Unit Name: Camsell Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Early Devonian (416 - 397.5 ma)
Age Justification: No fauna in breccia facies and a poorly preserved fauna in the banded facies consisting of silicified stromatoporoids, some colonial corals (Coenites rectinlinearis Simpson), and occasional stromatolites.
Province/Territory: Northwest Territories

Originator: Douglas and Norris, 1961.

Type Locality:
No designated type section or area, but originally described from the Whittaker and Delorme ranges in the Root River map-area (95K), District of Mackenzie. These are now taken to be the type area (62° 15' to 62° 58'N; 124 ° 25' to 125° 25'W).

The Camsell Formation is confined to the Mackenzie Mountains. The breccia facies reaches a maximum thickness of 534 m (1,750 ft) in the type area but nearby subsurface anhydritic sections are more than 1,941 m (6,363 ft) thick. The Camsell is confined to two areas or basins separated by the Redstone arch and its northern continuation, the Twitya Uplift. One Camsell sub-basin (Williams, 1977a) occurs on the east side of the Redstone arch and another occurs as a narrow northwest trending pod on the west side of the arch (Morrow, observation, 1979). Both of these sub-basins occur within the carbonate shelf sequence east of the shale-carbonate transition. The Camsell thins and disappears towards the edge of these basins.

In the type area, the Camsell is a limestone breccia variably silty with some breccia fragments more than 3 m (9 ft) across in a yellow and orange weathering matrix with some thick intervals of featureless lime mudstone. South and west from the type area the Camsell is colour-banded and consists of thick- to medium-bedded orange weathering dolomite and light yellowish-grey dolomite. In the subsurface, the Camsell is formed of interbedded anhydrite and silty dolomite and limestone.

The Camsell conformably overlies, and may be in part laterally equivalent to the Delorme Formation and is conformably overlain by the Sombre and Arnica formations throughout most of the Mackenzie Mountains. South of the type area in the Virginia Falls map-area (95F) the Camsell Formation passes laterally to siltstones and shales of the Road River Formation in the Prairie Creek Embayment (Morrow et al., 1978).

Other Citations:
Douglas and Norris, 1963; Gabrielse et al., 1965; Gabrielse et al., 1973; Law, 1971.

Douglas, R.J.W. and Norris, D.K., 1961. Camsell Bend and Root River map-areas, Northwest Territories; Geological Survey of Canada, Paper 61-13, 36 p.
Douglas, R.J.W. and Norris, D.K., 1963. Dahadinni River and Wrigley map-areas, District of Mackenzie, Northwest Territories; Geological Survey of Canada, Paper 62-33, 34 p.
Gabrielse, H., Blusson, S.L., and Roddick, J.A., 1973. Geology of the Flat River, Glacier Lake and Wrigley Lake map-areas, District of Mackenzie and Yukon Territory; Geological Survey of Canada, Memoir 366 (Parts I and II), 421 p.
Gabrielse, H., Roddick, J.A., and Blusson, S. L., 1965. Flat River, Glacier Lake and Wrigley Lake, District of Mackenzie and Yukon Territory, 95E, 95L and 95M (Report and Maps 35-1964, 36-1964, and 37-1964); Geological Survey of Canada, Paper 64-52, 30 p. + Preliminary Map 35-1964, Geology, Flat River, Yukon Territory - District of Mackenzie, Scale 1:253 440 or 1 inch to 4 miles, Preliminary Map 36-1964, Geology, Glacier Lake, District of Mackenzie, Scale 1:253 440 or 1 inch to 4 miles, and Preliminary Map 37-1964, Geology, Wrigley Lake, District of Mackenzie, Scale 1:253 440 or 1 inch to 4 miles.
Law, James, 1971. Regional Devonian geology and oil and gas possibilities, upper Mackenzie River area; Canadian Society of Petroleum Geologists (CSPG), Bulletin of Canadian Petroleum Geology, vol. 19, no. 2 (June), pp. 437-484.
Morrow, D.W., Krouse, H.R., Ghent, E.D., Taylor, G.C., and Dawson, K.R., 1978. A hypothesis concerning the origin of barite in Devonian Carbonate rocks of northeastern British Columbia; Canadian Journal of Earth Sciences = Journal Canadien des Sciences de la Terre, vol. 15, no. 9 (September), pp. 1391-1406.
Williams, G.K., 1977a. Some observations on the Horn Plateau, District of Mackenzie; Geological Survey of Canada, Report of Activities, Paper 77-lB, pp. 191-196.

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.W. Morrow
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 06 Aug 2009