Unit Name: Dunedin Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Middle Devonian (397.5 - 385.3 ma)
Province/Territory: British Columbia
Originator: Taylor, G.C., 1967; Taylor, G.C. and MacKenzie, W.S., 1976.
Type Locality:
In and along the stream bed of One Ten Creek adjacent to the Alaska Highway west of Mount St. Paul, Tuchodi Lakes (94K) map-area, northeastern British Columbia. Geographical co-ordinates of the type section: 58 deg 41'N, 124 deg 48'W.
Distribution:
Recognized from Redfern Lake in the Trutch (94G) map-area, where the Dunedin passes laterally into and is overstepped by the Pine Point Formation, northward to the British Colurnbia-Yukon border where the carbonates pass laterally into equivalent Besa River shale. The Dunedin is approximately 250 m (820 ft) thick at the type section, increasing in thickness westward to approximately 400 m (1,312 ft) near Muncho Lake. South of the type section the Dunedin thins to 120 m (394 ft) near Mount Helen, near the facies front of the Pine Point Formation.
Lithology:
A monotonous sequence of argillaceous and locally siliceous and dolomitic dark grey, well-bedded limestones. Two facies are recognized, a lower dolomitic wackestone facies constituting a transgressive shoreface environment overlain by a thicker, grainstone-wackestone facies of subtidal origin. Basal sands occur in the southern areas of Dunedin exposure.
Relationship:
Disconformably overlies the Stone Formation, except in the northernmost region of its development, and is conformably overlain by Besa River shales, except at its southerly termination, where it is overstepped by the Pine Point Formation. The Dunedin Formation correlates with parts of the Hume Formation, and the Nahanni Formation of the Northwest Territories.
Other Citations:
Griffin, 1967; Morrow, 1978; Taylor, 1967; Taylor and MacKenzie, 1970; Taylor and Stott, 1973.
Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: G.C. Taylor
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 29 Apr 2003