Unit Name: Monteith Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Late Jurassic - Early Cretaceous (161.2 - 99.6 ma)
Age Justification: The Monteith Formation ranges in age from Tithonian (latest Jurassic) to earliest Valanginian (Early Cretaceous). It contains fauna from the Zones of Buchia fisheriana to B. uncitoides and B. cf. keyserlingi (Stott, 1975).
Province/Territory: Alberta; British Columbia
Originator: Mathews, W.H., 1947, p. 10.
Type Locality:
Mathews indicated that excellent exposures are present on the north face of Mount Monteith and also at Beattie Peaks. However he neither defined nor described a type section. Hughes (1964a, section 10) briefly described the general succession at Beattie Peaks.
Distribution:
The Monteith is recognized between Berland River in the Alberta Foothills and Prophet River in northeastern British Columbia. It attains a maximum thickness of about 600 m (1,968 ft) in western sections between Peace and Pine rivers, but decreases eastward in the foothills to less than 300 m (984 a) to 150 m (492 ft) in the subsurface (Stott, 1975).
Lithology:
Most of the Monteith consists of fine-grained argillaceous sandstone. Alternating units of fine-grained sandstone and dark grey shale commonly occur in the lower part of the formation. In addition, fine- to coarse-grained quartzose sandstone occurs at the top of the formation in the eastern foothills between Goodrich Peak and Sikanni Chief River.
Relationship:
The formation is conformable on the underlying Jurassic Fernie Formation and grades transitionally downward into a succession of shales and thin sandstones. The contact with the overlying Beattie Peaks is marked by a distinct change from thick-bedded sandstone to silty mudstone and thin-bedded silty sandstone.
Other Citations:
Hughes, 1964a; Mathews, 1947; Stott, 1967, 1975.
Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: D.F. Stott
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 26 May 2004