Langis-Hudson Bay Silver-Cobalt Project Summary
The Langis Mine (past producer of high-grade silver) Project is located near Cobalt in eastern Ontario, 15 km north of Temiskaming Shores and 500 km north of Toronto. Highway 65 runs through the property and many established secondary roads provide year-round access. Power, railways, mills, a permitted refinery, and assay lab are located at or near the site.
The Langis Project represents a unique opportunity in a silver district that is underexplored using modern techniques. New discovery potential is high, and a strong possibility exists to generate mineral resources from extensions to historical workings and new exploration. 2018 drilling hit new high grade silver-cobalt: 6m of 4719 g/t silver and 3m of 1.23% Cobalt
Historically, the Langis Mine produced over 10.4 Moz Ag with a recovered grade of approximately 25 oz/t from shallow depths, and 358,340 lbs of cobalt. (see production history)
Historically, the Hudson Bay Mine produced 6.4 Moz Ag at 123 oz/t, and 185,570 lbs of cobalt from 58,000 tons.
The Langis and the Hudson Bay Projects do not currently contain any mineral resources or mineral reserves.
Native silver from Langis Mine
Brixton Metals holds 2,516 Ha of mineral title lands in the Cobalt Camp. High-grade silver mineralization occurs as steeply-dipping veins within any of the three main rock types: Archean Keewatin volcanics, Coleman Member sediments and Nipissing diabase.
Archean Keewatin volcanics: These rocks comprise both metavolcanics and metasediments. The volcanics are most commonly intermediate to mafic pillowed basalt and massive flows. Between flows, deep-water cherty sediments and pyroclastic rocks were deposited. These interflow sediments are commonly rich in pyrite, pyrrhotite, chalcopyrite, galena, and sphalerite. Throughout the area, the volcanics are intruded by various mafic and ultra-mafic dykes.
Algoman intrusive: A large hornblende syenite pluton intruding the mine property has potential for gold mineralization but is underexplored to date.
Proterozoic Huronian Supergroup: Huronian rocks comprise the majority of exposed outcrop on the Langis property and consist of gently-dipping, unaltered clastic, glacially-derived sediments unconformably overlying the older Keewatin volcanic and intrusive rocks (Lowes, 1963). These sediments form the Coleman Member of the Gowganda Formation and consist of para- and ortho-conglomerates, pebbly sandstone and greywacke, and thinly-bedded argillites.
Early Proterozoic (Keewenawan): Rocks of this age are represented by the Nipissing diabase sill, a prominent and important rock type in the Cobalt Basin. The diabase intrudes in the form of extensive sheets as well as less prominent dykes and plugs.
The earliest known structural event resulted in isoclinal folding of Keewatin volcanics and interflow sediments during the Kenoran Orogeny 2.5 billion years ago (Jambor, 1971). Precambrian age faults, fractures, and joints observed within the mine area exhibit variable dips.
Regional faults occur as prominent north to northwest structures which extend for hundreds of kilometres and weak northeast-trending sets (Andrews et al., 1986). Many smaller faults are present locally and are likely related to these large-scale fault systems. The major faults are believed to have been active in the late Archean; before, during, and after Huronian sedimentation; and during and after intrusion of the Nipissing diabase emplacement (Andrews et al., 1986). Post-diabase tectonic activity is considered a possible mechanism for creation of the structures hosting the silver-cobalt vein systems in the Cobalt Camp (Andrews et al., 1986).
Carbonate species are the most common gangue minerals: calcite, dolomite, as well as quartz are associated with mineralized veins. Generally, distribution of this alteration assemblage is within approximately 100 m of the Nipissing diabase contact where there is mineralization (Jambor, 1971).
Owsiacki (1988) indicates “significant high‐grade silver intersections have been recovered from within all three rock types being Nipissing Diabase, Coleman sediments, and, Archean volcanics at the western margin of this trough. One of the best assays to date is 50 ounces over 9.45 m, intersected in the volcanic rocks.”
The most important ore mineral is native silver and secondary metals are cobalt, nickel and copper. All silver-bearing veins in the Langis Mine area are steeply dipping and are categorized as either single-vein or multiple-vein type structures (Jerome, 1969).
Silver-Cobalt Project – Structural Targets Map:
Silver Camp History
The camp has historically produced over 420 Moz of silver. One reported mine workings from the Cobalt Camp reached 255,146 g/t Ag (or 9,000 oz/t Ag) over 0.36 metres. This single stope at the 30 m level on this vein produced 4.5 Moz Ag.
The “Camp History” photo shows some headframes established within the Cobalt mining camp (photo source: Cobalt Mining Museum). While today most of the mine sites have been reclaimed or are under ongoing reclamation.
Silver was discovered at Cobalt in 1903 during the construction of the Timiskaming and Northern Ontario Railway from North Bay to develop the agricultural land in the New Liskeard area. Fred LaRose, a blacksmith employed in the construction of the railway, is credited with the first discovery, but the first application for claims, filed on August 13, 1903, was made by J.H. McKinley and E.F. Darragh, subcontractors who supplied ties for the railroad. They found silver-bearing float at the south end of Cobalt Lake. The first assay results showed bismuth but no silver. McKinley subsequently sent the ore for assay to McGill University, and was informed by Dr. Milton Hersey of Montreal that the ore contained 4,000 ounces of silver per ton. Dr. Willet G. Miller, Ontario’s first provincial geologist, visited the area in November 1903 and found that four veins had been located, three very rich in silver. In addition, Tom Hebert had staked the property that later became the Nipissing Mine. Dr. Miller reported the news through an article in the Mining Journal of New York and through an Ontario Bureau of Mines publication. The final discovery in 1903 was made by Neil King who staked the property on which the O’Brien mine was to rise in 1906 and to continue production without a break until 1966 (Zoldy, 2006).
Photo of Camp History
Native silver from Langis Mine:
Information Sources: Cobalt Museum Thompson 2015; Technical Report on the Langis Project by Dale R. Alexander, P.Geo, May 17, 2013; Approved Filing Statement for Everfront Ventures Corp July 31, 2013; Annual Report, Agnico Eagle Mines 1987; Interim Report, Agnico Eagle Mines Q2-1986; Agnico Eagle Mines, Langis Mine-New Mine Site, Plan & Section 1987;