Unit Name: Debolt Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: Meramecian (340 - 333 ma)
Province/Territory: Alberta; British Columbia

Originator: Macauley, 1958.

Type Locality:
Amerada Crown GF23-11, in 6-11-73-26W5M, between 1,893.4 and 2,137.8 m (6,212 and 7,014 ft), in the Peace River area near Debolt, Alberta.

Distribution:
At the type section the Debolt is 244.4 m (802 ft) thick, consisting of 102.7 m (337 ft) of lower Debolt and 141.7 m (465 ft) of upper Debolt. It is recognized in the subsurface of the Peace River and northern plains areas of Alberta and in northeastern British Columbia. The maximum thickness of approximately 366 m (1201 ft) is found in the southwestern part of the subsurface area. The formation thins to the northeast, mainly as a result of erosion.

Locality Data:
WELL 100061107326W500; HESS CROWN G 06-11-73-26. Thickness(m): Maximum 366. Interval(m): From 1893.4, To 2137.8.

Lithology:
The Debolt Formation has been divided by Macauley into a lower and an upper member. In its type area the lower Debolt consists mainly of brown, cherty, massive bioclastic limestone, partly crinoidal, that is more dolomitic eastward. Northward the shale content increases. The proportion of argillaceous rocks is greatest in the basal part. Westward, towards the foothills there is an increase in chert and dolomite as the lower Debolt passes laterally into Member B of the Prophet Formation. The upper Debolt is light brown, mainly microcrystalline to finely crystalline dolomite with some anhydrite and micritic limestone. In northeastern British Columbia it is dominantly limestone with less dolomite and shale.

Relationship:
Shale and argillaceous carbonate of the underlying Shunda Formation grades upward into the argillaceous carbonate generally present in the lowermost Debolt. The upper contact with the Golata Formation (Stoddart Group) generally is gradational and conformable, but there is evidence of erosion in the type area. Eastward of the Stoddart Group erosional edge the Debolt is overlain successively by Permian, Triassic, Jurassic and Cretaceous strata. The lower Debolt passes westwards into cherty carbonates of Member B of the Prophet Formation and northwestward into carbonates and calcareous shale of the middle part of the Flett Formation. The Turner Valley Formation of western Alberta is continuous with the lower Debolt. Equivalents of the upper part of the lower Debolt include the Wileman, Baril and Salter members of the Mount Head Formation in southwestern Alberta. The upper Debolt is equivalent to, and continuous with Member C and the upper part of Member B of the Prophet Formation. Correlative rocks occur in the upper Mount Head Formation (Loomis and lower Marston members) of southwestern Alberta.

Other Citations:
Bamber and Mamet, 1978; Halbertsma, 1959; Halbertsma and Staplin, 1960; McCrossan and Glaister, 1964; Macauley,1958; Rutgers, 1958.

References:
Bamber, E.W. and Mamet, B.L., 1978. Carboniferous biostratigraphy and correlation, northeastern British Columbia and southwestern District of Mackenzie; Geological Survey of Canada, Bulletin 266, 65 p.
Halbertsma, H.L. and Staplin, F.L., 1960. The Mississippian-Pennsylvanian boundary from the Peace River area to the Williston Basin; Canadian Society of Petroleum Geologists, Journal of the Alberta Society of Petroleum Geologists, vol. 8, no. 12, pp. 363-373.
Halbertsma, Henk Leendert, 1959. Nomenclature of Upper Carboniferous and Permian strata in the subsurface of the Peace River area; Canadian Society of Petroleum Geologists, Journal of the Alberta Society of Petroleum Geologists, vol. 7, no. 5 (May), pp.109-118.
Macauley, G., 1958. Late Paleozoic of Peace River area, Alberta. In: Jurassic and Carboniferous of western Canada; Goodman, A.J. (Ed.), p. 289-308. Amer. Assoc. Petrol. Geol.
McCrossan, R.G. and Glaister, R.P. (eds.), 1964. Geological History of Western Canada: Alberta Society of Petroleum Geologists, 232 p.
Rutgers, A.T.C., 1958. Stoddart formation of northeast British Columbia; in: Jurassic and Carboniferous of western Canada, Goodman, A.J. (ed.), p. 327-330.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: P.A. Monahan; H.L. Halbertsma
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 23 Nov 2010