| Purcell Supergroup | |
|---|---|
| Stratigraphic range: | |
| Type | Geological supergroup |
| Sub-units | Many |
| Underlies | Windermere Supergroup |
| Overlies | Canadian Shield |
| Area | 15,000 km2 (5,800 sq mi) |
| Thickness | more than 10,000 m (33,000 ft)[1] |
| Lithology | |
| Primary | Argillite, dolomite, quartzite |
| Other | Limestone, igneous rocks |
| Location | |
| Region |  Alberta British Columbia |
| Country |  Canada |
| Type section | |
| Named for | Purcell Mountains |
| Named by | R.A. Daly, 1912.[2] |
The Purcell Supergroup is composed primarily of argillites, carbonate rocks, quartzites, and mafic igneous rocks of late Precambrian (Mesoproterozoic) age. It is present in an area of about 15,000 km2 (5,800 sq mi) in southwestern Alberta and southeastern British Columbia, Canada, and it extends into the northwestern United States where it is called the Belt Supergroup. It was named for the Purcell Mountains of British Columbia by R.A. Daly in 1912.[2] Fossil stromatolites and algal structures are common in some of the Purcell Supergroup rocks,[3][4] and the Sullivan ore body at Kimberley, British Columbia, a world-class deposit of lead, zinc, and silver, lies within the Alderidge Formation in the lower part of the Purcell.[5]
Spectacular outcrops of Purcell and Belt Supergroup rocks can be seen in Glacier National Park in northwestern Montana[6] and Waterton Lakes National Park in southwestern Alberta.[7]
- ^ Glass, D.J. (editor) 1997. Lexicon of Canadian Stratigraphy, vol. 4, Western Canada including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba. Canadian Society of Petroleum Geologists, Calgary, 1423 p. on CD-ROM. ISBN 0-920230-23-7.
- ^ a b Daly, R.A. 1912. Geology of the North American Cordillera at the Forty-ninth parallel. Geological Survey of Canada, Memoir 38, p. 119-136.
- ^ O'Connor, M.P. 1972. Classification and environmental interpretation of the cryptalgal organosedimentary "Molar-Tooth" structure from the Late Precambrian Belt-Purcell Supergroup. Journal of Geology, vol. 80, no. 5, p. 592-610.
- ^ McMechan, M.E. 1981. The Middle Proterozoic Purcell Supergroup in the southwestern Rocky and southeastern Purcell Mountains, British Columbia, and the initiation of the Cordilleran Miogeocline, southern Canada and adjacent United States. Bulletin of Canadian Petroleum Geology, vol. 29, no. 4, p. 583-621.
- ^ Lydon, John W. "Geology and metallogeny of the Belt-Purcell Basin. In: Goodfellow, W.D. (ed.), Mineral deposits of Canada: a synthesis of major deposit types, district metallogeny, the evolution of geological provinces, and exploration methods. Geological Association of Canada, Mineral Deposits Division, Special Publication no. 5, p. 581-607". Retrieved 29 April 2018.
- ^ Alt, D.D. and Hyndman, D.W. 1986. Roadside geology of Montana. Mountain Press Publishing Co., Missoula, Montana, 427 p. ISBN 0-87842-202-1,
- ^ Gordy, P.L., Frey, F.R. and Norris, D.K. 1977. Geological guide for the CSPG 1977 Waterton-Glacier Park Field Conference. Canadian Society of Petroleum Geologists, Calgary, Alberta, 93 p.