Lower Cambrian Cranbrook Formation quartzites, dolomites and phyllitic argillites host medium to coarse-grained crystalline magnesite. The occurrence is at the western end of the rocky ridge north of Driftwood Creek. Beds of slatey phyllites, overlain by a fine-grained dark, cherty dolomite, form the footwall to a strike exposure of about 110 metres of magnesite beds. The stratigraphy trends 290 degrees northwest and dips 80 to 85 degrees southwest.
Southwest and overlying the dolomite is a 65 metre thick sequence of medium to coarse-grained magnesite containing cherty blebs and lenses. This section also hosts two continuous horizons of massive magnesite 4.5 and 2.2 metres thick. A metallurgical test sample was collected from the lower, 4.5 metre thick, magnesite body and ran 42.5 per cent MgO. The upper part of this unit is host to a horizon of white to yellow, fine-grained orthoquartzite similiar to that exposed below slatey phyllites.
The upper 45 metres of the section is a massive, medium to coarse-grained magnesite with no visible impurities and is exposed for several hundred metres along strike. A bulk sample from this section contained 40 per cent MgO.