Osisko Mining Reports Windfall Drilling Intercepted Wide High-Grade In Lynx

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 27 intercepts in 8 drill holes (1 from surface, 8 from underground) and 8 wedges. Infill intercepts are located inside defined January 2022 mineral resource estimate (“MRE”) blocks (see Osisko news release dated January 10, 2022). Expansion intercepts are located outside the January 2022 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 infill program at Windfall continues to intercept high-grade mineralization. Today’s wide headline hole comes from Triple Lynx wireframe 3161 which has another wide zone of 41.4 g/t Au over 9.0 metres. Infill at Underdog is also returning intercepts of over one ounce per tonne over more than two meters.”

Selected high-grade intercepts include: 58.9 g/t Au over 14.7 metres in WST-21-0996A; 41.4 g/t Au over 9.0 metres in WST-21-0928; 88.0 g/t Au over 3.0 metres in WST-21-0997; 49.8 g/t Au over 3.9 metres in WST-21-0914; 81.5 g/t Au over 2.0 metres in WST-21-0936A; and 60.0 g/t Au over 2.4 metres in OSK-W-21-2463-W3. Maps showing hole locations and full analytical results are available at www.osiskomining.com. Maps: Long Section_In EN 20220329, PR_EN_20220329_Surface, PR_EN_20220329_UG.

Infill Drilling

Notes: True widths are estimated at 55 – 80% of the reported core length interval. See “Quality Control and Reporting Protocols” below. CA2= Caribou 2, LX4 = Lynx 4, LSW = Lynx Southwest, TLX = Triple Lynx and UDD=Underdog.

Expansion Drilling

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

Drill hole location

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.

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 in thickness. 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.

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.