Shaunavon Formation

Shaunavon Formation Stratigraphic range: Bathonian PreЄ Є O S D C P T J K Pg N ↓
Type	Geological formation
Sub-units	Upper Shaunavon Lower Shaunavon
Underlies	Sawtooth Formation
Overlies	Gravelbourg Formation
Thickness	up to 48 metres (160 ft)^[1]
Lithology
Primary	Limestone
Other	Sandstone, shale
Location
Coordinates	49°27′50″N 107°30′50″W / 49.464°N 107.514°W / 49.464; -107.514 (Shaunavon Formation)Coordinates: 49°27′50″N 107°30′50″W / 49.464°N 107.514°W / 49.464; -107.514 (Shaunavon Formation)
Region	WCSB
Country	Canada
Type section
Named for	Shaunavon, Saskatchewan
Named by	R.L. Milner and G.E. Thomas, 1954

The Shaunavon Formation is a stratigraphical unit of Bathonian age in the Western Canadian Sedimentary Basin.

It takes the name from the town of Shaunavon, and was first described in the Tidewater A.O. Eastend Crown No. 1 well, drilled south-west of the settlement, by R.L. Milner and G.E. Thomas in 1954.^[2]

Lithology

The Shaunavon Formation is composed of two members. The lower member consists of buff microcrystalline massive limestone in the lower part with an oolitic bed at the top. The upper member consists of calcareous sandstone and oolitic limestone, shell coquina and argillaceous limestone with interbeds of gray and green shale. ^[1] Dolomitisation can occur in both members. Lenticular beds separated by sedimentation breaks are common in the upper member. Channels also occur in the upper Shaunavon.

Hydrocarbon production

Oil is produced from the Shaunavon Formation in south-western Saskatchewan.

Distribution

The Shaunavon Formation reaches a maximum thickness of 48 metres (160 ft).^[1] It occurs in the sub-surface in south-western Saskatchewan. In the Williston Basin it appears present in Montana and North Dakota as the lower part of the Sawtooth Formation and Piper Formation. East of Weyburn, it grades into the shaley facies of the Melita Formation of Manitoba.

Relationship to other units

The Shaunavon Formation is conformably overlain by the Sawtooth Formation and conformably overlays the Gravelbourg Formation.^[1]

It is equivalent to the Sawtooth Formation in southern Alberta, as well as to the Bowes member and Firemoon Member of the Piper Formation in Montana.

References

1 2 3 4 Lexicon of Canadian Geologic Units. "Shaunavon Formation". Retrieved 2010-01-01.
↑ Milner, R.L. and Thomas, G E., 1954. Jurassic System in Saskatchewan. In: Western Canada Sedimentary Basin American Association of Petroleum Geologists, p. 250-267

Western Canadian Sedimentary Basin

Hydrocarbon history	Oil sands and heavy oil Frontier exploration and development Natural gas liquids Natural gas

Depositional Regions	Southern Alberta Central Alberta Northwestern Alberta Plains South-central Canadian Rockies foothills North-east Plains North-central foothills Liard River Fort Nelson Northern Rocky Mountains Fort St. John Saskatchewan Western Manitoba

Saskatchewan	Cypress Hills FM Ravenscrag FM Frenchman FM Whitemud FM Eastend FM Bearpaw FM Judith River GRP Belly River FM Oldman FM Foremost FM Lea Park FM Pakowki FM Milk River FM Colorado GRP Viking FM Mannville GRP Pense FM Cantuar FM Success FM Vanguard FM Ellis GRP Swift FM Rierdon FM Sawtooth FM Shaunavon FM Piper FM Gravelbourg FM Gypsum Springs FM Watrous FM Big Snowy GRP Madison GRP Charles FM Poplar Ratcliffe Midale Mission Canyon FM Kisbey SS Alida Tilston Lodgepole FM Souris Valley Three Forks GRP Bakken FM Big Valley FM Torquay FM Saskatchewan GRP Birdbear FM Duperow FM Manitoba GRP Souris River FM Elk Point GRP Davson Bay FM Prairie FM Winnipegosis FM Ashern FM Interlake FM Stonewall FM Stony Mountain FM Herald FM Yeoman FM Winnipeg FM Deadwood FM Canadian Shield

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