This is a 1000 m cell-sized raster dataset of the upper surface of the Lacombe Member aquitard, modelled from the >65% silt and clay point data derived by depth-slice analysis of well-log data. Alberta Geological Survey Bulletin 66 provides details on this grid dataset. The dataset is in ESRI ASCII grid format.

The AMDO (Alberta Mineral Deposits and Occurrences) application was created by the Minerals and Coal Geoscience Section of the Alberta Geological Survey as a database for mineral deposits in Alberta in the early 1990s. It was originally released as Open File Report OFR 1991-17. Industrial minerals from that data source have been extracted into Microsoft Access, their locations refined or corrected and presented in GIS format.