The area is underlain by the calcareous siltstone and limestone of the Espanola Formation and a Nipissing-type gabbro body (Card 1984). The Brazil Lake mineralised occurrence, which consists of cobaltite, pyrrhotite and chalcopyrite is hosted in a quartz-carbonate vein located at the contact between the hornfels calcareous unit and the intruded metamorphosed gabbro. The vein is 12 m wide and can be followed over several hundreds of meters. Pyrrhotite and chalcopyrite are mostly found within the vein, whereas cobaltite is found along the walls of the vein, in association with actinolite an amphibolite mineral.
At the site of the vein, an adit of about 28 m long has been driven into a hill and a large rock dump exists at the mouth of the adit. Above the adit, the quartz vein cutting gabbroic rock and containing massive blocks of sulphides (pyrrhotine, chalcopyrite and pyrite) is exposed in an historic trench. Please visit the website for further information on Brazil Lake.