Where we Operate

O3 Mining has a portfolio of assets in Val-d’Or, Quebec, spanning more than 65,000 hectares. Our projects host 2.86 million gold ounces of M&I resources at 1.18 g/t Au, and 0.77 million gold ounces of inferred resources at 3.04 g/t Au.





Cadillac Break Properties

Property Summary

The Cadillac Break Properties are located in the southeastern Abitibi Greenstone Belt of the Archean Superior Province in the Canadian Shield. The properties are located in the Val-d’Or municipality of the Abitibi-Temiscamingue administrative region in the Province of Quebec. They are easily accessed via all-season public paved roads, public gravel roads, all-terrain vehicle trails, and bush roads. The Cadillac Break Properties are located at the boundary between the Abitibi Subprovince and the Pontiac Subprovince, which is marked by the Cadillac-Larder Lake Fault zone (CLLFZ) and stretch for over 35 km along the break. The CLLFZ is a regional-scale strike fault and/or shear zone and is one of the most important structural controls on the gold mineralization in the Abitibi Greenstone Belt, which has produced 100 million ounces of gold since the early 1900’s. Discoveries in the region (Lapa and Goldex), at depths between 500 and 1,500 meters, show that the Cadillac Break Group of properties is highly under-explored, as most recent drilling has been in the upper 150 meters over the whole package, only locally testing down to 300 meters depth.


Marban Property

Property Summary

The Malartic property is located in the western portion of the province of Quebec, Canada, about midway between the towns of Val-d’or and Malartic and is comprised of 171 mining claims and 3 mining concessions. The property lies at the junction of Dubuisson, Fournière, Malartic, and Vassan townships.

Project Description

Marban Engineering

Focused on the completion of the Marban Feasibility Study by Q4 2023

  • Hosts 2.6 Moz Au1
  • Marban PFS completed on September 2022 post-tax net present value (NPV5%) of C$423M &unlevered IRR 23.2% with 161Koz gold average annual production LOM
  • 54,000 metres Brownfield exploration program
  • Key infrastructure: railway, hydropower, experienced local labour force and technical services

New mineral resource table from the March 2022 resource estimate:

Marban Regional: Greenfield Exploration ProgramThe minimally drilled area is three times larger than the Marban Engineering area and hosts numerous historical gold showings.

(M oz)
Au Grade
Measured & Indicated67.72.41.09
Total Resources170.82.61.14


The Malartic property hosts the Marban project, which lies within the Archean Abitibi greenstone belt of the Superior Province, Quebec, which consists of alternating east-trending metavolcanic-plutonic and sedimentary belts that are bounded by crustal-scale faults. The metavolcanic rocks within the Malartic mining district are composed of allochthonous komatiitic to tholeiitic volcanic suites that are interpreted to have been derived from volcanic plateaus and volcanic islands juxtaposed during the late Archean.

The metavolcanic rocks within the Malartic property are cut by three major northwest to westnorthwest striking shear zones of regional extent – the North, Norbenite, and Marbanite shears. The Marbanite shear hosts the Marban resource, while the Norbenite shear hosts both the Kierens and Norlartic gold resources. The historic Kierens, Norlartic, and Marban gold mines all exploited zones lying within the basalts and ultramafic rocks of the Jacola Formation, which have been intruded by numerous diorites and felsic porphyry dikes and sills.

Gold Mineralization

Gold mineralization at the Malartic property occurs primarily as mesothermal deposits that lie within the north-dipping shear zones and associated felsic to intermediate sills and dikes. In addition to the resource areas, previous operators have been actively exploring sub-parallel gold-mineralized horizons within the Malartic property at the North-North, North, and Gold Hawk zones. The most significant gold
mineralization defined to date is currently known in 3 main zones: Marban, Kierens and Norlartic.

The Marban resource is located on the northern flank of a west-northwest-trending syncline. From north to south, the units include:

  • An alternating sequence of sheared ultramafic volcanic rocks and granodiorite dikes;
  • The “Mine Sequence” of pillowed, sheared, aphanitic and fine-grained basalts; and
  • Sheared and massive or pillowed ultramafic volcanic rocks.

These units dip 45 to 70° to the north. The mineralized zones occur almost exclusively within the Mine Sequence basalts, which frequently have been converted to chloritic schists within the Marbanite shear. Gold is associated with quartz-carbonate veinlets, pyrite, and pyrrhotite. There is also disseminated replacement-type gold mineralization in tholeiitic-komatiitic volcanic rocks of the Jacola Formation, and locally there is gold in granodioritic dikes.

The Kierens and Norlartic resources are localized in the Norbenite shear, an important northwest-trending deformation zone that dips moderately to steeply northeast. Mafic volcanic rocks, talc-chlorite schists, and felsic dikes are included within the shear zone. The gold mineralization is closely associated with altered and pyritized intermediate intrusions that cut sheared mafic and ultramafic volcanic rocks.

Harricana Property

Property Summary

The Harricana property is located 9 km northeast of the town of Val-d’Or, on the eastern shore of Blouin Lake, and hosts the Aurbel deposit. The property is accessible by Highway 397 from the town of Val-d’Or.

Geologically, the property is underlain by two distinct units; the Dubuisson Formation, consisting of massive mafic flows, porphyritic flows and breccia flows, and the Bourlamaque Batholith (granodiorite and quartz diorite). The contact between these two units is a major shear zone, which hosts the main mineralization.

Gold mineralization occurs in quartz veins associated with various shear zones. The Aurbel deposit mineralization occurs in two sets of quartz veins within the main shear zone. In the volcanic units, mineralization is hosted in smoky quartz, with minor tourmaline stringers and local concentrations of ankerite. Sulphides occur as finely disseminated pyrite and local chalcopyrite and pyrrhotite. Quartz veins in the main and minor shear zones within the Bourlamaque Batholith are composed of white quartz, tourmaline and chlorite patches, with coarse-grained pyrite often associated with higher gold grades.

Alpha Property

Property Summary

The Alpha Property has been explored by various operators since the early 1930’s, with more than 2,400 drill holes completed since that time. Other work includes multi-property geophysical and geochemical programs, and trenching and mapping, all of which are being compiled into a single database. Discoveries in the region (Lapa and Goldex), at depths between 500m and 1,500m, show that the Cadillac Break Group of properties are highly under-explored, as most recent drilling has been in the upper 150m over the whole package, only locally testing down to 300m depth.

Project Description


Geologically, the dominant feature underlying the properties is the Cadillac Break; a regional fault zone that separates metasedimentary rocks of the Pontiac Group on the south side from predominantly volcanic rocks and associated intrusive rocks on the north. However, this large property package hosts a variety of geological environments favourable for gold mineralization, including those, which are known elsewhere to host large gold deposits, including:

  • Shear- Zone

  • Gold-rich massive sulphide

  • Porphyry gold-copper and skarn

  • Disseminated gold

  • Gold Mineralization

The most significant gold mineralization defined to date is currently known on the Alpha property. Gold mineralization in Orenada Zones 2 and 4, within the Alpha property group of claims, share many geological attributes with other vein-type gold deposits of the Val-d’Or district in terms of host rock composition, mineralogy and hydrothermal alteration, also known as orogenic gold deposits. The gold mineralized “corridors” at Alpha have been interpreted based on drilling, historic showings and the style of mineralization identified in drill core and field observations (see Alpha Map). The main targets on the Alpha property include Bulldog, Epsilon, Pontiac East/West, Mid-Canada, and Akasaba.


Gwillim Property

Property Summary

The Gwillim property is located in the Barlow township, close to Chibougamau, consisting of 38 mining claims, covering 1715 Ha.

Project Description


The Gwillim property is underlain by massive and pillowed mafic to intermediate volcanics of the upper Gilman Formation. Andesite predominates in the north, whereas basalt is dominant in the southern half of the property. Pillows indicate tops to the south. The volcanics are locally intercalated with volcanoclastic sediments, which occur on the north flank of the east trending Chibougamau syncline. The Blondeau Formation, a series of felsic volcanic and volcaniclastic rocks and graphitic shales, underlies the southwest part of the property.  Dioritic and gabbroic sills, up to 250m wide, intrude the volcanic units parallel to the lake. These are considered co-magmatic with the host volcanic rocks. The volcanics and intrusives rocks host disseminated and fracture filling pyrite and occasionally pyrrhotite and chalcopyrite. The sills are magnetic with disseminated magnetite and in the diorite the magnetite is not evenly distributed. All of the volcanic units are carbonatized with calcite forming along foliation planes and microfractures, and pervasive chlorite alteration.

Gold Mineralization

Gold mineralization on the Gwillim property appears to be related to an early episode of east-west shearing, in turn possibly related to the Gwillim Lake. The Cadillac vein, as an example of this, consists of milky to smoky quartz with ankerite, chlorite, sericite, tourmaline and varying amounts of pyrite and traces of chalcopyrite.  Gold mineralization is erratic and discontinuous with local very high grades.


Other Properties

Wydee Gold Property

Property Summary

The Wydee Project is located approximately 6 kilometres west-northwest of the town of Matachewan, Ontario, 60 kilometres west of Kirkland Lake and 50 Kilometres south-southeast of Timmins, Ontario. The eastern boundary of the Wydee project is located 6 kilometres northwest of Alamos Gold’s Young Davidson Mine. The Young Davidson Mine complex also includes a fully operational 10,000 tons per day mill.

Geologically, the property is located in the Archean Abitibi Greenstone Belt and is mainly underlain by steeply dipping mafic to intermediate volcanic rocks, that are intruded by ultramafic to felsic intrusions of various sizes. The eastern part of the property covers an 8 kilometres E-W strike along the Galer Branch Deformation Zone, a splay of the Larder Lake Cadillac Deformation Zone.

The property hosts numerous gold occurrences that remain largely underexplored. Mineralization mostly consists of visible gold in narrow quartz veins, as well as associated with disseminated pyrite within or at contacts to altered syenitic intrusions.

Matachewan Property

Property Summary

The Matachewan property is located in the southwest portion of Cairo Township in the Mining District of Timiskaming, Ontario. The property is located 1.5 km East of the town of Matachewan, Ontario. The property consists of 35 mining titles. All claims are in good standing and verified on the website of the Ministry of Northern Development and Mines. The infrastructure and accessibility are excellent as it is located on the east side of Matachewan, a community with a long mining tradition, and is bisected by Highway 66.

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