Unit Name: Muskwa Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Frasnian (385.3 - 374.5 ma)
Province/Territory: Alberta; British Columbia; Northwest Territories

Originator: Gray and Kassube, 1963.

Type Locality:
Western National Gas et al. Fort Nelson a-95-J, 94-J-10, near Fort Nelson, British Columbia, between 1,986 and 2,022 m (6,510 and 6,630 ft).

It is 37 m (120 ft) thick in the type well, which is typical. Present in northern Alberta, northeastern British Columbia and southern Northwest Territories.

Locality Data:
WELL 200A095J094J1000; GULF STATES FORT NELSON NO. 2 A-095-J/094-J-10. Thickness(m): Typical 37. Interval(m): From 1986, To 2022.

Black bituminous shale with abundant pyrite.

In the type well the Muskwa is a member of the Horn River Formation, underlain by the Otter Park Member and overlain by the Fort Simpson Formation. South and east of the Slave Point carbonate front the Muskwa overlies the Slave Point Formation; still further south and east the Muskwa overlies the Waterways Formation (previously Beaverhill Lake Formation). Griffin (1965) proposed formation status; in the opinion of Griffin (1965), Bassett and Stout (1967) and others the base of the Muskwa is a widespread erosional unconformity. Williams (1977c), however, considered the Muskwa to be a condensed section equivalent to the Waterways Formation as well as younger strata.

Other Citations:
Williams, 1977a.

Bassett, H.G. and Stout, J.G., 1967. Devonian in Western Canada, pp. 717-752: in Oswald D.H. (ed.), International Symposium on the Devonian System, Alberta Society of Petroleum Geologists, Calgary, vol. 1, 1055 p.
Gray, F.F. and Kassube, J.R., 1963. Geology and stratigraphy of Clarke Lake Gas Field, British Columbia; America Association of Petroleum Geologists (AAPG), AAPG Bulletin, vol. 47, no. 3 (March), pp. 467-483.
Griffin, D.L., 1965. The facies front of the Devonian Slave Point - Elk Point sequence in northeastern British Columbia and the Northwest Territories; Journal of Canadian Petroleum Techology, vol. 4, no. 1, pp. 13-22.
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.
Williams, G.K., 1977c. The Hay River Formation and its relationship to adjacent formations, Slave River map-area, N.W.T.; Geological Survey of Canada, Paper 75-12, 17 p.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: G.K. Williams
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 10 May 2011