Unit Name: Elm Point Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Eifelian ? - Eifelian (397.5 - 391.8 ma)
Province/Territory: Manitoba
Originator: Kindle, E.M., 1914.
Type Locality:
Exposed in cliffs near Elm Point on the eastern shore of Lake Manitoba. Suggested reference core hole providing complete section is Manitoba Mineral Resources Division core hole M-1-72, in Lsd. 16, Sec. 26, Twp. 24, Rge. 10WPM, between 26.8 and 46.8 m (88 and 153.5 ft).
Distribution:
The maximum known thickness in the outcrop belt is 19.8 m (65 ft). The unit occurs only in the southern portion of the Manitoba outcrop belt, from approximately Oak Point to Waterhen Lake (Twps. 17 to 37). To the north along the outcrop belt, and to the west in the subsurface Elm Point limestones pass abruptly by facies change to dolomites of the Winnipegosis Formation. Isolated occurrences of a basal limestone facies equivalent to the Elm Point are reported throughout the subsurface or southwestern Manitoba and Saskatchewan.
Lithology:
Limestone, medium yellowish brown, thin-bedded, very fine-grained, dense, fossiliferous micrite with faint to prominent yellowish grey mottles resulting from partial dolomitization. The degree of dolomitization ranges from slight in areas of high calcium limestone to moderate in areas where mottles are almost totally dolomitized. Stylolites are common, and vugs and veinlets containing secondary calcite are abundant. Exceptionally well-preserved frilled brachiopod Atrypa arctica Warren are abundant in several thin interbeds.
Relationship:
The Elm Point is underlain with possible unconformity by red shales and argillaceous dolomites of the Ashern Formation. It is overlain conformably by dolomites of the Winnipegosis Formation. It passes laterally to dolomites of the lower Winnipegosis platform facies (Uyeno et al., 1980).
Other Citations:
Baillie, 1951; Jones, 1965; Kindle, 1914; Uyeno et al., 1980.
Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: H .R. McCabe
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 29 Apr 2003