Kootenay Group
| Kootenay Group Stratigraphic range: Late Jurassic to Early Cretaceous |
|
|---|---|
| Type | Group |
| Sub-units |
Elk Formation Mist Mountain Formation Morrissey Formation |
| Underlies | Blairmore Group |
| Overlies | Fernie Formation |
| Thickness | maximum 1,335 m (4,380 ft) |
| Lithology | |
| Primary | Sandstone, siltstone, mudstone |
| Other | Coal, conglomerate |
| Location | |
| Region |
 British Columbia Alberta
|
| Country |
 Canada
|
| Type section | |
| Named by | D. W. Gibson, 1979 |
The Kootenay Group, originally called the Kootenay Formation, is a geologic unit of latest Jurassic to earliest Cretaceous age in the Western Canada Sedimentary Basin that is present in the mountains and foothills of southeastern British Columbia and southwestern Alberta. It includes economically important deposits of high-rank bituminous and semi-anthracite coal, as well as plant fossils and dinosaur trackways.
The strata of the Kootenay Group were originally described as the Kootenay Formation. D. W. Gibson revised the sequence as the Kootenay Group and defined it as encompassing the stratigraphic interval between the Jurassic Fernie Formation and the Lower Cretaceous Blairmore Group. He subdivided it into three formations as shown below and designated a type section for each of the formations, thus eliminating the need for a type section for the group.
The Kootenay Group is an eastward-thinning wedge of sediments derived from the erosion of newly uplifted mountains to the west. The sediments were transported eastward by river systems and deposited in a variety of river channel, floodplain, swamp, coastal plain, deltaic and shoreline environments along the western edge of the Western Interior Seaway.
Fossils are rare in the Morrissey Formation, but the Mist Mountain Formation includes plant fossils and dinosaur trackways, and the Elk Formation includes plant fossils, trace fossils and bivalves.
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