Unit Name: McNaughton Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Tommotian (534 - 530 ma)
Age Justification: No skeletal fossils have yet been found in the McNaughton Formation. Trace fossils such as Cruziana and Rusophycus from its uppermost beds in most areas, and from lower parts of it near Pine River suggest an earliest Cambrian age (Tommotian).
Province/Territory: Alberta; British Columbia
Originator: Walcott ,C.D., 1913.
Type Locality:
Mount McNaughton, about 32 km (20 mi) southeast of Mount Robson, and several kilometres north of Yellowhead Pass, Alberta-British Columbia.
Distribution:
Thickness quite variable along strike of mountains, outlining a series of arches and basins during deposition. About 600 m (2,000 ft) in the Pine Pass area, where a complete section is difficult to find, or becomes indefinable within the Misinchinka Group. The McNaughton Formation is a useful field term between Jasper and Pine Pass in the Rocky Mountains. West of the Rocky Mountain Trench it is equivalent to the Yanks Peak and Midas formations.
Lithology:
Characteristically a monotonous, thick sequence of bedded quartzose sandstone or quartzite. In the western ranges of the Rocky Mountains a brown weathering unit of interbedded sandstone and shale is designated the Holmes River Member. The base of the McNaughton is locally conglomeratic and feldspathic. Moving upward in the section grain sizes and feldspar content both gradually diminish. Paleo-current analysis indicate derivation of clastic material from the northeast.
Relationship:
Contact with underlying Miette Group generally abrupt, locally unconformable, and locally gradational and conformable, particularly in westerly sections. Upper contact with Mural Formation is sharp and apparently conformable, although local preservation of hematite bed at contact may represent a soil-forming hiatus.
Other Citations:
Campbell, Mountjoy and Young, 1979; Slind and Perkins, 1966; Walcott, 1913; Young, 1979.
Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: F.G. Young
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 29 Apr 2003