This GIS dataset is part of a digital compilation of the bedrock geology of Alberta. It is one of the datasets used to produce Alberta Geological Survey (AGS) Map 600.
This dataset represents the compilation of existing geological maps and original geological mapping by AGS staff. Mapping in support of the dataset included field observations and creating three-dimensional models of subsurface stratigraphy based on the interpretation of geophysical logs from oil and gas wells. Each three-dimensional formation surface was projected to a model of the bedrock surface, and the intersection formed the first approximation of the position of the geological contact at the base of the surficial deposits. We adjusted these preliminary contacts to honour outcrop data and the interpretation of the bedrock unit immediately below surficial deposits in individual wells.
The data were created in geodatabase format and output for public distribution in shapefile format.
AGS Open File Report 2013-02 presents additional information on data sources related to this dataset.
This dataset represents the compilation of existing geological maps and original geological mapping by Alberta Geological Survey (AGS) staff. The representation of the Canadian Shield and Athabasca Basin is based on compilation. The geology of the Rocky Mountains and the Rocky Mountain Foothills is also the product of compilation with rare instances of new geological interpretation (e.g., the interpretation of bedrock geology beneath drift-filled valleys). The Devonian geology of northeastern Alberta is also largely a product of compilation with some reinterpretation based partly on field observations. The Cretaceous geology of the Plains throughout most of northern and east-central Alberta is based on new geological mapping of the Fort St. John Group, the Dunvegan Formation, the Smoky Group, the Mannville Group, the Colorado Group, and the Belly River Group. In addition, the Battle Formation (Cretaceous) and the Scollard Formation (Cretaceous-Paleogene) are based on new mapping north of Township 17 and east of Range 4, West of the 6th Meridian.
The extents of upland gravel units south of 56° N are based upon GSC Map 22-1967, AGS Open File Report 1994-06, GSC Map NM-12-G, and AGS Map 601.
The extents of upland gravel units north of 56° N (Clear Hills, Halverson Ridge and Caribou Mountains) are based upon field observations by AGS staff in 2011 and 2012.
To produce this dataset, we combined digital versions of 117 existing and several newly mapped areas into an Alberta-wide GIS dataset. We processed the data as follows:
1. Collected and assessed input data. This involved collecting datasets from various sources, assessing quality, and standardizing the attribute table in the ArcGIS environment. When necessary, we corrected datasets that were digitized by third parties.
2. Created a standard provincial schema to house selected original and new map attributes.
3. Merged input data into one seamless layer, edge-matched the boundaries.
4. Generalized the dataset (reducing number of polygons) by eliminating small polygons not applicable to the 1 000 000-scale map and dissolved the boundaries between adjacent polygons representing the same geological unit.
5. Ran a topology check on the entire dataset to ensure no gaps, overlaps, slivers, or blank polygons were present.