280 g/t Au Over 2.2 Metres in Lynx

(Toronto, May 26, 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.

Significant new analytical results presented below include 55 intercepts in 18 drill holes (3 from surface, 15 from underground) and 9 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 and expansion drilling results continue to return high grade intervals. Of note is hole OSK-W-21-2391-W3 which again extends Triple Lynx down plunge (initially extended OSK-W-21-2391, see March 17, 2021 news release).”

Selected high-grade intercepts include: 280 g/t Au over 2.0 metres in WST-21-0712; 69.3 g/t Au over 2.0 metres in OSK-W-21-2498, 23.9 g/t Au over 5.1 metres in OSK-W-21-2067-W6, 25.4 g/t Au over 4.7 metres in OSK-W-21-2480, 44.4 g/t Au over 2.5 metres in OSK-W-21-2473, 26.3 g/t Au over 3.8 metres in OSW-W-21-2492-W1, 39.3 g/t Au over 2.3 metres in WST-21-0756, 12.6 g/t Au over 3.7 metres in OSK-W-2391-W3 and 21.0 g/t Au over 2.0 metres in WST-21-0751. Maps showing hole locations and full analytical results are available at www.osiskomining.com

Infill 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-21-2067-W6	1010.9	1013.1	2.2	4.61		TLX_3183	Triple Lynx
including	1010.9	1011.2	0.3	13.1
	1015.0	1017.0	2.0	3.82		TLX_3183	Triple Lynx
including	1016.0	1016.4	0.4	13.1
	1032.5	1034.5	2.0	6.53		TLX_3163	Triple Lynx
	1108.9	1114.0	5.1	23.9		TLX_3172	Triple Lynx
including	1109.2	1110.2	1.0	48.4
	1119.0	1121.0	2.0	9.48		TLX_3172	Triple Lynx
	1129.7	1131.9	2.2	34.2	14.9	TLX_3172	Triple Lynx
including	1131.0	1131.3	0.3	241	100
OSK-W-21-2275-W5	800.8	807.5	6.7	5.20		TLX_3171	Triple Lynx
including	800.8	801.1	0.3	31.3
and	806.8	807.5	0.7	17.0
	809.0	811.0	2.0	4.57		TLX_3171	Triple Lynx
including	809.8	810.2	0.4	15.0
	826.6	828.6	2.0	4.53		TLX_3184	Triple Lynx
including	827.0	827.4	0.4	19.3
OSK-W-21-2416-W4	951.6	954.6	3.0	6.74		TLX_3171	Triple Lynx
	968.9	971.0	2.1	15.6		TLX_3161	Triple Lynx
including	968.9	969.6	0.7	41.4
	992.0	994.0	2.0	12.5		TLX_3164	Triple Lynx
including	992.0	992.5	0.5	48.1
OSK-W-21-2470-W2	886.0	889.0	3.0	23.4		TLX_3163	Triple Lynx
including	886.9	887.4	0.5	90.4
OSK-W-21-2480	1111.0	1113.2	2.2	23.6		LX4_3430	Lynx 4
including	1112.0	1112.6	0.6	49.5
	1119.5	1124.2	4.7	25.4		LX4_3430	Lynx 4
including	1119.5	1120.4	0.9	65.3
OSK-W-21-2480-W2	731.5	733.5	2.0	13.5		LXM_3304	Lynx
including	731.8	732.5	0.7	38.4
OSK-W-21-2487-W2	667.0	669.0	2.0	11.0		LX4_3424	Lynx 4
including	667.6	667.9	0.3	70.6
OSK-W-21-2492-W1	765.2	769.0	3.8	26.3		LX4_3424	Lynx 4
including	768.5	769.0	0.5	64.3
OSK-W-21-2498	779.9	782.0	2.1	10.2		TLX_3199	Triple Lynx
including	780.3	781.0	0.7	28.3
	825.7	827.7	2.0	69.3	35.1	TLX_3195	Triple Lynx
including	826.2	826.8	0.6	214	100
WST-21-0651	323.7	325.7	2.0	31.5		LXSW_3556	Lynx
including	324.3	325.1	0.8	77.9
	335.0	337.0	2.0	15.7		LXSW_3502	Lynx
including	335.7	336.4	0.7	44.8
WST-21-0653A	368.8	371.3	2.5	24.9		LXSW_3556	Lynx
	376.0	378.0	2.0	11.4		LXSW_3556	Lynx
including	376.0	377.0	1.0	22.8
WST-21-0696	48.2	50.8	2.6	3.82		LXM_3339	Lynx
WST-21-0712	78.0	80.0	2.0	280	25.3	LXM_3304	Lynx
including	78.8	79.3	0.5	1120	100
WST-21-0715	79.0	81.0	2.0	8.56		LXM_3304	Lynx
including	80.1	81.0	0.9	19.0
WST-21-0751	222.7	225.7	3.0	7.04		TLX_3161	Triple Lynx
	232.5	234.9	2.4	9.44		TLX_3161	Triple Lynx
including	233.5	233.9	0.4	50.6
WST-21-0752	207.0	209.2	2.2	14.5		TLX_3161	Triple Lynx
WST-21-0760	356.4	359.4	3.0	9.13		TLX_3165	Triple Lynx
including	359.0	359.4	0.4	44.8
WST-21-0806	178.3	181.0	2.7	32.1		LXM_3304	Lynx
including	179.9	181.0	1.1	74.8

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 No.	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	584.9	587.0	2.1	5.00		Triple Lynx	Triple Lynx
OSK-W-21-2391-W3	1383.3	1387.0	3.7	12.6	11.9	TLX_3172	Triple Lynx
including	1383.3	1383.6	0.3	109	100
OSK-W-21-2416-W4	987.4	989.5	2.1	4.53		Triple Lynx	Triple Lynx
including	987.4	987.8	0.4	23.6
OSK-W-21-2470-W2	913.0	915.0	2.0	5.14		Triple Lynx	Triple Lynx
OSK-W-21-2473	679.5	682.0	2.5	44.4	33.8	Lynx	Lynx
including	680.3	681.1	0.8	133	100
	842.0	844.0	2.0	6.88		Triple Lynx	Triple Lynx
OSK-W-21-2478-W3	553.4	555.6	2.2	9.58		Triple Lynx	Triple Lynx
OSK-W-21-2480-W2	689.2	691.6	2.4	4.68		Lynx	Lynx
including	690.0	690.6	0.6	10.9
OSK-W-21-2498	835.0	837.0	2.0	4.40		Triple Lynx	Triple Lynx
	899.0	901.2	2.2	7.73		Triple Lynx	Triple Lynx
including	899.0	899.3	0.3	24.2
	986.0	988.0	2.0	3.83		Triple Lynx	Triple Lynx
including	986.7	987.0	0.3	13.4
WST-21-0640A	79.6	82.0	2.4	3.52		LXM_3361	Lynx
including	79.6	80.3	0.7	9.79
WST-21-0680	474.0	476.1	2.1	4.68		Lynx 4	Lynx
including	475.4	475.8	0.4	23.9
	476.9	479.0	2.1	7.35		Lynx 4	Lynx
including	478.2	478.5	0.3	43.1
WST-21-0694	303.0	305.0	2.0	4.83		Lynx SW	Lynx SW
including	304.3	304.6	0.3	28.7
WST-21-0751	268.1	270.1	2.0	21.0	15.2	Triple Lynx	Triple Lynx
including	269.5	269.8	0.3	139	100
WST-21-0756	158.7	161.0	2.3	39.3	28.0	Lynx	Lynx
including	159.2	159.8	0.6	144	100
WST-21-0760	192.3	194.5	2.2	16.7		Lynx	Lynx
including	193.3	193.8	0.5	72.9
	314.7	317.5	2.8	3.67		Triple Lynx	Triple Lynx
including	314.7	315.0	0.3	13.6
WST-21-0761	300.8	303.0	2.2	3.77		Triple Lynx	Triple Lynx
	363.0	365.0	2.0	3.74		Triple Lynx	Triple Lynx
including	363.0	363.7	0.7	10.1
WST-21-0786	30.6	32.6	2.0	5.04		Lynx	Lynx
WST-21-0806	202.1	205.9	3.8	10.5		Lynx	Lynx

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

 

Drill hole location

Hole Number	Azimuth (°)	Dip (°)	Length (m)	UTM E	UTM N	Elevation	Section
OSK-W-21-2067-W6	123	-53	1281	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-21-2416-W4	123	-54	1125	453169	5435624	412	3650
OSK-W-21-2470-W2	132	-59	1197	453304	5435639	415	3775
OSK-W-21-2473	123	-56	1272	453420	5435610	413	3875
OSK-W-21-2478-W3	128	-54	1080	452997	5435607	425	3500
OSK-W-21-2480	121	-55	1230	453412	5435633	412	3875
OSK-W-21-2480-W2	121	-55	789	453412	5435633	412	3875
OSK-W-21-2487-W2	359	-73	777	454135	5435058	397	4225
OSK-W-21-2492-W1	122	-53	843	453687	5435676	401	4125
OSK-W-21-2498	129	-57	999	453007	5435385	412	3400
WST-21-0640A	165	-51	456	453104	5435064	231	3325
WST-21-0651	153	-52	400	452954	5435003	253	3175
WST-21-0653A	155	-65	427	453104	5435065	231	3325
WST-21-0680	161	-47	559	453322	5435235	55	3600
WST-21-0694	162	-61	384	453103	5435065	231	3325
WST-21-0696	137	-49	492	453229	5435127	134	3475
WST-21-0712	156	-3	91	453359	5435194	83	3625
WST-21-0715	158	-9	94	453359	5435194	83	3625
WST-21-0751	133	-56	331	453357	5435273	15	3650
WST-21-0752	148	-53	562	453357	5435273	15	3650
WST-21-0756	131	-43	411	453357	5435273	15	3650
WST-21-0760	145	-37	575	453257	5435209	96	3525
WST-21-0761	149	-34	485	453258	5435209	96	3525
WST-21-0786	150	-40	169	453320	5435235	54	3600
WST-21-0806	112	-33	93	453508	5435327	-7	3800

 

 

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

78.5 g/t Au Over 2.0 Metres in Zone 27

(Toronto, May 18, 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.

Significant new analytical results presented below include 61 intercepts in 20 drill holes (15 from surface, 5 from underground) and 9 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 drilling results in the Main Zone areas of Windfall, including Underdog, mirror the results reported over the past weeks in Lynx: infill drilling continues to define grade continuity inside our MRE blocks and expansion drilling is adding ounces in the immediate surrounding areas. All infill and expansion drilling at Windfall is in support of our upcoming feasibility study.”

Selected high-grade intercepts include: 78.5 g/t Au over 2.0 metres, 58.3 g/t Au over 2.0 metres and 40.0 g/t Au over 2.0 metres in OSK-W-21-2479, 43.5 g/t Au over 2.7 metres and 38.5 g/t Au over 2.7 metres in OSK-W-21-2442-W1, 18.3 g/t Au over 6.1 metres in OSK-W-21-2496, 40.3 g/t Au over 2.4 metres in OSK-W-21-2455-W1, 44.4 g/t Au over 2.0 metres in OSK-W-21-2463, 42.8 g/t Au over 2.0 metres in WST-21-0643, and 40.2 g/t Au over 2.0 metres in OSK-W-20-2439. 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-17-777	839.0	841.0	2.0	3.52		Underdog_4101	Underdog
	849.0	851.0	2.0	5.41		Underdog_4101	Underdog
including	850.6	851.0	0.4	20.0
	856.9	858.9	2.0	5.63		Underdog_4101	Underdog
including	857.5	857.8	0.3	27.0
OSK-W-20-913-W2	801.0	803.0	2.0	5.04		Caribou_2220	Caribou
OSK-W-21-1827-W2	504.0	506.0	2.0	15.3		Caribou_2231	Caribou
including	504.9	505.5	0.6	42.7
	511.3	513.9	2.6	5.11		Caribou_2231	Caribou
including	511.3	512.1	0.8	11.5
OSK-W-21-2442-W1	447.0	449.0	2.0	5.81		Z27_1203	Zone 27
including	448.3	449.0	0.7	16.3
	637.3	640.0	2.7	43.5	31.5	Underdog_4101	Underdog
including	637.3	637.6	0.3	74.5
and	639.6	640.0	0.4	181	100
	960.1	962.8	2.7	38.5	34.7	Underdog_4910	Underdog
including	962.5	962.8	0.3	134	100
OSK-W-21-2455-W1	588.6	590.7	2.1	4.72		Caribou_2232	Caribou
	661.6	663.6	2.0	5.50		Caribou_2208	Caribou
including	663.0	663.6	0.6	17.0
	666.5	668.8	2.3	4.86		Caribou_2208	Caribou
	770.6	773.0	2.4	40.3	37.6	Caribou	Caribou
including	772.1	773.0	0.9	107	100
OSK-W-21-2463	843.0	845.0	2.0	44.4	22.6	Underdog_4111	Underdog
including	843.3	843.7	0.4	209	100
OSK-W-21-2463-W2	840.6	843.0	2.4	3.75		Underdog_4110	Underdog
including	840.6	840.9	0.3	15.9
	927.0	929.0	2.0	17.3		Underdog_4101	Underdog
including	927.4	928.1	0.7	41.2
	959.0	961.0	2.0	4.27		Underdog_4100	Underdog
including	960.0	960.5	0.5	14.3
	972.0	974.0	2.0	4.77		Underdog_4102	Underdog
including	972.0	972.5	0.5	18.1
	1082.0	1084.0	2.0	5.38		Underdog_4511	Underdog
including	1082.6	1083.0	0.4	26.5
OSK-W-21-2479	638.0	640.0	2.0	40.0	37.2	Underdog_4100	Underdog
including	639.0	639.7	0.7	108	100
	642.6	649.5	6.9	8.06		Underdog_4100	Underdog
including	645.3	646.1	0.8	22.0
and	649.0	649.5	0.5	22.8
OSK-W-21-2486	533.0	535.3	2.3	4.89		Caribou_2232	Caribou
including	534.6	535.3	0.7	10.2
OSK-W-21-2496	208.0	214.1	6.1	18.3		F51_6008	F-51
including	209.0	210.0	1.0	45.3
OSK-W-21-2504	163.0	165.4	2.4	5.69		F51_6008	F-51
including	163.5	164.5	1.0	13.3
OSK-W-21-777-W1	610.7	612.9	2.2	17.1		Caribou_2233	Caribou
OSK-W-21-777-W2	568.0	570.0	2.0	35.2		Caribou_2211	Caribou
	572.0	574.4	2.4	4.90		Caribou_2211	Caribou
	611.0	613.0	2.0	9.76		Caribou_2233	Caribou

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

 

 

 

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-20-2399-W1	451.0	453.6	2.6	4.00		Caribou	Caribou
OSK-W-20-2406	404.0	406.0	2.0	4.76		Caribou	Caribou
	506.0	508.0	2.0	11.5		Caribou	Caribou
including	506.4	507.0	0.6	28.2
OSK-W-20-2432	405.0	407.0	2.0	3.65		Caribou	Caribou
	763.0	767.0	4.0	11.7		Caribou	Caribou
including	763.0	764.0	1.0	40.7
OSK-W-20-2439	35.0	37.0	2.0	40.2		F11	F11
including	35.0	36.0	1.0	77.0
OSK-W-20-2440	314.0	316.9	2.9	3.67		Caribou	Caribou
OSK-W-20-2441	181.5	184.4	2.9	5.07		Caribou	Caribou
OSK-W-21-1882-W1	744.0	746.0	2.0	5.16		Underdog	Underdog
OSK-W-21-2442-W1	945.0	947.1	2.1	8.49		Underdog	Underdog
	948.0	950.0	2.0	3.52		Underdog	Underdog
OSK-W-21-2451	436.0	438.0	2.0	4.32		Caribou	Caribou
including	436.4	437.0	0.6	14.0
OSK-W-21-2455	440.0	442.0	2.0	3.66		Caribou	Caribou
OSK-W-21-2463	323.0	325.0	2.0	3.55		Caribou	Caribou
including	324.0	324.4	0.4	10.2
	962.0	964.1	2.1	5.85		Underdog	Underdog
including	963.1	964.1	1.0	12.2
	1126.9	1129.0	2.1	7.07		Underdog	Underdog
including	1126.9	1127.3	0.4	28.1
OSK-W-21-2463-W2	940.0	942.0	2.0	4.23		Underdog	Underdog
	1051.0	1053.0	2.0	4.17		Underdog	Underdog
OSK-W-21-2479	482.0	484.0	2.0	78.5	16.8	Z27	Zone 27
including	482.3	482.6	0.3	511	100
	485.4	489.0	3.6	10.4		Z27	Zone 27
	616.0	618.3	2.3	11.3		Underdog	Underdog
including	617.0	617.3	0.3	84.3
	625.1	627.1	2.0	27.8		Underdog	Underdog
including	626.3	627.1	0.8	69.0
	630.0	632.0	2.0	4.97		Underdog	Underdog
including	630.6	631.0	0.4	22.6
	899.9	901.9	2.0	58.3	37.3	Underdog	Underdog
including	900.2	900.9	0.7	160	100
	913.7	916.8	3.1	25.0	17.7	Underdog	Underdog
including	916.5	916.8	0.3	176	100
OSK-W-21-2483	282.2	284.5	2.3	7.55		Caribou	Caribou
OSK-W-21-2490	436.9	439.0	2.1	5.06		Caribou	Caribou
including	437.9	438.2	0.3	35.0
	560.1	562.1	2.0	4.32		Caribou	Caribou
including	561.3	561.6	0.3	10.7
WST-21-0597	17.7	19.9	2.2	6.48		Bobcat	Bobcat
WST-21-0642	150.0	152.0	2.0	4.13		Bobcat	Bobcat
including	150.6	151.0	0.4	16.8
WST-21-0643	163.0	165.0	2.0	42.8		Bobcat	Bobcat
including	163.0	164.0	1.0	85.4
WST-21-0644	86.4	89.6	3.2	6.69		Bobcat	Bobcat
including	86.4	87.2	0.8	17.2
WST-21-0651	88.0	90.2	2.2	3.83		Bobcat	Bobcat
including	88.3	89.0	0.7	8.60

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

 

Drill hole location

Hole Number	Azimuth (°)	Dip (°)	Length (m)	UTM E	UTM N	Elevation	Section
OSK-W-17-777	330	-59	1221	452678	5434500	403	2675
OSK-W-20-2399-W1	333	-54	876	452875	5434553	398	2875
OSK-W-20-2406	333	-56	693	452633	5434281	400	2525
OSK-W-20-2432	333	-57	864	452809	5434415	404	2750
OSK-W-20-2439	147	-50	360	452515	5436029	406	3275
OSK-W-20-2440	330	-52	807	452738	5434475	401	2725
OSK-W-20-2441	338	-59	405	452715	5434606	397	2775
OSK-W-20-913-W2	334	-52	913	452878	5434419	401	2825
OSK-W-21-1827-W2	331	-58	690	452506	5434390	403	2475
OSK-W-21-1882-W1	328	-57	1197	452469	5434405	400	2450
OSK-W-21-2442-W1	347	-53	1011	452315	5434419	399	2325
OSK-W-21-2451	330	-58	803	452809	5434415	404	2750
OSK-W-21-2455	328	-53	780	452738	5434476	401	2725
OSK-W-21-2455-W1	328	-53	798	452738	5434476	401	2725
OSK-W-21-2463	339	-65	1335	452616	5434449	403	2600
OSK-W-21-2463-W2	339	-65	1325	452616	5434449	403	2600
OSK-W-21-2479	344	-55	993	452315	5434419	399	2325
OSK-W-21-2486	334	-57	1167	452596	5434392	401	2550
OSK-W-21-2483	328	-58	756	452731	5434634	397	2800
OSK-W-21-2490	338	-61	786	452756	5434466	400	2725
OSK-W-21-2496	158	-50	279	453484	5435967	403	4100
OSK-W-21-2504	161	-47	186	453533	5435947	403	4125
OSK-W-21-777-W1	330	-59	969	452678	5434500	403	2675
OSK-W-21-777-W2	330	-59	1170	452678	5434500	403	2675
WST-21-0597	151	-2	132	452817	5434943	275	3025
WST-21-0642	149	-38	172	452955	5435003	253	3175
WST-21-0643	129	-41	220	452955	5435003	253	3175
WST-21-0644	130	-4	120	452955	5435003	254	3175
WST-21-0651	153	-52	400	452954	5435003	253	3175

 

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.

 

Zone 27

Mineralization most commonly occurs as replacement-type characterized by 5% to 50% disseminated, stringer, semi-massive or stockwork pyrite, ptygmatic tourmaline veins, quartz-tourmaline crustiform veins, local quartz-carbonate veins, and local visible gold. Mineralization is associated with moderate to strong sericite, weak to strong silica, weak chlorite and carbonate and locally weak fuchsite and is hosted in strongly altered andesites, in or at the contact of the rhyolite, or along the contacts with felsic porphyritic intrusions.

F-Zones

Mineralization is hosted in sheared andesites with carbonate replacement or quartz veining and occurs as quartz ± ankerite veinlets or as replacement type in shear zones and is 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.

Underdog

Mineralization most commonly occurs in gold-bearing quartz-pyrite (± tourmaline) veins and as disseminated, stringer, semi-massive to massive pyrite with minor sphalerite, chalcopyrite and molybdenite associated with strong sericite and silica alteration. Mineralization is hosted along the intrusive contacts of a three-phase composite felsic porphyritic unit which cross-cuts felsic and mafic volcanic sequences.

 

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

180 g/t Au Over 2.2 Metres

46.8 g/t Au Over 3.3 Metres

(Toronto, May 11, 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.

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

124 g/t Au Over 2.7 Metres in Triple Lynx

78.7 g/t Au over 2.0 metres in Lynx SW

(Toronto, May 04, 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.

Significant new analytical results presented below include 52 intercepts in 35 drill holes (9 from surface, 15 from underground) and 11 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 highlighted intercepts in the Lynx and Triple Lynx zones, as seen on the accompanying long sections available on our website, demonstrate the continued distribution of high-grade intersected throughout these areas in both infill and expansion drilling.”

Selected high-grade intercepts include: 124 g/t Au over 2.7 metres in WST-21-0729; 78.7 g/t Au over 2.0 metres and 39.3 g/t Au over 2.2 metres in WST-21-0703, 34.6 g/t Au over 3.6 metres in OSK-W-21-2465, 41.6 g/t Au over 2.9 metres in WST-21-0696, 41.9 g/t Au over 2.1 metres in WST-21-0652, 31.5 g/t Au over 2.4 metres in OSK-W-21-2472 and 37.1 g/t Au over 2.0 metres in WST-21-0749. Maps showing hole locations and full analytical results are available at www.osiskomining.com

Infill 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-20-2252-W11	851.0	853.0	2.0	3.99		TLX_3189	Triple Lynx
OSK-W-20-2283-W2	789.6	791.8	2.2	4.14		TLX_3171	Triple Lynx
including	790.9	791.2	0.3	18.5
OSK-W-21-2394-W4	643.2	646.2	3.0	9.31		TLX_3171	Triple Lynx
including	643.2	643.6	0.4	18.8
OSK-W-21-2394-W6	674.6	676.7	2.1	10.7		TLX_3171	Triple Lynx
including	675.1	676.0	0.9	21.7
	694.0	696.0	2.0	4.57		TLX_3184	Triple Lynx
OSK-W-21-2436-W3	805.0	807.0	2.0	21.4	20.4	LX4_3437	Lynx 4
including	806.6	807.0	0.4	105	100
OSK-W-21-2445-W3	601.6	605.1	3.5	3.68		TLX_3171	Triple Lynx
OSK-W-21-2470	976.0	978.0	2.0	4.62		TLX_3163	Triple Lynx
OSK-W-21-2478	887.0	889.2	2.2	8.94		TLX_3184	Triple Lynx
including	887.8	888.2	0.4	44.7
OSK-W-21-2492	775.0	777.5	2.5	17.2		LX4_3414	Lynx 4
including	776.9	777.5	0.6	42.9
	783.9	786.2	2.3	22.4	20.9	LX4_3414	Lynx 4
including	784.8	785.2	0.4	109	100
OSK-W-21-2495	659.0	661.0	2.0	3.65		LXM_3304	Lynx
including	659.4	659.7	0.3	20.9
WST-21-0652	336.0	338.1	2.1	41.9	22.1	LXSW_3556	Lynx
including	337.7	338.1	0.4	204	100
WST-21-0658	185.0	187.1	2.1	15.7		TLX_3161	Triple Lynx
including	185.0	185.6	0.6	51.3
WST-21-0671A	171.0	173.0	2.0	25.0		LXM_3304	Lynx
including	171.0	172.0	1.0	43.6
WST-21-0675	159.2	161.4	2.2	14.2		LXM_3304	Lynx
including	159.2	159.9	0.7	39.4
WST-21-0676	152.7	155.1	2.4	3.93		LXM_3304	Lynx
including	152.7	153.3	0.6	10.4
WST-21-0677	399.0	401.0	2.0	8.52		TLX_3165	Triple Lynx
	409.5	411.5	2.0	11.4		TLX_3165	Triple Lynx
including	410.5	411.0	0.5	28.8
WST-21-0692	334.2	336.4	2.2	5.34		TLX_3131	Triple Lynx
WST-21-0698	138.3	140.3	2.0	10.3		LXM_3334	Lynx
WST-21-0703	252.0	256.2	4.2	11.6		LXSW_3506	Lynx
including	255.1	255.5	0.4	66.5
	463.7	465.9	2.2	39.3	28.1	LXSW_3502	Lynx
including	464.7	465.3	0.6	141	100
WST-21-0729	304.9	307.6	2.7	124	23.5	TLX_3166	Triple Lynx
including	305.9	306.3	0.4	780	100
WST-21-0739	128.2	130.2	2.0	23.5		LXM_3304	Lynx
including	129.0	129.7	0.7	63.8
WST-21-0749	144.9	146.9	2.0	37.1		LXM_3304	Lynx

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 No.	From (m)	To (m)	Interval (m)	Au (g/t) uncut	Au (g/t)         cut to 100 g/t	Zone	Corridor
OSK-W-21-2394-W6	914.0	916.0	2.0	5.70		TLX_3195	Triple Lynx
including	914.8	915.2	0.4	27.2
OSK-W-21-2436-W2	614.2	617.0	2.8	7.16		Lynx 4	Lynx
OSK-W-21-2445-W1	878.0	880.0	2.0	4.68		Triple Lynx	Triple Lynx
OSK-W-21-2445-W2	618.2	620.6	2.4	4.22		Triple Lynx	Triple Lynx
OSK-W-21-2445-W4	918.5	920.5	2.0	16.9		Triple Lynx	Triple Lynx
including	918.5	919.5	1.0	32.0
OSK-W-21-2465	919.0	921.0	2.0	8.88		Lynx 4	Lynx
	951.4	955.0	3.6	34.6		Lynx 4	Lynx
including	952.0	954.0	2.0	54.3
OSK-W-21-2465	962.5	964.6	2.1	12.4		Lynx 4	Lynx
OSK-W-21-2470	1020.9	1023.0	2.1	6.37		Triple Lynx	Triple Lynx
including	1021.8	1022.1	0.3	39.1
	1178.0	1180.1	2.1	5.63		Triple Lynx	Triple Lynx
including	1179.2	1180.1	0.9	12.9
OSK-W-21-2470-W1	963.0	968.0	5.0	10.8		Triple Lynx	Triple Lynx
including	963.0	964.0	1.0	41.4
	987.0	989.0	2.0	27.7	27.6	Triple Lynx	Triple Lynx
including	987.3	987.7	0.4	101	100
OSK-W-21-2472	731.8	734.2	2.4	31.5		LX4_3437	Lynx 4
including	733.4	734.2	0.8	78.3
	781.1	783.9	2.8	11.2		Lynx 4	Lynx
including	783.1	783.9	0.8	31.8
OSK-W-21-2473	625.6	630.0	4.4	10.0		Lynx	Lynx
including	625.6	626.2	0.6	49.1
OSK-W-21-2478	1117.0	1119.0	2.0	7.22		Triple Lynx	Triple Lynx
OSK-W-21-2482	782.0	784.0	2.0	11.7		Triple Lynx	Triple Lynx
including	782.0	782.9	0.9	26.0
OSK-W-21-2489	1005.0	1007.0	2.0	8.26		Triple Lynx	Triple Lynx
WST-21-0652	216.0	218.0	2.0	4.15		Lynx SW	Lynx SW
	448.0	450.0	2.0	4.35		Lynx SW	Lynx SW
including	448.7	449.2	0.5	15.6
WST-21-0657	442.3	444.3	2.0	4.26		Triple Lynx	Triple Lynx
WST-21-0696	370.7	373.6	2.9	41.6	36.7	Triple Lynx	Triple Lynx
including	371.8	372.7	0.9	116	100
	464.0	466.0	2.0	5.62		Lynx 4	Lynx
WST-21-0703	43.2	45.2	2.0	78.7	37.1	Lynx SW	Lynx SW
including	43.5	44.2	0.7	219	100
WST-21-0706	314.5	316.9	2.4	14.1		Lynx SW	Lynx SW
including	315.3	315.9	0.6	54.1
WST-21-0729	174.3	177.6	3.3	8.95		Lynx	Lynx

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See “Quality Control and Reporting Protocols” below. TLX = Triple Lynx, LX4 = Lynx 4, and SW = Southwest.

 

 

 

 

Drill hole location

Hole Number	Azimuth (°)	Dip (°)	Length (m)	UTM E	UTM N	Elevation	Section
OSK-W-20-2252-W11	129	-54	1191	453241	5435694	415	3750
OSK-W-20-2283-W2	135	-50	1011	452997	5435607	425	3500
OSK-W-21-2394-W4	138	-52	920	452923	5435467	414	3375
OSK-W-21-2394-W6	138	-52	978	452923	5435467	414	3375
OSK-W-21-2436-W2	130	-57	789	453709	5435618	400	4125
OSK-W-21-2436-W3	130	-57	879	453709	5435618	400	4125
OSK-W-21-2445-W1	141	-50	909	452906	5435433	415	3325
OSK-W-21-2445-W2	141	-50	822	452906	5435433	415	3325
OSK-W-21-2445-W3	141	-50	753	452906	5435433	415	3325
OSK-W-21-2445-W4	141	-50	944	452906	5435433	415	3325
OSK-W-21-2465	123	-61	1253	453397	5435557	413	3825
OSK-W-21-2470	132	-59	1230	453304	5435639	415	3775
OSK-W-21-2470-W1	132	-59	1227	453304	5435639	415	3775
OSK-W-21-2472	12	-72	900	454135	5435058	397	4225
OSK-W-21-2473	123	-56	1272	453420	5435610	413	3875
OSK-W-21-2478	128	-54	1257	452997	5435607	425	3500
OSK-W-21-2482	131	-57	939	453009	5435387	413	3400
OSK-W-21-2489	133	-54	1140	453121	5435509	419	3550
OSK-W-21-2492	122	-53	870	453687	5435676	401	4125
OSK-W-21-2495	123	-54	1257	453426	5435565	410	3850
WST-21-0652	128	-60	481	452955	5435003	253	3175
WST-21-0657	141	-56	448	453357	5435272	16	3650
WST-21-0658	137	-49	255	453357	5435272	16	3650
WST-21-0671A	142	-51	372	453507	5435327	-7	3800
WST-21-0675	133	-40	336	453508	5435327	-7	3800
WST-21-0676	129	-32	318	453508	5435327	-7	3800
WST-21-0677	144	-42	652	453257	5435209	96	3525
WST-21-0692	157	-54	541	453356	5435272	16	3650
WST-21-0696	137	-49	492	453229	5435127	134	3475
WST-21-0698	167	-40	160	453356	5435272	16	3650
WST-21-0703	146	-60	489	453104	5435065	231	3325
WST-21-0706	165	-54	417	453104	5435065	231	3325
WST-21-0729	132	-49	510	453229	5435127	135	3475
WST-21-0739	164	-37	195	453507	5435326	-7	3800
WST-21-0749	136	-30	196	453357	5435272	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 defined by Osisko, as disclosed in the news release dated February 17, 2021 and supported by the technical report entitled “Mineral Resource Estimate Update for the Windfall Project, Eeyou Istchee James Bay, Québec, Canada” dated March 8, 2021 (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