The Liza Lake C magnesite showing on the northwest side of the Liza Creek valley is within carbonate and silica-rich altered ultra- mafic rocks (or listwanite) of the Permian and older Shulaps Ultramafic Complex. Most ultramafic rocks comprise a slice adjacent to Upper Triassic Pioneer Formation (Cadwallader Group) greenstones and Upper Triassic Hurley Formation (Cadwallader Group) clastic sedimentary rocks. The ultramafic rocks are tectonic slices intercalated with Cadwallader Group rocks and parallels the regional northwest trend in the area.

The magnesite concentration is irregularly shaped, approximately 25 by 15 metres on surface. The magnesite is hard, compact to crystalline and generally very fine-grained, with chalcedonic quartz veins throughout; the chalcedony is more resistant to weathering and stands out as ribs. The rocks are limonite-stained on surface. Adjacent listwanite is mostly a mixture of serpentinite with calcite, talc, and mariposite with minor disseminated opaque minerals (probably magnetite plus or minus chromite?).