Crowsnest Formation
The Crowsnest Formation, also called the Crowsnest Volcanics, is a geological formation in southwestern Alberta, Canada, on the southwestern margin of the Western Canada Sedimentary Basin. It was named for the Crowsnest Pass near Coleman, Alberta. The formation consists mostly of pyroclastic rocks that were laid down in a series of explosive eruptions about 100 million years ago during the Albian stage of the Early Cretaceous epoch. It contains unusual minerals such as melanite (a variety of andradite garnet) and analcime (a variety of zeolite).
| Crowsnest Formation | |
|---|---|
| Stratigraphic range: | |
The west end of the type section of the Crowsnest Formation, on the Crowsnest Highway west of Coleman, Alberta. | |
| Type | Geological formation |
| Unit of | Blairmore Group |
| Underlies | Blackstone Formation |
| Overlies | Ma Butte Formation |
| Thickness | Up to 488 metres (1,600 ft) |
| Lithology | |
| Primary | Volcanic rocks, pyroclastic breccia |
| Other | Sandstone |
| Location | |
| Coordinates | 49°38′51″N 114°31′48″W |
| Region | Alberta |
| Country | Canada |
| Extent | Western Canadian Sedimentary Basin |
| Type section | |
| Named for | Crowsnest Pass |
| Named by | G.M. Dawson |
Crowsnest Formation (Canada) | |
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