Belcourt Formation
| Ishbel Group Stratigraphic range: Permian |
|
|---|---|
Calcareous siltstone exposed along the Johnston Creek west of Banff
|
|
| Type | Geological formation |
| Underlies | Spray River Group |
| Overlies | Tunnel Mountain Formation, Kananaskis Formation |
| Thickness | up to 427 metres (1,400 ft) |
| Lithology | |
| Primary | Carbonate, sandstone |
| Other | Chert, siltstone |
| Location | |
| Region | WCSB |
| Country |
 Canada
|
| Type section | |
| Named for | Mount Ishbel |
| Named by | A. McGugan, 1963 |
The Ishbel Group is a stratigraphical unit of Permian age in the Western Canadian Sedimentary Basin.
It was first defined by A. McGugan in 1963. It is named for Mount Ishbel of the Sawback Range, and parts of the group were first described in the vicinity of the mountain (Ranger Canyon, Johnston Canyon).
The Ishbel Group is composed of carbonate, sandstone, chert and siltstone.
The Ishbel Group was laid down under Phosphoria depositional conditions; among the fossils that can be found are productid, chonetid and spiriferid brachiopods, omphalotrochid gastropod and edestid elasmobranch fish.
The Ishbel Group reaches a maximum thickness of 427 metres (1,400 ft). It occurs in the front ranges of the Canadian Rockies as far north as the Peace River.
The Ishbel Group is disnconformably overlain by the Spray River Group and unconformably overlays the Tunnel Mountain Formation and the Kananaskis Formation in Kananaskis Country.
It is equivalent to the Phosphoria Formation in Montana and Idaho.
...
Wikipedia