Clearwater Formation
| Clearwater Formation Stratigraphic range: Albian |
|
|---|---|
| Type | Geological formation |
| Unit of | Mannville Group |
| Sub-units | Wabiskaw Member |
| Underlies | Grand Rapids Formation |
| Overlies | McMurray Formation |
| Thickness | up to 85 metres (280 ft) |
| Lithology | |
| Primary | Shale |
| Other | Sandstone, siltstone |
| Location | |
| Coordinates | 58°00′49″N 111°20′38″W / 58.01365°N 111.34377°W |
| Region | northeastern and central  Alberta
|
| Country |
 Canada
|
| Type section | |
| Named for | Clearwater River |
| Named by | R.G. McConnell, 1893 |
The Clearwater Formation is a stratigraphic unit of Early Cretaceous (Albian) age in the Western Canada Sedimentary Basin in northeastern Alberta, Canada. It was first defined by R.G. McConnell in 1893 and takes its name from the Clearwater River near Fort McMurray.
Impermeable marine shales in the Clearwater Formation provided part of the trapping mechanism for the underlying Athabasca oil sands in the McMurray Formation. Sandstone units in the Clearwater Formation, including the Wabiskaw Member, can contain oilsand and heavy oil resources.
Nearly complete specimens of plesiosaurs and ichthyosaurs, as well as one ankylosaur, have been recovered from the formation during oilsand mining.
The Clearwater Formation consists of primarily of black and green shale, with some interbedded grey and green sandstone and siltstone, and ironstone concretions. To the southeast of Cold Lake it includes massive hydrocarbon-bearing, glauconitic salt-and-pepper sandstones with interbedded shales.
The Wabiskaw Member forms the base of the Clearwater Formation. It consists of glauconitic sandstones with interbeds of black fissile shale, and it includes oilsand and heavy oil in some areas. It was defined in well Barnsdall West Wabiskaw No. 1 (located between Wabasca River and Lesser Slave Lake in central Alberta) by P.C. Badgley in 1952.
...
Wikipedia