Evaporitic deposits of western Canada

This compilation gives a general description from published and unpublished sources of the many Paleozoic and Mesozoic evaporitic deposits present in the Interior Plains and eastern Cordillera of Western Canada. The description of each deposit includes a discussion of the general geology, stratigraphy, paleogeography, structural geology and environment of deposition. Some evaporitic deposits dissolve in circulating groundwater and are not exposed at the surface in their original form. The lithologie descriptions of the evaporitic deposits and the maps showing their distribution and thicknesses are thus based largely on subsurface information. The evaporitic deposits are subdivided into minor and major deposits. The minor deposits are of Ordovician, Silurian, Mississippian, Triassic and Jurassic age. They do not contain salt and are interbedded with redbeds and/or carbonates. The major evaporitic deposits are of Cambrian and Devonian age and include thick and economically important salt beds. These deposits were studied in detail and their description includes new information. The evaporites include many lithologies such as redbeds, anhydrite, gypsum, rock salt and potash salt. Typical lithologies of the major evaporitic deposits are described with the aid of photographs. The interpretation of the environment of deposition of the various facies in the two major evaporitic deposits is based largely on the study of cores and it is shown that the deposits include fabrics of primary and secondary origin. A substantial amount of the Devonian anhydrite and potash salt is of secondary or replacement origin.