Ishbel Group
The Ishbel Group is a stratigraphic unit of Permian age in the Western Canadian Sedimentary Basin. It is present in the Canadian Rockies of Alberta and British Columbia. First defined by A. McGugan in 1963, it is named for Mount Ishbel of the Sawback Range in Banff National Park, and parts of the group were first described in the vicinity of the mountain at Ranger Canyon and Johnston Canyon.
Lithology
The Ishbel Group is composed of carbonate rocks and sandstone, with minor chert and siltstone.Depositional conditions were similar to those of the Phosphoria Formation to the south in United States.
Paleontology
Among the fossils that have been found in the Ishbel Group are corals, bryozoa, crinoids, and conodonts, as well as productid, chonetid and spiriferid brachiopods, omphalotrochid gastropods, and edestid elasmobranch fish.Distribution
The Ishbel Group reaches a maximum thickness of up to about 425 metres. It is present in the front ranges of the Canadian Rockies as far north as the Peace River.Subdivisions
| Sub-unit | Age | Lithology | Max. Thickness | Reference |
| Kindle Formation | Asselian to early Artinskian | siltstone, shale | ||
| Belloy Formation | Permian | limestone, dolomite, and sandstone | ||
| Fantasque Formation | Permian | spicular chert, shale, and siltstone | ||
| Mowitch Formation | Roadian to Wordian | sandstone with gypsum | ||
| Ranger Canyon Formation | Roadian to Wordian | dark chert, silicified sandstone, evaporite minerals | ||
| Ross Creek Formation | late Sakmarian to Artinskian | shaly siltstone, calcareous siltstone, silty carbonate, phosphatic coquinas | ||
| Telford Formation | Asselian to Sakmarian | sandy limestone and dolomite | ||
| Johnston Canyon Formation | late Sakmarian to Artinskian | phosphatic siltstone, calcareous siltstone, and silty limestone and dolomite | ||
| Belcourt Formation | Asselian to Sakmarian | silty dolomite with chert |