Unit Name: Puskwaskau Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Santonian (85.8 - 83.5 ma)
Age Justification: The Puskwaskau carries Inoceramus, Scaphites s. 1 and Baculites, with some brackish water clams appearing near the top. The Foraminifera include planktonics, and calcareous and arenaceous benthonics (Wall, 1960).
Province/Territory: Alberta; British Columbia
Originator: Wall, J.H., 1960, p. 6.
Type Locality:
Lower Smoky River, Alberta near the mouth of Puskwaskau Creek and upstream (55 deg 28'N, 118'12'W).
Distribution:
The shales are 200 m (656 ft) thick near Pouce Coupe and thin to 123 m (403 ft) in the Smoky River area. Found throughout the Peace River area of Alberta and south of the Pine River in northeastern British Columbia.
Lithology:
Thinly bedded, dark marine shales with some speckled shale in midportion; some nodules sporadically appearing in lower part and silty beds toward the top. Includes the Chinook Sandstone in the transitional zone with the overlying Wapiti Formation. Recessive in outcrop.
Relationship:
Belonging to the Smoky Group. The Puskwaskau is underlain conformably by the Bad Heart Formation and overlain by the Wapiti Formation with a transitional zone carrying the Chinook Member in the British Columbia-Alberta boundary area. It correlates with the upper part of the Wapiabi Formation of the central foothills of Alberta, with most of the First White Speckled Shale of the Colorado Group and the lower part of the Lea Park Formation of the east-central Alberta Plains, with the upper portion of the Labiche Formation of northeastern Alberta, and is the equivalent of the Kotaneelee Formation of the Liard River area.
History:
This name was introduced for McLearn's (1918) "Upper shale member" of the Smoky River Formation, now the Smoky Group.
Other Citations:
McLearn, 1919; Rutherford, 1930; Stott, 1963; Wall, 1960.
References:
Wall, J.H., 1960. Upper Cretaceous Foraminifera from the Smoky River area, Alberta; Research Council of Alberta, Alberta Geological Survey, Bulletin 6, 43 p.
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.R. Stelck; G.E. McCune
Entry Reviewed: No
Name Set: Lithostratigraphic Lexicon
LastChange: 28 May 2008