Unit Name: Sullivan Formation
Unit Type: Lithostratigraphic
Usage: Currently in use
Age Interval: Dresbachian (499 - 496.8 ma)
Age Justification: The Sullivan contains an abundant diverse trilobite fauna of the Cedaria Zone of Dresbachian age.
Province/Territory: Alberta; British Columbia
Originator: Walcott, C.D., 1920, 1923.
On the north side of Glacier Lake Valley a 439.2 m (1,440 ft) interval was designated the type section. Walcott also included the south cliffs and slopes of Sullivan Peak in the type locality, in Alberta.
Walcott's type section was indicated to be over 427 m (1,400 ft) thick, but it included 99 m (325 ft) of "Lyell" limestone at the top of the section. Aitken and Greggs (1967) revised the Sullivan to conform to Walcott's description, and measured 424 m (1,390 ft) at the type section. Elsewhere in the front ranges thicknesses of 61 to 92 m (200 to 300 ft) are more characteristic; although to the south at Mount Ogden it is more than 153 m (500 ft) thick.
Thickness(m): Minimum 61, Typical 424.
A markedly recessive unit of greenish grey and brown shales interbedded with thin, plate oolitic and bioclastic limestone; it grades upward into the massive carbonates of the Lyell Formation.
The Sullivan is gradationally overlain by carbonates of the Lyell Formation, and in very sharp, presumably conformable contact with the underlying Waterfowl Formation. The unit passes northward into strata assigned to the lower Lynx Group.
Aitken, J.D. and Greggs, R.G., 1967. Upper Cambrian formations, southern Rocky Mountains of Alberta, an interm report; Geological Survey of Canada, Paper 66-49, 91 p.
Walcott, C.D., 1920. Explorations and field work of the Smithsonian Institute in 1919. Smithsonian Miscellaneous Collections, vol. 72, no. 1, pp. 1-16.
Walcott, C.D., 1923. Nomenclature of some post-Cambrian and Cambrian Cordilleran formations: Cambrian geology and paleontology, Part 4. Smithsonian Miscellaneous Collections, vol. 67, no. 8, pp. 457-476.
Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: R.G. Greggs
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 28 Mar 2014