The Clayoquot Sound East deposit consists of a band of Pennsylvanian to Permian limestone of the Buttle Lake Group. The band correlates with the Azure Lake Formation of the Buttle Lake uplift and the Mount Mark Formation of the Cowichan Uplift, both units of the new Buttle Lake Group. See Cream 1,3 (092F 220) for a description of the revised stratigraphy nomenclature.

The band is up to 500 metres wide and extends for 2 kilometres along the east shore of Clayoquot Arm, 55 kilometres west-southwest of Port Alberni. The limestone is underlain by volcanic breccia, tuff and argillite and overlain by basalts of the Upper Triassic Vancouver Group, Karmutsen Formation to the east. The entire sequence strikes north and dips 30 to 45 degrees east.