This dataset has stratigraphic and lithological picks of the upper bedrock and Quaternary geological units in the Athabasca Oil Sands Area extending north from Cold Lake to the Fort McMurray region. The picks were compiled from the mid-1970s to 2006 to construct maps of the subsurface distribution, structure, topography and thickness of near-surface bedrock and Quaternary stratigraphic units. Alberta Geological Survey staff, as well as staff from industry and other government departments, interpreted the data.

The dataset includes subsurface stratigraphic picks of the tops of the Horseshoe Canyon/Wapiti and Battle formations in the west-central Alberta Plains (Townships 15 to 67, Ranges 16W4 to 3W6) made from wireline geophysical well logs. The dataset supplements Alberta Geological Survey Open File Report 2011-08, which describes the methodology. We screened the well data to detect errors resulting from deviated wells, as well as incorrect well-header ground and kelly bushing elevation data. Statistical methods identified local and regional statistical outliers, which were examined individually.

The dataset includes subsurface stratigraphic picks for the top of the Foremost Formation (Belly River Group) in the Alberta Plains (Townships 1 to 52, Ranges 1W4 to 5W5) made from downhole wireline geophysical well logs. The top of the Foremost was picked at the base of a continuous sandstone or siltstone bed (low-gamma-ray) of variable thickness overlying the Taber coal zone. Well data were screened to detect errors resulting from deviated wells, as well as incorrect ground and kelly bushing elevation data. We used statistical methods to identify local and regional statistical outliers, which were examined individually.

The dataset includes subsurface stratigraphic picks of the top of the Belly River Group in the Alberta Plains (Townships 1 to 50, Ranges 1W4 to 2W5) made from wireline, geophysical well logs. The dataset supplements Alberta Geological Survey Open File Report 2010-10, which describes the methodology. We screened the well data to detect errors resulting from deviated wells, as well as incorrect ground and kelly bushing elevation data. We used statistical methods to identify local and regional statistical outliers, which were examined individually.

The dataset includes subsurface stratigraphic picks for the interfingering members that define the transition between the Belly River Group and the Lea Park Formation in east-central Alberta (Townships 1 to 62, Ranges 1W4 to 21W4) made from wireline geophysical well logs. Coarsening upwards, siltstone to sandstone-dominated members of the Belly River Group include (from youngest to oldest) the upper Birch Lake, lower Birch Lake, Ribstone Creek, Victoria, and Brosseau members. Interfingering mudstone-dominated members of the Lea Park Formation include the Mulga, Grizzly Bear, Vanesti, and Shandro members. Where the top and base are present, we calculated isochore values for each member. Well data were screened to detect errors resulting from deviated wells, as well as incorrect ground and kelly bushing elevation data. We used statistical methods to identify local and regional statistical outliers, which were examined individually.

The dataset includes subsurface stratigraphic picks for the top of the Oldman Formation (base of the Dinosaur Park Formation) in the Alberta Plains (Townships 1 to 47, Ranges 1W4 to 5W5) made from wireline geophysical well logs. The dataset supplements Alberta Geological Survey Open File Report 2011-13, which describes the methodology used to make the picks. Well data were screened to detect errors resulting from deviated wells, as well as incorrect ground and kelly bushing elevation data. We used statistical methods to identify local and regional statistical outliers, which we examined individually.

The base of the Paskapoo Formation is unconformable with the underlying Scollard Formation. Alberta Geological Survey differentiates the Paskapoo Formation from the underlying Scollard Formation by the first thick sandstone above the uppermost coal seam of the Ardley coal zone. We defined 'thick sandstone' to be 5 m or more thick. This dataset contains the gridded results of the structural surface of the base of the Paskapoo Formation modelled from stratigraphic picks of the >5 m sand above the Scollard Formation coal from oil and gas industry gamma-ray logs. We modelled only the undeformed part of the Paskapoo Formation, which lies east of the Rocky Mountains deformation belt. Because of uncertainty in defining the Paskapoo-Scollard contact, we selected the P20 (20th percentile or low estimate) modelled surface of those data, which is about 5 m deeper than the P50 or median estimated surface. Subsequent boundaries of slices were constructed parallel to this surface, recognizing that, locally, the base of the Paskapoo Formation has an undulating to incised erosional contact with the underlying Scollard Formation. The model illustrates an elongated, concave surface with a central region plunging westwards towards the Alberta syncline and elevated limbs to the northwest and southeast.

The dataset includes subsurface stratigraphic picks of the Milk River 'shoulder' in the Alberta Plains (Townships 1 to 73, Ranges 1W4 to 2W6) made from wireline geophysical well logs. The Milk River 'shoulder' is an informal term often used to refer to a distinctive 'shoulder' (deflection) on resistivity, sonic, density, and porosity logs. The Milk River 'shoulder' corresponds to the top of the Milk River Formation in southernmost Alberta, where it represents juxtaposition between paralic deposits of the underlying Deadhorse Coulee Member of the Milk River Formation and overlying marine shale of the Pakowki Formation. It is characterized by a leftward deflection (decreasing resistivity) upwards across the contact, forming the distinctive 'shoulder signature'. To the north, the Milk River 'shoulder' represents the boundary between the Alderson Member (lower Lea Park Formation) and the upper Lea Park Formation (Pakowki equivalent). In these areas, silty sands and mudstones of the Alderson Member are overlain by shales of the upper Lea Park Formation. Well data were screened to detect errors resulting from deviated wells, as well as incorrect ground and kelly bushing elevation data. We used statistical methods to identify local and regional statistical outliers, which we examined individually.

The dataset includes subsurface stratigraphic picks for the formations that comprise the Beaverhill Lake Group (Townships 29 to 113, Ranges 1W4 to 13W6) made from wireline geophysical well logs. The dataset also includes picks for the underlying Elk Point Group, and the overlying Woodbend Group. Lithostratigraphic picks for the Beaverhill Lake Group include the Fort Vermilion Formation, the Swan Hills Formation, the Slave Point Formation, and the Waterways Formation (top of the Beaverhill Lake Group). Lithostratigraphic picks for the underlying Elk Point Group include the Prairie Evaporite Formation, the Sulphur Point Formation, and the Watt Mountain Formation (base of the Beaverhill Lake Group). Lithostratigraphic picks for the overlying Woodbend Group include the Cooking Lake Formation, or its equivalent.

The dataset includes subsurface stratigraphic picks for the base of the Belly River Group/Wapiti Formation in the Alberta Plains (Townships 1 to 94, Ranges 1W4 to 14W6) made from wireline geophysical well logs. In general, the pick was made at the base of the lowest sandstone bed (overlying the Pakowki or Lea Park Formation) that was overlain by coal. If coal is absent, the pick was made at the base of the first sandstone. We screened the well data to detect errors resulting from deviated wells, as well as incorrect ground and kelly bushing elevation data. We used statistical methods to identify local and regional statistical outliers, which were examined individually.