O3 Mining Inc. (TSX-V: OIII) (OTCQX: OIIIF)  is pleased to announce that it has received the final results of its 1,806 metre drill program completed over the Upper Camflo area (North-West of the Kierens pit), within the Marban Alliance project, in Val-d’Or, Québec, Canada.

Highlights:

• O3 Mining drilled eight holes for a total of 1,806 metres over the Upper Camflo area along the up-dip extension of a gold-bearing structure identified during the compilation of historical exploration drilling completed by Barrick Gold on the former Camflo mine.
• The Upper Camflo drill program tested an area of 800 metres along strike for near surface gold mineralization near the border of the property.
• The program intersected 1.6 g/t Au over 1.5 metres in hole O3MA-23-503, associated with an andesite containing 5% quartz-calcite-pyrite veinlets

O3 Mining’s President and Chief Executive Officer, Mr. Jose Vizquerra commented: “We are encouraged by the work completed on the Camflo deposit to date and are excited to continue our drill program over our Marban Alliance property to potentially expand resources. The results are in addition to the many gold zones found near the surface in the area. We hope that with further drilling we can demonstrate that these areas form the potential footprint of a larger deposit..”

The Upper Camflo drill program tested an area of 800 metres along strike for near-surface gold mineralization from the border of the property. The drill program was initiated after compilation work of Barrick Gold’s historical drilling revealed parallel zones north of the former Camflo mine. One of the zones was intersected by a series of holes drilled horizontally by Barrick toward the north from the border of the property at the 2400 mining level (700 metres from surface). In particular, hole O3MA-23-503 intersected 1.6 g/t Au overs 1.5 metres near the surface and was associated with an andesite containing 5% quartz-calcite-pyrite veinlets. Drilling completed thus far constituted the first phase of drilling to be completed over the Upper Camflo area to explore the near-surface potential within the Camflo ore body footprint. More drilling is required to continue testing this target.

In 2021 and 2022, exploration efforts by O3 Mining aimed to test the depth extensions of the historic Camflo deposit, as well as to test for additional high-grade zones (See news release of O3 Mining dated June 30, 2022 and entitled “O3 Mining Expands Mineralization Corridor At Camflo Extension, Intersecting 94 Metres at 1.1 g/t Au”). Over the course of the 2021-2022 drill program, a total of 6,338 metres in 2 drill holes and 3 wedges were drilled on the Camflo Extension. The results of the 2022 drill program are summarized in Table 2 below.

Table 1: Significant Results from previous drilling and Upper Camflo campaign

Table 2: Drill Hole Results from June 30, 2022 at Camflo Extension. Only intercepts above 5 g/t Au * m are reported.

Table 3: Drill Hole Parameters from 2023 Program

About the Camflo Area

The Camflo deposit was first discovered in 1962 by Camflo Mines, and was in production for 30 years from 1962 to 1992. It produced a total of 1.89 million ounces of gold from 10.3 million tonnes of ore grading 5.7 g/t Au. From this amount, 0.24 million ounces of gold were extracted within the current Marban Alliance project claims (Source: QERPUB-M.E.R. Publication DV93-01 Rapports des Géologues Résidents sur l’Activité Minière Régionale, 1993). Historically, gold production was mainly restricted to the Camflo Plug, a cigar shaped quartz-monzonitic intrusion that plunges 60° towards the north-east. Although the Camflo plug at surface is outside O3 Mining’s property claims, the extension of the plug and the mine below 800 vertical metres is within the Marban Alliance project, as it plunges toward the north-east

Figure 1: Marban Alliance Project Map

Figure 2: Location of significant intercepts at Upper Camflo

Figure 3: Camflo Extension Cross Section

Qualified Persons

The scientific and technical content of this news release has been prepared, reviewed and approved by Mr. Sébastien Vigneau (OGQ #993), Principal Geologist of O3 Mining, who is a “qualified person” within the meaning of National Instrument 43-101 – Standards of Disclosure for Mineral Projects.

Quality Assurance/Quality Control

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 quality assurance and quality control program. Third-party assays are submitted to other designated laboratories for 5% of mineralized samples. Drill program design, 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. 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 and expertise of a team of industry leaders as it grows towards becoming 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 (62,000 hectares) in Québec. O3 Mining trades on the TSX Venture Exchange and OTC Markets. The Corporation is focused on delivering superior returns to its shareholders and long-term benefits to its stakeholders.