This GIS dataset is a result of the compilation of all existing Alberta Geological Survey sand and gravel geology and resource data into digital format. Data sources include Alberta Geological Survey maps and reports produced between 1976 and 2006.
References are provided as an attribute so the user can refer back to the original maps and reports. Attributes include study level, material description, references, area, sand and gravel thickness, and gravel and sand volumes.
In 2009, data from newly mapped area NTS 83N/NE were added.
If polygons were found without any corresponding attribute data, data were retrieved from existing maps and reports and entered into the database. If no attribute data could be found (meaning there is no evidence that the deposit is real) the polygon was deleted. The attribute data have been verified at least once after they were entered (note: a number of people were involved in the data compilation phase). We corrected duplicate records found in the database and ArcInfo coverages. Pick lists were used for material type and study level to reduce the chance for errors.
The digitized polygons were compared with the original maps and are accurate to within 0.5 mm on the original maps. ArcInfo functions were used to ensure the coverages are topologically correct. We encoded polygons encoded with a unique deposit number; however, a deposit may comprise more than one polygon. The position of the polygons relative to the rivers, lakes, roads and other base data is as best as could be accomplished as the base data used for some of the original maps were generally not the same as the base data used during the making of this dataset. Efforts were made to ensure water-related deposits (e.g., river terraces) occur on the correct side of the river according to the current base data.
Sand and gravel deposits (polygons) were digitized into ArcInfo coverages from existing had- copy maps and reports. Most of the maps and reports were made by Alberta Geological Survey between 1976 and 2000.
Attribute data were entered for each deposit in an Excel spreadsheet. The hard-copy data sources were collected over 25+ years, so some reinterpretation was necessary to standardize the data. The attribute data collected in Excel spreadsheets were transferred to an Access database called the Sand and Gravel Geology and Resources Database.
Attribute data were joined to ArcInfo coverages and shapefiles were created using ArcView 3.2a.