- 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
The Permian Ishbel Group in the Canadian Rockies represents Phosphoria depositional conditions and has a minimal age span of Wolfcampian to Guadalupian. Fossils described from ten stratigraphic sections [productid, chonetid, and spiriferid brachiopods, an omphalotrochid gastropod, and an edestid elasmobranch fish] suggest time correlation not only with the Phosphoria Formation of the U.S.A., but also with Permian successions in Oregon, British Columbia, Northwest Territories and Yukon, Canadian Arctic Islands, Greenland, Svalbard, Russia, and West Pakistan. Similarity in age of faunas above and below an extensive physical unconformity within the Permian implies differential time lapse with diachronism of the beds above the unconformity.