Crowsnest Formation

The Crowsnest Formation, or Crowsnest Volcanics, is an Early Cretaceous geological formation in southwestern Alberta that preserves evidence of explosive volcanism along the edge of the Western Canada Sedimentary Basin. Formed about 100 million years ago during the Albian, it consists mainly of pyroclastic deposits and volcanic-rich sediments laid across an inland floodplain, probably from volcanoes to the west near present-day Cranbrook, British Columbia. Later thrust faulting shifted the deposits eastward. As the uppermost unit of the Blairmore Group, it is especially notable for an unusual mineral assemblage, including melanite, analcime, and the rare rock blairmorite, making it an important record of volcanism in western Canada.

Alberta · Canada