Type Locality:

Upper part of south facing cliffs on Nahanni Butte (61°03'N, 123°37'W).

Distribution:

137 m (450 ft) at the type locality, 61 m (200 ft) Grizzly Bear Lake, Thunder Cloud Range, 35 m (115 ft) 9.6 km (6 mi) west of South Redstone River, 69 m (225 ft) 9.6 km (6 mi) southeast of Little Dal Lake, 81 m (265 ft) east of Little Dal Lake (= Coates Lake), 76 - 84 m (250 - 275 ft) (Rouge and Dusky Ranges) in the west thinner to the east. It is found in the southern Mackenzie Mountains, District of Franklin and northeastern British Columbia.

Lithology:

Dolomitic limestone, bedded, dark grey, light grey weathering, dense, and limestone dense, finely crystalline, more argillaceous near the base.

Relationship:

It is conformably overlain by the Fort Simpson Formation in the Root River and western Camsell Bend map-areas and the Horn River Formation in the Horn River map-area and eastern Camsell map-area. The combined Headless and Nahanni formations are equivalent to the Hume Formation. The lower contact with the Headless is diachronous becoming younger westward (Noble and Ferguson, 1973). The upper part of the formation is interpreted to be equivalent to the Lonely Bay, Pine Point and Little Buffalo formations of the Great Slave Lake area, the Keg River Formation of north-central Alberta, and the Hume of the central Mackenzie region. The Nahanni Formation changes facies to shales of the Headless Formation in the west of the type area. It may interbed with the Manetoe Formation (Morrow, 1977).

History:

As currently used, it is restricted to the upper part of Hage's section, the lower has been split off into the Headless Formation which conformably underlies it (Douglas and Norris, 1961).

Other Citations:

Blusson, 1971; Braun, 1978; Chatterton, 1978; Douglas and Norris, 1960a; Douglas and Norris, 1960b, 1963; Gabrielse et al., 1965; Gabrielse et al., 1973; Law, 1971; Noble and Ferguson, 1971; Norford et al., 1970.

References:

Blusson, S.L., 1971. Sekwi Mountain map-area, Yukon Territory and District of Mackenzie (105 P); Geological Survey of Canada, Paper 71-22, 17 p. + "A" Series Map 1333A, Geology, Sekwi Mountain, Northwest Territories - Yukon Territories; Scale: 1:250 000.

Braun, W.K., 1978. Devonian ostracodes and biostratigraphy of western Canada; pp. 259-288: in Stelck, C.R. and Chatterton, B.D.E. (eds.), Western and Arctic Canadian Biostratigraphy, Geological Association of Canada Special Paper no. 18, 602 p.

Chatterton, B.D.E., 1978. Aspects of late Early and Middle Devonian conodont biostratigraphy of western and northwestern Canada; in, Western and Arctic Canadian biostratigraphy, Stelck, C.R. and Chatterton, B.D.E. (Eds.); Geological Association of Canada, P.S. Warren biostratigraphy symposium Western and Arctic Canadian biostratigraphy, Edmonton, AB, (May 19, 1976) (Conference), Special Paper 18, pp. 161-231.

Douglas, R.J.W. and Norris, A.W., 1960a. Horn River Map area, Northwest Territories; north halves of 85 and 95 (parts of); Geological Survey of Canada, Paper 59-11, 23 p.

Douglas, R.J.W. and Norris, D.K., 1960b. Virginia Falls and Sibbeston Lake map-areas, Northwest Territories (95F and 95G); Geological Survey of Canada, Paper 60-19, 26 p.

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., 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.

Hage, C.O., 1945. Geological reconnaissance along the lower Liard River, Northwest Territories, Yukon and British Columbia; Geological Survey of Canada, Paper 45-22, 33 p. + Preliminary Map 45-22A, Lower Liard River, Northwest Territories, Yukon and British Columbia; Scale: 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., 1977. The Prairie Creek Embayment and associated slope, shelf, and basin deposits; in, Report of Activities, Part A, Blackadar, R.G., Griffin, P.J., Dumych, H., and Irish, E.J.W. (Eds. and Compilers); Geological Survey of Canada, Paper 77-1A, pp. 361-370.

Noble, J.P.A. and Ferguson, R.D., 1971. Facies and faunal relations at edge of early mid-Devonian carbonate shelf, south Nahanni River area, N.W.T.; Canadian Society of Petroleum Geologists (CSPG), Bulletin of Canadian Petroleum Geology, vol. 19, no. 3 (September), pp. 570-588.

Noble, J.P.A. and Ferguson, R.D., 1973. Facies relations at edge of Early Mid-Devonian carbonate shelf, South Nahanni River area, N.W.T.; in, Arctic Geology, Pitcher, M.G. (Ed.); American Association of Petroleum Geologists (AAPG), Memoir 19, pp. 83-96.

Norford, B.S., Braun, W.K., Chamney, T.P., Fritz, W.H., McGregor, D.C., Norris, A.W., Pedder. A.E.H., and Uyeno, T.T., 1970. Biostratigraphic determinations of fossils from the subsurface of the Yukon Territory and the Districts of Mackenzie and Franklin (Report and 1 figure); Geological Survey of Canada, Paper 70-15, 19 p.