Slave Point Formation
Encyclopedia
The Slave Point Formation is a stratigraphical
unit of Middle Devonian age
in the Western Canadian Sedimentary Basin
.
It takes the name from Slave Point, a promontory on the north-west shore of the Great Slave Lake
, and was first described in outcrop on the southern shore of the lake and along the Buffalo River by A.E. Cameron in 1918 It was subsequently defined in the subsurface by J. Law in 1955, based on lithology
encountered in the California Standard Steen River 2-22-117-5W6M well in Alberta
.
, crystalline dolomite
and shale
laminae.
It contains stromatoporoids in north-eastern British Columbia
and southern Northwest Territories
and in the Peace River Arch.
, northeastern British Columbia
and northern Alberta
.
overlain by the Beaverhill Lake Group
or Waterways Formation in northern Alberta
and by the Otter Park Member or Muskwa Member of the Horn River Formation
in north-eastern British Columbia. It conformably overlays the Fort Vermilion Formation (or is unconformably
overlain by the Watt Mountain Formation) in northern Alberta and it is conformably overlain by the Sulphur Point Formation or Presqu'ile Formation in north-eastern British Columbia.
It is equivalent to the lower Swan Hills Formation and partly to the Livock River Formation.
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
unit of Middle Devonian age
Geochronology
Geochronology is the science of determining the age of rocks, fossils, and sediments, within a certain degree of uncertainty inherent to the method used. A variety of dating methods are used by geologists to achieve this, and schemes of classification and terminology have been proposed...
in the Western Canadian Sedimentary Basin
Western Canadian Sedimentary Basin
The Western Canadian Sedimentary Basin is a vast sedimentary basin underlying of Western Canada including southwestern Manitoba, southern Saskatchewan, Alberta, northeastern British Columbia and the southwest corner of the Northwest Territories. It consists of a massive wedge of sedimentary rock...
.
It takes the name from Slave Point, a promontory on the north-west shore of the Great Slave Lake
Great Slave Lake
Great Slave Lake is the second-largest lake in the Northwest Territories of Canada , the deepest lake in North America at , and the ninth-largest lake in the world. It is long and wide. It covers an area of in the southern part of the territory. Its given volume ranges from to and up to ...
, and was first described in outcrop on the southern shore of the lake and along the Buffalo River by A.E. Cameron in 1918 It was subsequently defined in the subsurface by J. Law in 1955, based on lithology
Lithology
The lithology of a rock unit is a description of its physical characteristics visible at outcrop, in hand or core samples or with low magnification microscopy, such as colour, texture, grain size, or composition. It may be either a detailed description of these characteristics or be a summary of...
encountered in the California Standard Steen River 2-22-117-5W6M well in Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
.
Lithology
The Slave Point Formation is composed of brown limestoneLimestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
, crystalline dolomite
Dolomite
Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....
and shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
laminae.
It contains stromatoporoids in north-eastern British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
and southern Northwest Territories
Northwest Territories
The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...
and in the Peace River Arch.
Distribution
The Slave Point Formation has a thickness ranging from 30 metres (98.4 ft) to 120 metres (393.7 ft). It occurs in southern Northwest TerritoriesNorthwest Territories
The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...
, northeastern British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
and northern Alberta
Northern Alberta
Northern Alberta is a region located in the Canadian province of Alberta.Its primary industry is oil and gas, with large heavy oil reserves being exploited at the Athabasca Oil Sands and Wabasca Area in the east of the region...
.
Relationship to other units
The Slave Point Formation is unconformablyUnconformity
An unconformity is a buried erosion surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger, but the term is used to describe...
overlain by the Beaverhill Lake Group
Beaverhill Lake Group
The Beaverhill Lake Group is a stratigraphical unit of Middle Devonian to Late Devonian age in the Western Canadian Sedimentary Basin.It takes the name from Beaverhill Lake, and was first described in the well Anglo-Canadian Beaverhill Lake No...
or Waterways Formation in northern Alberta
Northern Alberta
Northern Alberta is a region located in the Canadian province of Alberta.Its primary industry is oil and gas, with large heavy oil reserves being exploited at the Athabasca Oil Sands and Wabasca Area in the east of the region...
and by the Otter Park Member or Muskwa Member of the Horn River Formation
Horn River Formation
The Horn River Formation is a stratigraphical unit of Devonian age in the Western Canadian Sedimentary Basin.It takes the name from the Horn River, a tributary of the Mackenzie River, and was first described in outrop on the banks of Horn River in the Northwest Territories by Whittaker in 1922...
in north-eastern British Columbia. It conformably overlays the Fort Vermilion Formation (or is unconformably
Unconformity
An unconformity is a buried erosion surface separating two rock masses or strata of different ages, indicating that sediment deposition was not continuous. In general, the older layer was exposed to erosion for an interval of time before deposition of the younger, but the term is used to describe...
overlain by the Watt Mountain Formation) in northern Alberta and it is conformably overlain by the Sulphur Point Formation or Presqu'ile Formation in north-eastern British Columbia.
It is equivalent to the lower Swan Hills Formation and partly to the Livock River Formation.