Unit Name: Montney Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Anisian (245 - 237 ma)
Province/Territory: Alberta; British Columbia
Originator: Armitage, J.H., 1962.
Type Locality:
Peace River area, Texaco N.F.A. Buick Creek No. 7 well, in 6-26-87-21W6M, 41.6 km (26 mi) northwest of Fort St. John, British Columbia, between 1,715 and 1,981 m (5,625 and 6,500 ft).
Distribution:
The formation reaches its maximum thickness in the foothills and deep basin area [280 to (918 ft) at Nose Creek to 200 m (656 ft) at Kakwa] and thins to an eastern eroded edge near Peace River northwestern Alberta, and south of Fort Nelson, northeastern British Columbia.
Lithology:
The Montney Formation generally consists of siltstones and dark grey shales. The lower Montney is a dark grey, dolomitic siltstone, interbedded with shales. The upper Montney is a light brown, blocky siltstone with interlaminated fine-grained sands. The sand or arenaceous content increases to the east and traces of glauconite are observed.
Relationship:
The contact between the Montney and overlying Doig Formation is placed at the base of the prominent phosphatic pellet Black Shale zone. The base of the formation rests unconformably on the Permo-Carboniferous beds of the Stoddart Group, or on Mississippian carbonates where the Permo-Carboniferous has been eroded. The Montney may be overlain by Jurassic or Cretaceous beds at its erosional limit. Laterally the Montney can be correlated to the lower Toad-Grayling Formation, and the Vega and Phroso members of the Sulphur Mountain Formation.
Other Citations:
Armitage, 1962; A.S.P.G., 1964; Hunt and Ratcliffe, 1959; Pelletier, 1960.
Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: C. Dawes
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 26 May 2004