The Muskwa Formation is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin. It takes the name from Muskwa River, and was first described in the Western National Gas Fort Nelson a-95-J/94-J-10 well by F.F. Gray and J.R. Kassube, in 1963. Lithology The Muskwa Formation is composed of bituminous shale. Pyrite is a common accessory mineral. Gas production Gas is produced from the Muskwa Formation shales in the Horn River Basin in the Greater Sierra oil field in north-eastern British Columbia. Horizontal drilling and fracturing techniques are used to extract the gas from the low permeability shales (see Shale gas). Distribution The Muskwa Formation occurs in northern Alberta, north-eastern British Columbia and in the southern part of the Northwest Territories, and typically has a thickness of . Relationship to other units The Muskwa Formation is a sub-unit of the Horn River Formation; it is conformably overlain by the Fort Simpson Formation and conformably underlain by the Otter Park Member. See also Muskwa Ranges References Geologic formations of Alberta Shale formations Oil-bearing shales in Canada Natural gas fields in Canada Western Canadian Sedimentary Basin Devonian System of North America Upper Devonian Series Devonian Alberta Devonian British Columbia Devonian Northwest Territories Peace River Country Frasnian Stage