Unit Name: Kechika Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Late Cambrian - Late Ordovician (499 - 443.7 ma)
Province/Territory: British Columbia

Originator: Pyle and Barnes, 2000.

Type Locality:
The type section of the Kechika Formation is at 57° 48'N, 125° 13'W in Ware map area (Cecile and Norford, 1979).

Distribution:
The Kechika Formation is laterally extensive in northeastern British Columbia in the Toodoggone, Ware, Trutch and Tuchodi Lakes map area. It has also been reported from the Halfway River and Rabbit River map areas (Cecile and Norford, 1979).

Locality Data:
Thickness(m): Minimum 300, Maximum 600.

Lithology:
At the type locality, the Kechika Formation comprises shale, slate, calcareous phyllite, phyllite, limestone and limestone conglomerate. It typically comprises a succession of grey and light grey, cleaved, phyllitic calcareous shale and thin-bedded argillaceous limestone and grainstone (Pyle and Barnes, 2000). It represents a sedimentary package which accumulated on a broad, gentle ramp as indicated by an east to west transition from shallow to deeper water facies (Cecile and Norford, 1979).

Fossils:
Graptolites, minor trilobites, brachiopods, bryzoans and cephalopods provide an age of Late Cambrian to Early Ordovician (Glass, 1990).

Relationship:
The Kechika Formation is divided into five members: Lloyd George, Quentin, Grey Peak, Haworth and Mount Sheffield (Pyle and Barnes, 2000). The formation underlies the Skoki Formation (Pyle and Barnes, 2001) and disconformably overlies the Lower Cambrian Rosella Formation. The contact marks an abrupt change from resistant carbonates and siltstone to recessive shale of the Kechika Formation (Pyle and Barnes, 2000).

History:
Pyle and Barnes (2000) revised the rank of the Kechika Group of Gabrielse (1963) to Formation.

References:
Cecile, M.P. and Norford, B.S., 1979. Basin to platform transition, lower Paleozoic strata of Ware and Trutch map areas, northeastern British Columbia; in, Current Research, Part A, Geological Survey of Canada, Paper 79-1A, pp. 219-226.
Gabrielse, H., 1963. McDame map-area, Cassiar District, British Columbia; Geological Survey of Canada, Memoir 319, 138 p.
Glass, D.J. 1990. Lexicon of Canadian Stratigraphy, Volume 4-Western Canada; Canadian Society of Petroleum Geologists, Calgary, Alberta, 772 p.
Pyle, L.J. and Barnes, C.R. 2000. Upper Cambrian to Lower Silurian stratigraphic framework of platform-to-basin facies, northeast British Columbia. Bulletin of Canadian Petroleum Geology. 48:2. pp. 123-149.
Pyle, L.J. and Barnes, C.R. 2000. Upper Cambrian to Lower Silurian stratigraphic framework of platform-to-basin facies, northeast British Columbia; Bulletin of Canadian Petroleum Geology, v. 48, p. 123-149.

Source: GEOLOGICAL SURVEY OF CANADA
Contributor: M. T. Adamson
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 24 Nov 2010