Unit Name: Bug Creek Group
Unit Type: Lithostratigraphic
Rank: Group
Status: Formal
Usage: Currently in use
Age Interval: Sinemurian - early Oxfordian (196.5 - 159.6 ma)
Age Justification: Ammonites, pelecypods, belemnites, Foraminifera, and palynomorphs.
Province/Territory: Northwest Territories; Yukon Territory; Alaska
Originator: Poulton, Leskiw and Audretsch, 1982.
Type Locality:
See component formations and members.
Distribution:
The group thickens west-northwestward from about 100 m (330 ft) in Aklavik Range and McDougall Pass areas to at least 830 m (2,720 ft) near the head of Waters River. It occurs throughout the northern Richardson Mountains and western Mackenzie Delta. Certain of the sandstones extend southwestward as far as eastern Keele Range and westward as far as the head of Johnson Creek near Bonnet Lake.
Locality Data:
Thickness(m): Minimum 100, Maximum 830.
Lithology:
Sandstone, siltstone, argillaceous sandstone and siltstones, shales; variably bioturbated, cross-bedded, planar bedded, irregularly bedded or massive. The component formations and members listed in ascending order are: 1) Murray Ridge Formation, Sinemurian, argillaceous with the basal conglomeratic sandstone Scho Creek Member; 2) Almstrom Creek Formation, approximately Pliensbachian, sandstone; 3) Manuel Creek Formation, Toarcian-Lower Bajocian with a local upper sandstone the Anne Creek Member; 4) Richardson Mountains Formation, Middle Bajocian through Early Oxfordian, with two members distinguished locally: the Little Bell Member (sandstone) and Waters River Member (sandstone); and 5) Aklavik Formation, Early Oxfordian, sandstone.
Relationship:
The Group paraconformably overlies Devonian and Late Paleozoic strata and is abruptly overlain by the Husky Formation, or locally gradationally by the Porcupine River Formation. Locally also, it is paraconformably overlain by Cretaceous rocks. The group is the southeastern basin - marginal arenaceous equivalent of the lower part of the Kingak Formation. There is a large degree of intertonguing of the two units.
History:
The Bug Creek Group replaces the Bug Creek Formation erected by Jeletzky (1967).
References:
Jeletzky, J.A., 1967. Jurassic and (?) Triassic rocks of the eastern slope of Richardson Mountains Northwestern District of Mackenzie: Geological Survey of Canada, Paper 66-50, 171 p.
Poulton, T.P., Leskiw, K., and Audretsch, A., 1982. Stratigraphy and microfossils of the Jurassic Bug Creek Group of northern Richardson Mountains, northern Yukon and adjacent Northwest Territories; Geological Survey of Canada, Bulletin 325, 137 p.
Source: CSPG Lexicon of Canadian Stratigraphy, Volume 2, Yukon Territory and District of Mackenzie; L.V. Hills, E.V. Sangster and L.B. Suneby (editor)
Contributor: T.P. Poulton; L.V. Hills
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 20 Jul 2009