Unit Name: Cedared Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Eifelian (397.5 - 391.8 ma)
Province/Territory: British Columbia

Originator: Belyea and Norford, 1967.

Type Locality:
Unnamed gully near Hatch Creek, Brisco Range, Western Ranges of the Rocky Mountains, southeastern British Columbia (51 deg 00'N, 116 deg 23'W).

Distribution:
213 m (699 ft) at the type section; apparently thins to the northwest and southeast, except where thickened by tongues of the evaporitic Burnais Formation. Present through much of the Western Ranges and Main Ranges.

Lithology:
Dolomites with floating quartz sand and silt, dark aphanitic dolomites, dolomitic quartz sandstones; rare quartzites, mudstones, argillaceous limestones, and breccias, all well bedded and with diverse light weathering colors. Charophytes, fiery rare ostracods, gastropods and brachiopods are present. Internal dating by charophytes indicates Middle Devonian; Lower Devonian charophytes are unknown from western Canada. Externally the stratigraphic position below the Eifelian Harrogate Formation restricts the age to Eifelian.

Relationship:
The Cedared is part of an intricate facies-complex of Middle Devonian formations. Its base is an unconformity mostly on Upper Ordovician and Lower Silurian horizons within the Beaverfoot Formation, and locally on the Lower Silurian Tegart Formation. The upper contact is concordant with the Harrogate Formation, but is covered in all known outcrops. Eastward its relations to the basal Devonian unit in the Main Ranges and to the Upper Devonian Yahatinda Formation of the Front Ranges are uncertain. Regionally the Cedared is coeval with much of the lower Elk Point Group of Alberta and Saskatchewan.

History:
Originally applied in the Western Ranges; later its basal unit was recognized locally in the eastern Purcell Range but included within the Mount Forster Formation.

References:
Belyea, H.R. and Norford, B.S., 1967. The Devonian Cedared and Harrogate formations in the Beaverfoot, Brisco and Stanford ranges, southeast British Columbia; Geological Survey of Canada, Bulletin 146, 64 p.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: B.S. Norford
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 24 Dec 2008