Unit Name: Brandon Formation
Unit Type: Lithostratigraphic
Rank: Formation
Status: Formal
Usage: Currently in use
Age Interval: ? Llandovery (443.7 - 428.2 ma)
Province/Territory: Manitoba; Saskatchewan

Originator: King, 1964a, b.

Type Locality:
Dome Pelican Lake well, in 7-34-4-15WPM, Manitoba, between 837.9 and 851.3 m (2,749 and 2,793 ft).

The Brandon Formation is approximately 12 m (39 ft) thick in the type area and thickens gently to the north to about 21 m (69 ft). Strata equivalent to the Brandon Formation extend throughout the Williston Basin, but the name is not commonly used in the subsurface.

Locality Data:
Interval(m): From 837.9, To 851.3.

Subdivided into two members. The lower member consists of fine- to medium-grained skeletal, oolitic and stromatolitic dolomites that grade laterally and vertically to either cryptocrystalline or microcrystalline dolomite. The top of the lower member is marked by the sandy argillaceous u2 marker bed, and the base by the u2 marker bed. The upper Brandon consists of cryptocrystalline dolomite, with only a few occurrences of coarser-grained dolomite. The top of this unit is defined by the top of the v marker.

The Brandon Formation overlies the Strathclair Formation and is overlain by the Cedar Lake Formation. Both the top and bottom contacts of the unit are marked by thin, sandy, argillaceous "non-sequential" marker beds (Porter and Fuller, 1959) which probably represent slight disconformities. The Brandon is equivalent to the lower part of the East Arm, Atikameg and Moose Lake formations in the Manitoba outcrop belt. It is approximately equivalent to the combined Fife Lake and Guernsey formations in the subsurface of Saskatchewan.

King (1964a) attempted to correlate into the subsurface of Manitoba the units defined by Stearn (1956b) for the Interlake Group of the Manitoba outcrop belt. Not all the formations could be correlated so King subdivided the Interlake into three formations, from bottom to top the Strathclair, Brandon and Cedar Lake.

Other Citations:
Haidl, 1987; Jamieson, 1979; Johnson and Lescinsky, 1986; Magathan, 1987.

Haidl, F.M., 1987. Stratigraphic and lithologic relationships, Interlake Formation (Silurian), southern Saskatchewan; in, Summary of Investigations 1987; Saskatchewan Geological Survey, Miscellaneous Report 87-4, pp. 187-193.
Jamieson, E.R., 1979. Well data and lithologic descriptions of the Interlake Group (Silurian) in southern Saskatchewan. Saskatchewan Dept. Min. Res., Rept. 139.
Johnson, M.E. and Lescinsky, H.L., 1986. Depositional dynamics of cyclic carbonates from the Interlake Group (lower Silurian) of the Williston Basin. Palaios, v. 1, p. 111-121.
King, K.R., 1964b. The Silurian Interlake Group in Manitoba, in, Third International Williston Basin Symposium; Saskatchewan, North Dakota and Billings Geological Societies, pp. 51-55.
King, Kenneth Ross, 1964a. The stratigraphy of the Interlake Group (Silurian) in Manitoba; University of Manitoba, Winnipeg, MB, Unpublished M.Sc. thesis, 118 p.
Magathan, E.R., 1987. Silurian Interlake Group:A sequence of cyclic marine and fresh water carbonate deposits in the central Williston Basin. 5th Int. Williston Basin Symp, North Dakota Geol. Surv., Misc. Series 69, p. 59-88.
Porter, J.W. and Fuller, J G.C.M., 1959. Lower Paleozoic rocks of northern Williston Basin and adjacent areas. Amer. Assoc. Petrol. Geol. Bull., v. 43, p. 124-189.
Stearn, C.W., 1956b. Stratigraphy and palaeontology of the Interlake Group and Stonewall Formation of southern Manitoba; Geological Survey of Canada, Memoir 281.

Source: CSPG Lexicon of Canadian Stratigraphy, Volume 4, western Canada, including eastern British Columbia, Alberta, Saskatchewan and southern Manitoba; D.J. Glass (editor)
Contributor: H .R. McCabe; F.M. Haidl
Entry Reviewed: Yes
Name Set: Lithostratigraphic Lexicon
LastChange: 26 Jun 2009