Bluesky Formation | |
---|---|
Stratigraphic range: | |
Type | Geological formation |
Unit of | Fort St. John Group |
Underlies | Wilrich Member |
Overlies | Gething Formation |
Thickness | up to 46 metres (150 ft) [1] |
Lithology | |
Primary | Sandstone |
Location | |
Coordinates | 56°02′39″N118°07′39″W / 56.0442°N 118.1274°W |
Region | Western Alberta |
Country | Canada |
Type section | |
Named for | Bluesky, Alberta |
Named by | Peter C. Badgley, 1952 |
The Bluesky Formation is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the hamlet of Bluesky, and was first described in Shell's Bluesky No. 1 well by Badgley in 1952. [2]
The formation is composed of mudstones, conglomerates and sandstones which can be quartzose or contain chert grains. [1] Many of the Bluesky sandstones do not display bedding features although some low and moderate-angle large scale cross-bedding has been observed in some sections. [3] The sediments were deposited in both marginally marine nearshore and fully marine offshore settings following a transgression of the ancient Moosebar Sea. [4] Bluesky sediments are separated from Gething strata by a scoured or loaded contact and occasionally by a burrowed Glossifungites surface. [3] The Bluesky Formation can be very porous and produces hydrocarbons in many areas across Western Canada. [5] Heavy oil is produced from the Bluesky formation in the Peace River area.
The Bluesky Formation reaches a thickness of 46 meters (151 ft) in the Pouce Coupe area, and thins out toward north and west. Thin sands can be found in the Peace River area.
Although some early workers included the Bluesky Formation in the Bullhead Group, it is usually classified as the basal unit of the Fort St. John Group. [6] It is conformably overlain by the Wilrich Member of the Spirit River Formation and conformably underlain by the Gething Formation. Northeast of the town of Peace River it was deposited unconformably on Mississippian limestone. It is equivalent with the Glauconitic Sandstone of the Mannville Group in central and southern Alberta, as well as with the Wabiskaw Member of the Clearwater Formation in the eastern part of northern Alberta.
The Bluesky deposit of bitumen comes from the "clean estuarine reservoir sands of the Cretaceous-age Bluesky Formation" in the Peace River. Secondary production area is the Gething Formation. The combined Bluesky-Gething deposit is the primary target area for oil sands development in the Peace River area. There is a reservoir at about 600 m (2,000 ft)–700 m (2,300 ft) below the surface. Heavy oil in the Peace River, produced from bitumen deposit is extracted using wells not by mining. [7] : 9
The oil sands of the Bluesky-Gething were deposited during the Cretaceous Period within a transgressive system, with the lower fluvial to nonmarine Gething Formation at the base and the estuarine Bluesky Formation at the top. Deposition of the Bluesky-Gething reservoir and nonreservoir units was controlled by topography of the pre-Cretaceous unconformity. The Red Earth Highlands separate the Bluesky-Gething into northeast and southwest accumulations and includes part of the Seal Lake area. In the Peace River oil sands areas, the Bluesky-Gething is overlain by the marine shales of the Wilrich Member.
— AER March 2014
The Cadomin Formation is a stratigraphic unit of Early Cretaceous age in the western part of the Western Canada Sedimentary Basin. It is extends from southeastern British Columbia through western Alberta to northeastern British Columbia, and it contains significant reservoirs of natural gas in some areas. It was named after the mining town of Cadomin, which is an acronym of "Canadian Dominion Mining".
Gething Formation is a stratigraphic unit of Lower Cretaceous (Aptian) age in the Western Canada Sedimentary Basin. It is present in northeastern British Columbia and western Alberta, and includes economically important coal deposits.
The Cardium Formation is a stratigraphic unit of Late Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the fossilized heart-shaped cockle shells in the family Cardiidae present. It was first described along the Bow River banks by James Hector in 1895. It is present throughout western Alberta and in northeastern British Columbia, and it is a major source of petroleum and natural gas.
Bullhead Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin of northeastern British Columbia and western Alberta. It was first defined by F.H. McLearn in 1918 as the Bullhead Mountain Formation, but later was upgraded to group status. It consists of the Cadomin and Gething Formations, although some early workers included the Bluesky Formation and others in the group.
The Fort St. John Group is a stratigraphic unit of Lower Cretaceous age in the Western Canada Sedimentary Basin. It takes the name from the city of Fort St. John, British Columbia and was first defined by George Mercer Dawson in 1881.
The Spirit River Formation is a stratigraphical unit of middle Albian age in the Western Canadian Sedimentary Basin.
The Dunvegan Formation is a stratigraphical unit of Cenomanian age in the Western Canadian Sedimentary Basin.
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.
The McMurray Formation is a stratigraphic unit of Early Cretaceous age of the Western Canada Sedimentary Basin in northeastern Alberta. It takes the name from Fort McMurray and was first described from outcrops along the banks of the Athabasca River 5 kilometres (3.1 mi) north of Fort McMurray by F.H. McLearn in 1917. It is a well-studied example of fluvial to estuarine sedimentation, and it is economically important because it hosts most of the vast bitumen resources of the Athabasca Oil Sands region.
The Mannville Group is a stratigraphical unit of Cretaceous age in the Western Canadian Sedimentary Basin.
The Joli Fou Formation is a allostratigraphical unit of middle Albian age in the Western Canadian Sedimentary Basin. It takes the name from the Joli Fou Rapids on the Athabasca River, and was first described in an outcrop along the river, 8 kilometers (5.0 mi) downstream from Joli Fou Rapids, by RTD Wickenden in 1949.
The Mist Mountain Formation is a geologic formation of latest Jurassic to earliest Cretaceous age in the Western Canada Sedimentary Basin that is present in the southern and central Canadian Rockies. It was named for outcrops along the western spur of Mist Mountain in Alberta by D.W. Gibson in 1979. The Mist Mountain Formation contains economically important coal seams that have been mined in southeastern British Columbia and southwestern Alberta.
The Grosmont Formation is a stratigraphical unit of Frasnian age in the Western Canadian Sedimentary Basin.
The Morrissey Formation is a stratigraphic unit of Late Jurassic (Portlandian) age in the Western Canada Sedimentary Basin. It is named for outcrops on Morrissey Ridge, 16 kilometres (10 mi) southeast of Fernie, British Columbia, and is present in southeastern British Columbia and southwestern Alberta.
The Elk Formation is a stratigraphic unit of the Western Canada Sedimentary Basin that is present in southeastern British Columbia and southwestern Alberta. It is probably of Early Cretaceous age, but in some areas its strata could be as old as Late Jurassic. It includes minor thin coal beds and was named for outcrops near the now-abandoned Elk River coal mine east of Fernie, British Columbia.
The Blairmore Group, originally named the Blairmore Formation, is a geologic unit of Early Cretaceous age in the Western Canada Sedimentary Basin that is present in southwestern Alberta and southeastern British Columbia. It is subdivided into four formations: Cadomin Formation, Gladstone, Beaver Mines and Ma Butte, all of which are defined by type sections, most of which contain plant fossils. In some areas the Blairmore contains significant reservoirs of natural gas.
The Boulder Creek Formation is a geologic formation in northeastern British Columbia. It was named for a tributary to Commotion Creek in the Pine Pass area by E.M. Spieker in 1921. At one time considered to be a member of the Commotion Formation, it was elevated to formation status by D.F. Stott in 1982.
The Battle Formation is a geologic formation of Late Cretaceous (Maastrichtian) age in the Western Canada Sedimentary Basin. It is present throughout much of the central Alberta plains, where it is an important stratigraphic marker in the nonmarine Upper Cretaceous sequence. It was formally named by G.M. Furnival in 1942 and given formation status by E.J.W. Irish in 1970.
The Gladstone Formation is a stratigraphic unit of Early Cretaceous (Aptian) age in the Western Canada Sedimentary Basin. It is present in the foothills of southwestern Alberta and is named for outcrops along Gladstone Creek, a tributary of the Castle River south of the Crowsnest Pass.
The Blood Reserve Formation, also known as the Blood Reserve Sandstone, is a geologic formation of Late Cretaceous (Campanian) age in the Western Canada Sedimentary Basin. It is present in southwestern Alberta, Canada, and was named for Blood Indian Reserve No. 148 by L.S. Russell in 1932. It is an aquifer and a source of fresh groundwater.