Unit Name: Tatsieta Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Early Devonian (416 - 397.5 ma)
Age Justification: None.
Province/Territory: Northwest Territories
Originator: Pugh, 1983.
Type Locality:
In borehole R.O.C. Grandview Hills No. 1 (A37; 67 deg 06'21"N, 130 deg 52'30"W) across the Mackenzie River from Tatsieta Lake between 1,055 and 994 m (3,462 and 3,262 ft).
Distribution:
It is 61 m (200 ft) in the type well and attains a maximum thickness of 165 m (541 ft) in the west. It occurs throughout much of the Peel River map-area.
Locality Data:
Thickness(m): Maximum 165, Typical 61. Interval(m): From 1055, To 944.
Lithology:
Limestone and micropyritic green shale, and locally calcareous dolomite. The limestone is buff, aphanitic with some white and chalky. Pale grey silty dolomite in the upper part occurs northeastward from the Peel River. In the Tree River area, the Tatsieta can be subdivided into three subunits as follows: a basal subunit of buff aphanitic limestone and some pale green and pale green-brown shale; a middle subunit of buff calcareous dolomite grading upward to microcrystal-line dolomitic limestone; an uppermost subunit of buff dolomitic limestone and pale green, micro-pyritic shale.
Relationship:
It unconformably overlies the Peel Fm. It is overlain with sharp contact by the Arnica Formation (formerly the Dolomite member of the Gossage Fm). In the Richardson Mountains it is transitional to part of the Road River Fm; to the southwest, it may be equivalent to Michelle Formation; to the east it may be equivalent to the basal part of Fort Norman Fm. Morrow pers. comm. 1980) considers that the Tatsieta Fm may be equivalent to the Camsell and Delorme Formations to the south but that nothing definite can be stated because the Delorme-Camsell relationship is not understood. The age is based on stratigraphic position.
Other Citations:
Pugh, in press.
References:
Pugh, D.C., 1983. Pre-Mesozoic geology in the subsurface of Peel River map area, Yukon Territory and District of Mackenzie; Geological Survey of Canada, Memoir 401, 61 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: L.V. Hills; D.C. Pugh
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 13 Mar 2009