The Liza Lake A magnesite showing is located 1.2 kilometres northeast of the southern end of Liza Lake. The prospect is within a sliver of serpentinized peridotite that is partly carbonate and silica altered to listwanite. These rocks are assigned to the Permian and older Shulaps Ultramafic Complex. Chert and greenstone of the Mississippian to Jurassic Bridge River Complex (Group) are in fault contact with the ultramafic rocks on either side.

The prospect consists of irregular bodies of massive and crystalline magnesite, cut by numerous veinlets of clear chalcedonic quartz. Locally, the crystalline magnesite is vuggy and filled with chalcedony. Minor mariposite and chromite are present as scattered grains and clusters. A sample analysed by the Geological Survey of Canada in 1915 (Summary Report 1915) indicated 43.42 per cent MgO, 0.46 per cent CaO, 0.56 per cent FeO, 0.25 per cent Fe2O3, 0.23 per cent Al2O3, 47.28 per cent CO2, 7.46 per cent SiO2 and 0.68 per cent H2O.