Ellis Group

Ellis Group Stratigraphic range: Bajocian-Oxfordian PreЄ Є O S D C P T J K Pg N
Type	Geological formation
Sub-units	Swift Formation Rierdon Formation Sawtooth Formation
Underlies	Mannville Group
Overlies	Rundle Group, Shaunavon Formation
Thickness	up to 150 metres (490 ft)^[1]
Lithology
Primary	Shale, sandstones
Other	Siltstone, limestone
Location
Region	WCSB
Country	Canada
Type section
Named for	Fort Ellis
Named by	A.C. Peale, 1893

The Ellis Group is a stratigraphical unit of Bajocian-Oxfordian age in the Western Canadian Sedimentary Basin.

It takes the name from Fort Ellis, Montana, and was first described in outcrop in the Rocky Creek Canyon by .C. Peale in 1893.^[2]

Lithology

The Ellis Group is composed of shale and sandstones deposited in marine and transitional environment. ^[1]

Hydrocarbon production

Oil is produced from the Sawtooth Formation in south-eastern Alberta.

Distribution

The Ellis Group Lateral occurs in the sub-surface in southern Alberta and northern and central Montana.^[1] It is typically 80 metres (260 ft), but thickens on either side of the Sweetgrass Arch and reaches up to 150 metres (490 ft) in south-eastern Alberta.

Subdivisions

The Ellis Group includes the following formations, from top to bottom:

Sub-unit	Age	Lithology	Max. Thickness	Reference
Swift Formation	Oxfordian	marine shale, transitional shale, siltstone and sandstone	41 m (130 ft)	^[3]
Rierdon Formation	Bathonian to Callovian	marine shale and limestone	60 m (200 ft)	^[4]
Sawtooth Formation	Bajocian to Bathonian	quartzose sandstone with shale	41 m (130 ft)	^[5]
Piper Formation	Middle Jurassic	sandy limestone (top) papery shale siltstone and shale grey limestone white gypsum (base)	23 m (80 ft)	^[6]

Relationship to other units

The Ellis Group is unconformably overlain by the shale and sandstone of the Mannville Group and rests on the carbonates of the Rundle Group. It grades westwards to the Fernie Group shale, and eastwards to shale, sandstones and limestone of the Vanguard Formation and Shaunavon Formation.^[1]

References

1 2 3 4 Lexicon of Canadian Geologic Units. "Ellis Group". Retrieved 2010-01-01.
↑ Peale, A.C., 1893. The Paleozoic section in the vicinity of Three Forks, Montana. United States Geological Survey, Bulletin 110, p.9-56.
↑ Lexicon of Canadian Geologic Units. "Swift Formation". Retrieved 2010-01-03.
↑ Lexicon of Canadian Geologic Units. "Rierdon Formation". Retrieved 2010-01-03.
↑ Lexicon of Canadian Geologic Units. "Sawtooth Formation". Retrieved 2010-01-03.
↑ Lexicon of Canadian Geologic Units. "Piper Formation". Retrieved 2010-01-03.

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

Southern Alberta plains	Cypress Hills FM Porcupine Hills FM Ravenscrag FM Edmonton GRP Belly River GRP Oldman FM Foremost FM Pakowki FM Milk River FM Colorado GRP Mannville GRP Ellis GRP Swift FM Rierdon FM Sawtooth FM Rundle GRP Banff FM Exshaw FM Bakken FM Wabamun FM Crowfoot FM Nisku FM Ireton FM Leduc FM Cooking Lake FM Beaverhill Lake GRP Elk Point GRP Canadian Shield

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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