| McMurray Formation Stratigraphic range: late Barremian to Aptian |
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Outcrop along the Athabasca River, c. 1900 |
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| Type | Geological formation |
| Unit of | Mannville Group |
| Sub-units | Upper, Middle and Lower Member |
| Underlies | Clearwater Formation (Wabiskaw Member) |
| Overlies | Banff Formation, Wabamun Formation |
| Area | 140,000 km2 (54,000 sq mi)[1] |
| Thickness | up to 60 metres (200 ft)[2] |
| Lithology | |
| Primary | Sandstone |
| Other | Siltstone |
| Location | |
| Named for | Fort McMurray |
| Named by | F.H. McLearn,1917 |
| Region | north-eastrn Alberta |
| Country | Canada |
The McMurray Formation is a stratigraphical unit of Cretaceous age in the Western Canadian Sedimentary Basin.
It takes the name from Fort McMurray, and was first described in the outcrop occurring on the banks of the Athabasca River (5 kilometres (3.1 mi) north of Fort McMurray) by F.H. McLearn in 1917.[3]
Contents |
The McMurray Formation consists of fine grained quartzitic bitumenous sand and sandstone.
Three members were described inside the McMurray Formation, and can be differentiated in outcrops (to a lesser degree in the sub-surface):
Bitumen is produced from the McMurray Formation in the Athabasca Oil Sands by open pit mining and from the sub-surface with SAGD techniques. East of Fort McMurray, it contains water instead of bitumen.
The McMurray Formation reaches a maximum thickness of 60 metres (200 ft) in the Athabasca Oil Sands. It thins out towards the west and south. It is completely eroded north of the outcrop area.
The McMurray Formation is conformably overlain by the Wabiskaw Member of the Clearwater Formation and rests unconformably on Paleozoic limestone beds of the Banff Formation, Wabamun Formation or Winterburn Formation. The McMurray Formation is equivalent with the Ostracod Beds of the Mannville Group in central Alberta, with the Dina Member in the Lloydminster area and the Gething Formation of western and northern Alberta and northeastern British Columbia. In some interpretations it is considered part of the Mannville Group.
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