Horseshoe Canyon Formation

The Horseshoe Canyon Formation is a Late Cretaceous rock unit in Alberta’s Western Canada Sedimentary Basin, named for Horseshoe Canyon near Drumheller and exposed widely around Drumheller, Trochu, and Edmonton. Part of the Edmonton Group, it consists of mudstone, sandstone, carbonaceous shale, and coal seams deposited in floodplains, estuarine channels, and coal swamps, with evidence that marine waters periodically entered these settings. It is especially significant for its rich fossil record, including many dinosaurs, mammals, amphibians, fish, invertebrates, and plants. Its lower Drumheller Coal Zone also supported major coal mining from 1911 to 1979 and later became an important source of coalbed methane.

Alberta · Canada