wireframe.

Osisko Chief Executive Officer John Burzynski commented: “The continued success of the infill and expansion drill programs at Lynx demonstrate how robust the system is with respect to grade and growth. Windfall is demonstrating its consistency with more high-grade infill and expansion holes, and we expect to complete our major drill program as scheduled this fall.”

Selected high-grade intercepts include: 184 g/t Au over 2.1 metres in OSK-W-21-2480-W3; 34.1 g/t Au over 7.1 metres in OSK-W-21-2495-W1, 94.1 g/t Au over 2.0 metres in OSK-W-21-2480-W4, 40.3 g/t Au over 4.0 metres and 41.2 g/t Au over 2.9 metres in OSK-W-21-2067-W7; 36.0 g/t Au over 4.0 metres in OSK-W-21-2503; and 41.0 g/t Au over 2.5 metres in OSK-W-21-2465-W2. 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-21-2067-W7	1029.0	1033.0	4.0	5.08		TLX_3183	Triple Lynx
	1039.5	1042.4	2.9	41.2	21.7	TLX_3183	Triple Lynx
including	1039.5	1039.8	0.3	180	100
and	1042.1	1042.4	0.3	209	100
	1115.0	1119.0	4.0	40.3	18.6	TLX_3170	Triple Lynx
including	1117.0	1117.5	0.5	274	100
	1132.1	1134.2	2.1	34.2	15.5	TLX_3172	Triple Lynx
including	1133.9	1134.2	0.3	231	100
OSK-W-21-2478-W3	891.1	893.4	2.3	5.78		TLX_3161	Triple Lynx
including	892.7	893.4	0.7	14.2
OSK-W-21-2478-W4	842.8	846.5	3.7	7.00		TLX_3171	Triple Lynx
	863.9	866.0	2.1	4.13		TLX_3184	Triple Lynx
	874.3	876.3	2.0	26.2		TLX_3184	Triple Lynx
including	874.3	874.7	0.4	90.3
	877.7	880.2	2.5	5.65		TLX_3161	Triple Lynx
including	879.7	880.2	0.5	20.0
OSK-W-21-2480-W3	757.4	759.5	2.1	184	78.2	LXM_3304	Lynx
including	758.4	759.2	0.8	350	100
OSK-W-21-2480-W4	734.6	737.2	2.6	8.59		LXM_3304	Lynx
including	734.6	735.2	0.6	23.3
	686.0	688.0	2.0	94.1	27.2	LX4_3414	Lynx 4
including	686.7	687.0	0.3	546	100
OSK-W-21-2492-W3	803.4	805.5	2.1	8.19		LX4_3414	Lynx 4
including	804.0	804.5	0.5	18.4
	864.0	866.0	2.0	10.1		LX4_3437	Lynx 4
OSK-W-21-2495-W1	1038.0	1045.1	7.1	34.1	33.5	LX4_3430	Lynx 4
including	1040.0	1041.0	1.0	105	100
OSK-W-21-2503	1008.0	1013.0	5.0	6.59		TLX_3163	Triple Lynx
	1087.0	1089.0	2.0	3.53		TLX_3162	Triple Lynx
including	1088.3	1088.6	0.3	12.6
	1113.0	1117.0	4.0	36.0	22.4	TLX_3172	Triple Lynx
including	1115.1	1115.8	0.7	178	100
	1120.0	1122.1	2.1	11.5		TLX_3172	Triple Lynx
including	1120.3	1120.6	0.3	72.8
OSK-W-21-2522	735.0	737.0	2.0	4.54		LXM_3345	Lynx
WST-21-0650	232.5	236.1	3.6	9.91		LXSW_3507	Lynx
including	232.5	233.0	0.5	51.3
WST-21-0684	267.9	269.9	2.0	6.55		LXSW_3556	Lynx
including	268.6	269.0	0.4	32.0
WST-21-0725	262.4	264.5	2.1	7.65		TLX_3185	Triple Lynx
WST-21-0727A	334.1	336.1	2.0	15.0		TLX_3163	Triple Lynx
including	334.1	334.7	0.6	44.7
WST-21-0734A	323.7	325.9	2.2	6.99		LXSW_3556	Lynx
including	325.2	325.9	0.7	21.1
WST-21-0736	202.0	204.0	2.0	14.0		LXSW_3507	Lynx
including	202.0	202.7	0.7	35.1
	297.0	299.6	2.6	13.4		LXSW_3556	Lynx
including	297.0	297.9	0.9	31.6
	354.0	356.2	2.2	12.7		LXSW_3502	Lynx
including	355.3	355.6	0.3	33.9
WST-21-0768	365.0	367.0	2.0	17.0		LXSW_3502	Lynx
including	366.1	366.7	0.6	56.2
WST-21-0769	79.1	81.3	2.2	10.3		LXM_3311	Lynx
including	79.1	79.9	0.8	27.0
WST-21-0774	479.6	482.0	2.4	12.1		LX4_3450	Lynx 4
including	480.3	481.1	0.8	35.5
WST-21-0782	169.3	172.0	2.7	20.6		LXM_3304	Lynx
including	169.3	170.2	0.9	49.1
WST-21-0787	129.4	133.0	3.6	5.66		LXM_3334	Lynx
WST-21-0790	95.0	97.3	2.3	5.00		LXM_3339	Lynx
including	96.0	96.7	0.7	12.3
	105.0	107.0	2.0	10.7		LXM_3339	Lynx
including	105.4	106.0	0.6	24.3

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 LXSW = Lynx Southwest.

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-21-2275-W5	1053.0	1057.1	4.1	17.2		Triple Lynx	Triple Lynx
including	1053.5	1053.8	0.3	37.2
and	1056.3	1057.1	0.8	72.5
OSK-W-21-2391-W3	1251.0	1253.1	2.1	3.64		Triple Lynx	Triple Lynx
OSK-W-21-2391-W4	1404.5	1406.5	2.0	6.39		Triple Lynx	Triple Lynx
including	1404.5	1404.8	0.3	36.2
	1409.0	1412.2	3.2	6.03		Triple Lynx	Triple Lynx
including	1409.0	1409.9	0.9	18.0
	1417.0	1419.0	2.0	3.90		Triple Lynx	Triple Lynx
including	1417.6	1418.1	0.5	12.5
OSK-W-21-2465-W2	763.7	766.2	2.5	41.0	39.1	Triple Lynx	Triple Lynx
including	765.0	765.3	0.3	111	100
and	765.6	766.2	0.6	99.6	97.1
OSK-W-21-2470-W2	921.0	923.0	2.0	4.27		Triple Lynx	Triple Lynx
	925.4	928.6	3.2	6.01		Triple Lynx	Triple Lynx
including	925.4	925.9	0.5	18.5
	991.7	995.0	3.3	4.20		Triple Lynx	Triple Lynx
including	991.7	992.1	0.4	19.1
	1125.0	1127.0	2.0	7.82		Triple Lynx	Triple Lynx
including	1125.3	1125.6	0.3	29.8
OSK-W-21-2470-W3	975.7	977.7	2.0	8.24		Triple Lynx	Triple Lynx
OSK-W-21-2480-W2	678.8	682.0	3.2	7.66		Lynx	Lynx
OSK-W-21-2495-W1	604.0	606.1	2.1	4.18		Lynx	Lynx
including	605.3	605.7	0.4	15.4
	1157.9	1160.0	2.1	5.79		Lynx 4	Lynx
including	1158.5	1159.3	0.8	12.6
	1190.7	1193.0	2.3	4.83		Lynx 4	Lynx
including	1191.8	1192.2	0.4	26.8
WST-21-0661	171.0	173.0	2.0	5.37		Lynx SW	Lynx SW
including	171.9	172.4	0.5	21.4
WST-21-0663	191.0	193.0	2.0	5.65		Lynx SW	Lynx SW
including	191.0	191.4	0.4	27.4
WST-21-0681	419.0	421.9	2.9	10.4		Triple Lynx	Triple Lynx
	444.0	446.0	2.0	8.90		Triple Lynx	Triple Lynx
including	445.0	446.0	1.0	17.4
WST-21-0734A	192.0	194.0	2.0	4.76		Lynx SW	Lynx SW
WST-21-0736	247.0	249.0	2.0	11.6		Lynx SW	Lynx SW
WST-21-0767	268.0	270.2	2.2	4.67		Lynx SW	Lynx SW
including	268.6	269.3	0.7	12.1
WST-21-0768	263.0	265.2	2.2	18.2	14.3	Lynx SW	Lynx SW
including	264.1	264.4	0.3	129	100
	312.0	314.0	2.0	13.5		Lynx SW	LynSW
including	313.0	313.3	0.3	83.5
WST-21-0769	320.0	322.0	2.0	4.38		Lynx SW	Lynx SW
including	320.4	321.2	0.8	10.9
	329.3	331.3	2.0	17.1	15.6	LXSW_3502	Lynx SW
including	329.3	329.6	0.3	110	100
WST-21-0774	332.0	334.0	2.0	3.64		Triple Lynx	Triple Lynx
	677.5	683.0	5.5	16.4	11.0	Lynx 4	Lynx
including	677.5	677.8	0.3	198	100
WST-21-0777	311.0	313.0	2.0	3.59		Lynx SW	Lynx SW
WST-21-0781	227.8	229.8	2.0	23.5		Triple Lynx	Triple Lynx
including	229.2	229.5	0.3	99.6
WST-21-0782	151.0	153.0	2.0	4.26		Lynx	Lynx
including	151.3	151.6	0.3	27.2
WST-21-0783	170.5	172.5	2.0	12.4		Lynx	Lynx
including	170.5	170.8	0.3	68.0
WST-21-0803	157.0	159.4	2.4	23.1		Triple Lynx	Triple Lynx

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

Drill hole location

Hole Number	Azimuth (°)	Dip (°)	Length (m)	UTM E	UTM N	Elevation	Section
OSK-W-21-2067-W7	123	-53	1166	453241	5435697	416	3750
OSK-W-21-2275-W5	127	-49	1242	452888	5435583	409	3400
OSK-W-21-2391-W3	117	-57	1566	453281	5435894	408	3900
OSK-W-21-2391-W4	117	-57	1212	453281	5435894	408	3900
OSK-W-21-2465-W2	123	-61	831	453397	5435557	413	3825
OSK-W-21-2470-W2	132	-59	1197	453304	5435639	415	3775
OSK-W-21-2470-W3	132	-59	1209	453304	5435639	415	3775
OSK-W-21-2478-W3	128	-54	1080	452997	5435607	425	3500
OSK-W-21-2478-W4	127	-53	744	452997	5435607	425	3500
OSK-W-21-2480-W2	121	-55	789	453412	5435633	412	3875
OSK-W-21-2480-W3	121	-55	810	453412	5435633	412	3875
OSK-W-21-2480-W4	121	-55	780	453412	5435633	412	3875
OSK-W-21-2492-W3	122	-53	720	453687	5435676	401	4125
OSK-W-21-2495-W1	123	-54	1301	453426	5435565	410	3850
OSK-W-21-2503	126	-58	1080	453333	5435641	413	3800
OSK-W-21-2522	128	-54	450	453451	5435594	411	3900
WST-21-0650	139	-60	466	452954	5435003	253	3175
WST-21-0661	163	-34	253	452954	5435003	254	3175
WST-21-0663	164	-40	214	452954	5435003	253	3175
WST-21-0681	160	-43	721	453322	5435235	55	3600
WST-21-0684	150	-44	301	452955	5435003	253	3175
WST-21-0725	160	-67	391	453506	5435327	-7	3800
WST-21-0727A	146	-69	361	453507	5435327	-7	3800
WST-21-0734A	129	-56	360	452956	5435003	253	3175
WST-21-0736	146	-53	448	452955	5435003	253	3175
WST-21-0767	175	-55	354	453104	5435065	231	3325
WST-21-0768	169	-53	453	453104	5435065	231	3325
WST-21-0769	171	-49	396	453103	5435064	231	3325
WST-21-0774	148	-40	724	453373	5435296	-26	3675
WST-21-0777	144	-49	352	452954	5435003	253	3175
WST-21-0781	129	-59	283	453508	5435327	-7	3800
WST-21-0782	123	-36	207	453508	5435327	-7	3800
WST-21-0783	119	-28	201	453508	5435327	-6	3800
WST-21-0787	143	-46	517	453320	5435235	54	3600
WST-21-0790	171	-65	64	453104	5435065	231	3325
WST-21-0803	162	-44	364	453356	5435271	16	3650

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