Unit Name: Starbird Formation
Unit Type: Lithostratigraphic
Usage: Currently in use
Age Interval: Frasnian (385.3 - 374.5 ma)
Age Justification: Corals, stromatoporoids, brachiopods, conodonts, echinoderm debris. Conodonts from the basal beds indicate the upper part of the Polygnathus disparilis Zone; higher brachiopods indicate the Eleutherokomma leducensis and E. jasperensis zones.
Province/Territory: British Columbia
Originator: Walker, C.T., 1926.
Summit of Mount Forster, Purcell Range, southwestern British Columbia (50 deg 36'N, 116 deg 17'W).
The Starbird Formation is only 17 m (56 ft) thick at its type section, but no top is seen. Some 270 m (886 ft) are reported from farther west in the Purcell Range.
Thickness(m): Maximum 270, Typical 17.
Dolomite, dark grey, weathering light olive-grey, grey and light grey, with coarse dolomite stringers, some siliceous content, platy, argillaceous dolomite, dolomitic siltstone, quartzite, argillite.
No younger rocks are known in contact with the Starbird, which unconformably overlies the Middle Devonian Mount Forster Formation and locally the Precambrian Horsethief Creek Group (Root, 1985). The formation is coeval with the lower part of the Fairholme Group of the Rocky Mountains and with the Beaverhill Lake and Souris River formations of Alberta and Saskatchewan.
Walker based the Starbird on 78 m (256 ft) of strata at the peak of Mount Forster, together with an isolated outcrop on the west slope of the mountain that probably is higher stratigraphically. Norford modified the formation substantially by placing the lowest 61 m (200 ft) in the underlying Mount Forster Formation. Root mapped the Starbird west from Mount Forster to the core of the Purcell Range.
Douglas et al., in: Douglas (Ed.), 1970; Norford, 1981; North and Henderson, 1954; Root, 1983, 1985; Walker, 1926.
Root, K.B., 1985. Re-interpretation of the age of a succession of Proterozoic strata, Delphine Creek, southeastern British Columbia, in, Current Research, Part A; Geological Survey of Canada, Paper 85-1A, pp. 727-730.
Walker, J.F., 1926. Geology and mineral deposits of Windermere map-area, British Columbia; Geological Survey of Canada, Memoir 148.
Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: B.S. Norford
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 30 Mar 2009