O3 Mining Reports New Results from Its 2021 Infill Drilling Program at its Marban Project

Drilling Highlights:

Marban

• 35.8 g/t Au over 8.9 metres, including 440.0 g/t Au over 0.7 metres in hole O3MA-21-187 located in the proposed Preliminary Economic Assessment ("PEA") pit. Subsidiary zones were also intersected along the same drill hole yielding 1.0 g/t Au over 37.0 metres, 3.3 g/t Au over 3.2 metres, and 1.3 g/t Au over 31.4 metres;
• 11.1 g/t Au over 5.0 metres and 5.3 g/t Au over 7.2 metres in hole O3MA-21-232 located in the proposed PEA pit;

Norlartic

• 44.1 g/t Au over 2.3 metres including 192.0 g/t Au over 0.5 metre in hole O3MA-21-203 located in the proposed PEA pit. This intercept is bordered by two historical openings and the gold endowment goes beyond those openings, 1.1 g/t Au over 6.4 metres and 2.1 g/t Au over 1.6 metres were also intercepted immediately before and after;
• 2.1 g/t Au over 17.4 metres and 3.0 g/t Au over 9.8 metres in hole O3MA-21-211 located in the proposed PEA pit. The hole also intercepted 1.5 g/t Au over 7.9 metres and 3.2 g/t Au over 2.3 metres surrounding a historical opening;
• 2.1 g/t Au over 13.7 metres and 1.8 g/t Au over 25.2 metres on each side of a historical opening in hole O3MA-21-143 located in the proposed PEA pit.

O3 Mining's President and Chief Executive Officer, Mr. Jose Vizquerra, commented, "We are very pleased to begin the year with these latest results from our successfully completed infill drilling program at the Marban Project. Not only do the results offer us the potential to expand the overall scope of the project, but we are also seeing higher grades than the average resource grade, which we are confident will be reflected in our updated mineral resource in early 2022 and will be an important component in the completion of Marban's Pre-Feasibility Study."

Table 1: Drill Hole Intercepts (only intercepts above 20.0 g/t Au * m are reported, cut-off 0.3 g/t Au and above 200 vertical metres or within the PEA proposed pits)

The Marban zone drilling highlights consist of an array of veins and veinlets composed of quartz, calcite, and chlorite within a folded basaltic unit. The Norlartic zone drilling highlights consist of a stockwork of quartz veinlets with disseminated pyrite within intermediate and mafic dykes as well as a basaltic unit within the hanging wall of the Norbenite Shear. This geology is consistent with the description of the mineralized zones of the historical mines in and around the Marban project. Many drill holes published today have crossed historical mining stopes and confirmed the presence of high-grade material within the mining walls and wide envelopes on both sides of those mining openings.

A portion of the 2021 drilling program was designed to convert a significant proportion of the in-pit Marban resources of the inferred category into the indicated category. There are 1,662 assays pending in 32 infill drill holes which O3 Mining expects to release as they become available in the coming weeks. All intercepts listed in today's news release are part of this program and will be included in an updated resource for Marban, which is expected to be released during the first quarter of 2022.

Figure 1: Marban Project Drilling Map

Figure 2: Kierens -Norlartic Longitudinal Section

Drilling Update

O3 Mining continues to execute its large-scale drilling program in the coming months with additional health and safety procedures to keep its employees safe and mitigate COVID-19 transmission. As part of this program, the winter drilling season at Marban will focus on the Camflo deposit extension at depth. At Alpha, the focus will be put on the expansion of the Kappa and Bulldog deposits and exploration in the Omega sector.

The Corporation has drilled 118,951 metres in 2021 on its Val-d'Or properties testing for Potential Economic Material ("PEM") with 100-metre step-outs aiming to expand current resources of 2.4 million ounces measured and indicated (62.0 Mt @ 1.22 g/t Au)¹ and 1.3 million ounces inferred (19 Mt @ 2.13 g/t Au)¹ and make new discoveries.

Figure 3: Marban and Alpha Properties Overview

Marban - Project Development

The Marban project is in the heart of the Malartic gold mining camp. It covers 7,525 hectares and is located 12 kilometres from the Canadian Malartic Mine. The Marban PEA outlined production of an average 115,000 ounces of gold per year over the 15.2 year mine life.

Drilling at Marban has focused on expanding mineralization in and outside of the proposed PEA pit areas, as well as discovering new mineralization for an underground mining scenario. In 2021, 63,756 metres were drilled to achieve this goal with up to eight drill rigs testing for PEM, as well as aiming to convert resources from Inferred to Measured and Indicated, to ultimately become part of Marban's maiden mineral reserve.

A PEA was completed on the project in 2020, and a Pre-Feasibility Study ("PFS") is currently underway and due to be completed in 2022 as the next step to advance the project to production. O3 Mining aims to become a leading gold producer and put the Marban project into production by 2026.

Alpha - Advanced Exploration

The Alpha property is located eight kilometres east of Val-d'Or, Québec, and three kilometres south of the El Dorado Lamaque Mine. The property covers more than 7,754 hectares and includes 20 kilometres of the prolific Cadillac Break. O3 Mining has an option agreement that grants the right to acquire 100 percent interest in the Aurbel Mill located only 10 kilometres from the Alpha property for C$5.0M within the next five years.

Drilling at Alpha is at an earlier stage than at Marban and has focused on grassroots exploration, deposit delineation, and resource expansion. A 54,121 metres program was executed in 2021. In 2022, O3 Mining will have up to three drill rigs testing for new discoveries using its PEM drilling strategy as well as focusing on deposit delineation and expansion of the current resource.

1/ Mineral Inventory: i) Marban Technical Report 2020 Prepared by Ausenco Engineering Canada, Moose Mountain Technical Services and WSP Canada, ii) Orenada Technical Report 2018 Prepared by InnovExplo Inc., iii) Akasaba Technical Report 2014 Prepared by Geologica Inc. and Geopointcom Inc., iv) Simkar Gold Technical Report 2015 Prepared by MRB & Associates, v) East Cadillac Technical Report 2017 Prepared by MRB & Associates vi) Sleepy Technical Report 2014 Prepared by Geologica Group-Counseil Inc. and GeoPointCom Inc.

Qualified Person

The scientific and technical content of this news release has been reviewed, prepared, and approved by Mr. Sébastien Vigneau. (OIQ #993), Principal Geologist, 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 currently unknown but is estimated at 65-80% of the reported core length interval for the zones. Assays are uncut except where indicated. Intercepts occur within geological confines of major zones but have not been correlated to individual vein domains at this time. Half-core samples are shipped to Agat laboratory in Val-d'Or, Québec, and Mississauga, Ontario for assaying. The core is crushed to 75% passing -2 mm (10 mesh), a 250 g split of this material is pulverized to 85% passing 75 microns (200 mesh) and 50 g is analyzed by Fire Assay (FA) with an Atomic Absorption Spectrometry (AAS) finish. Samples assaying >10.0 g/t Au are re-analyzed with a gravimetric finish using a 50 g charge. Commercial certified standard material and blanks are systematically inserted by O3 Mining's geologists into the sample chain after every 18 core samples as part of the QA/QC program. Third-party assays are submitted to other designated laboratories for 5% of all samples. Drill program design, Quality Assurance/Quality Control ("QA/QC"), and interpretation of results are performed by qualified persons employing a QA/QC program consistent with NI 43-101 and industry best practices.

About O3 Mining Inc.

O3 Mining Inc., an Osisko Group company, is a gold explorer and mine developer on the road to produce from its highly prospective gold camps in Québec, Canada. O3 Mining benefits from the support, previous mine-building success, and expertise of the Osisko team as it grows towards being a gold producer with several multi-million ounce deposits in Québec.

O3 Mining is well-capitalized and owns a 100% interest in all its properties (137,000 hectares) in Québec. O3 Mining trades on the TSX Venture Exchange (TSX.V: OIII) and OTC Markets (OTCQX: OIIIF). The Corporation is focused on delivering superior returns to its shareholders and long-term benefits to its stakeholders. Further information can be found on our website at https://o3mining.com

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. The information in this news release about the transaction; and any other information herein that is not a historical fact may be "forward-looking information". Any statement that involves discussions with respect to 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", "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 forward-looking information is based on reasonable assumptions and estimates of management of the Corporation, at the time it was made, involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements of the companies to be materially different from any future results, performance or achievements expressed or implied by such forward-looking information. Such factors include, among others, risks relating to the restart of operations; further steps that might be taken to mitigate the spread of COVID-19; the impact of COVID-19 related disruptions in relation to the Corporation's business operations including upon its employees, suppliers, facilities and other stakeholders; uncertainties and risk that have arisen and may arise in relation to travel, and other financial market and social impacts from COVID-19 and responses to COVID 19. 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, the parties cannot assure shareholders and prospective purchasers of securities 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 the Corporation nor any other person assumes responsibility for the accuracy and completeness of any such forward-looking information. The Corporation 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.

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SOURCE O3 Mining Inc.



Contact
José Vizquerra Benavides, President, CEO and Director, Toll-Free: +1 (833) 979-3516, Telephone: +1 (873) 381-2014