The stratigraphic nomenclature for the Devonian differs both between this surface and subsurface and platform and basin. Outcrop platform units include The Flume, Cairn, and Southesk Formations. The Southesk is subidivided into the Peechee, Arcs, and Ronde/Simla members. Basinal facies include the Maligne, Perdrix, Mount Hawk, and Sassenach formations. The Flume Formation unconformably overlies Cambrian rocks that were transgressed during the late Givetian.