On the west flank of the Bayonne batholith, west of Kootenay Lake, a band of quartz-muscovite-kyanite schist forms the youngest unit of the Helikian Dutch Creek Formation belonging to the Purcell Supergroup of Middle Proterozoic age (Leclair, 1983). Kyanite porphyroblasts, up to 5 centimetres long, are common in this area (Leclair, 1982). In the various pelitic units, flanking the Bayonne batholith of post-metamorphic middle Cretaceous age, garnets up to 2 centimetres in diameter are also common (Leclair, 1982). The area is also shown as lying in kyanite amphibolite grade by Geological Survey of Canada Map 1714A.