Wabamun Formation

For other uses, see Wabamun (disambiguation).

Wabamun Formation
Stratigraphic range: Famennian PreꞒ Ꞓ O S D C P T J K Pg N
Type	Geological formation
Sub-units	Crossfield Member
Underlies	Exshaw Formation, Blairmore Group, Mannville Group
Overlies	Graminia Formation (Winterburn Group)
Thickness	up to 240 metres (790 ft)[1]
Lithology
Primary	Limestone, dolomite
Other	Anhydrite
Location
Coordinates	53.3851°N 114.5123°W / 53.3851; -114.5123 (Anglo Canadian Wabamun Lake No. 1)
Region	Alberta
Country	Canada
Type section
Named for	Wabamun Lake
Named by	Imperial Oil, 1950

The Wabamun Formation is a stratigraphic unit of Late Devonian (Famennian) age in the Western Canada Sedimentary Basin.^[2] It takes the name from Wabamun Lake and was first described in the Anglo Canadian Wabamun Lake No. 1 well (located between the Wabamun Lake and the North Saskatchewan River) by Imperial Oil in 1950.^[3]

Lithology

The Wabamun Formation is composed of dolomitic limestone and calcareous dolomite with anhydrite interbeds. ^[1] Halite and anhydrite are present at the base of the formation in the Stettler region. It is composed entirely of limestone in north-western Alberta. Secondary pyrite is found at the top of the formation.

Hydrocarbon potential

The Wabamun Formation had an initial established recoverable oil reserve of 7.2 million m³, with 3.2 million m³ already produced as of 2008.^[4] Gas reserves totaled 102.8 million m³, with 53.5 million m³ already produced.^[5]

Distribution

The Wabamun Formation reaches a maximum thickness of 240 metres (790 ft) in the sub-surface of central Alberta.^[1] It thins out and wedges towards the east, and thickens towards the Canadian Rockies foothills.

Relationship to other units

The Wabamun Formation is disconformably overlain by the Exshaw Formation in southern Alberta, by the Blairmore Group in western Alberta and by the Mannville Group in eastern Alberta. It rests conformably on the Graminia Formation siltstone of the Winterburn Group.^[1]

In the Calgary area, the formation is divided into a lower and an upper part separated by the porous dolomitic Crossfield Member.

It is equivalent to the Three Forks Formation in Montana, the Palliser Formation in the Canadian Rockies, the sum of the Kotcho Formation and Tetcho Formation in northeastern British Columbia.

References

1. Lexicon of Canadian Geologic Units. "Wabamun Formation". Retrieved 2009-03-01.
2. Mossop, G.D. and Shetsen, I., (compilers), Canadian Society of Petroleum Geologists and Alberta Geological Survey (1994). "The Geological Atlas of the Western Canada Sedimentary Basin, Chapter 13: Devonian Wabamun Group of the Western Canada Sedimentary Basin". Retrieved 2014-10-18.
3. Imperial Oil Limited, Geological Staff, Western Division, 1950. Devonian nomenclature in Edmonton area, Alberta, Canada. Bull. American Association of Petroleum Geologists, v. 34, p. 1807-1825.
4. Mossop, G.D. and Shetsen, I - Canadian Society of Petroleum Geologists (1994). "The Geological Atlas of the Western Canada Sedimentary Basin - Summary of oil reserves and production data". Retrieved 2009-03-06.
5. Mossop, G.D. and Shetsen, I - Canadian Society of Petroleum Geologists (1994). "The Geological Atlas of the Western Canada Sedimentary Basin - Summary of gas reserves and production data". Retrieved 2009-03-06.