Unit Name: Garbutt Formation
Unit Type: Lithostratigraphic
Usage: Currently in use
Age Interval: early Aptian (125 - 121 ma)
Age Justification: The ammonites Puzosia, Arcthoplites and Pachygrycia have been collected in the Liard-La Biche region and are of Early Albian age. Basal Cretaceous sandstone at Jackfish Gap was found by Braman and Hills (1977) to contain Cretaceous palynomorphs. A meagre microfauna assemblage was recovered from lower beds at Scatter River.
Province/Territory: British Columbia; Northwest Territories
Originator: Kindle, E.D., 1944.
Exposures along Garbutt Creek, tributary of Liard River in the Toad River map-area (94N) northeastern British Columbia, but no continuous section occurs there. The most complete sequence is found on Toreva Creek, a small tributary of Scatter River (Stott, 1982).
Extends northward from the junction of the Toad and Liard rivers in northeastern British Columbia in a narrow, recessive belt across the Crow and Beaver rivers, along the flanks of the Kotaneelee Syncline west of the Liard Range of the Northwest Territories. The thickness is in the order of 290 m (951 ft) at Scatter River.
The formation consists of two main subdivisions. The lower comprises silty mudstone, argillaceous siltstone, sideritic concretions and a few thin seams of bentonite. The basal mudstone is glauconitic. The upper subdivision is mainly rubbly mudstone, with rows of reddish brown weathering, sideritic concretions. The upper beds include argillaceous siltstone and thin beds of finely laminated sandstone.
The Garbutt Formation unconformably orverlies the Triassic Toad Formation in the region of Scatter and Liard rivers, but in the vicinity of Kotaneelee River it lies on Permian mudstone and sandstone. It has a transitional upper contact with the overlying Scatter Formation. Where the Scatter is no longer recognizable Garbutt equivalents are included in the Buckinghorse Formation.
Braman and Hills, 1977; Kindle, 1944; Stott, 1982.
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: 18 May 2004