- GeoRef, Copyright 2004, American Geological Institute. Reference includes data from Bibliography and Index of North American Geology, U. S. Geological Survey, Reston, VA, United States
This widespread Meramecian formation of the Rundle Group consists of 500 to 1,000 feet of limestones and dolomites, with local shales, sandstones, siltstones and solution breccias, all of shallow marine origin. In the eastern ranges six members are clearly recognizable from Crowsnest Pass to Bow Valley, north of which they lose their distinctive character. Facies changes in the lower four members progress westward into skeletal limestones of the underlying Livingstone Formation. The dolomites and micritic limestones of the overlying lagoonal members pass westward into barrier shoal and open marine beds of the Opal Member, a new name; only the upper part of the Carnarvon Member extends west to overlie the Opal, with a return to lagoonal conditions. Correlations across facies changes are supported by the stratigraphic distribution of four assemblages of corals and brachiopods.